Analysis of the correlation between vitamin D and β-cell function in type 1 diabetic patients

Abstract

Objective To determine vitamin D levels in patients with type 1 diabetes mellitus (T1DM),and to explore the relationship of vitamin D and pancreatic β-cell function in these patients.Methods Sixty-five patients with T1DM,78 controls with normal glucose tolerance (NGT),as well as 87 type 2 diabetes mellitus (T2DM) patients,whose HbA1C,blood glucose levels,and duration of diabetes were matched with those in the T1 DM group,were enrolled from January 2011 to April 2012.The differences in serum 25-hydroxyvitamin D3 [25 (OH) D3] levels among the three groups were compared.Pearson correlation analysis was used for investigating the relationship between fasting C-peptide levels and other variables in T1DM group,all P＜0.05 variables then were included in a stepwise multiple linear regression analysis.Results Serum 25 (OH) D3 levels were significantly lower in T1 DM group than those in NGT and T2DM groups [7.7 (4.8-14.9)vs 13.9 (10.0-17.9),12.5 (9.3-17.4)ng/mg,both P＜0.01].Stepwise multiple linear regression analysis showed that fasting serum C-peptide concentration was independently associated with serum 25 (OH) D3 level in T1 DM group.Conclusions T1DM patients had lower vitamin D levels than NGT and T2DM subjects,vitamin D status showed independently a positive association with β-cell function in T1DM patients.Whether supplement of vitamin D to TIDM patients is a topic worth studying. Key words: Vitamin D; Diabetes mellitus, type 1 ; β-cell function