Category: Endocrinology

Week 38 – ACCORD

“Effects of Intensive Glucose Lowering in Type 2 Diabetes”

by the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study Group

N Engl J Med. 2008 Jun 12;358(24):2545-59. [free full text]
—

We all treat type 2 diabetes mellitus (T2DM) on a daily basis, and we understand that untreated T2DM places patients at increased risk for adverse micro- and macrovascular outcomes. Prior to the 2008 ACCORD study, prospective epidemiological studies had noted a direct correlation between increased hemoglobin A1c values and increased risk of cardiovascular events. This correlation implied that treating T2DM to lower A1c levels would result in the reduction of cardiovascular risk. The ACCORD trial was the first large RCT to evaluate this specific hypothesis through comparison of events in two treatment groups – aggressive and less aggressive glucose management.

The trial enrolled patients with T2DM with A1c ≥ 7.5% and either age 40-79 with prior cardiovascular disease or age 55-79 with “anatomical evidence of significant atherosclerosis,” albuminuria, LVH, or ≥ 2 additional risk factors for cardiovascular disease (dyslipidemia, HTN, current smoker, or obesity). Notable exclusion criteria included “frequent or recent serious hypoglycemic events,” an unwillingness to inject insulin, BMI > 45, Cr > 1.5, or “other serious illness.” Patients were randomized to either intensive therapy targeting A1c to < 6.0% or to standard therapy targeting A1c 7.0-7.9%. The primary outcome was a composite first nonfatal MI or nonfatal stroke and death from cardiovascular causes. Reported secondary outcomes included all-cause mortality, severe hypoglycemia, heart failure, motor vehicle accidents in which the patient was the driver, fluid retention, and weight gain.

10,251 patients were randomized. The average age was 62, the average duration of T2DM was 10 years, and the average A1c was 8.1%. Both groups lowered their median A1c quickly, and median A1c values of the two groups separated rapidly within the first four months. (See Figure 1.) The intensive-therapy group had more exposure to antihyperglycemics of all classes. See Table 2.) Drugs were more frequently added, removed, or titrated in the intensive-therapy group (4.4 times per year versus 2.0 times per year in the standard-therapy group). At one year, the intensive-therapy group had a median A1c of 6.4% versus 7.5% in the standard-therapy group.

The primary outcome of MI/stroke/cardiovascular death occurred in 352 (6.9%) intensive-therapy patients versus 371 (7.2%) standard-therapy patients (HR 0.90, 95% CI 0.78-1.04, p = 0.16).  The trial was stopped early at a mean follow-up of 3.5 years due to increased all-cause mortality in the intensive-therapy group. 257 (5.0%) of the intensive-therapy patients died, but only 203 (4.0%) of the standard-therapy patients died (HR 1.22, 95% CI 1.01-1.46, p = 0.04). For every 95 patients treated with intensive therapy for 3.5 years, one extra patient died. Death from cardiovascular causes was also increased in the intensive-therapy group (HR 1.35, 95% CI 1.04-1.76, p = 0.02). Regarding additional secondary outcomes, the intensive-therapy group had higher rates of hypoglycemia, weight gain, and fluid retention than the standard-therapy group. (See Table 3.) There were no group differences in rates of heart failure or motor vehicle accidents in which the patient was the driver.

Intensive glucose control of T2DM increased all-cause mortality and did not alter the risk of cardiovascular events. This harm was previously unrecognized. The authors performed sensitivities analyses, including non-prespecified analyses, such as group differences in use of drugs like rosiglitazone, and they were unable to find an explanation for this increased mortality.

The target A1c level in T2DM remains a nuanced, patient-specific goal. Aggressive management may lead to improved microvascular outcomes, but it must be weighed against the risk of hypoglycemia. As summarized by UpToDate, while long-term data from the UKPDS suggests there may be a macrovascular benefit to aggressive glucose management early in the course of T2DM, the data from ACCORD suggest strongly that, in patients with longstanding T2DM and additional risk factors for cardiovascular disease, such management increases mortality.

The 2019 American Diabetes Association guidelines suggest that “a reasonable A1c goal for many nonpregnant adults is < 7%.” More stringent goals (< 6.5%) may be appropriate if they can be achieved without significant hypoglycemia or polypharmacy, and less stringent goals (< 8%) may be appropriate for patients “with a severe history of hypoglycemia, limited life expectancy, advanced microvascular or macrovascular complications…”

Of note, ACCORD also simultaneously cross-enrolled its patients in studies of intensive blood pressure management and adjunctive lipid management with fenofibrate. See this 2010 NIH press release and the links below for more information.

Further Reading/References:
1. ACCORD @ Wiki Journal Club
2. ACCORD @ 2 Minute Medicine
3. American Diabetes Association – “Glycemic Targets.” Diabetes Care (2019).
4. “Effect of intensive treatment of hyperglycaemia on microvascular outcomes in type 2 diabetes: an analysis of the ACCORD randomised trial.” Lancet (2010).

