Characteristics associated with informed consent for genetic studies in the ACCORD trial.

BACKGROUND: Prior studies found that some groups have lower genetic consent rates than others. Participant consent for genetic studies enables randomized trials to examine effects of interventions compared to control in participants with different genotypes. METHODS: Unadjusted and multivariate associations between genetic consent rates and participant, study, and consent characteristics in 9573 participants approached for genetics consent in the multicenter Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, which used a layered genetics consent. RESULTS: Eighty-nine percent of eligible participants consented to genetic studies ("Any Consent") and 64.7% consented to studies of any genes by any investigator ("Full Consent"), with similar rates in randomized groups. Controlling for multiple characteristics, African-Americans had lower consent rates than others (Any Consent Odds Ratio, OR = 0.62, p = 0.0004; Full Consent OR = 0.67, p < 0.0001). Those with high school or higher education level had higher rates than less than high school graduates (Full Consent ORs 1.41-1.69, p-values < 0.0001). Consent rates were lower when genetics consent was separate from the main trial consent on the same day (Any Consent OR 0.30; Full Consent OR 0.52, p values < 0.0001) or on a subsequent day (Any Consent OR 0.70, p = 0.0022; Full Consent OR 0.76, p = 0.0002). CONCLUSION: High rates of consent for genetic studies can be obtained in complex randomized trials, with lower consent rates in African-Americans, in participants with less than high-school education, and for sharing samples with other investigators. A genetics consent separated from the main trial consent was associated with lower consent rates.

Effects of combination lipid therapy in type 2 diabetes mellitus.

BACKGROUND: We investigated whether combination therapy with a statin plus a fibrate, as compared with statin monotherapy, would reduce the risk of cardiovascular disease in patients with type 2 diabetes mellitus who were at high risk for cardiovascular disease. METHODS: We randomly assigned 5518 patients with type 2 diabetes who were being treated with open-label simvastatin to receive either masked fenofibrate or placebo. The primary outcome was the first occurrence of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The mean follow-up was 4.7 years. RESULTS: The annual rate of the primary outcome was 2.2% in the fenofibrate group and 2.4% in the placebo group (hazard ratio in the fenofibrate group, 0.92; 95% confidence interval [CI], 0.79 to 1.08; P=0.32). There were also no significant differences between the two study groups with respect to any secondary outcome. Annual rates of death were 1.5% in the fenofibrate group and 1.6% in the placebo group (hazard ratio, 0.91; 95% CI, 0.75 to 1.10; P=0.33). Prespecified subgroup analyses suggested heterogeneity in treatment effect according to sex, with a benefit for men and possible harm for women (P=0.01 for interaction), and a possible interaction according to lipid subgroup, with a possible benefit for patients with both a high baseline triglyceride level and a low baseline level of high-density lipoprotein cholesterol (P=0.057 for interaction). CONCLUSIONS: The combination of fenofibrate and simvastatin did not reduce the rate of fatal cardiovascular events, nonfatal myocardial infarction, or nonfatal stroke, as compared with simvastatin alone. These results do not support the routine use of combination therapy with fenofibrate and simvastatin to reduce cardiovascular risk in the majority of high-risk patients with type 2 diabetes. (ClinicalTrials.gov number, NCT00000620.)

Effects of intensive blood-pressure control in type 2 diabetes mellitus.

BACKGROUND: There is no evidence from randomized trials to support a strategy of lowering systolic blood pressure below 135 to 140 mm Hg in persons with type 2 diabetes mellitus. We investigated whether therapy targeting normal systolic pressure (i.e., <120 mm Hg) reduces major cardiovascular events in participants with type 2 diabetes at high risk for cardiovascular events. METHODS: A total of 4733 participants with type 2 diabetes were randomly assigned to intensive therapy, targeting a systolic pressure of less than 120 mm Hg, or standard therapy, targeting a systolic pressure of less than 140 mm Hg. The primary composite outcome was nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The mean follow-up was 4.7 years. RESULTS: After 1 year, the mean systolic blood pressure was 119.3 mm Hg in the intensive-therapy group and 133.5 mm Hg in the standard-therapy group. The annual rate of the primary outcome was 1.87% in the intensive-therapy group and 2.09% in the standard-therapy group (hazard ratio with intensive therapy, 0.88; 95% confidence interval [CI], 0.73 to 1.06; P=0.20). The annual rates of death from any cause were 1.28% and 1.19% in the two groups, respectively (hazard ratio, 1.07; 95% CI, 0.85 to 1.35; P=0.55). The annual rates of stroke, a prespecified secondary outcome, were 0.32% and 0.53% in the two groups, respectively (hazard ratio, 0.59; 95% CI, 0.39 to 0.89; P=0.01). Serious adverse events attributed to antihypertensive treatment occurred in 77 of the 2362 participants in the intensive-therapy group (3.3%) and 30 of the 2371 participants in the standard-therapy group (1.3%) (P<0.001). CONCLUSIONS: In patients with type 2 diabetes at high risk for cardiovascular events, targeting a systolic blood pressure of less than 120 mm Hg, as compared with less than 140 mm Hg, did not reduce the rate of a composite outcome of fatal and nonfatal major cardiovascular events. (ClinicalTrials.gov number, NCT00000620.)

