Relationship between Plasma Leptin Level and Chronic Kidney Disease.

Background. Leptin is an adipose tissue-derived hormone shown to be related to several metabolic, inflammatory, and hemostatic factors related to chronic kidney disease. Recent animal studies have reported that infusion of recombinant leptin into normal rats for 3 weeks fosters the development of glomerulosclerosis. However, few studies have examined the association between leptin and CKD in humans. Therefore, we examined the association between plasma leptin levels and CKD in a representative sample of US adults. Methods. We examined the third National Health and Nutrition Examination Survey participants >20 years of age (n = 5820, 53.6% women). Plasma leptin levels were categorized into quartiles (≤4.3 Fg/L, 4.4-8.7 Fg/L, 8.8-16.9 Fg/L, >16.9 Fg/L). CKD was defined as a glomerular filtration rate of <60 mL/min/1.73 m(2) estimated from serum creatinine. Results. Higher plasma leptin levels were associated with CKD after adjusting for age, sex, race/ethnicity, education, smoking, alcohol intake, body mass index (BMI), diabetes, hypertension, and serum cholesterol. Compared to quartile 1 of leptin (referent), the odds ratio (95% confidence interval) of CKD associated with quartile 4 was 3.31 (1.41 to 7.78); P-trend = 0.0135. Subgroup analyses examining the relation between leptin and CKD by gender, BMI categories, diabetes, and hypertension status also showed a consistent positive association. Conclusion. Higher plasma leptin levels are associated with CKD in a representative sample of US adults.