Summary by Duncan F. Moore, MD

Image Credit: Omstaal, CC BY-SA 4.0, via Wikimedia Commons

Week 14 – IDNT

“Renoprotective Effect of the Angiotensin-Receptor Antagonist Irbesartan in Patients with Nephropathy Due to Type 2 Diabetes”

aka the Irbesartan Diabetic Nephropathy Trial (IDNT)

N Engl J Med. 2001 Sep 20;345(12):851-60. [free full text]
—

Diabetes mellitus is the most common cause of ESRD in the US. In 1993, a landmark study in NEJM demonstrated that captopril (vs. placebo) slowed the deterioration in renal function in patients with T1DM. However, prior to this 2002 study, no study had addressed definitively whether a similar improvement in renal outcomes could be achieved with RAAS blockade in patients with T2DM. Irbesartan (Avapro) is an angiotensin II receptor blocker that was first approved in 1997 for the treatment of hypertension. Its marketer, Bristol-Meyers Squibb, sponsored this trial in hopes of broadening the market for its relatively new drug.

This trial randomized patients with T2DM, hypertension, and nephropathy (per proteinuria and elevated Cr) to treatment with either irbesartan, amlodipine, or placebo. The drug in each arm was titrated to achieve a target SBP ≤ 135, and all patients were allowed non-ACEi/non-ARB/non-CCB drugs as needed. The primary outcome was a composite of the doubling of serum Cr, onset of ESRD, or all-cause mortality. Secondary outcomes included individual components of the primary outcome and a composite cardiovascular outcome.

1715 patients were randomized. The mean blood pressure after the baseline visit was 140/77 in the irbesartan group, 141/77 in the amlodipine group, and 144/80 in the placebo group (p = 0.001 for pairwise comparisons of MAP between irbesartan or amlodipine and placebo). Regarding the primary composite renal endpoint, the unadjusted relative risk was 0.80 (95% CI 0.66-0.97, p = 0.02) for irbesartan vs. placebo, 1.04 (95% CI 0.86-1.25, p = 0.69) for amlodipine vs. placebo, and 0.77 (0.63-0.93, p = 0.006) for irbesartan vs. amlodipine. The groups also differed with respect to individual components of the primary outcome. The unadjusted relative risk of creatinine doubling was 33% lower among irbesartan patients than among placebo patients (p = 0.003) and was 37% lower than among amlodipine patients (p < 0.001). The relative risks of ESRD and all-cause mortality did not differ significantly among the groups. There were no significant group differences with respect to the composite cardiovascular outcome. Importantly, a sensitivity analysis was performed which demonstrated that the conclusions of the primary analysis were not impacted significantly by adjustment for mean arterial pressure achieved during follow-up.

In summary, irbesartan treatment in T2DM resulted in superior renal outcomes when compared to both placebo and amlodipine. This beneficial effect was independent of blood pressure lowering. This was a well-designed, double-blind, randomized, controlled trial. However, it was industry-sponsored, and in retrospect, its choice of study drug seems quaint. The direct conclusion of this trial is that irbesartan is renoprotective in T2DM. In the discussion of IDNT, the authors hypothesize that “the mechanism of renoprotection by agents that block the action of angiotensin II may be complex, involving hemodynamic factors that lower the intraglomerular pressure, the beneficial effects of diminished proteinuria, and decreased collagen formation that may be related to decreased stimulation of transforming growth factor beta by angiotensin II.” In September 2002, on the basis of this trial, the FDA broadened the official indication of irbesartan to include the treatment of type 2 diabetic nephropathy. This trial was published concurrently in NEJM with the RENAAL trial [https://www.wikijournalclub.org/wiki/RENAAL]. RENAAL was a similar trial of losartan vs. placebo in T2DM and demonstrated a similar reduction in the doubling of serum creatinine as well as a 28% reduction in progression to ESRD. In conjunction with the original 1993 ACEi in T1DM study, these two 2002 ARB in T2DM studies led to the overall notion of a renoprotective class effect of ACEis/ARBs in diabetes. Enalapril and lisinopril’s patents expired in 2000 and 2002, respectively. Shortly afterward, generic, once-daily ACE inhibitors entered the US market. Ultimately, such drugs ended up commandeering much of the diabetic-nephropathy-in-T2DM market share for which irbesartan’s owners had hoped.

Further Reading/References:
1. “The effect of angiotensin-converting-enzyme inhibition on diabetic nephropathy. The Collaborative Study Group.” NEJM 1993.
2. CSG Captopril Trial @ Wiki Journal Club
3. IDNT @ Wiki Journal Club
4. IDNT @ 2 Minute Medicine
5. US Food and Drug Administration, New Drug Application #020757
6. RENAAL @ Wiki Journal Club
7. RENAAL @ 2 Minute Medicine

Summary by Duncan F. Moore, MD

Image Credit: Skirtick, CC BY-SA 4.0, via Wikimedia Commons

Week 13 – VERT

“Effects of Risedronate Treatment on Vertebral and Nonvertebral Fractures in Women With Postmenopausal Osteoporosis”

by the Vertebral Efficacy with Risedronate Therapy (VERT) Study Group

JAMA. 1999 Oct 13;282(14):1344-52. [free full text]
—

Bisphosphonates are a highly effective and relatively safe class of medications for the prevention of fractures in patients with osteoporosis. The VERT trial published in 1999 was a landmark trial that demonstrated this protective effect with the daily oral bisphosphonate risedronate.

