GHb Is a Better Predictor of Cardiovascular Disease Than Fasting or Postchallenge Plasma Glucose in Women Without Diabetes: The Rancho Bernardo Study

Abstract

OBJECTIVE To examine the relation between GHb, fasting plasma glucose (FPG), postchallenge plasma glucose (PCPG), and mortality from cardiovascular disease (CVD) and ischemic heart disease (IHD) in older adults. RESEARCH DESIGN AND METHODS A community-based study of 1,239 nondiabetic older adults followed for an average of 8 years, from baseline (1984–1987) to 1993. RESULTS GHb, but not FPG or PCPG, was significantly related to CVD and IHD mortality in women but not men. The age-adjusted relative hazard for those in the highest quintile of GHb (≥ 6.7%) compared with women with lower levels was 2.37 for fatal CVD (95% CI = 1.30−4.31, P = 0.005) and 2.43 for IHD (95% CI = 1.12−5.25, P = 0.024). This association persisted after adjustment for all covariates (age, systolic blood pressure, BMI, LDL, HDL, triglycerides, cigarette smoking, antihypertensive medication use, and estrogen use). GHb was significantly associated with LDL and HDL levels in women, but the association between GHb and CVD or IHD persisted after adjustment for these lipoproteins. CONCLUSIONS We concluded that GHb is a better predictor of CVD and IHD mortality than FPG or PCPG in women without diabetes; no single measure of glycemia was predictive in men. The reason for the sex difference is unexplained.