Non-fasting and Fasting Triglyceride Levels and the Risk of Diabetes Mellitus: The Circulatory Risk in Communities Study

AIMS: Non-fasting triglyceride measurements have become increasingly common in screening for atherosclerotic cardiovascular disease. However, evidence of its predictive value for diabetes mellitus is limited to only a few studies. METHODS: This prospective cohort study included two groups of individuals aged 40-74 years without diabetes mellitus: 7,673 who provided non-fasting blood samples and 4,055 who provided fasting samples. We used annual health checkup data to identify new cases of diabetes mellitus, employed Cox proportional hazard models to estimate hazard ratios, and conducted decision curve analyses to assess clinical utility. RESULTS: During a median follow-up of 13 years, 727 and 444 participants were diagnosed with diabetes mellitus in the non-fasting and fasting groups, respectively. After adjusting for the glucose levels and other potential confounders measured at baseline, both non-fasting and fasting triglyceride levels were positively associated with the hazard of diabetes mellitus; the hazard ratios (95% confidence intervals) for the highest versus lowest quartiles were 1.99 (1.50-2.64) and 1.58 (1.11-2.26), respectively. Adding non-fasting or fasting triglyceride levels to a model based on traditional predictors can slightly improve the net benefit for 15-year risk prediction, corresponding to an approximate gain of 1 to 2 additional individuals per 1,000 screened. The improvement was slightly greater under non-fasting conditions than under fasting conditions. CONCLUSION: Both the non-fasting and fasting triglyceride levels were associated with an increased hazard of diabetes mellitus. Adding the triglyceride levels can therefore provide modest but potentially useful supplementary information for diabetes prediction, particularly under non-fasting conditions.