The trial enrolled post-menopausal women with either 2 or more vertebral fractures per radiography or 1 vertebral fracture with decreased lumbar spine bone mineral density. Patients were randomized to the treatment arm (risedronate 2.5mg PO daily or risedronate 5mg PO daily) to the daily PO placebo control arm. Measured outcomes included: 1) the prevalence of new vertebral fracture at 3 years follow-up, per annual imaging, 2) the prevalence of new non-vertebral fracture at 3 years follow-up, per annual imaging, and 3) change in bone mineral density, per DEXA q6 months.

2458 patients were randomized. During the course of the study, “data from other trials indicated that the 2.5mg risedronate dose was less effective than the 5mg dose,” and thus the authors discontinued further data collection on the 2.5mg treatment arm at 1 year into the study. All treatment groups had similar baseline characteristics. 55% of the placebo group and 60% of the 5mg risedronate group completed 3 years of treatment. The prevalence of new vertebral fracture within 3 years was 11.3% in the risedronate group and 16.3% in the placebo group (RR 0.59, 95% CI 0.43-0.82, p = 0.003; NNT = 20). The prevalence of new non-vertebral fractures at 3 years was 5.2% in the treatment arm and 8.4% in the placebo arm (RR 0.6, 95% CI 0.39-0.94, p = 0.02; NNT = 31). Regarding bone mineral density (BMD), see Figure 4 for a visual depiction of the changes in BMD by treatment group at the various 6-month timepoints. Notably, change from baseline BMD of the lumbar spine and femoral neck was significantly higher (and positive) in the risedronate 5mg group at all follow-up timepoints relative to the placebo group and at all timepoints except 6 months for the femoral trochanter measurements. Regarding adverse events, there was no difference in the incidence of upper GI adverse events among the two groups. GI complaints “were the most common adverse events associated with study discontinuance,” and GI events lead to 42% of placebo withdrawals but only 36% of the 5mg risedronate withdrawals.

Oral risedronate reduces the risk of vertebral and non-vertebral fractures in patients with osteoporosis while increasing bone mineral density. Overall, this was a large, well-designed RCT that demonstrated a concrete treatment benefit. As a result, oral bisphosphonate therapy has become the standard of care both for treatment and prevention of osteoporosis. This study, as well as others, demonstrated that such therapies are well-tolerated with relatively few side effects. A notable strength of this study is that it did not exclude patients with GI comorbidities.  One weakness is the modification of the trial protocol to eliminate the risedronate 2.5mg treatment arm after 1 year of study. Although this arm demonstrated a reduction in vertebral fracture at 1 year relative to placebo (p = 0.02), its elimination raises suspicion that the pre-specified analyses were not yielding the anticipated results during the interim analysis and thus the less-impressive treatment arm was discarded.

Further Reading/References:
1. Weekly alendronate vs. weekly risedronate
2. Comparative effectiveness of pharmacologic treatments to prevent fractures: an updated systematic review (2014)

Summary by Duncan F. Moore, MD

Image Credit: Nick Smith, CC BY-SA 3.0, via Wikimedia Commons

Week 3 – NICE-SUGAR

“Intensive versus Conventional Glucose Control in Critically Ill Patients”

by the Normoglycemia in Intensive Care Evaluation–Survival Using Glucose Algorithm Regulation (NICE-SUGAR) investigators

N Engl J Med 2009;360:1283-97. [free full text]
—

On the wards we often hear 180 mg/dL used as the upper limit of acceptable for blood glucose with the understanding that tighter glucose control in inpatients can lead to more harm than benefit. The relevant evidence base comes from ICU populations, with scant direct data in non-ICU patients. The 2009 NICE-SUGAR study is the largest and best among this evidence base.

The study randomized ICU patients (expected to require 3 or more days of ICU-level care) to either “intensive” glucose control (target glucose 81 to 108 mg/dL) or conventional glucose control (target of less than 180 mg/dL). The primary outcome was 90-day all-cause mortality.

6104 patients were randomized to the two arms, and both groups had similar baseline characteristics. 27.5% of patients in the intensive-control group died versus 24.9% in the conventional-control group (OR 1.14, 95% CI 1.02-1.28, p= 0.02). Severe hypoglycemia (< 40 mg/dL) was found in 6.8% of intensive patients but only 0.5% of conventional patients.