Effect of intensive compared with standard glycemia treatment strategies on mortality by baseline subgroup characteristics: the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

OBJECTIVE: To determine if baseline subgroups in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial can be identified for whom intensive compared with standard glycemia treatment had different effects on all-cause mortality. RESEARCH DESIGN AND METHODS: Exploratory post hoc intention-to-treat comparisons were made between intensive and standard glycemia groups on all-cause mortality by subgroups defined by baseline characteristics. RESULTS: There were few significant interactions between baseline characteristics and effects of intensive versus standard glycemia treatment on mortality: self-reported history of neuropathy (hazard ratio [HR] 1.95, 95% CI 1.41-2.69) versus no history of neuropathy (0.99, 0.79-1.26; P value for interaction 0.0008), higher A1C (A1C >8.5%: HR 1.64, 95% CI 1.22-2.22; A1C 7.5-8.4%: 1.00, 0.75-1.34; A1C <7.5%: 1.00, 0.67-1.50; P value for interaction 0.04), and aspirin use (HR 1.45, 95% CI 1.13-1.85, compared with 0.96, 0.72-1.27, in nonusers; P value for interaction 0.03). CONCLUSIONS: We found a remarkable similarity of effect from intensive compared with standard glycemia treatment on mortality across most baseline subgroups. No differential effect was found in subgroups defined by variables anticipated to have an interaction: age, duration of diabetes, and previous history of cardiovascular disease. The three baseline characteristics that defined subgroups for which there was a differential effect on mortality may help identify patients with type 2 diabetes at higher risk of mortality from intensive regimens for glycemic control. Further research is warranted.

The Scientific Foundation for personal genomics: recommendations from a National Institutes of Health-Centers for Disease Control and Prevention multidisciplinary workshop.

The increasing availability of personal genomic tests has led to discussions about the validity and utility of such tests and the balance of benefits and harms. A multidisciplinary workshop was convened by the National Institutes of Health and the Centers for Disease Control and Prevention to review the scientific foundation for using personal genomics in risk assessment and disease prevention and to develop recommendations for targeted research. The clinical validity and utility of personal genomics is a moving target with rapidly developing discoveries but little translation research to close the gap between discoveries and health impact. Workshop participants made recommendations in five domains: (1) developing and applying scientific standards for assessing personal genomic tests; (2) developing and applying a multidisciplinary research agenda, including observational studies and clinical trials to fill knowledge gaps in clinical validity and utility; (3) enhancing credible knowledge synthesis and information dissemination to clinicians and consumers; (4) linking scientific findings to evidence-based recommendations for use of personal genomics; and (5) assessing how the concept of personal utility can affect health benefits, costs, and risks by developing appropriate metrics for evaluation. To fulfill the promise of personal genomics, a rigorous multidisciplinary research agenda is needed.

Effects of intensive glucose lowering in type 2 diabetes.

BACKGROUND: Epidemiologic studies have shown a relationship between glycated hemoglobin levels and cardiovascular events in patients with type 2 diabetes. We investigated whether intensive therapy to target normal glycated hemoglobin levels would reduce cardiovascular events in patients with type 2 diabetes who had either established cardiovascular disease or additional cardiovascular risk factors. METHODS: In this randomized study, 10,251 patients (mean age, 62.2 years) with a median glycated hemoglobin level of 8.1% were assigned to receive intensive therapy (targeting a glycated hemoglobin level below 6.0%) or standard therapy (targeting a level from 7.0 to 7.9%). Of these patients, 38% were women, and 35% had had a previous cardiovascular event. The primary outcome was a composite of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The finding of higher mortality in the intensive-therapy group led to a discontinuation of intensive therapy after a mean of 3.5 years of follow-up. RESULTS: At 1 year, stable median glycated hemoglobin levels of 6.4% and 7.5% were achieved in the intensive-therapy group and the standard-therapy group, respectively. During follow-up, the primary outcome occurred in 352 patients in the intensive-therapy group, as compared with 371 in the standard-therapy group (hazard ratio, 0.90; 95% confidence interval [CI], 0.78 to 1.04; P=0.16). At the same time, 257 patients in the intensive-therapy group died, as compared with 203 patients in the standard-therapy group (hazard ratio, 1.22; 95% CI, 1.01 to 1.46; P=0.04). Hypoglycemia requiring assistance and weight gain of more than 10 kg were more frequent in the intensive-therapy group (P<0.001). CONCLUSIONS: As compared with standard therapy, the use of intensive therapy to target normal glycated hemoglobin levels for 3.5 years increased mortality and did not significantly reduce major cardiovascular events. These findings identify a previously unrecognized harm of intensive glucose lowering in high-risk patients with type 2 diabetes. (ClinicalTrials.gov number, NCT00000620.)

