CHRONIC KIDNEY DISEASE;

CORRELATION BETWEEN FREE THYROXIN, THYROTROPHIN AND GLOMERULAR FILTRATION RATE

Abstract

Introduction: Chronic kidney disease (CKD) is defined as kidney damage or glomerular filtration rate <60ml/min/1.73m
for 3 months or more, irrespective of cause. Objective: To measure glomerular filtration rate, free thyroxin, thyrotrophin in chronic kidney
disease patients and to find out the correlation between glomerular filtration rate, free thyroxin and thyrotrphin in these patients. Study
Design: Cross sectional analytical study. Setting: Post Graduate Medical Institute (PGMI), Lahore General Hospital (LGH) Lahore. Period:
6 months (Nov 2011 to April 2012). Material and Methods: Sixty five patients were included in the study. Serum Creatinine, TSH and Free
T4 were measured; Thyroid function tests TSH, FT4 were measured in these chronic kidney disease patients through enzyme linked
immunosorbant assay method. GFR was calculated through Cock-croft-Gualt formula and the relevant data was entered in a predesigned
Proforma. Results: In the study total 65 chronic kidney disease patients were taken. Out of which thirty six (55.4%) were male and twenty
nine (44.6%) were female. Thirty five (53.8%) CKD patients whose TSH levels were above the normal limit while in the remaining patients
the TSH values were in the normal range. Eight patients (12.3%) out of sixty five patients in whom FT4 values were below the normal limit
while in the remaining fifty seven patients (87.6%) FT4 values were within the reference range. Those eight patients whose FT4 was
below the normal value, their TSH values were above the normal value too. Thirty five patients, whose TSH levels were above the normal
2 limit, their mean age was 50.60± 11.95, mean serum creatinine was 4.73± 2.94 mg/dl, mean GFR was 22.17± 12.48 ml/min/1.73m ,
mean TSH was 6.68± 0.87 mIU/L and mean FT4 was 0.97± 0.35 ng/dl. The p-value of TSH was < 0.001 and FT4 was < 0.05 in
comparing with normal. Glomerular filtrations rate with TSH and FT4 the co-efficient of correlation (r) value for 35 patients to be – 0.713
and 0.47 for TSH and FT4 respectively. Their p- values were 0.000 and 0.004 respectively, and p < 0.001 collectively. This was found to
be statistically significant. Linear regression line was obtained between GFR and TSH and GFR and FT4 in CKD patients. Conclusions:
From these correlation studies I concluded that the chronic kidney disease is associated with biochemical thyroid dysfunctions causing
most commonly subclinical hypothyroidism.