Pancreatic beta-cell function as a predictor of cardiovascular outcomes and costs: findings from the Cardiovascular Health Study.

OBJECTIVE: To explore relationships between beta-cell function and incident cardiovascular events, death, and medical costs among elderly individuals. RESEARCH DESIGN AND METHODS: In a prospective, population-based cohort of 4555 elderly individuals, we examined the effect of beta-cell function on incident cardiovascular events and mortality. We also examined costs for 3715 of these individuals. We used the computer-based homeostasis model assessment (HOMA) to calculate indices of beta-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S) using baseline fasting glucose and insulin levels. All subjects were followed from 1992/1993 for 6 years or until death. MAIN OUTCOME MEASURES: Discrete-time survival model of the effects of beta-cell function on incident cardiovascular events and all-cause mortality; and semiparametric estimators for calculations of mean 6-year costs. RESULTS: Controlling for HOMA-%S, a 20% decrease in HOMA-%B was associated with increased odds of incident cardiovascular events (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.05-1.14) and death (OR, 1.10; 95% CI, 1.07-1.14). The relationships persisted after controlling for clinical and sociodemographic confounders. A 20% decrease in HOMA-%B was also associated with increased costs (cost ratio, 1.03; 95% CI, 1.01-1.05). The significant association did not persist after controlling for confounders. LIMITATIONS: The sample comprises relatively healthy elderly individuals and is based on data from 1992 through 1999, which may not reflect current experience. The measure of beta-cell function is an estimate generated from single measures of glucose and insulin. CONCLUSIONS: Beta-cell function as measured by HOMA-%B is a significant predictor of incident cardiovascular events and mortality but not of costs, controlling for HOMA-%S and sociodemographic and clinical confounders.

Duke Scholars

Author Lawrence Liao Medicine, Cardiology

Author Lesley H. Curtis Population Health Sciences

Author Bradley Gordon Hammill Population Health Sciences

Author Kevin J. Anstrom Biostatistics & Bioinformatics, Division of Biostatistics