Serum γ-Glutamyltranspeptidase Predicts All-cause, Cardiovascular and Liver Mortality in Older Adults

Background: Serum gamma-glutamyltranspeptidase (GGT), a marker of fatty liver disease (FLD), predicts mortality in young adults. However, the association between serum GGT and mortality in older adults is unclear. Objectives: To examine if elevated serum GGT predicts all-cause, cardiovascular disease (CVD), and liver mortality in community-dwelling older adults. Design and setting: A prospective cohort study including 2364 participants (mean age 70 years, BMI-24.5 kg/m(2), 54% women) from the Rancho Bernardo Study who attended a research visit in 1984-87 when multiple metabolic co-variates were ascertained including serum GGT. They were followed for a mean (+/- standard deviation) of 13.7 +/- 6.2) years. Measurement: Multi-variable-adjusted Cox-proportional hazards analyses were conducted to examine the association between elevated serum GGT (> 51 U/L in men and > 33 U/L in women) and all-cause, CVD, and liver mortality. Results: In these older men and women, cumulative mortality was 56.2% (n = 1329) with CVD and liver mortality accounting for 49.4% and 2.3% of all deaths, respectively, over 32,387 person-years of follow-up. In multivariate analyses (adjusted for age, sex, alcohol use, body mass index, total cholesterol, HDL cholesterol, serum triglyceride, smoking status, systolic blood pressure, diabetes mellitus, serum interleukin-6, and C-reactive protein), serum GGT elevation was significantly associated with all-cause (HR, 1.55, 95% CI, 1.21-1.98), CVD (HR, 1.51, 95% CI, 1.04-2.17), and liver mortality (HR, 9.10, 95% CI, 3.42-24.26). Conclusions: In community-dwelling older adults, serum GGT is an independent predictor of all-cause, CVD, and liver mortality.