[Show abstract][Hide abstract] ABSTRACT: Serum adiponectin protects against incident ischemic heart disease (IHD). However, in patients with existing IHD, higher adiponectin levels are paradoxically associated with worse outcomes. We investigated this paradox by evaluating the relationship between adiponectin and cardiovascular events in patients with existing IHD.
We measured total serum adiponectin and cardiac disease severity by stress echocardiography in 981 outpatients with stable IHD who were recruited for the Heart and Soul Study between September 2000 and December 2002. Subsequent heart failure hospitalizations, myocardial infarction, and death were recorded.
During an average of 7.1 years of follow-up, patients with adiponectin levels in the highest quartile were more likely than those in the lowest quartile to be hospitalized for heart failure (23% vs. 13%; demographics-adjusted hazard ratio (HR) 1.63, 95% confidence interval (CI) 1.04-2.56, p=0.03) or die (49% vs. 31%; HR 1.67, 95% CI 1.24-2.26, p<0.008), but not more likely to have a myocardial infarction (12% vs. 17%; HR 0.64, 95% CI 0.38-1.06, p=0.08). The combined outcome of myocardial infarction, heart failure, or death occurred in 56% (136/245) of participants in the highest quartile of adiponectin vs. 38% (94/246) of participants in the lowest quartile (HR 1.54, 95% CI 1.31-2.21, p<0.002). Adjustment for left ventricular ejection fraction, diastolic dysfunction, inducible ischemia, C-reactive protein, and NT-proBNP attenuated the association between higher adiponectin and increased risk of subsequent events (HR 1.43, 95% CI 0.98-2.09, p=0.06).
Higher concentrations of adiponectin were associated with heart failure and mortality among patients with existing IHD.
[Show abstract][Hide abstract] ABSTRACT: Resistin is a pro-inflammatory signaling molecule that is thought to contribute to atherosclerosis. We sought to evaluate whether resistin is predictive of worse cardiovascular outcomes among ambulatory patients with stable coronary heart disease (CHD).
We measured baseline serum resistin in 980 participants with documented CHD. After a mean follow-up of 6.1 (range, 0.1 to 9.0) years, 358 (36.5%) were hospitalized for myocardial infarction or heart failure or had died. As compared with participants who had resistin levels in the lowest quartile, those with resistin levels in the highest quartile were at an increased risk of heart failure (hazard ratio [HR], 2.06; 95% confidence interval [CI], 1.26-3.39) and death (HR, 1.56; 95% CI, 1.11-2.18), adjusted for age, sex, and race. Further adjustments for obesity, hypertension, insulin resistance, dyslipidemia, and renal dysfunction eliminated these associations. Resistin levels were not associated with an increased risk of non-fatal myocardial infarction (unadjusted HR, 1.18; 95% CI, 0.68-2.05).
Elevated serum resistin is associated with higher rates of mortality and hospitalization for heart failure. However, this appears to be explained by the association of resistin with traditional measures of cardiovascular risk. Thus, serum resistin does not add prognostic information among high-risk persons with established CHD.
[Show abstract][Hide abstract] ABSTRACT: Leptin is an adipokine with both protective and harmful effects on the cardiovascular (CV) system. Prior studies evaluating the association between leptin and CV outcomes have yielded conflicting results. Thus, we sought to investigate the relationship between leptin and CV events and mortality in patients with chronic stable coronary artery disease (CAD).
We performed a prospective cohort study of 981 outpatients with stable CAD. Leptin levels were measured in fasting venous samples at baseline. We used proportional hazards models to evaluate the association of baseline leptin with subsequent CV events (myocardial infarction, stroke, transient ischemic attack) and death.
During a mean follow-up of 6.2±2.1 years, there were 304 deaths, 112 myocardial infarctions, and 52 strokes/TIAs. In models adjusted for age, sex, and race, low leptin was associated with a 30% increased risk of the combined outcome (HR 1.30, CI 1.05-1.59, p=0.01). After further adjustment for obesity, traditional CV risk factors and biomarkers, low leptin remained associated with a 37% increased risk of events (HR 1.37, CI 1.06-1.76, p=0.02).
Low leptin is associated with increased CV events and mortality in patients with stable coronary artery disease. This association is independent of known factors affecting leptin levels, including gender and obesity.
[Show abstract][Hide abstract] ABSTRACT: Resistin is an adipocytokine involved in insulin resistance, inflammation, and atherosclerosis. Its role in the development and progression of coronary heart disease (CHD) is not yet well-characterized. We performed a cross-sectional study to evaluate the association between serum resistin levels, exercise capacity, and exercise-induced cardiac ischemia among patients with stable CHD.
We measured serum resistin concentrations and determined treadmill exercise capacity and inducible ischemia by stress echocardiography in 899 outpatients with documented CHD. Of these, 215 (24%) had poor exercise capacity (<5 metabolic equivalent tasks), and 217 (24%) had inducible ischemia. As compared with participants who had resistin levels in the lowest quartile, those with resistin levels in the highest quartile were more likely to have poor exercise capacity (33% versus 16%, odds ratio [OR] 2.68, P<0.0001) and inducible ischemia (30% versus 17%, OR 2.08, P=0.001). Both associations remained robust after adjusting for numerous clinical risk factors, metabolic variables, and markers of insulin resistance (poor exercise capacity adjusted OR 1.73, P=0.04; inducible ischemia adjusted OR 1.82, P=0.01). However, further adjustments for C-reactive protein, interleukin-6, and tumor necrosis factor-α eliminated the association with poor exercise capacity (adjusted OR 1.50, P=0.14) and substantially weakened the association with inducible ischemia (adjusted OR 1.72, P=0.03).
Elevated serum resistin is associated with poor exercise capacity and exercise-induced cardiac ischemia in patients with stable coronary disease. Adjustment for inflammatory markers attenuated these associations, suggesting a possible role for resistin in inflammation and CHD pathophysiology.
[Show abstract][Hide abstract] ABSTRACT: Elevated concentrations of adiponectin are associated with a favorable metabolic profile but also with adverse cardiovascular outcomes. This apparent discrepancy has raised questions about whether adiponectin is associated with an increased or decreased risk of coronary heart disease (CHD). We sought to determine whether higher adiponectin levels are associated with exercise-induced ischemia in patients with stable CHD.
We measured total serum adiponectin concentrations and evaluated exercise-induced ischemia by stress echocardiography in a cross-sectional study of 899 outpatients with documented stable CHD. Of these, 217 (24%) had inducible ischemia. Although adiponectin levels correlated negatively with diabetes prevalence, body mass index, serum insulin, fasting glucose, low-density lipoprotein cholesterol, and triglycerides and positively with high-density lipoprotein cholesterol (all P<0.005), elevated adiponectin concentrations were also associated with a greater risk of inducible ischemia. Each standard deviation (0.08 microg/mL) increase in log adiponectin was associated with a 35% greater odds of inducible ischemia (unadjusted odds ratio 1.35; 95% confidence interval 1.15-1.57; P=0.0002). Although attenuated, this association remained present after multivariable adjustment for traditional cardiovascular risk factors and other measures of cardiac function (adjusted odds ratio 1.21; 95% confidence interval 1.02-1.43; P=0.03).
Elevated concentrations of adiponectin are independently associated with inducible ischemia in patients with stable CHD. These findings raise the possibility that the presence of chronic inducible ischemia may alter the cardio-protective effects afforded by adiponectin secretion in the healthy population.