The association of plasma cysteine and gamma-glutamyltransferase with BMI and obesity.
Elshorbagy, Amany K Refsum, Helga Smith, A David Graham, Ian M
Elshorbagy, Amany K
Refsum, Helga
Smith, A David
Graham, Ian M
Advisors
Editors
Other Contributors
Date
2009-07
Date Submitted
Keywords
Other Subjects
Subject Mesh
Adult
Body Mass Index
Cross-Sectional Studies
Cysteine
Female
Humans
Linear Models
Logistic Models
Male
Middle Aged
Obesity
Predictive Value of Tests
Risk Factors
gamma-Glutamyltransferase
Body Mass Index
Cross-Sectional Studies
Cysteine
Female
Humans
Linear Models
Logistic Models
Male
Middle Aged
Obesity
Predictive Value of Tests
Risk Factors
gamma-Glutamyltransferase
Planned Date
Start Date
Collaborators
Principal Investigators
Alternative Titles
Publisher
Abstract
We recently reported a strong positive association of plasma total cysteine (tCys) with fat mass in over 5,000 subjects. As gamma-glutamyltransferase (GGT) enzyme increases cysteine availability by catalyzing glutathione breakdown and is positively associated with BMI and adiposity, we hypothesized that GGT might explain the association of tCys with adiposity. To study whether the associations of tCys and serum GGT with BMI and obesity were interrelated we conducted a cross-sectional study using data from 1,550 subjects recruited from nine European countries in the COMAC project. Multiple linear and logistic regression models and concentration-response curves were used. In age and sex-adjusted analyses, tCys showed strong positive associations with BMI (partial r = 0.19, P < 0.001), and obesity (odds ratio (OR) for 4th vs. 1st tCys quartile: 2.8; 95% confidence interval: 1.6-5.0, P < 0.001), both of which remained robust after adjustment for GGT and other metabolic and lifestyle confounders. Serum GGT was also a positive predictor of BMI (partial r = 0.17, P < 0.001) and obesity (OR for 4th vs. 1st GGT quartile: 4.8; 95% confidence interval: 2.5-9.2, P < 0.001), independent of tCys. However, the associations of GGT with BMI and obesity were weakened by adjustment for obesity-related factors such as serum lipids and blood pressure. These results indicate that tCys is a strong positive predictor of BMI and obesity, independent of GGT and other obesity-related factors. We also suggest that the association of serum GGT with BMI and obesity is unrelated to the role of GGT in cysteine turnover. The potential link between cysteine and fat metabolism should be further evaluated.
Language
en
ISSN
1930-7381
eISSN
ISBN
DOI
10.1038/oby.2008.671
PMID
19214177