Revista argentina de endocrinología y metabolismo
On-line version ISSN 1851-3034
BAROVERO, M et al. Study on Renal Function in Patients with Subclinical Hypothyroidism: Response to Treatment with Levothyroxine. Rev. argent. endocrinol. metab. [online]. 2012, vol.49, n.3, pp. 115-118. ISSN 1851-3034.
Chronic Kidney Disease (CKD) has been recently recognized as a public health problem. Subclinical Hypothyroidism (SCH) presents with a low Glomerular Filtration Rate (GFR) due to a reduction in renal blood flow. Objective: To evaluate renal function in patients with SCH at diagnosis and after treatment with levothyroxine (LT4) Materials and Methods: Thirty-three patients between 18 and 85 years of age with SCH (TSH 4.5-10 mIU/L and FT4 0.8-1.9 ng/dL, CLIA method), whose GFR was assessed prior to LT4 treatment, and twenty-four patients post-treatment average ≥ 6 months. TPOAb (CLIA VR < at 22 KUI/L), glucose, uremia, creatinine, lipid profile were determined (method: autoanalyzer, Siemens Dimension RXL Max). To calculate the GFR, the MDRD4 formula was applied and were grouped into 4 stages according to the values obtained. We worked with a significance level of 5 %. The SPSS v. 17 software was used for statistical analysis, applying chi-square test, and calculation of mean and standard deviation for quantitative variables. Results: The pre- and post-treatment clinical and biochemical aspects are as follows, respectively: 52 vs. 51 years of age, TSH (mIU/mL) 5.42 vs. 1.72, (p < 0.5), FT4 1.13 vs. 1.21 ng/dl, creatinine 0.93 vs. 0.82 mg/dl (p < 0.5), glucose 84 vs. 87 mg/dl, total cholesterol 202 vs. 190 mg/dl, triglycerides 127 vs. 124 mg/dl, LDL-c 120 vs. 110 mg/dl, HDL-c 55 vs. 54 mg/dl and uremia 36 vs. 35 mg/dl. Normalization of TSH and a fall in creatinine were observed (TSH p < 0.0001; creatinine p < 0.036), remaining parameters p > 0.5. Only 24 % of the patients have an estimated GFR ≥ 90 ml/min/1.73 m2 prior to treatment. Changes in the GFR were observed after the administration of LT4: 74.6 ± 17 vs. 84.5 ± 22 ml/min/1.73 m2 p < 0.5. We recommend studying the renal function in every patient with thyroid dysfunction. Excluding other causes of kidney failure, an improvement in GFR is expected in patients with subclinical hypothyroidism after being treated with levothyroxine. The authors do not have conflicts of interest.
Keywords : Hypothyroidism; Renal failure; Levothyroxine; Changes in the glomerular filtration rate.