Characteristics and six-month outcomes in a cohort of 8288 diabetic and non-diabetic patients with previous history of acute coronary syndrome or stroke: the French PREVENIR 3 survey

Impact of type 2 diabetes mellitus on recurrent myocardial infarction in China

To evaluate the influence of type 2 diabetes mellitus on the long-term outcomes of Chinese patients with previous myocardial infarction, we studied 864 patients with previous myocardial infarction, including 251 with type 2 diabetes mellitus and 613 without type 2 diabetes mellitus, over a median follow-up time of 2.9 years. The type 2 diabetes mellitus patients were subdivided into 95 insulin-treated diabetes mellitus and 156 non-insulin-treated diabetes mellitus subjects. The crude incidences (per 1000 patient-years) in the type 2 diabetes mellitus subjects versus the non-type 2 diabetes mellitus subjects were 43.7 versus 25.1 for recurrent myocardial infarction, 68.7 versus 28.3 for all-cause death and 99.8 versus 49.9 for the composite end point (i.e. recurrent myocardial infarction or all-cause death). Cox regression analysis showed that the adjusted hazard ratios for recurrent myocardial infarction, all-cause death and their combination were 1.67 (95% confidence interval: 1.06-2.74), 1.90 (1.25-2.90) and 1.72 (1.23-2.40), respectively. Significant associations were also observed between insulin treatment and all-cause death. Our findings suggested that type 2 diabetes mellitus is an independent risk factor for recurrent myocardial infarction, all-cause death and the composite end point among previous myocardial infarction patients.

Change of energy expenditure from physical activity is the most powerful determinant of improved insulin sensitivity in overweight patients with coronary artery disease participating in an intensive lifestyle modification program

The objective was to evaluate the determinants of change (Δ) in insulin sensitivity in overweight coronary artery disease male patients without diabetes after an intensive lifestyle intervention. All patients received nutritional counseling and performed 4 months of exercise training (ET) according to 1 of 2 protocols: aerobic ET (65%-70% of peak aerobic capacity [VO(2)]) 25 to 40 minutes 3 times a week (n = 30) or walking (50%-60% of peak VO(2)) 45 to 60 minutes at least 5 times a week (n = 30). Data from participants of both ET groups were pooled, and post-intensive lifestyle intervention results were compared with baseline data. The primary outcome was Δ insulin sensitivity (m-value) assessed by the criterion standard technique, the euglycemic-hyperinsulinemic clamp. Changes in weight, body mass index, total and percentage fat mass (by dual-energy x-ray absorptiometry scan), waist circumference, total abdominal and visceral fat (by computed tomographic scan), high-sensitivity C-reactive protein, peak VO(2), daily energy intake, and physical activity energy expenditure (PAEE) (by doubly labeled water technique) were also assessed. Daily energy intake decreased by 335 kcal, and PAEE increased by 482 kcal/d (all P < .0001). The mean weight loss was 6.4 kg, and the mean improvement in m-value was 1.6 mg/kg fat-free mass per minute. Univariate determinants of Δ m-value were low baseline PAEE, walking protocol, Δ weight, Δ body mass index, Δ total and percentage fat mass, Δ waist circumference, Δ total abdominal and visceral fat, and Δ PAEE (all P < .05). In multivariate analysis, the only significant determinant of Δ m-value was Δ PAEE (P < .02). In this analysis, the most powerful determinant of improved insulin sensitivity in overweight coronary artery disease patients is the change in PAEE.

A PPARα promoter variant impairs ERR-dependent transactivation and decreases mortality after acute coronary ischemia in patients with diabetes

Activation of peroxisome proliferator-activated receptor alpha (PPARα) occurs in animal models of diabetes (DM) and is implicated in pathological responses to myocardial ischemia. Using bioinformatics, we identified a single nucleotide polymorphism (SNP) in the PPARα gene promoter (PPARA -54,642 G>A; rs135561) that altered the consensus sequence for a nuclear receptor binding site. Electrophoretic mobility shift assays showed that the domain bound two known PPARA transcriptional activators, estrogen-related receptor (ERR)-α and -γ and that PPARA G bound with greater affinity than PPARA A (>2-fold; P<0.05). Likewise, promoter-reporter analyses showed enhanced transcriptional activity for PPARA G vs. PPARA A for both ERR-α and -γ (3.1 vs.1.9-fold; P<0.05). Since PPARα activation impairs post-ischemic cardiac function in experimental models of DM, we tested whether decreased PPARA transcription in PPARA A carriers favorably impacted outcome after acute coronary ischemia in 705 patients hospitalized with acute coronary syndromes (ACS; 552 Caucasian, 106 African American). PPARA A allele frequencies were similar to non-diseased subjects. However, PPARA genotype correlated with 5-year mortality in diabetic (22.2% AA vs. 18.8% AG vs. 39.5% GG; P = 0.008), but not non-diabetic (P = 0.96) subjects (genotype by diabetes interaction P = 0.008). In the diabetic ACS subjects, PPARA A carriers had strikingly reduced all-cause mortality compared to PPARA G homozygotes, (unadjusted HR 0.44, 95% CI 0.26-0.75; P = 0.003; adjusted HR 0.48, 95% CI 0.27-0.83; P = 0.009). Consistent with previous descriptions of PPARα in experimental models and human disease, we describe a novel PPARA promoter SNP that decreases transcriptional activation of PPARA and protects against mortality in diabetic patients after ACS.

Differentiating ischemic stroke subtypes: risk factors and secondary prevention

Ischemic strokes account for 87% of all strokes in the US. Patients who suffer an initial ischemic stroke or transient ischemic attack are at risk for recurrent strokes, as well as ischemic events in the coronary and peripheral vasculatures. Lifestyle modifications and pharmacological and surgical interventions are effective in reducing the risk of recurrent events in all stroke patients, and evidence-based guidelines for secondary stroke prevention are available. However, increasing evidence indicates that risk factors may be differentially associated with specific ischemic stroke subtypes. In the future, exploiting these differential associations may facilitate secondary stroke prevention and, therefore, improve patient outcomes.