Objective：Low vitamin D has been implicated in the development of type 2 diabetes. However, whether vitamin D continues to have a clinically significant effect in existing diabetes is unclear. The objective of this study was to examine the association of serum vitamin D with glycemic control in established type 2 diabetes.
Methods: This was a retrospective analysis of medical records. Characteristics of 487 patients with type 2 diabetes were stratified by vitamin D status and serum glycosylated hemoglobin (HbA1c). Vitamin D deficiency among the subjects was studied. The relationship between vitamin D and glycemic control was explored by multiple linear regression, multivariate analysis of variance (MANOVA) and chi-square test. Patients were stratified into overweight and non-overweight group based on body mass index (BMI), and the association of serum vitamin D concentration with glycemic control was evaluated in each group. Insulin resistance and C-peptide as mediators between vitamin D and HbA1c was tested. The impact of vitamin D on cholesterol metabolism was also assessed.
Results: (1) Vitamin D deficiency was highly prevalent, accounting for 88.3% of the study sample. (2) Serum vitamin D levels were significantly inversely associated with serum HbA1c. This correlation was stronger in overweight group than in non-overweight group. There was no significant relationship between serum vitamin D levels and fasting plasma glucose (FPG). HbA1c was significantly lower in vitamin D insufficiency group than in vitamin D severe deficiency group. (3) Insulin resistance partially mediated the association between vitamin D and HbA1c. (4) No significant association of Vitamin D with low density lipoprotein (LDL) or high density lipoprotein (HDL) was found in this study.
Conclusions: There was an inverse association between serum vitamin D levels and HbA1c. The inverse correlation of serum vitamin D level and HbA1c was stronger in overweight group than in non-overweight group, which indicates patients with obesity might benefit more from vitamin D supplementation. / published_or_final_version / Public Health / Master / Master of Public Health
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/193833 |
| Date | January 2013 |
| Creators | Zhuang, Xiaoming, 庄小鸣 |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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