Thyroid hormones regulate the growth, development and functioning of almost all the tissues as well as kidneys. Hypothyroidism with defective hormone production is being one of the most pathologic hormone deficiencies among endocrine disorders. Hypothyroidism leads to hemodynamic variations such as reduction in renal plasma flow and Glomerular Filtration Rate (GFR). As a result of that serum creatinine and uric acid levels get increased. Due to the reduction of thyroid hormones levels, purine metabolism is also affected leading to uric acid level changes, leading to hyperuricemia and gout. However, estimation of serum uric acid, creatinine and eGFR in hypothyroid patients and evaluate the possibility to lead to renal impairment and further adverse effects, yet to be studied. This study aims to compare serum uric acid, creatinine and eGFR between hypothyroid patients attending endocrine clinic, Teaching Hospital Jaffna and healthy individuals in Faculty of AHS, University of Jaffna. 

This laboratory-based case control study was performed among 36 confirmed hypothyroid patients attending to endocrine clinic Teaching Hospital Jaffna and 36 healthy individuals in Faculty of Allied Health Sciences, University of Jaffna. Blood samples were collected together with their clinical and medical history using the clinical record books. The uric acid level was measured by the uricase peroxidase coupled reaction method and creatinine level was measured by the Colorimetric Jaffe Alkaline picric acid kinetic method. eGFR was calculated by the chronic kidney disease – Epidemiology collaboration (CKD-EPI) equation. Then data was analysed by Statistical Package for Social Science (SPSS) version 25. When considering the overall results, the mean serum creatinine level[0.92 (± 0.35) mg/dl] and the mean serum uric acid level[5.33(± 1.30)mg/dl] of case group were higher than the control group[0.86(± 0.20)mg/dl] and [4.13(± 0.91)mg/dl] respectively. The difference between the groups were statistically significant (p<0.01, p<0.01). The mean eGFR of case group [90.84(± 30.21)ml/min] was lower than the control group[93.24(± 20.52)ml/min]. The difference was statistically significant (p<0.01). According to our study, serum creatinine level and serum uric acid level were significantly high in hypothyroid patients than in healthy individuals. The eGFR value was lower in hypothyroid patients than in healthy individuals. In accordance with these results, there is a possibility of getting renal impairment and affecting uric acid metabolism due to hypothyroidism. Elevation of serum uric acid level may further lead to gout condition. It is essential to estimate the serum uric acid, serum creatinine and eGFR in hypothyroid patients as routine investigation to prevent renal impairment and further adverse effects. 

Keywords: Serum uric acid, estimated Glomerular Filtration Rate, Hypothyroid