Evaluation of Serum Creatinine and Serum Uric Acid In Hypothyroid Patients: A Cross-sectional Study

Abstract

Introduction: Hypothyroidism, a prevalent endocrine disorder, leads to a generalised metabolic slowdown due to insufficient thyroid hormone production, potentially resulting in elevated levels of serum uric acid and creatinine, thus affecting renal function and purine metabolism. Aim: To assess serum creatinine and serum uric acid levels in hypothyroid patients while establishing correlations with their thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels. Materials and Methods: A comparative cross-sectional study was conducted in the Department of Biochemistry, Government Medical College, Kozhikkode, Kerala, India. The study involved 140 participants, including 70 recently diagnosed hypothyroid patients and 70 age- and sex-matched euthyroid individuals. Thyroid hormone levels (FT3, FT4) and TSH were quantified using the Cobas e411 electro-chemiluminescence technique. Serum creatinine levels were measured using the Modified Jaffe’s method, and serum uric acid levels were assessed through the Uricase method (Enzokit). Data analysis was performed using Statistical Package for the Social Sciences (SPSS) version 21.0, and tables and graphs were generated using Microsoft Word and Excel. Results: The mean age of study participants of control group was 39.02 years and of the hypothyroid group was 36.80 years. The comparative cross-sectional analysis revealed significantly higher levels of serum uric acid and serum creatinine in hypothyroid patients compared to euthyroid controls. Specifically, hypothyroid patients exhibited a mean serum uric acid level of 10.77±2.34 mg/dL, while euthyroid controls had a mean of 4.37±0.94 mg/dL. Mean serum creatinine levels for hypothyroid patients and euthyroid controls were 2.16±0.80 mg/dL and 0.75±0.14 mg/dL, respectively. Notably, a significant positive correlation was observed between serum uric acid and serum creatinine levels with TSH (r=0.42, p-value<0.001 and r=0.45, p=0.00, respectively). Conclusion: The study identified significantly higher levels of serum uric acid and creatinine in hypothyroid patients compared to euthyroid individuals, potentially attributed to haemodynamic changes and disruptions in purine metabolism. Regular monitoring of these parameters is crucial for individuals with hypothyroidism.