In conclusion, intensive glucose control increases mortality in ICU patients. The fact that only 20% of these patients had diabetes mellitus suggests that much of the hyperglycemia treated in this study (97% of intensive group received insulin, 69% of conventional) was from stress, critical illness, and corticosteroid use. For ICU patients, intensive insulin therapy is clearly harmful, but the ideal target glucose range remains controversial and by expert opinion appears to be 140-180. For non-ICU inpatients with or without diabetes mellitus, the ideal glucose target is also unclear – the ADA recommends 140-180, and the Endocrine Society recommends a pre-meal target of < 140 and random levels < 180.

References / Further Reading:
1. ADA Standards of Medical Care in Diabetes 2016 (skip to page S99)
2. NICE-SUGAR @ Wiki Journal Club

Summary by Duncan F. Moore, MD

Week 50 – VERT

“Effects of Risedronate Treatment on Vertebral and Nonvertebral Fractures in Women With Postmenopausal Osteoporosis”

by the Vertebral Efficacy with Risedronate Therapy (VERT) Study Group

JAMA. 1999 Oct 13;282(14):1344-52. [free full text]
—

Bisphosphonates are a highly effective and relatively safe class of medications for the prevention of fractures in patients with osteoporosis. The VERT trial published in 1999 was a landmark trial that demonstrated this protective effect with the daily oral bisphosphonate risedronate.

The trial enrolled post-menopausal women with either 2 or more vertebral fractures per radiography or 1 vertebral fracture with decreased lumbar spine bone mineral density. Patients were randomized to the treatment arm (risedronate 2.5mg PO daily or risedronate 5mg PO daily) to the daily PO placebo control arm. Measured outcomes included: 1) the prevalence of new vertebral fracture at 3 years follow-up, per annual imaging, 2) the prevalence of new non-vertebral fracture at 3 years follow-up, per annual imaging, and 3) change in bone mineral density, per DEXA q6 months.

2458 patients were randomized. During the course of the study, “data from other trials indicated that the 2.5mg risedronate dose was less effective than the 5mg dose,” and thus the authors discontinued further data collection on the 2.5mg treatment arm at 1 year into the study. All treatment groups had similar baseline characteristics. 55% of the placebo group and 60% of the 5mg risedronate group completed 3 years of treatment. The prevalence of new vertebral fracture within 3 years was 11.3% in the risedronate group and 16.3% in the placebo group (RR 0.59, 95% CI 0.43-0.82, p = 0.003; NNT = 20). The prevalence of new non-vertebral fractures at 3 years was 5.2% in the treatment arm and 8.4% in the placebo arm (RR 0.6, 95% CI 0.39-0.94, p = 0.02; NNT = 31). Regarding bone mineral density (BMD), see Figure 4 for a visual depiction of the changes in BMD by treatment group at the various 6-month timepoints. Notably, change from baseline BMD of the lumbar spine and femoral neck was significantly higher (and positive) in the risedronate 5mg group at all follow-up timepoints relative to the placebo group and at all timepoints except 6 months for the femoral trochanter measurements. Regarding adverse events, there was no difference in the incidence of upper GI adverse events among the two groups. GI complaints “were the most common adverse events associated with study discontinuance,” and GI events lead to 42% of placebo withdrawals but only 36% of the 5mg risedronate withdrawals.

Oral risedronate reduces the risk of vertebral and non-vertebral fractures in patients with osteoporosis while increasing bone mineral density. Overall, this was a large, well-designed RCT that demonstrated a concrete treatment benefit. As a result, oral bisphosphonate therapy has become the standard of care both for treatment and prevention of osteoporosis. This study, as well as others, demonstrated that such therapies are well-tolerated with relatively few side effects. A notable strength of this study is that it did not exclude patients with GI comorbidities.  One weakness is the modification of the trial protocol to eliminate the risedronate 2.5mg treatment arm after 1 year of study. Although this arm demonstrated a reduction in vertebral fracture at 1 year relative to placebo (p = 0.02), its elimination raises suspicion that the pre-specified analyses were not yielding the anticipated results during the interim analysis and thus the less-impressive treatment arm was discarded.

Further Reading/References:
1. Weekly alendronate vs. weekly risedronate [https://www.ncbi.nlm.nih.gov/pubmed/15619680]
2. Comparative effectiveness of pharmacologic treatments to prevent fractures: an updated systematic review (2014) [https://www.ncbi.nlm.nih.gov/pubmed/25199883]

Summary by Duncan F. Moore, MD

Image Credit: Nick Smith, CC BY-SA 3.0, via Wikimedia Commons

Week 46 – ACCORD

“Effects of Intensive Glucose Lowering in Type 2 Diabetes”

by the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study Group

N Engl J Med. 2008 Jun 12;358(24):2545-59. [free full text]
—

We all treat type 2 diabetes mellitus (T2DM) on a daily basis, and we understand that untreated T2DM places patients at increased risk for adverse micro- and macrovascular outcomes. Prior to the 2008 ACCORD study, prospective epidemiological studies had noted a direct correlation between increased hemoglobin A1c values and increased risk of cardiovascular events. This correlation implied that treating T2DM to lower A1c levels would result in the reduction of cardiovascular risk. The ACCORD trial was the first large RCT to evaluate this specific hypothesis through comparison of events in two treatment groups – aggressive and less aggressive glucose management.