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale.

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension.

Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial: design and methods.

Most patients with type 2 diabetes mellitus develop cardiovascular disease (CVD), with substantial loss of life expectancy. Nonfatal CVD contributes greatly to excess healthcare costs and decreased quality of life in patients with diabetes. The current epidemic of obesity has raised expectations that CVD associated with type 2 diabetes will become an even greater public health challenge. Despite the importance of this health problem, there is a lack of definitive data on the effects of the intensive control of glycemia and other CVD risk factors on CVD event rates in patients with type 2 diabetes. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is a randomized, multicenter, double 2 x 2 factorial design study involving 10,251 middle-aged and older participants with type 2 diabetes who are at high risk for CVD events because of existing CVD or additional risk factors. ACCORD is testing the effects of 3 medical treatment strategies to reduce CVD morbidity and mortality. All participants are in the glycemia trial, which is testing the hypothesis that a therapeutic strategy that targets a glycosylated hemoglobin (HbA1c) level of <6.0% will reduce the rate of CVD events more than a strategy that targets an HbA1c level of 7.0%-7.9%. The lipid trial includes 5,518 of the participants, who receive either fenofibrate or placebo in a double-masked fashion to test the hypothesis of whether, in the context of good glycemic control, a therapeutic strategy that uses a fibrate to increase high-density lipoprotein cholesterol and lower triglyceride levels together with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) to lower low-density lipoprotein cholesterol will reduce the rate of CVD events compared with a strategy that uses a statin plus a placebo. The blood pressure trial includes the remaining 4,733 participants and tests the hypothesis that a therapeutic strategy that targets a systolic blood pressure of <120 mm Hg in the context of good glycemic control will reduce the rate of CVD events compared with a strategy that targets a systolic blood pressure of <140 mm Hg. The primary outcome measure for all 3 research questions is the first occurrence of a major CVD event, specifically nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Upon the expected completion of participant follow-up in 2009, the ACCORD trial should document for the first time the benefits and risks of intensive glucose control, intensive blood pressure control, and the combination of fibrate and statin drugs in managing blood lipids in high-risk patients with type 2 diabetes.

Prevention of cardiovascular disease in persons with type 2 diabetes mellitus: current knowledge and rationale for the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

Patients with type 2 diabetes mellitus die of cardiovascular disease (CVD) at rates 2-4 times higher than patients without diabetes but with similar demographic characteristics. The prevalence of diabetes is increasing in the United States and, thus, the prevention of CVD in patients with diabetes poses an urgent public health challenge. The objective of this report is to review the current knowledge base for the prevention of CVD in patients with diabetes, with particular emphasis on the control of glycemia, lipids, and blood pressure. Epidemiologic analyses suggest that each 1% increase in glycosylated hemoglobin increases the risk for CVD by approximately 18%; however, evidence from the randomized trials that have examined whether glucose lowering reduces this risk is conflicting. Randomized trials have shown that lowering low-density lipoprotein cholesterol reduces CVD event rates by 17%-43% in patients with diabetes. Limited data support a role for lowering triglycerides and increasing high-density lipoprotein cholesterol in the prevention of CVD. Evidence from clinical trials shows that reducing systolic blood pressure to <140 mm Hg results in 30%-60% reductions in CVD events; however, epidemiologic evidence suggests that lowering to optimal systolic blood pressure levels (<120 mm Hg) may be additionally beneficial. Important questions regarding prevention of CVD in patients with diabetes remain unresolved, including the benefits of near-normal glycemic control, comprehensive therapy for diabetes-related dyslipidemia, and optimal blood pressure control. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial will test hypotheses to address these unanswered questions.

Severe hypoglycemia monitoring and risk management procedures in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

Hypoglycemia is a potentially serious side effect of blood glucose lowering in diabetes mellitus. The intensive glycemia treatment arm of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is designed to treat patients with type 2 diabetes with target glycemia within the normal range (ie, glycosylated hemoglobin <6%). Because it is known that treating glycemia to such a low level in patients with diabetes will result in episodes of hypoglycemia, it is necessary to address prevention and treatment of such episodes to ensure patient safety. Thus, several approaches are being taken in the ACCORD trial to prevent initial episodes of severe hypoglycemia, to monitor the frequency of episodes that do occur, and to prevent recurrence. This report describes the processes used in the ACCORD trial, including the definition of severe hypoglycemia, the type of education provided to participants and staff members to prevent initial and subsequent episodes of severe hypoglycemia, and the monitoring systems implemented to identify severe hypoglycemia and prevent its recurrence. The ACCORD trial conducts review and oversight of individual cases of severe hypoglycemia and monitors rates of severe hypoglycemia by clinical site and treatment arm. If the ACCORD intensive glycemia treatment is found to be efficacious in preventing cardiovascular disease events, assessment of the risk and benefit will be essential. In addition, translation of the principles behind the monitoring of severe hypoglycemia in ACCORD into feasible strategies for use in clinical practice will be needed.

