Endocrine Abstracts

Aims

Diabetic nephropathy (DN) is a leading cause of chronic kidney disease (CKD). Renal impairment may affect not only glycemic control, but also metabolism of biologically active cytokines such as adiponectin. Taking into account multiple effects of adiponectin the purpose of the study was to assess its changes in patients with type 1 diabetes (T1D) and comorbid CKD.

Materials and methods

We recruited 129 patients with T1D and 39 healthy controls. T1D patients were divided into 2 groups according to GFR. The group 1 comprised 67 patients with GFR > 60 ml/min, group 2–62 patients with GFR < 60 ml/min. Biochemical parameters, lipid profile, HbA1c, NGAL, serum adiponectin levels were measured. Nonparametric statistical methods were used. A P-value < 0.05 was considered significant.

Results

Comparison groups were matched by age, gender, BMI, duration of T1D, HbA1c levels. Comparative analysis of patients in the subgroups according to GFR revealed reliable differences in basal adiponectin levels. Mediana of adiponectin levels in patients with GFR > 60 ml/min (15.65 [9.34; 32.58]) were lower than those in GFR < 60 ml/min (28.21 [16.73; 45.34]), control group had 37.58 [27.38; 42.86]). Then we divided T1D patients according CKD stages. Adiponectin level was 15.65 [9.34; 32.58] in CKD 1–2 (n = 67), in CKD 3 (n = 32) was 25.36 [14.02; 39.40], in CKD 4 (n = 14) was 27.46 [12.83; 69.31], in CKD 5 (n = 16) was 32.76 [23.54; 57.34]. It was found that the values of the median adiponectin levels progressively increase with deterioration of renal function towards end-stage CKD (P = 0.002), which suggests the possibility of considering this parameter as an indirect marker of decreased renal function. In both comparison groups, correlations of adiponectin levels with marker of renal damage NGAL were obtained (ρ¹ =–0.413 and ρ² =–0.427, resp.). Patients with T1D and GFR < 60 ml/min had relationship between adiponectin and serum creatinine (ρ = 0.302) and eGFR (ρ =–0.298), which indicates the sensitivity of this parameter to decrease in renal function. The increase in adiponectin levels is most likely due to the non-absolute content of adiponectin in the serum, but the relative increase in the amount due to the decrease in renal clearance. We didn’t observed relationship of adiponectin and BMI, gender, HbA1c.

Conclusion

In patients with T1D and diabetic nephropathy decline of GFR is accompanied by an increase of serum adiponectin levels due to decrease in renal clearance. Correlation of adiponectin and renal impairment markers suggests the possibility of considering this parameter as an indirect marker of decreased renal function.