The trial enrolled patients with T2DM with A1c ≥ 7.5% and either age 40-79 with prior cardiovascular disease or age 55-79 with “anatomical evidence of significant atherosclerosis,” albuminuria, LVH, or ≥ 2 additional risk factors for cardiovascular disease (dyslipidemia, HTN, current smoker, or obesity). Notable exclusion criteria included “frequent or recent serious hypoglycemic events,” an unwillingness to inject insulin, BMI > 45, Cr > 1.5, or “other serious illness.” Patients were randomized to either intensive therapy targeting A1c to < 6.0% or to standard therapy targeting A1c 7.0-7.9%. The primary outcome was a composite first nonfatal MI or nonfatal stroke and death from cardiovascular causes. Reported secondary outcomes included all-cause mortality, severe hypoglycemia, heart failure, motor vehicle accidents in which the patient was the driver, fluid retention, and weight gain.

10,251 patients were randomized. The average age was 62, the average duration of T2DM was 10 years, and the average A1c was 8.1%. Both groups lowered their median A1c quickly, and median A1c values of the two groups separated rapidly within the first four months. (See Figure 1.) The intensive-therapy group had more exposure to antihyperglycemics of all classes. See Table 2.) Drugs were more frequently added, removed, or titrated in the intensive-therapy group (4.4 times per year versus 2.0 times per year in the standard-therapy group). At one year, the intensive-therapy group had a median A1c of 6.4% versus 7.5% in the standard-therapy group.

The primary outcome of MI/stroke/cardiovascular death occurred in 352 (6.9%) intensive-therapy patients versus 371 (7.2%) standard-therapy patients (HR 0.90, 95% CI 0.78-1.04, p = 0.16).

The trial was stopped early at a mean follow-up of 3.5 years due to increased all-cause mortality in the intensive-therapy group. 257 (5.0%) of the intensive-therapy patients died, but only 203 (4.0%) of the standard-therapy patients died (HR 1.22, 95% CI 1.01-1.46, p = 0.04). For every 95 patients treated with intensive therapy for 3.5 years, one extra patient died. Death from cardiovascular causes was also increased in the intensive-therapy group (HR 1.35, 95% CI 1.04-1.76, p = 0.02).

Regarding additional secondary outcomes, the intensive-therapy group had higher rates of hypoglycemia, weight gain, and fluid retention than the standard-therapy group. (See Table 3.) There were no group differences in rates of heart failure or motor vehicle accidents in which the patient was the driver.

Intensive glucose control of T2DM increased all-cause mortality and did not alter the risk of cardiovascular events. This harm was previously unrecognized.

The authors performed sensitivities analyses, including non-prespecified analyses, such as group differences in use of drugs like rosiglitazone, and they were unable to find an explanation for this increased mortality.

The target A1c level in T2DM remains a nuanced, patient-specific goal. Aggressive management may lead to improved microvascular outcomes, but it must be weighed against the risk of hypoglycemia. As summarized by UpToDate, while long-term data from the UKPDS suggests there may be a macrovascular benefit to aggressive glucose management early in the course of T2DM, the data from ACCORD suggest strongly that, in patients with longstanding T2DM and additional risk factors for cardiovascular disease, such management increases mortality.

The 2019 American Diabetes Association guidelines suggest that “a reasonable A1c goal for many nonpregnant adults is < 7%.” More stringent goals (< 6.5%) may be appropriate if they can be achieved without significant hypoglycemia or polypharmacy, and less stringent goals (< 8%) may be appropriate for patients “with a severe history of hypoglycemia, limited life expectancy, advanced microvascular or macrovascular complications…”

Of note, ACCORD also simultaneously cross-enrolled its patients in studies of intensive blood pressure management and adjunctive lipid management with fenofibrate. See this 2010 NIH press release and the links below for more information.

ACCORD Blood Pressure – NEJM, Wiki Journal Club

ACCORD Lipids – NEJM, Wiki Journal Club

Further Reading/References:
1. ACCORD @ Wiki Journal Club
2. ACCORD @ 2 Minute Medicine
3. American Diabetes Association – “Glycemic Targets.” Diabetes Care (2019).
4. “Effect of intensive treatment of hyperglycaemia on microvascular outcomes in type 2 diabetes: an analysis of the ACCORD randomised trial.” Lancet (2010).

Summary by Duncan F. Moore, MD

Week 9 – NICE-SUGAR

“Intensive versus Conventional Glucose Control in Critically Ill Patients”

by the Normoglycemia in Intensive Care Evaluation–Survival Using Glucose Algorithm Regulation (NICE-SUGAR) investigators

N Engl J Med 2009;360:1283-97. [free full text]
—

On the wards we often hear 180 mg/dL used as the upper limit of acceptable for blood glucose with the understanding that tighter glucose control in inpatients can lead to more harm than benefit. The relevant evidence base comes from ICU populations, with scant direct data in non-ICU patients. The 2009 NICE-SUGAR study is the largest and best among this evidence base.

