Endocrine Abstracts

Background and aims: A growing number of studies show the impact of vitamin D deficiency on chronic diseases, such as obesity, type 2 diabetes, cardiovascular disorders etc. Recently the lower limit of vitamin D sufficiency, appeared to be safe and sufficient for skeletal health in the healthy general population, was documented as 20 ng/ml (50 nmol/l). The aim of current work is to evaluate whether the 25-OH vitamin D status is associated with the glucose control in type 1 diabetic young patients.

Materials and methods: We have randomly investigated 64 type 1 diabetic patients of 20–35 years of age, with the duration of diabetes > 5 years. This is the age of bone plateau, when the maximal bone mineral density is already achieved, and is relatively stable period for bone metabolism. The male/female ratio of all investigated patients was 1/1.13, mean age was 24.06 ± 1.08. Fasting serum 25-OH vitamin D and HbA1c levels were measured. Anthropometric and anamnestic data was collected. The patients were divided into three groups depending on their 25-OH vitamin D status: < 20 ng/ml, 20–30 ng/ml, and > 30 ng/ml. All analyses were performed using statistical software (IBM SPSS Statistics for Windows, Version 21.0). In all cases values of P < 0.05 were considered statistically significant.

Results: 39.1% (n = 25) of investigated patients found to have vitamin D insufficiency (< 20 ng/ml); 35.9% (n = 23) – vitamin D low sufficiency (20–30 ng/ml); and 25% (n = 16) – vitamin D sufficiency (> 30 ng/ml). The groups were comparable based on mean age, sex and diabetes duration. No correlation was found between vitamin D and HbA1c absolute levels. But the mean HbA1c in the groups were as follows: 9.96 ± 0.83; 8.26 ± 0.64 and 7.82 ± 0.79, respectively, showing that in the groups with higher 25-OH vitamin D the glucose control was better (P < 0.05). No any connection between sex, age, duration of diabetes, weight and vitamin D status in the groups was revealed.

Conclusion: Lower 25-OH vitamin D is associated with the poorer glucose control in type 1 diabetic young patients. The vitamin D threshold levels should be further revised and investigated, particularly considering the presence of chronic diseases, such as type 1 diabetes, which we suppose should be different from the general population threshold.