A prospective study of uric acid by glucose tolerance status and survival: the Rancho Bernardo Study

Abstract

Little is known about uric acid (UA) levels and mortality in the context of glycaemia. We examined whether serum UA levels predict all-cause and cardiovascular disease (CVD) mortality differentially in older adults by glucose tolerance status. Between 1984 and 1987, 2342 community-dwelling men and women had an oral glucose tolerance test, UA measurement, and assessment of traditional CVD risk factors. We defined glucose tolerance status as normoglycaemia (NG), pre-diabetes (pre-DM), and type 2 diabetes mellitus (T2DM). Ninety per cent were followed for vital status up to 23 years. Death certificates were coded using the Ninth International Classification of Diseases. Baseline age was 69.5 years; 44.4% were men. At baseline 939 had NG, 957 pre-DM, and 446 T2DM. The mean UA by glucose tolerance status was 327.1, 362.8, and 374.7 micromol L(-1). During follow-up, there were 1318 deaths 46.8% attributed to CVD. In Cox-regression analysis, each 119 micromol L(-1) (2 mg dL(-1)) increment in UA levels predicted an increased hazard ratio (HR) for all-cause deaths independent of age, smoking, body mass index, alcohol, physical activity, diuretic use and estimated glomerular filtration rate in all groups (NG: HR 1.25 95% CI 1.06-1.47, P =0.005; pre-DM: HR 1.20 95% CI 1.06-1.37, P = 0.04; T2DM: HR 1.20 95% CI 1.01-1.47, P = 0.04). After adjusting for CVD risk factors, the UA association with CVD mortality was significant only in the pre-DM and T2DM groups. All-cause mortality was independently associated with UA in all groups, but UA predicted CVD mortality only in those with abnormal glucose tolerance.