Endocrine Abstracts

Aims: Thyroid status disturbances are not rare among DKD patients. It is known that the genesis of anemia in DKD has a multifactorial nature, and the combination of DKD and anemia significantly impairs quality of life. In addition, anemia in diabetic patients with DKD occurs earlier and tends to be more severe compared with CKD patients without diabetes. The purpose of the study was to investigate potential relationship between thyroid status and iron metabolism profile in patients with type 1 diabetes (T1D) and DKD.

Materials and methods: We recruited 166 patients with T1D. GFR was estimated by CKD-MDRD formula. Kidney injury was assessed using NGAL. All patients were divided into 2 groups: the group 1 comprised 79 patients with GFR>60 ml/min; group 2–87 patients with GFR<60 ml/min. Biochemical parameters, HbA1c, thyroid hormones, NGAL, iron homeostasis parameter were measured. Nonparametric statistical methods were used. A P-value <0.05 was considered significant.

Results: Groups were matched by gender, age of T1D manifestation, HbA1c, BMI. Age, duration of T1D, NGAL differed by groups. Comparative analysis of patients in the subgroups revealed reliable differences in fT3 (P=0.012), AbTSH-R (P=0.003). Groups did not differ by TSH, fT4, AbTPO, TG. Correlation of fT3 and Hb (ρ=0.312 P<0.05), erythrocytes (ρ=0.329, P<0.05) was observed in group 1. Levels of serum iron correlates with fT3 (ρ=−0.267, P<0.05) in group 2. When the study sample was divided into groups according fT3 levels: the values in the reference range and low fT3, the groups were matched by age, BMI, duration of T1D and DKD, lipid profile and NGAL. However, significant differences were found in Hb levels (P=0.023), erythrocytes (P=0.005). In low fT3 group these parameters were statistically significantly lower than in patients with normal values of fT3. Risk of developing anemia (Hb<120g/l) was 1.51 times higher (OR 1.59, 95% CI (0.74–3.07)) in patients with T1D and low fT3 than in patients with normal values of fT3.

Conclusion: Since the serum parameters of iron homeostasis are important determinants of anemia, therefore, the presence of additional influencing factors such as fT3 associated with the development of anemia, regardless of the stage of DKD, may be of fundamental importance in predicting the risks of anemia, as well as discovering therapeutic window for iron profile correction.