The study randomized ICU patients (expected to require 3 or more days of ICU-level care) to either “intensive” glucose control (target glucose 81 to 108 mg/dL) or conventional glucose control (target of less than 180 mg/dL). The primary outcome was 90-day all-cause mortality.

6104 patients were randomized to the two arms, and both groups had similar baseline characteristics. 27.5% of patients in the intensive-control group died versus 24.9% in the conventional-control group (OR 1.14, 95% CI 1.02-1.28, p= 0.02). Severe hypoglycemia (< 40 mg/dL) was found in 6.8% of intensive patients but only 0.5% of conventional patients.

In conclusion, intensive glucose control increases mortality in ICU patients. The fact that only 20% of these patients had diabetes mellitus suggests that much of the hyperglycemia treated in this study (97% of intensive group received insulin, 69% of conventional) was from stress, critical illness, and corticosteroid use. For ICU patients, intensive insulin therapy is clearly harmful, but the ideal target glucose range remains controversial and by expert opinion appears to be 140-180. For non-ICU inpatients with or without diabetes mellitus, the ideal glucose target is also unclear – the ADA recommends 140-180, and the Endocrine Society recommends a pre-meal target of < 140 and random levels < 180.

References / Further Reading:
1. ADA Standards of Medical Care in Diabetes 2016 (skip to page S99)
2. Wiki Journal Club
3. Visual Abstract @ VisualMed

Summary by Duncan F. Moore, MD

Image Credit: Dietmar Rabich / Wikimedia Commons / “Würfelzucker — 2018 — 3564” / CC BY-SA 4.0

Week 45 – Look AHEAD

“Cardiovascular Effects of Intensive Lifestyle Intervention in Type 2 Diabetes”

by the Look AHEAD (Action for Health in Diabetes) Research Group

N Engl J Med. 2013 Jul 11;369(2):145-54. [free full text]
—

NIH treatment guidelines recommend weight loss in patients with T2DM and overweight or obesity. Such weight loss is associated with improvements in glycemic control, hypertension, and quality of life. While retrospective cohort studies and a prospective trial of bariatric surgery in T2DM suggested that weight loss was associated with reduction in rates of cardiovascular events and mortality, no prospective trial has demonstrated such benefits from non-surgical weight loss. The Look AHEAD study was designed to determine if aggressive lifestyle intervention for weight loss in T2DM could provide benefits in hard cardiovascular outcomes.

Population: patients with T2DM, age 45-75, and BMI 25+ (27+ if on insulin), A1c < 11%, SBP < 160 mmHg, DBP < 100 mmHg, and the ability to complete a maximal exercise test

Intervention: an “intensive lifestyle intervention” with goal weight loss ≥ 7.0%, implemented via weekly group and individual counseling (decreasing in frequency over course of study). Specific recommended interventions: caloric restriction to 1200-1800 kcal/day, use of meal-replacement products, ≥ 175 min/wk of moderate-intensity exercise

Comparison: “diabetes support and education” comprised of three group meetings per year focused on diet, exercise, and social support (yearly meetings starting year 5)
Outcome:
Primary – composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for angina.

Of note, hospitalization for angina was not a pre-specified component of the primary outcome. It was added 2 years into the trial after event rates of the other cardiovascular components were lower than expected.

Secondary

  • composite of death from cardiovascular causes, nonfatal MI, nonfatal stroke (the original primary outcome)
  • composite of death (all-cause), nonfatal MI, nonfatal stroke, hospitalization for angina
  • composite of death (all-cause), nonfatal MI, stroke, hospitalization for angina, CABG, PCI, hospitalization for heart failure, or peripheral vascular disease

Results:
2570 patients were randomized to the intensive lifestyle intervention (ILI) group, and 2575 were randomized to the diabetes support and education (DSE) group. Baseline characteristics were similar in both groups. Mean BMI was 36.0, and 14% of patients had a history of cardiovascular disease.

At one year, mean weight loss from baseline was 8.6% in the ILI group and 0.7% in the DSE group (p < 0.001); however, weight loss at the end of the study was 6.0% in the ILI group and 3.5% in the DSE group (p < 0.001). The average group difference in A1c was 0.22% lower in the ILI group (p < 0.001) although A1c values were slightly higher than baseline in both groups at the end of the study (see Figure 1D for the time course).

The trial was terminated prematurely after interim analysis revealed that the likelihood of a significant positive primary result was approximately 1%. Median follow up was 9.6 years at the time of termination.

There was no group difference in rates of the primary composite cardiovascular endpoint. The endpoint occurred in 403 patients in the ILI group and 418 patients in the DSE group (1.83 and 1.92 events per 100 person-years, respectively; HR 0.95, 95% CI 0.83-1.09, p = 0.51).

There were no group differences in rates of the secondary composite outcomes.

