J-shaped association between plasma glucose concentration and cardiovascular disease mortality over a follow-up of 32 years

Abstract

OBJECTIVE: We aimed at examining the association between plasma glucose (PG) concentration and cardiovascular mortality in a population sample from Switzerland over a follow-up time of 32 years. METHODS: We analyzed 7984 men and women enrolled in the first National Research Program (NRP1A, 1977-1979) and followed up for survival until 2008. Mortality hazard ratios (HR) were calculated using adjusted Cox regression models. PG was measured in fasting state or randomly with known fasting time. Models were adjusted for age, sex, socio-demographic, lifestyle and cardiovascular risk factors. RESULTS: PG concentrations ≥6.1mmol/L were associated with increased risk of cardiovascular disease (CVD) and all-cause mortality. Compared to normal PG (3.8-4.9mmol/L) the adjusted HR (95% CI) for CVD mortality was 1.26 (1.01-1.58) for PG ≥6.1-6.9mmol/L, 1.56 (1.18-2.06) for PG ≥7mmol/L, 1.67 (1.22-2.30) for known diabetes. All-cause mortality essentially showed the same patterns. All-cause mortality was increased [HR (95% CI): 1.35 (1.01-1.80)] also for PG <3.8mmol/L. CONCLUSION: Plasma glucose remained significantly and independently associated with CVD mortality even after full follow-up. The relationship was J-shaped. In order to prevent premature death, persons with abnormal PG concentrations on both extremes should be screened and counseled for other CVD risk factors.