Postprandial glucose improves the risk prediction of cardiovascular death beyond the metabolic syndrome in the nondiabetic population

Abstract

Objective: With increasing evidence about the cardiovascular risk associated with postprandial nonfasting glucose and lipid dysmetabolism, it remains uncertain whether the postprandial glucose concentration increases the ability of metabolic syndrome to predict cardiovascular events.

Research design and methods: This was an observational study of 15,145 individuals aged 35-75 years without diabetes or cardiovascular diseases. Postprandial glucose was obtained 2 h after a lunch meal. Metabolic syndrome was diagnosed using the criteria of the U.S. National Cholesterol Education Program Adult Treatment Panel III. Cardiovascular and all-cause deaths were primary outcomes.

Results: During a median follow-up of 6.7 years, 410 individuals died, including 82 deaths from cardiovascular causes. In a Cox model adjusting for metabolic syndrome status as well as age, sex, smoking, systolic blood pressure, LDL, and HDL cholesterol levels, elevated 2-h postprandial glucose increased the risk of cardiovascular and all-cause death (per millimole per liter increase, hazard ratio 1.26 [95% CI 1.11-1.42] and 1.10 [1.04-1.16], respectively), with significant trends across the postprandial glucose quintiles. Including 2-h postprandial glucose into a metabolic syndrome-included multivariate risk prediction model conferred a discernible improvement of the model in discriminating between those who died of cardiovascular causes and who did not (integrated discrimination improvement 0.4, P = 0.005; net reclassification improvement 13.4%, P = 0.03); however, the improvement was only marginal for all-cause death.

Conclusions: Given the risk prediction based on metabolic syndrome and established cardiovascular risk factors, 2-h postprandial glucose improves the predictive ability to identity nondiabetic individuals at increased risk of cardiovascular death.

Figures

Figure 1

Association of postprandial hyperglycemia with the risk of cardiovascular and all-cause death according to the presence or absence of metabolic syndrome. Postprandial hyperglycemia was defined as 2-h postprandial glucose ≥7.8 mmol/l (140 mg/dl). Relative risk was adjusted for age-groups (35–44, 45–54, 55–64, 65–74, and ≥75 years), sex, smoking status (yes/no), systolic blood pressure (quintile groups), HDL cholesterol (quintile groups), and LDL cholesterol (quintile groups) in a Cox proportional hazards analysis. The dashed vertical lines represent the corresponding overall point estimates, and the solid horizontal lines represent the 95% CI. Pinteraction was obtained by the interaction test between metabolic syndrome and postprandial hyperglycemia.