[The association between the changes in triglyceride levels and the risk of incident type 2 diabetes mellitus: a 15 years followed-up results from the Chinese Multi-provincial Cohort Study].

ABSTRACT

OBJECTIVE: To explore the 15-years change in fasting TG level and the accumulative incidence of type 2 diabetes mellitus (T2DM) from 1992 to 2007, and to assess the association between the change in TG level and the accumulative onset risk of T2DM. METHODS: A total of 11 387 subjects aged 35 - 64 years were recruited from 6 provinces in China in the baseline survey in 1992, and were followed-up for cardiovascular disease till 2007. In 2007, 9184 subjects were successfully followed-up and 5966 subjects entered into the second examination. Totally 5408 participants, who were free of diabetes at baseline and had complete information for both check ups, were included in this analysis. Fasting TG levels were categorized into three groups < 1.70 mmol/L, 1.70 - 2.25 mmol/L and ≥ 2.26 mmol/L. The association between 15-years change in TG level and the accumulative onset risk of T2DM was assessed by logistic regression analysis. RESULTS: In 1992, the mean level of TG was 1.49 mmol/L in male and 1.26 mmol/L in female. During the 15 years, TG levels increased by 0.25 mmol/L and 0.53 mmol/L in male and female, respectively. The prevalence of elevated TG (< 1.70 mmol/L) increased from 23.4% in 1992 to 39.0% in 2007. The 15-year accumulative incidence of diabetes was 13.9% in male and 11.8% in female. The incidence rates were 10.5%, 16.2% and 26.6% for TG levels of < 1.70 mmol/L, 1.70 - 2.25 mmol/L and ≥ 2.26 mmol/L, respectively. Multivariate logistic regression analysis showed that the baseline TG level was significantly associated with the onset risk of diabetes after adjustment for other cardiovascular risk factors. At any given baseline TG level, the onset risk of diabetes increased with the TG levels in the second examination in 2007. After adjusting other risk factors, participants with the highest categories of both baseline and follow-up TG levels had 2.1 folds higher accumulative onset risk of diabetes (RR = 3.39, 95%CI 2.49 - 4.61) than those with the lowest categories of both baseline and follow-up TG levels. CONCLUSION: Baseline TG level is independently associated with diabetes onset risk, and the change of TG level in a 15-year interval predicts the onset risk of diabetes beyond the baseline TG level.