One-hour postload glucose levels predict mortality from cardiovascular diseases and malignant neoplasms in healthy...

Little is known about biological markers, at levels within their normal ranges which might predict future mortality. We aimed at identifying possible predictors of future death in participants before pathological conditions manifest. We analyzed data from a population-based prospective cohort study (the Ohasama study), comprised of 993 participants who underwent 75-g oral glucose tolerance tests (OGTTs). We collected blood parameters, including those measured during OGTTs, and divided the study population into two groups based on the median value of each parameter, followed by analyses of mortality during follow-up in both groups. In addition, we extracted subjects with normal glucose tolerance (NGT) (n = 595) and analyzed the association between 1-h postload plasma glucose during OGTTs (1-hrPG) and mortality as well as the causes of death. Among all parameters evaluated, 1-hrPG was found to be most significantly associated with all-cause mortality during the mean follow-up of 14.3 years. When we focused on subjects with NGT, Harrell's C concordance index analysis revealed a cut-off of 1-hrPG ≥170 mg/dL to be most strongly associated with all-cause mortality (0.8066). The Kaplan-Meier plots showed nearly double the proportion of the 1-hrPG ≥170 group to have died as compared with the 1-hrPG <170 group throughout the follow-up period after the third year. Cardiovascular diseases and malignant neoplasms both strongly contributed to the increased mortality in the high 1-hrPG group. Thus, 1-hrPG ≥170 is a powerful predictor of future death in subjects with NGT. Atherosclerotic and malignant diseases both contributed to the increased mortality.