title: The relationship between gamma-glutamyl transferase levels and chronic kidney disease among Appalachian adults.
abstract: BACKGROUND
  Serum gamma-glutamyl transferase (GGT), a marker of oxidative stress has been associated with diabetes and hypertension, which are risk factors for chronic kidney disease (CKD). However, it is unclear whether serum GGT is independently associated with CKD.
  
  
  METHODS
  We analyzed data from a population-based study of Appalachian adults residing in six communities in Ohio and West Virginia, who were aged > or = 18 years (n = 55,187, 52% women). Serum GGT was examined as gender-specific quintiles (quintiles 1-5 in women: 0-11 U/L, 12-14 U/L, 15-19 U/L, 20-29 U/L and > 29 U/L; quintiles 1-5 in men: 0-17 U/L, 18-23 U/L, 24-30 U/L, 31-45 U/L, and > 45 U/L). The main outcome of interest was CKD (n = 4482), defined as an estimated glomerular filtration rate of < 60 mL/ min/1.73 m2 from serum creatinine.
  
  
  RESULTS
  Higher serum GGT levels were not found to be associated with CKD after adjusting for age, education, smoking, alcohol intake, body mass index (BMI), diabetes, hypertension and total cholesterol. In women, compared to quintile 1 of GGT, the odds ratio (OR) (95% confidence interval [CI]) of CKD associated with quintile 5 was 0.93 (0.82-1.06); p-trend = 0.3102. Similarly, in men, compared to quintile 1 of GGT, the odds ratio (OR) (95% confidence interval [CI]) of CKD associated with quintile 5 was 0.94 (0.80-1.10); p-trend = 0.4372. Subgroup analyses that examined the relation between GGT and CKD by alcohol intake and BMI categories also showed a consistent null association.
  
  
  CONCLUSIONS
  In a community-based sample of Appalachian adults, higher serum GGT was not found to be independently associated with CKD.
authors.forename: Loretta R
authors.initials: LR
authors.lastname: Cain
authors.forename: Alan M
authors.initials: AM
authors.lastname: Ducatman
authors.forename: Anoop
authors.initials: A
authors.lastname: Shankar
mesh_terms: D000328:Adult; D001061:Appalachian Region / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D048909:Diabetes Complications / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate; D006306:Health Surveys; D006801:Humans; D006977:Hypertension, Renal / Q000150:complications; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D012016:Reference Values; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D011795:Surveys and Questionnaires; D014903:West Virginia / Q000453:epidemiology; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D005723:gamma-Glutamyltransferase