Endocrine Abstracts

Introduction: Influence of vitamin D status on metabolic control of type 1 diabetes (T1DM) remains controversial. The marker of long-term metabolic control that was not evaluated in this context is tissue accumulation of advanced glycation endproducts (AGEs), measured using skin autofluorescence. Aim of the study was to determine the association between serum 25-hydroxyvitamin D3 (25(OH)D3) concentration and accumulation of AGEs in adults with T1DM.

Materials and methods: We included 100 consecutive patients with T1DM (55 men, 45 women) aged 29(6) years (mean(S.D.)) with diabetes duration 13(6) years, 35 had diagnosed at least one microangiopathic complication (retinopathy or nephropathy or neuropathy).

Exclusion criteria were: acute disease requiring hospitalization, chronic kidney disease with eGFR lower than 50 ml/min per 1.73 m², history of parathyroid or thyroid disease, history of sarcoidosis, or systemic steroid therapy. Skin accumulation of AGEs was determined using AGE Reader device (DiagnOptics, Groningen, The Netherlands), that measures skin autofluorescence (AF). Mean from three consecutive AF measurements was used. Serum 25(OH)D3 concentration was measured using automated immunoassay (Liaison analyser). In statistical analysis Pearson’s correlation and multivariate linear regression were used.

Results: Mean 25(OH)D3 level was low and equalled 17.1(9.7) ng/ml. In 70 patients 25(OH)D3 level was lower than 20 ng/ml and in 18 patients was lower than 10 ng/ml. Serum 25(OH)D3 concentration was less decreased in women than in men (20.4(10.9) vs 14.2(7.3) ng/ml) and correlated negatively with skin AF (r=−0.26, P=0.009). In multivariate linear regression model this association was independent from age, sex, BMI, presence of hypertension, cigarette smoking, eGFR, HbA1c value and serum LDL-cholesterol concentration (Beta: −0.29, P=0.006, r² 0.29).

Conclusion: Vitamin D deficiency is common in adults with T1DM. In this group, low serum 25(OH)D3 concentration is associated with increased skin accumulation of AGEs, independently from other parameters of metabolic control of diabetes.