Implication/Discussion:
Among patients with T2DM and overweight or obesity, an intensive lifestyle intervention for weight loss was not associated with improved cardiovascular outcomes, when compared to a control group-based diabetes support and education intervention.

Overall, this trial was a notable failure. Despite the trial’s adequate power and its authors shifting the goalposts at 2 years into the study, the intervention did not demonstrate “hard” cardiovascular benefits. Furthermore, generalizability of this study is limited by its exclusion of patients who could not complete a maximal-fitness test at baseline. With respect to diet, this trial did not address diet composition, only caloric restriction and increased physical activity.

The authors suggest that “a sustained weight loss of more than that achieved in the intervention group may be required to reduce the risk of cardiovascular disease,” and thus the trial failed to return a positive result.

Weight loss in patients with T2DM and overweight or obesity remains a Class A recommendation by the American Diabetes Association. The ADA also notes that weight loss may be achieved at 2 years with a “Mediterranean” diet. The 2013 PREDIMED study demonstrated that such a diet reduces the risk of ASCVD in high-risk patients.

Further Reading/References:
1. Look AHEAD @ Wiki Journal Club
2. American Diabetes Association. “Executive Summary: Standards of Medical Care in Diabetes – 2013.”
3. PREDIMED @ Wiki Journal Club

Summary by Duncan F. Moore, MD

Week 39 – ACCORD

“Effects of Intensive Glucose Lowering in Type 2 Diabetes”

by the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study Group

N Engl J Med. 2008 Jun 12;358(24):2545-59. [free full text]
—

We all treat type 2 diabetes mellitus (T2DM) on a daily basis, and we understand that untreated T2DM places patients at increased risk for adverse micro- and macrovascular outcomes. Prior to the 2008 ACCORD study, prospective epidemiological studies had noted a direct correlation between increased hemoglobin A1c values and increased risk of cardiovascular events. This correlation implied that treating T2DM to lower A1c levels would result in the reduction of cardiovascular risk. The ACCORD trial was the first large RCT to evaluate this specific hypothesis through comparison of events in two treatment groups – aggressive and less-aggressive glucose management.

Population: patients with T2DM and A1c ≥ 7.5% and if age 40-79 with prior cardiovascular disease or if age 55-79 had “anatomical evidence of significant atherosclerosis,” albuminuria, LVH, or ≥ 2 additional risk factors for cardiovascular disease (dyslipidemia, HTN, current smoker, or obesity)

Notable exclusion criteria: “frequent or recent serious hypoglycemic events,” unwillingness to inject insulin, BMI > 45, Cr > 1.5, or “other serious illness”

Intervention: intensive therapy targeted to A1c < 6.0%

Comparison: standard therapy targeted to A1c 7.0-7.9%

Outcome:
Primary – composite of first nonfatal MI or nonfatal stroke and death from cardiovascular causes

Reported secondary outcomes included:

  • all-cause mortality
  • severe hypoglycemia
  • heart failure
  • motor vehicle accidents in which the patient was the driver
  • fluid retention
  • weight gain

Results:
10,251 patients were randomized. The average age was 62, the average duration of T2DM was 10 years, and the average A1c was 8.1%. There were no group differences in baseline characteristics (see Table 1). Both groups lowered their median A1c quickly, and median A1c values of the two groups separated rapidly within the first four months (see Figure 1). The intensive-therapy group had more exposure to antihyperglycemics of all classes (see Table 2), and drugs were more frequently added, removed, or titrated in the intensive-therapy group (4.4 times per year, versus 2.0 times per year in the standard-therapy group). At one year, the intensive-therapy group had a median A1c of 6.4% versus 7.5% in the standard-therapy group.

The primary outcome of MI/stroke/cardiovascular death occurred in 352 (6.9%) intensive-therapy patients versus 371 (7.2%) standard-therapy patients (HR 0.90, 95% CI 0.78-1.04, p = 0.16).

The trial was stopped early at a mean follow-up of 3.5 years due to increased all-cause mortality in the intensive-therapy group. 257 (5.0%) of the intensive-therapy patients died, but only 203 (4.0%) of the standard-therapy patients died (HR 1.22, 95% CI 1.01-1.46, p = 0.04). For every 95 patients treated with intensive therapy for 3.5 years, one extra patient died. Death from cardiovascular causes was also increased in the intensive-therapy group (HR 1.35, 95% CI 1.04-1.76, p = 0.02).

Additional secondary outcomes: the intensive-therapy group had higher rates of hypoglycemia, weight gain, and fluid retention than the standard-therapy group (see Table 3). There were no group differences in rates of heart failure or motor vehicle accidents in which the patient was the driver.

Implication/Discussion:
Intensive glucose control of T2DM increased all-cause mortality and did not alter the risk of cardiovascular events. This harm was previously unrecognized.

The authors performed sensitivities analyses, including non-prespecified analyses, such as group differences in use of drugs like rosiglitazone, and they were unable to find an explanation for this increased mortality.

