[Non-alcoholic fatty liver disease increases the incidence rate of type 2 diabetes mellitus: a cohort study based on a rural town elderly population of southern Jiangsu].

Objective: To investigate the impact of non-alcoholic fatty liver disease (NAFLD) on the incidence of type 2 diabetes mellitus (T2DM) in an elderly population. Methods: A rural elderly population of Kunshan city, Jiangsu Province were used as the research subject. Prior diabetes mellitus, heavy alcohol consumption and incomplete data were excluded from prospective cohort study analysis. Annual physical examination and follow-up were conducted from 2007 to 2016. T2DM onset, death and loss to follow-up visits were observed as the research subject end points. According to the baseline physical examination results, the study subjects were divided into NAFLD and control groups, and further baseline data of both groups were analyzed whether there were match. The cumulative incidence rate of T2DM were statistically analyzed and compared between the two groups. Simultaneously, the relationship between the two groups of various indexes and the newly developed T2DM were analyzed using Kaplan-Meier. The variables with P < 0.1 were selected and incorporated into the Cox proportional hazard regression model. The impact of NAFLD on the incidence of T2DM was analyzed in an elderly population. Results: At baseline, there were statistically significant differences in the distribution of age, sex, waist circumference, body mass index, systolic blood pressure, diastolic blood pressure, direct bilirubin, blood urea nitrogen and triglycerides between NAFLD and non-NAFLD groups. However, fasting blood glucose, serum creatinine, total bilirubin, total cholesterol, low density lipoprotein cholesterol and high-density lipoprotein cholesterol had no statistically significant differences between the two groups. After nine years of follow-up, 207 newly developed T2DM cases, 52 NAFLD cases and 155 control group were selected as the study subjects. The cumulative incidence rates were 4.25%, 10.34%, and 3.55%, respectively. Kaplan-Meier analysis result showed that there were statistically significant differences in the cumulative incidence rates between the two groups from five-year. NAFLD had increased the T2DM risk in an elderly population by approximately 2.14 times (2.14 CI: 1.132 ~ 4.047) at five-year, and then had increased year by year thereafter. Univariate analysis showed that T2DM risk was 2.76 times higher in NAFLD than non-NAFLD groups (95% CI: 2.015 ~ 3.777). After adjustment for gender, age, body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, serum creatinine, triglyceride, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol, T2DM risk ratio was 1.68 times higher in NAFLD than control groups (95% CI: 1.163 ~ 2.425). Conclusion: NAFLD is an independent long-term risk factor for the T2DM onset in an elderly population.