Impact of Thyroid Dysfunction on Estimated Glomerular Filtration Rate in Chronic Kidney Disease Patients Attending at Outpatient Department

Abstract Background: Thyroid dysfunction (TD) is a common endocrine disorder that frequently coexists with chronic kidney disease (CKD), potentially exacerbating renal impairment. The interplay between thyroid hormones and kidney function is complex, with thyroid abnormalities often leading to alterations in glomerular filtration rate (eGFR). Despite growing evidence, the specific impact of thyroid dysfunction on eGFR in CKD patients remains underexplored, particularly in resource-limited settings. This study aimed to evaluate the impact of thyroid dysfunction on eGFR in CKD patients attending at Outpatient Department of Nephrology at Community Based Medical College, Bangladesh. Methods:A cross-sectional observational study was conducted involving 87 CKD patients selected through purposive sampling. Data on thyroid function tests (TFTs) and eGFR were collected. Thyroid dysfunction was categorized based on serum TSH and free thyroxine (FT4) levels, while eGFR was calculated using the CKD-EPI equation. Data analysis was performed using the SPSS version 23.0 program. Results: Thyroid dysfunction was present in 38% of CKD patients, with hypothyroidism being the most common (25%). Hypothyroid patients had significantly lower eGFR levels compared to euthyroid patients (p < 0.01). A strong inverse correlation was found between TSH and eGFR (r = -0.62, p < 0.001). Thyroid dysfunction was an independent predictor of reduced eGFR (â= -0.48, p < 0.001). Conclusion:Thyroid dysfunction, particularly hypothyroidism, is prevalent in CKD patients and significantly associated with reduced eGFR. Routine thyroid screening and early intervention may help preserve renal function. Further studies are needed to explore causal relationships and long-term outcomes in CKD populations with thyroid dysfunction. Keywords: Thyroid dysfunction, Chronic kidney disease, Estimated glomerular filtration rate, Hypothyroidism, Renal function