title: The Association between 25-Hydroxyvitamin D and Hemoglobin A1c Levels in Patients with Type 2 Diabetes and Stage 1-5 Chronic Kidney Disease.
abstract: Aim. To examine the relationship between plasma 25-hydroxyvitamin D (25(OH)D) levels and blood hemoglobin A1c (HbA1c) levels in diabetic patients at various stages of chronic kidney disease (CKD). Methods. We screened for data collected between 2003 and 2012. The correlation between 25(OH)D and HbA1c levels was studied in patients categorized according to the severity of CKD and their vitamin D status. A multivariate linear regression model was used to determine whether 25(OH)D and HbA1c levels were independently associated after adjustment for a number of covariates (including erythrocyte metformin levels). Results. We identified 542 reports from 245 patients. The mean HbA1c value was 6.7 ± 1.0% in vitamin D sufficiency, 7.3 ± 1.5% in insufficiency, and 8.4 ± 2.0% in deficiency (P < 0.0001). There was a negative correlation between 25(OH)D and HbA1c levels for the population as a whole (r = -0.387, P < 0.0001) and in the CKD severity subgroups (r = -0.384, P < 0.0001 and r = -0.333, P < 0.0001 for CKD stages 1-3 and 4-5, resp.). In the multivariate analysis, the 25(OH)D level was the only factor associated with HbA1c (P < 0.0001). Conclusion. 25(OH)D levels were negatively correlated with HbA1c levels independently of study covariates.
authors.affiliation: Department of Endocrinology and Nutrition, University Hospital of Amiens, 80054 Amiens, France ; INSERM Unit 1088, Jules Verne University of Picardie, 80037 Amiens, France.
authors.forename: Farshad
authors.initials: F
authors.lastname: Kajbaf
authors.affiliation: INSERM Unit 1088, Jules Verne University of Picardie, 80037 Amiens, France ; Bone Biology and Endocrine Division, University Hospital of Amiens, 80054 Amiens, France.
authors.forename: Romuald
authors.initials: R
authors.lastname: Mentaverri
authors.affiliation: Clinical Research Center, University Hospital of Amiens, 80054 Amiens, France.
authors.forename: Momar
authors.initials: M
authors.lastname: Diouf
authors.affiliation: Department of Clinical Nephrology, University Hospital of Amiens, 80054 Amiens, France.
authors.forename: Albert
authors.initials: A
authors.lastname: Fournier
authors.affiliation: Bone Biology and Endocrine Division, University Hospital of Amiens, 80054 Amiens, France.
authors.forename: Said
authors.initials: S
authors.lastname: Kamel
authors.affiliation: Department of Endocrinology and Nutrition, University Hospital of Amiens, 80054 Amiens, France ; INSERM Unit 1088, Jules Verne University of Picardie, 80037 Amiens, France.
authors.forename: Jean-Daniel
authors.identifier: 0000-0001-7167-9872
authors.initials: JD
authors.lastname: Lalau