Endocrine Abstracts

Introduction: Decrease in thyroid hormones (TH) levels is associated with reduced blood flow to kidneys and decreased glomerular filtration rate (GFR) along with alteration of tubular reabsorption.

Deiodinase type 1 is an enzyme that is active in liver and kidneys and plays an important role in TH metabolism.

The aim of the research was to study the dependence of markers of renal function on C/T polymorphism in the DIO 1 gene in patients with DKD.

Material and Methods: The C/T polymorphism in the DIO1 gene was studied in 102 patients with diabetes type 2 (T2DM) complicated by CKD in stage ofmicroalbuminuria and 97 healthy subjects – control group.

To assess the dependence of biochemical markers of renal function on the C/T polymorphism in the DIO 1 gene, the following groups has been formed: 19 patients with CC genotype, 69 – with CT and 14 – with TT genotypes.

Blood sample was analysed for blood urea, serum creatinine, urine test for evaluation of microalbumin, creatinine levels. Albumin/creatinine ratio in urine and GFR by CKD-EPI formula were calculated. To access TH levels free triiodothyronine T₃(fT₃), free thyroxine T₄(fT₄), thyroid stimulating hormone (TSH) were determined.

Results: Disorders of distribution of genotype frequencies contributed by the reduction of CC genotype frequency was revealed in the group of enrolled patients comparing to the control group (χ² = 6.8, P < 0.05), while there was no significant difference between the frequencies of CT and TT genotypes (χ² = 2.4, P > 0.05 and χ² = 1.2, P > 0.05).

Blood urea (P = 0.032), blood cleatinine (P = 0.035) levels as well as microalbumin (P = 0.041) and creatinine content (P = 0.039) in urine were higher in group with TT genotype than in group with CC genotype.

Creatinine in blood serum (r = −0.362, P < 0.05), microalbumin in urine (r = −0.416, P < 0.05) correlated negatively with the level of fT₃. GFR correlated positively with fT₃ level (r = 0.374, P < 0.05) and negatively with fT₄ level (r = −0.326, P < 0.05).

Conclusions: 1. C allelehas protective properties against violation of TH metabolism in patients with T2DM.

2. Carriers of Tallele with DKD had significantly worse biochemical indices of renal function, that indicates the dependence of these markers on DIO1 polymorphism.

3. Results of correlation analyses showed the dependence between the levels of TH and biochemical indices of renal function.