title: Ultrasonographic hepatic steatosis increases prediction of mortality risk from elevated serum gamma-glutamyl transpeptidase levels.
abstract: The aim of the present study was to investigate the association of serum gamma-glutamyltransferase (GGT) levels with all-cause mortality and to assess the impact of ultrasonographic findings of hepatic hyperechogenicity in that association. We used data from 4,160 subjects (2,044 men and 2,116 women) recruited for the population-based Study of Health in Pomerania (SHIP) without baseline hepatitis B and C infections or liver cirrhosis. GGT was divided into age- and sex-dependent quintiles to calculate overall and sex-specific crude incidence mortality rates. Hepatic steatosis was defined by elevated GGT levels (>80%) and the presence of hyperechogenic liver ultrasound. We used multiple-adjusted Cox proportional hazards regression models, first, to assess the direct effect of GGT on all-cause mortality, second, to stratify according to the ultrasonographic finding, and third, to investigate potential mediating effects of cardiometabolic risk factors. During 29,810 person-years (7.3 years, median) of follow-up, 307 individuals (7.5%) died, resulting in a death rate of 0.86 deaths per 1000 person-years. Elevated GGT levels were associated with increased risk of mortality in men (hazard ratio [HR] 1.49; 95% confidence interval [CI], 1.08-2.05), but not in women (HR 1.30; 95% CI, 0.80-2.12). This association was even stronger in men with hepatic steatosis (HR 1.98; 95% CI, 1.21-3.27). Cause-specific mortality analysis by cardiovascular disease deaths confirmed the sex-specific association. Adjustment for cardiometabolic risk factors did not affect the estimates.
  
  
  CONCLUSIONS
  In the case of increased GGT levels, liver ultrasound should be performed, not only for diagnosis, but also for further risk stratification.
authors: Institute of Clinical Chemistry and Laboratory Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health, München, Germany. robin.haring@uni-greifswald.de
authors: Robin
authors: R
authors: Haring
authors: Henri
authors: H
authors: Wallaschofski
authors: Matthias
authors: M
authors: Nauck
authors: Marcus
authors: M
authors: Dörr
authors: Sebastian E
authors: SE
authors: Baumeister
authors: Henry
authors: H
authors: Völzke
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005234:Fatty Liver / Q000097:blood / Q000000981:diagnostic imaging* / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D012727:Sex Characteristics; D014463:Ultrasonography; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D005723:gamma-Glutamyltransferase