Increased levels of serum γ-glutamyltransferase and uric acid on metabolic, hepatic and kidney parameters in subjects at high altitudes.

BACKGROUND

Currently there are no studies on γ-glutamyltransferase (γGT) levels at high altitude or on the relationship between γGT, uric acid and several dysfunctions. The aim of the study was to determine the association between serum γGT and uric acid levels in subjects at high altitude with hemoglobin, glycemia, and lipidic, hepatic and kidney markers.

METHODS

The present study was performed in 487 subjects aged 30-75 years living at 4100 m of altitude. A venous blood sample was drawn from each subject to measure hemoglobin, glucose, and lipid levels and markers of liver and kidney function. Quartiles for serum γGT and uric acid were calculated and associated with different physiological variables. A p-value <0.05 was considered statistically significant.

RESULTS

Serum γGT values were higher in men (38.35± 2.54 IU/L) than in women (30.33±1.76 IU/L) (p<0.01). Similarly, serum uric acid levels were higher in men (5.78± 0.12 mg/dL) than in women (4.29±0.08 mg/dL; p<0.001). Serum γGT levels in the top quartile were associated with higher glycemia, overweight/obesity, increased levels of non-high-density lipoprotein (non-HDL) cholesterol, triglycerides, alanine aminotransferase, alkaline phosphatase, uric acid, creatinine, and hemoglobin. Levels of uric acid in the top quartile were associated with overweight/obesity, elevated non-HDL cholesterol, triglycerides, creatinine, γGT and hemoglobin. Higher arterial blood pressure was associated with high levels of uric acid but not with γGT levels.

CONCLUSIONS

At high altitude, increased γGT levels were associated with hyperglycemia; increased uric acid levels were associated with overweight/obesity, hemoglobin, dyslipidemia, high blood pressure and kidney disease.