The target A1c level in T2DM remains a nuanced, patient-specific goal. Aggressive management may lead to improved microvascular outcomes, but it must be weighed against the risk of hypoglycemia. As summarized by UpToDate [https://www.uptodate.com/contents/glycemic-control-and-vascular-complications-in-type-2-diabetes-mellitus], while long-term data from the UKPDS suggests there may be a macrovascular benefit to aggressive glucose management early in the course of T2DM, the data from ACCORD suggest strongly that, in patients with longstanding T2DM and additional risk factors for cardiovascular disease, such management increases mortality.

The 2017 American Diabetes Association guidelines suggest that “a reasonable A1c goal for many nonpregnant adults is < 7%.” More stringent goals (< 6.5%) may be appropriate if they can be achieved without significant hypoglycemia or polypharmacy, and less stringent goals (< 8%) may be appropriate for patients “with a severe history of hypoglycemia, limited life expectancy, advanced microvascular or macrovascular complications…”

Of note, ACCORD also simultaneously cross-enrolled its patients in studies of intensive blood pressure management and adjunctive lipid management with fenofibrate. See this 2010 NIH press release and the links below for more information.

ACCORD Blood Pressure – NEJM, Wiki Journal Club

ACCORD Lipids – NEJM, Wiki Journal Club


Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. American Diabetes Association – “Glycemic Targets.” Diabetes Care (2017).
4. “Effect of intensive treatment of hyperglycaemia on microvascular outcomes in type 2 diabetes: an analysis of the ACCORD randomised trial.” Lancet (2010).

Summary by Duncan F. Moore, MD

Week 18 – VERT

“Effects of Risedronate Treatment on Vertebral and Nonvertebral Fractures in Women With Postmenopausal Osteoporosis”

by the Vertebral Efficacy with Risedronate Therapy (VERT) Study Group

JAMA. 1999 Oct 13;282(14):1344-52. [free full text]
—

Bisphosphonates are a highly effective and relatively safe class of medications for the prevention of fractures in patients with osteoporosis. The VERT trial published in 1999 was a landmark trial that demonstrated this protective effect with the daily oral bisphosphonate risedronate.

Population: post-menopausal women with either 2 or more vertebral fractures per radiography or 1 vertebral fracture with decreased lumbar spine bone mineral density

Intervention: risedronate 2.5mg mg PO daily or risedronate 5mg PO daily

Comparison: placebo PO daily

Outcomes:
1. prevalence of new vertebral fracture at 3 years follow-up, per annual imaging
2. prevalence of new non-vertebral fracture at 3 years follow-up, per annual imaging
3. change in bone mineral density, per DEXA q6 months

Results:
2458 patients were randomized. During the course of the study, “data from other trials indicated that the 2.5mg risedronate dose was less effective than the 5mg dose,” and thus the authors discontinued further data collection on the 2.5mg treatment arm at 1 year into the study. All treatment groups had similar baseline characteristics. 55% of the placebo group and 60% of the 5mg risedronate group completed 3 years of treatment. The prevalence of new vertebral fracture within 3 years was 11.3% in the risedronate group and 16.3% in the placebo group (RR 0.59, 95% CI 0.43-0.82, p = 0.003; NNT = 20). The prevalence of new non-vertebral fractures at 3 years was 5.2% in the treatment arm and 8.4% in the placebo arm (RR 0.6, 95% CI 0.39-0.94, p = 0.02; NNT = 31). Regarding bone mineral density (BMD), see Figure 4 for a visual depiction of the changes in BMD by treatment group at the various 6-month timepoints. Notably, change from baseline BMD of the lumbar spine and femoral neck was significantly higher (and positive) in the risedronate 5mg group at all follow-up timepoints relative to the placebo group and at all timepoints except 6 months for the femoral trochanter measurements. Regarding adverse events, there was no difference in the incidence of upper GI adverse events among the two groups. GI complaints “were the most common adverse events associated with study discontinuance,” and GI events lead to 42% of placebo withdrawals but only 36% of the 5mg risedronate withdrawals.

Implication/Discussion:
Oral risedronate reduces the risk of vertebral and non-vertebral fractures in patients with osteoporosis while increasing bone mineral density.

Overall, this was a large, well-designed RCT that demonstrated a concrete treatment benefit. As a result, oral bisphosphonate therapy has become the standard of care both for treatment and prevention of osteoporosis. This study, as well as others, demonstrated that such therapies are well-tolerated with relatively few side effects.

A notable strength of this study is that it did not exclude patients with GI comorbidities.  One weakness is the modification of the trial protocol to eliminate the risedronate 2.5mg treatment arm after 1 year of study. Although this arm demonstrated a reduction in vertebral fracture at 1 year relative to placebo (p = 0.02), its elimination raises suspicion that the pre-specified analyses were not yielding the anticipated results during the interim analysis and thus the less-impressive treatment arm was discarded.

Further Reading/References:
1. Weekly alendronate vs. weekly risedronate
2. Comparative effectiveness of pharmacologic treatments to prevent fractures: an updated systematic review (2014)

Summary by Duncan F. Moore, MD