[A cohort study on plasma uric acid levels and the risk of type 2 diabetes mellitus among the oldest old in longevity areas of China].

To investigate the effect of plasma uric acid level on the incident risk of type 2 diabetes mellitus (T2DM) among the oldest old (those aged ≥80 years). Participants were recruited from the Healthy Aging and Biomarkers Cohort Study (HABCS), which conducted a baseline survey in 2008-2009 and follow-up of 3 times in 2011-2012, 2014, and 2017-2018, respectively. A total of 2 213 oldest old were enrolled in this study. The general demographic, socioeconomic, lifestyle and disease data of the oldest old were collected, and physical measurements were made for the oldest old. Fasting venous blood was collected for uric acid and blood glucose detection. Information on the incident and death of T2DM were collected through the follow-up. Cox proportional hazard regression model was used to explore the association of hyperuricemia and plasma uric acid level with the incidence of T2DM. Restricted cubic spline (RCS) function was used to explore the dose-response relationship of plasma uric acid levels with the risk of T2DM. The age of participants was (93.2±7.6) years old, and 66.7% of the participants (1 475) were female. The plasma uric acid level at baseline was (289.1±88.0)μmol/L, and the prevalence of hyperuricemia was 13.3% (294 cases). During 9 years of cumulative follow-up of 7 471 person-years (average of 3.38 years for each), 122 new cases of T2DM occurred and the incidence density was 1 632.98/10 person year. Cox proportional hazards regression analysis showed that per 10μmol/L increase in plasma uric acid level, the risk of T2DM increased by 1.1% [ (95%): 1.011 (1.004, 1.017)]. Compared with the participants with the lowest quintile of plasma uric acid (), the risk of diabetes increased by 20.7 % among the oldest old with uric acid in the highest quintile () [ (95%):1.207 (1.029, 1.416)]. The risk of T2DM was 19.2% higher in the hyperuricemia group than that in the oldest old with normal plasma uric acid [ (95%): 1.192 (1.033, 1.377)]. RCS function showed that the risk of T2DM increased with the increase in plasma uric acid levels in a nonlinear dose-response relationship (=0.016). The incident risk of T2DM increases with the elevates of plasma uric acid levels in the oldest old.