The Effect of Hyperthyroidism on the Level of Urinary Neutrophil Gelatinase Associated Lipocalin and Markers of Kidney Function

Abstract

Introduction: Thyroid hormones affect kidneys in various ways ranging from their development to their functions. Serum and urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL) are emerging as the most promising biomarkers for early determination of Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD). Aim: To evaluate the effects of hyperthyroidism (subclinical and overt) on the markers of kidney function. Materials and Methods: In this cross-sectional study, 300 subjects were recruited from May 2015 to June 2018 and divided in three categories of euthyroid, subclinical and overt hyperthyroid subjects. All the subjects were analysed for Thyroid function (Total T3, T4, Thyroid Stimulating Hormone (TSH)) and Kidney Function (Serum Urea, Serum Creatinine, Urinary NGAL, estimated Glomerular Filtration Rate (eGFR)). Results: Statistical analysis revealed a significant decrease in serum urea and serum creatinine in both subclinical (17.32±3.51 mg/dL and 0.58±0.13 mg/dL, respectively) and overt hyperthyroid (13.52±2.78 mg/dL and 0.29±0.10 mg/dL, respectively) patients as compared to euthyroids (19.99±5.38 mg/dL and 0.87±0.25 mg/dL, respectively). Urinary NGAL and eGFR were significantly increased in both subclinical (30.24±8.63 ng/mL and 119.57±11.31 mL/min, respectively) and overt hyperthyroid (44.05±13.02 ng/mL and 155.12±19.75 mL/min, respectively) patients as compared to euthyroids (21.94±18.06 ng/mL and 97.97±25.92 mL/min, respectively). A negative correlation of creatinine and positive correlation of urinary NGAL and eGFR with T3 and T4 was observed in both subclinical and overt hyperthyroidism (p<0.05). Conclusion: The study shows that there are negative effects of hyperthyroidism on kidney functions.

Keywords

• creatinine
• glomerular filtration rate
• lipocalin 2
• serum urea
• thyroid dysfunction