The Relationship Between Vitamin D Deficiency and Glycated Hemoglobin Levels in Patients with Type 2 Diabetes Mellitus

Hang Zhao,1 Yunfeng Zhen,1 Zijing Wang,1 Licui Qi,2 Yong Li,3 Luping Ren,1,* Shuchun Chen1,* 1Endocrinology Department, Hebei General Hospital, Shijiazhuang, Hebei 050051, People’s Republic of China; 2Graduate School of Hebei North University, Zhangjiakou, Hebei 07500, People’s Republic of China; 3Graduate School of North China University of Science and Technology, Caofeidian New Town, Tangshan, Hebei 063210, People’s Republic of China*These authors contributed equally to this workCorrespondence: Shuchun ChenEndocrinology Department, Hebei General Hospital, 348, Heping West Road, Shijiazhuang, Hebei 050051, People’s Republic of ChinaEmail guang6701@sina.comLuping RenEndocrinology Department, Hebei General Hospital, 348, Heping West Road, Shijiazhuang, Hebei 050051, People’s Republic of ChinaEmail renluping1122@163.comPurpose: The aims of this study were to determine the relationship between 25-hydroxyvitamin D [25(OH) D]and glycated hemoglobin (HbA1c) levels in male and female patients with type 2 diabetes mellitus (T2DM).Patients and Methods: The participants were adults diagnosed with T2DM recruited from Hebei General Hospital. Patient information and information regarding blood indicators were collected. The subjects were divided into no vitamin D deficiency group [25(OH) D > 20 ng/mL]and vitamin D deficiency group [25(OH) D < 20 ng/mL], and these groups were then further subdivided into male-only or female-only subgroups. And then, the subjects were divided into male group and female group in different 25(OH) D levels.Results: HbA1c levels in the vitamin D deficiency group were significantly higher than those in the no vitamin D deficiency group for all subjects. The same was true for female patients but not for male patients. There was no difference in HbA1c levels between male and female patients with T2DM, regardless of 25(OH) D deficiency. A negative correlation existed between 25(OH) D and HbA1c in all subjects, as well as in the male-only and female-only subgroups. Vitamin D deficiency was associated with high HbA1c levels before and after adjusting for confounding factors in all participants and in the female-only subgroup, but not in the male-only subgroup.Conclusion: This study confirmed that vitamin D deficiency was related with high HbA1c levels in patients with T2DM, and this relationship differs between female and male patients.Keywords: diabetes mellitus, type 2, 25-hydroxyvitamin D, glycated hemoglobin