Prevalence of hypothyroidism in chronic kidney disease: a single centre cross-sectional study

The kidney normally plays an important role in the metabolism, degradation and excretion of thyroid hormones. Chronic kidney disease (CKD) affects the hypothalamus pituitary thyroid axis and peripheral metabolism of thyroid hormone and thus affects thyroid function in many ways. Despite considerable overlap in the symptoms related to hypothyroidism and advanced chronic kidney disease, relatively little is known about the prevalence of thyroid abnormalities in persons with CKD. In patients with end-stage renal disease, it has been suggested that primary hypothyroidism may be more common in patients with end stage renal disease (ESRD) compared with the general population. Thus this study was conducted to estimate the prevalence of hypothyroid in CKD. Objectives: To study the prevalence of hypothyroid in CKD and to see if prevalence increases with advancement of CKD stage. Materials and methods: This study is a Cross-Sectional study that was conducted among nondialytic CKD patients attending Nephrology OPD of GMCH from March 2014 to Feb 2016. Out of 1742 CKD patients, 280 patients who met the study criteria were included in the study. Demographic features (age and sex) and medical history of each patient were noted at the time of diagnosis. Results: The mean age of patients with overt hypothyroid was 59.64 years, in sub-clinical hypothyroid group was 58.14 years, and in patients with normal thyroid function was 55.51 years. We observed that prevalence of hypothyroidism was increased in patients with reduced GFR, and it increases as estimated glomerular filtration rate (eGFR) decreases ranging from 13.33% in stage 2 to 35.55% in ESRD (end stage renal disease). We also found that 68.8% of hypothyroids have sub-clinical hypothyroidism. Conclusion: This study concludes that prevalence of hypothyroid in CKD is more than that of general population and it further increases as eGFR decreases.