Endocrine Abstracts

Introduction

Vitamin D deficiency is recognized as a global problem worldwide. Today, there is information about the relationship between vitamin D levels and the pathogenetic links in the development of classic forms of diabetes mellitus (DM). In particular, vitamin D deficiency has been shown to cause insulin deficiency, progression of insulin resistance, and β-cell dysfunction. There is growing evidence that vitamin D deficiency may be a risk factor for diabetes. At the same time, the role of vitamin D deficiency in the development of latent adult autoimmune diabetes (LADA) needs further study. The aim of our study was to determine the relationship between the level of vitamin D with carbohydrate metabolism and the level of antibodies to glutamic acid decarboxylase in patients with LADA.

Materials and methods

A study of 90 patients with diabetes (26 patients with type 1 diabetes mellitus (T1DM), 28-with type 2 diabetes mellitus (T2DM), 36-with LADA), as well as 25 members of the control group. Evaluated complaints, history, objective examination, carbohydrate metabolism, levels of antibodies to glutamic acid decarboxylase (antiGAD) and vitamin D. Vitamin D < 10 ng/ml was regarded as a deficiency, 10–30 ng/ml as a risk of insufficient consumption, > 30 ng/ml as the optimal level. Patients with LADA were divided into two groups depending on the level of antiGAD:LADA1 and LADA2.We studied the relationship between vitamin D levels and carbohydrate metabolism in the study groups.

Results

Vitamin D deficiency was found in most patients:T1DM-62%, T2DM-75%, LADA-67%, and 12% of healthy individuals. The indicator of the insufficient consumption was registered in 34% of patients with T1DM, 25% of patients with T2DM, 25% of patients with LADA and 40% of the control group. In the remaining patients of the experimental group and in 28% of the control, this indicator was registered at the lower limit of normal. 20% of the surveyed control groups had the optimal level of vitamin D. Patients with LADA have the highest frequency (71%) and the degree of deficiency of this vitamin in a subgroup with LADA2 phenotype (LADA1–63%). In patients with LADA, there was a negative correlation between vitamin D levels and antiGAD titres (P < 0.05), as well as HbA1C levels (P < 0.05), and a positive correlation between vitamin D and C-peptide levels (P < 0.05).

Conclusion

Most patients with LADA have vitamin D deficiency, which is associated with a higher degree of autoimmunity, loss of beta-cell function and poorer compensation of the disease, which may indicate its role in the development and progression of this variant of diabetes.