Thyrotropin as an Independent Factor of Renal Function and Chronic Kidney Disease in Normoglycemic Euthyroid Adults

Objectives. The relationship between thyroid status and renal function has been well characterized. However, renal function is affected by various factors, including sex and dysglycemia. Because these studies have yet to be undertaken in a normoglycemic population, this study sought to explore the association between thyroid and renal function in large population of normoglycemic euthyroid adults. Design. Population-based cross-sectional survey. Patients. A total of 8,418 normoglycemic euthyroid participants were recruited after excluding individuals with thyroid dysfunction (thyrotropin, TSH < 0.47 mU/L, TSH >= 5.0 mU/L) or dysglycemia (fasting glucose >= 100 mg/dL). Measurements. Anthropometric measurements were collected, and creatinine, TSH, and fasting glucose levels were evaluated. Renal function was determined by the estimated glomerular filtration rate (e-GFR) calculated using the simplified Modification of Diet in Renal Disease formula. Results. TSH levels were inversely correlated with e-GFR. After adjustment for confounding factors, multivariate analysis revealed that TSH remained an independent factor of e-GFR in both genders (beta = -1.512 in males and -1.685 in females), and TSH was an independent factor of chronic kidney disease (OR = 1.28, 95% CI = 1.021-1.604). Conclusions. TSH is an independent factor for determining renal function and chronic kidney disease in normoglycemic euthyroid adults.