Serum gamma-glutamyltransferase was differently associated with microalbuminuria by status of hypertension or diabetes: the Coronary Artery Risk Development in Young Adults (CARDIA) Study.
BACKGROUND
We hypothesized that serum gamma-glutamyltransferase (GGT) would positively predict the risk of microalbuminuria, a frequent consequence of both diabetes and hypertension, because serum GGT predicted diabetes and hypertension in dose-response relationships.


METHODS
In this prospective study, 2478 black and white men and women without microalbuminuria at year 10 provided urine samples 5 years later. Year 10 GGT cutpoints were 12, 18, and 29 U/L.


RESULTS
The incidence of microalbuminuria across year 10 GGT categories was U-shaped. Adjusted odds ratios across quartiles of serum GGT were 1.0, 0.39, 0.54, and 0.94 (P <0.01 for quadratic term), but the shape of association depended on the status of hypertension or diabetes (P <0.01 for interaction). Among individuals who ever had hypertension or diabetes, year 10 serum GGT showed a clear positive dose-response association with incident microalbuminuria (P <0.01 for trend), whereas among individuals with neither hypertension nor diabetes during the study, year 10 GGT showed a U-shaped association with it (P = 0.01 for quadratic term). When the long-term risk was evaluated in 3895 participants based on serum GGT at year 0 and prevalence of microalbuminuria at year 10 or year 15, the trends were similar but weaker than those of short-term incidence risk.


CONCLUSIONS
Serum GGT within the physiologic range predicted microalbuminuria among patients with hypertension or diabetes and may act as a predictor of microvascular and/or renal complications in these vulnerable groups. GGT showed a U-shaped association with microalbuminuria among persons who did not develop either hypertension or diabetes.
Lee
Duk-Hee
DH
Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
Jacobs
David R
DR
Gross
Myron
M
Steffes
Michael
M
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000453:epidemiology* / Q000209:etiology / Q000652:urine; D003324:Coronary Artery Disease / Q000453:epidemiology* / Q000209:etiology; D048909:Diabetes Complications / Q000453:epidemiology / Q000209:etiology; D003920:Diabetes Mellitus; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D015994:Incidence; D008297:Male; D015337:Multicenter Studies as Topic; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012306:Risk; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000097:blood*
D005723:gamma-Glutamyltransferase