Higher Serum Heavy Metal May Be Related with Higher Serum gamma-Glutamyltransferase Concentration in Koreans: Analysis of the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1, 2, 2010, 2011).
BACKGROUND
Abnormal serum gamma-glutamyltransferase (γ-GT) may be an early and sensitive marker for oxidative stress. This study was performed to evaluate the association between serum heavy metals and γ-GT concentration.


METHODS
This study is a cross-sectional analysis based on data from Korean National Health and Nutrition Examination Survey (V-1, 2, 2010, 2011) regarding serum heavy metal concentrations (lead, mercury, and cadmium) as well as serum γ-GT. Serum heavy metals were categorized into tertiles, and serum γ-GT concentration was compared using an analysis of covariance test after relevant variable adjustments. In addition, we evaluated the odds ratio (OR) of having the highest tertile of serum γ-GT in each heavy metal tertile using logistic regression.


RESULTS
The mean serum lead, mercury, and cadmium concentrations were 2.67, 5.08, and 1.02 µg/dL in men and 1.95, 3.60, and 1.21 µg/dL in women, respectively. Partial correlation showed a significant positive relation between each heavy metal and serum γ-GT concentration. Comparing serum γ-GT concentration by the tertile of each heavy metal, serum γ-GT concentration showed a significant increase as the tertiles of serum mercury and cadmium in men and that of serum mercury in women increased, but not with lead. The OR of having the highest tertile of serum γ-GT was significant for cadmium in men (OR, 4.02; 95% confidence interval [CI], 2.54 to 6.35) and mercury in women (OR, 2.00; 95% CI, 1.29 to 3.10) in the top tertile of each heavy metal.


CONCLUSIONS
Higher serum heavy metal concentration may be related with higher serum γ-GT concentration. In particular, serum cadmium in men and mercury in women showed significant correlation with serum γ-GT concentration.
Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon, Korea.
Sung-Jin
SJ
Kim
Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon, Korea.
Sung-Woo
SW
Han
Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon, Korea.
Duck-Joo
DJ
Lee
Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon, Korea.
Kwang-Min
KM
Kim
Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon, Korea.
Nam-Seok
NS
Joo
Cadmium; Mercury; gamma-Glutamyltransferase