Character of thyroid dysfunction in patients with type 2 diabetes and diabetic kidney disease

Abstract

Type 2 diabetes (T2D) is the most common metabolic disease that leads to numerous complications. Diabetic kidney disease (DKD) is one of the most frequent chronic complications of diabetes mellitus and includes functional, structural, and clinical disorders of the kidneys. Patients with DKD often have thyroid dysfunction, which complicates preexisting metabolic abnormalities. The aim of the work is to investigate the character of thyroid dysfunction in patients with T2D and DKD. Material and methods. 125 patients with T2D and DKD were included in the study. Patients were divided into three groups according to the risk degree of DKD progression. The moderate-risk group (group 1) included 76 people, the high-risk group (group 2) had 33 participants, and the very high-risk group (group 3) included 16 people. Body mass index was determined for all participants, and laboratory tests were performed, namely: glycated hemoglobin, total cholesterol, creatinine, urea, thyroidstimulating hormone, free triiodothyronine, and free thyroxine. To assess the functional state of the kidneys, the estimated glomerular filtration rate was calculated, and the albumin-creatinine ratio was determined. Results and discussion. According to the study, the rate of DKD progression was higher among women. The average age of all patients was 56± ±0.77 years; however, a higher risk of DKD progression was observed mainly in older individuals (55.11±0.91, 57.93±1.56 and 61.13±2.28 years, respectively; p<0.01), as well as in patients with longer duration of T2D (7.75±1.31, 8.39±0.84 and 10.15±1.23 years, respectively; p<0.05). All study participants were found to be obese (body mass index ≥30 kg/m2) (p=0.43) and had unsatisfactory glycemic control of T2D, as the HbA1c level exceeded 9% (p<0.05). It is important to note that the level of total cholesterol was increased only in group 2 (6.07±0.29 mmol/L) and group 3 (6.11±0.36 mmol/L) (p>0.05). In the considered groups of patients, an increase in the level of indicators of the kidney functional state, such as creatinine (85.93±1.98, 102.02±3.71 and 133.82±6.52 μmol/l), urea (5.34±0.99, 6.26±0.33 and 9.35±0.87 mmol/L) and albumin-creatinine ratio (120.85±7.09, 214.0±13.4 and 334.38±17.15 mg/g) (in all indicators p<0.01). A decrease in the level of estimated glomerular filtration rate was also noted in all groups (79.11±1.75, 60.76±2.78 and 41.33± ±2.34 mL/min/1.73 m2, respectively; p<0.01), which reflects the degree of risk for DKD progression. It is also worth noting the gradual increase in the level of thyroid-stimulating hormone in all groups (2.69±0.35, 3.12± ±0.57 and 4.89±0.80 μIU/mL; p<0.05) and at the same time the decrease in the levels of free triiodothyronine (2.48±0.21, 2.35±0.36 and 1.18±0.15 pg/mL; p<0.05) and free thyroxine (15.03±1.21, 12.40±1.81 and 6.14±0.83 pmol/L; p<0.05) are proportional to the degree of risk for DKD progression. Conclusions. It was found that in patients with T2D and DKD, thyroid dysfunction is observed, manifested by changes in the level of thyroid hormones, and indicates the relationship between thyroid function and the DKD progression. That is why it is essential to diagnose and prevent the development of these diseases in a timely manner.