Glycemic status and incident heart failure in elderly without history of diabetes mellitus: the health, aging, and body composition study

Abstract

Background: It is unclear whether measures of glycemic status beyond fasting glucose (FG) levels improve incident heart failure (HF) prediction in patients without history of diabetes mellitus (DM).

Methods and results: The association of measures of glycemic status at baseline (including FG, oral glucose tolerance testing [OGTT], fasting insulin, hemoglobin A(1c) [HbA(1c)] levels, and homeostasis model assessment of insulin resistance [HOMA-IR] and insulin secretion [HOMA-B]) with incident HF, defined as hospitalization for new-onset HF, was evaluated in 2386 elderly participants without history of DM enrolled in the Health, Aging, and Body Composition Study (median age, 73 years; 47.6% men; 62.5% white, 37.5% black) using Cox models. After a median follow-up of 7.2 years, 185 (7.8%) participants developed HF. Incident HF rate was 10.7 cases per 1000 person-years with FG <100mg/dL, 13.1 with FG 100-125 mg/dL, and 26.6 with FG >or=126 mg/dL (P=.002; P=.003 for trend). In adjusted models (for body mass index, age, history of coronary artery disease and smoking, left ventricular hypertrophy, systolic blood pressure and heart rate [HR], and creatinine and albumin levels), FG was the strongest predictor of incident HF (adjusted HR per 10mg/dL, 1.10; 95% CI, 1.02-1.18; P=.009); the addition of OGTT, fasting insulin, HbA(1c), HOMA-IR, or HOMA-B did not improve HF prediction. Results were similar across race and gender. When only HF with left ventricular ejection fraction (LVEF) <or=40% was considered (n=69), FG showed a strong association in adjusted models (HR per 10mg/dL, 1.15; 95% CI, 1.03-1.29; P=.01). In comparison, when only HF with LVEF >40%, was considered (n=71), the association was weaker (HR per 10mg/dL, 1.05; 95% CI; 0.94-1.18; P=.41).

Conclusions: Fasting glucose is a strong predictor of HF risk in elderly without history of DM. Other glycemic measures provide no incremental prediction information.

Figure 1. Incident heart failure by baseline glycemic status

The fasting glucose -only based definition s of glycemic status (upper panels) provide better prognostic separation for incident heart failure as compared to the respective OGTT-added definitions (lower panels), as indicated by the log-rank χ² statistics. Note that the risk for incident HF among participants in the intermediate glycemic categories (i.e., impaired FG in upper panels and impaired FG or OGTT in lower panels, respectively) is not distinctly different as compared to that among participants with normal glycemic status (Mantel-Cox χ² statistics for the comparisons between impaired and normal glycemic status all correspond to P>.25). ADA, American Diabetes Association; FG, Fasting glucose; OGTT, Oral glucose tolerance test; WHO, World Health Organization