Effects of individual components of multiple behavior changes: the PREMIER trial.

OBJECTIVES: To assess contributions of individual lifestyle changes on systolic blood pressure (SBP) changes. METHODS: We examined associations between lifestyle behavior changes and SBP after 6 and 18 months in 782 PREMIER trial participants. RESULTS: In multivariate models omitting weight, predicted SBP reductions ranged from (1)/2 to 1(1)/2 mm Hg for reduced urinary sodium, improved fitness, and adherence to the DASH diet (except sodium at 18 months). With weight included, only fitness change additionally predicted SBP at 18 months. CONCLUSIONS: Several lifestyle behavior changes are important for BP lowering, but are difficult to detect when weight is included in multivariate models.

Higher self-reported physical activity is associated with lower systolic blood pressure: the Dietary Intervention Study in Childhood (DISC).

OBJECTIVE: Children participating in a dietary clinical trial were studied to (1) assess physical activity patterns in boys and girls longitudinally from late childhood through puberty and (2) determine the association of level of physical activity on systolic blood pressure, low-density lipoprotein cholesterol, and BMI. PATIENTS AND METHODS: In the Dietary Intervention Study in Childhood, a randomized clinical trial of a reduced saturated fat and cholesterol diet in 8- to 10-year-olds with elevated low-density lipoprotein, a questionnaire that determined time spent in 5 intensity levels of physical activity was completed at baseline and at 1 and 3 years. An estimated-metabolic-equivalent score was calculated for weekly activity; hours per week were calculated for intense activities. We hypothesized that weekly self-reported physical activity would be associated with lower systolic blood pressure, low-density lipoprotein, and BMI over 3 years. Longitudinal data analyses were performed for each outcome (systolic blood pressure, low-density lipoprotein, and BMI) by using generalized estimating equations with estimated-metabolic-equivalent score per week as the independent variable adjusted for visit, gender, and Tanner stage (BMI was included in models for systolic blood pressure and low-density lipoprotein). RESULTS: The initial study cohort comprised 663 youths (362 boys [mean age: 9.7 years] and 301 girls [mean age: 9.0 years], of whom 623 (94%) completed the 3-year visit. For every 100 estimated-metabolic-equivalent hours of physical activity, there was a decrease of 1.15 mmHg of systolic blood pressure. There was a 1.28 mg/dL decline in low-density lipoprotein for a similar energy expenditure. For BMI, an analysis of intense physical activity showed that for every 10 hours of intense activity, there was a trend toward significance with a 0.2 kg/m2 decrease. CONCLUSIONS: Children with elevated cholesterol levels who lead a more physically active lifestyle have lower systolic blood pressure and a trend toward lower low-density lipoprotein over a 3-year interval. Long-term participation in intense physical activity may reduce BMI as well.

Design of the Trial of Activity in Adolescent Girls (TAAG).

The primary aim of the Trial of Activity in Adolescent Girls (TAAG) is to test an intervention to reduce by half the age-related decline in moderate to vigorous physical activity (MVPA) in middle school girls. The intervention will be evaluated using a group-randomized trial involving 36 middle schools. The primary endpoint is the mean difference in intensity-weighted minutes (i.e., MET-minutes) of MVPA between intervention and comparison schools assessed using accelerometry. The TAAG study design calls for two cross-sectional samples, one drawn from 6th graders at the beginning of the study and the second drawn from 8th graders at the end of the study following the 2-year implementation of the intervention. An important strength of this design over a cohort design is the consistency with the goals of TAAG, which focus on environmental-level rather than individual-level interventions to produce change. The study design specifies a recruitment rate of 80% and a smaller sample of girls at baseline (n=48 per school) than at follow-up (n=96 per school). A two-stage model will be used to test the primary hypothesis. In the first stage, MET-weighted minutes of MVPA will be regressed on school, time (baseline or follow-up), their interaction, ethnicity and week of data collection. The second stage analysis will be conducted on the 72 adjusted means from the first stage. In the main-effects model, we will regress the follow-up school mean MET-weighted minutes of MVPA on study condition, adjusting for the baseline school mean. The TAAG study addresses an important health behavior, and also advances the field of group-randomized trials through the use of a study design and analysis plan tailored to serve the main study hypothesis.