Plasma insulin and all-cause, cardiovascular, and noncardiovascular mortality - The 22-year follow-up results of the Helsinki Policemen Study

OBJECTIVE - To investigate the association of plasma insulin with all-cause , cardiovascular, and noncardiovascular mortality. RESEARCH DESIGN AND METHODS - We studied 22-year mortality data from the He lsinki Policemen Study; The study population comprised 970 men, 34-64 years of age, who were free of coronary heart disease, other cardiovascular dise ase, and diabetes. Area under the insulin response curve (AUC insulin) duri ng an oral glucose tolerance test was used to reflect plasma insulin levels . RESULTS - During the follow-up period, 276 men died: 130 from cardiovascula r and 146 from noncardiovascular causes. The hazard ratio (HR) for hyperins ulinemia (highest AUC insulin quintile vs. combined lower quintiles) with r egard to all-cause mortality, adjusting for age, was 1.94 (95% CI 1.20-3.13 ) during the first 10 years of the follow-up period and 1.51 (1.15-1.97) du ring the entire 22 years; adjusting for other risk factors, the HR was 1.88 (1.08-3.30) and 1.37 (1.00-1.87) during 10 and 22 years, respectively. The corresponding HRs for cardiovascular mortality during 10 and 22 years were 2.67 (1.35-5.29) and 1.73 (1.19-2.53), respectively, for age-adjusted and 2.30 (1.03-5.12) and 1.39 (0.90-2.15), respectively, for multiple-adjusted HRs. A U-shaped association was observed between insulin and noncardiovascu lar mortality; multiple-adjusted HRs for lowest and highest versus middle A UC insulin quintiles were 1.85 (1.20-2.86) and 1.43 (0.91-2.24), respective ly. CONCLUSIONS - Hyperinsulinemia was associated with increased all-cause and cardiovascular mortality in Helsinki policemen independent of other risk fa ctors, although these associations weakened with the lengthening of the fol low-up period. The association of insulin with noncardiovascular mortality was U-shaped.