Variation of Fasting Plasma Glucose: A Predictor of Mortality in Patients with Type 2 Diabetes

Abstract

BackgroundThe aim of this study was to examine whether time-dependent annual fasting plasma glucose (FPG) variation, as represented by coefficient of variation (CV), can predict mortality in subsequent all-cause, expanded, and nonexpanded cardiovascular disease-related mortality independent of mean FPG, renal function, mean hemoglobin A1C (HbA1C), HbA1C variation, and other risk factors in patients with type 2 diabetes. MethodsA computerized database of all patients with type 2 diabetes aged 30 years and over (n = 5008) enrolled in the Diabetes Care Management Program of China Medical University Hospital before 2007 was used in a time-dependent Cox proportional hazard regression model. ResultsThe mortality rates were 8.64, 12.71, and 30.82 per 1000 person-years in groups of first, second, and third tertiles of baseline FPG-CV, respectively. Among these patients with type 2 diabetes, 336, 1191, 914, 585, and 1979 patients provided 1, 2, 3, 4, and 5 or more years of annual FPG-CV measurements, respectively. After adjusting for mean FPG, mean HbA1C, HbA1C variation, and other risk factors, annual FPG-CV was independently associated with all-cause mortality and mortality due to expanded and nonexpanded cardiovascular disease, and the corresponding hazard ratios for third versus first tertile of annual FPG-CV were 5.53 (95% confidence interval [CI], 3.85-7.94), 3.21 (95% CI, 2.00-5.15), and 9.45 (95% CI, 5.37-16.63), respectively. ConclusionsTime-dependent variation of FPG was a strong predictor of all-cause, expanded, and nonexpanded cardiovascular disease-related mortality in patients with type 2 diabetes, suggesting that glucose variation may become a measure in clinical practice for the goal in the management of these patients.