Prevalance of Hypothroidism in Non-Diabetic Chronic Kidney Patients: A Cross Sectional study

BACKGROUND: Chronic kidney disease is influenced by a number of factors including thyroid homeostasis. A decrease in thyroxine level in the body is grossly associated with many endocrine disturbances with effects overall organ system including renal system. Hypothyroidism also contributes to the progress of chronic kidney disease by either directly reducing the renal plasma flow due to its various mechanisms like, increased peripheral vascular resistance, dyslipidemia, reduced myocardial contractility or indirectly via its paracrine effects by IGF-1 or VEGF. Hence this may lead to elevation of creatinine, decreased renin angiotensin axis and further hyponatremia and increase the need for dialysis and also for the complications of dialysis and chronic kidney disease perse. OBJECTIVES: The aim of the study is to find the prevalence of hypothyroidism in patients treated for chronic kidney disease and further subgroup analysis for finding thyroid dysfunction in chronic kidney disease. This may be useful for treating the patients at primary care level and reduce the frequency for dialysis and need for dialysis in later days. MATERIALS AND METHODS: Study design: A cross sectional study among chronic kidney disease patients. Intervention: To find the prevalence of hypothyroidism and implicate the most common type of hypothyroidism in chronic kidney disease patient after excluding diabetes mellitus and aiding in further treatment to improve renal function. Setting: In a dialysis ward of tertiary care hospital. Period of study: September 2018 to August 2019. Sample size: 118 patients. Study population: 118 chronic kidney disease patients aged 20 to 59 years of both genders are going to be chosen. RESULTS: The mean values of T3 & T4 were significantly low in uremia. The prevalence of low T3 in stage 4 is 51%, for stage 4 is 34% where low T3 prevalence will be more common in higher stages of CKD. Our study found a positive correlation between Total T3 and eGFR which is statistically significant with P<0.03 chi square 6.90. Total T4 values were reduced in 37% and normal in 61% of our study population. Nearly 54% of low T4 valued patients were found in CKD stage 4 & 34%in ckd stage 5. Our study found a positive correlation between Total T4 and eGFR which is statistically significant [P-value 0.04, chi square 9.9]. 43% of patients had normal TSH even though there is low Total T3 level. These set of patients exhibit abnormality in hypophyseal influence over TSH release in CKD patients due to the blunted TSH response to TRH as the stage of CKD progresses further. Normal TSH in the setting of low Total T3 levels was found in the CKD patients. In our study there were 28% patients with low T3 & 27% patients with low T4 with normal TSH. Totally there were 21 patients with shared features of secondary hypothyroidism/euthyroid sick syndrome status. CONCLUSION: As the CKD stage progresses the dysregulation of thyroid hormones also sets in indicating the compensatory mechanism of protein conservation for the homeostasis. Patients with low T3, low T4, normal TSH were mostly in CKD stage 4 and to notify that most of the patients with low T3 syndrome are of elderly population. Normal TSH valued patients were the most common group in CKD stage 5 indicating non thyroidal illness/euthyroid sick syndrome prevalence in higher grades of CKD. Primary hypothyroidism patients were present around 11% and they were mostly in stage 4 CKD. They also had sudden onset of chronic kidney disease. There was direct cause and effect between the creatinine excretion in the body and serum total T3 and T4 which was indirectly measured by estimated GFR. The total prevalence of hypothyroidism in this study was around 40%. Serum Thyroid stimulating hormone plays a important role in differentiating and defining various spectrum of hypothyroidism.