Replacement therapy of subclinical hypothyroidism in patients with various stages of chronic kidney disease

Background. Thyroid function disorders are often detected in comorbid patients, including in patients with chronic kidney disease (CKD). A decrease in the functional activity of the thyroid gland is associated with dysproteinemia, atherogenic dyslipidemia, electrolyte and nitrogen metabolism disorders. Recommendations for the detection and treatment of thyroid dysfunction in CKD patients have not yet been developed. Objective. Evaluation of the effect of levothyroxine replacement therapy on blood lipid profile and estimated glomerular filtration rate (eGFR) in patients with subclinical hypothyroidism and various CKD stages. Methods. 457 patients with various CKD stages were examined. Subclinical hypothyroidism (SHT) was revealed in 73 (16%) patients. SHT was associated with severe disorders of protein metabolism due to a decrease in the total protein (P=0.031) and albumin (P=0.047) levels, a significant increase in daily proteinuria (P=0.002), a decrease in the total calcium level (P=0.002), an increase in phosphorus inorganic (P=0.011) and chloride (P=0.017) levels, atherogenic dyslipidemia (increased total cholesterol (p<0.001), low-density lipoproteins; (P=0.045) and very low-density lipoproteins (P=0.025) levels). Patients were then randomized to treatment with levothyroxine (n=36) and observation (n=36). Statistical analysis was carried out using the StatTech v. 2.6.1. Results. After re-examination of patients in the treatment group at 6 months, there was a significant decrease in the thyroid-stimulating hormone (P<0.001), total cholesterol (P<0.001), low-density lipoproteins (P<0.001), creatinine (P=0.002), urea (P= 0.001) levels, and increased fT3 (P=0.028), fT4 (P=0.002), eGFR (P=0.003), and albumin (P=0.019) levels. In the observation group, a significant decrease in the high-density lipoprotein (P=0.010), thyroid-stimulating hormone (P=0.001) and total protein (P=0.045) levels over time was noted. Conclusion. SHT in CKD patients was associated with disorders of protein and lipid metabolism, abnormalities in the electrolyte levels. Replacement therapy with levothyroxine in CKD patients with SHT led to a significant improvement in blood lipids, eGFR, a decrease in creatinine and urea, and an increase in albumin levels.

chronic kidney disease, subclinical hypothyroidism, dyslipidemia, dysproteinemia, glomerular filtration rate