Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc
Journal website http://www.jocmr.org

Original Article

Volume 9, Number 12, December 2017, pages 1013-1018


Association of Glycosylated Hemoglobin Levels With Vitamin D Status

Figures

Figure 1.
Figure 1. Vitamin D - baseline and follow-up.
Figure 2.
Figure 2. HbA1c - baseline and follow-up. HbA1c: glycated hemoglobin.

Tables

Table 1. Baseline Characteristics of the Study Participants
 
Baseline characteristics
HbA1c: glycated hemoglobin; TSH: thyroid-stimulating hormone; FT4: free thyroxine; C.Ca: corrected calcium; T1DM: type 1 diabetes mellitus; T2DM: type 2 diabetes mellitus.
Age (years) (mean ± SD)43.124 ± 19.46
HbA1c pre-supplementation (%) (mean ± SD)10.55 ± 2.58
Vitamin D pre-supplementation (nmol/L) (mean ± SD)40.09 ± 23.13
HbA1c post-supplementation (%) (mean ± SD)7.70 ± 1.61
Vitamin D post-supplementation (nmol/L) (mean ± SD)80.5 ± 29.77
TSH (mIU/L) (mean ± SD)2.89 ± 2.48
FT4 (pmol/L) (mean ± SD)15.89 ± 8.08
C.Ca (mmol/L) (mean ± SD)2.32 ± 0.13
Male, N (%)397 (39.7%)
Female, N (%)603 (60.3%)
T1DM, N (%)338 (33.8%)
T2DM, N (%)662 (66.2%)

 

Table 2. Baseline Characteristics Grouped on Basis of Vitamin D Levels
 
Baseline characteristicsVitamin D groupP value
< 20≥ 20 and < 50≥ 50 and < 75≥ 75
HbA1c: glycated hemoglobin; TSH: thyroid-stimulating hormone; FT4: free thyroxine; C.Ca: corrected calcium; T1DM: type 1 diabetes mellitus; T2DM: type 2 diabetes mellitus.
Age (years) (mean ± SD)38.61 ± 18.8841.0 ± 19.3349.96 ± 17.551.64 ± 55.50.0001
HbA1c pre-supplementation (%) (mean ± SD)10.62 ± 2.4510.86 ± 2.69.93 ± 2.569.81 ± 2.520.0001
Vitamin D pre-supplementation (nmol/L) (mean ± SD)14.17 ± 3.8833.58 ± 8.2960.33 ± 7.0391.75 ± 15.140.0001
HbA1c post-supplementation (%) (mean ± SD)7.63 ± 1.617.89 ± 1.707.37 ± 1.397.4 ± 1.160.0001
Vitamin D post-supplementation (nmol/L) (mean ± SD)68.11 ± 29.0274.46 ± 25.8292.27 ± 20.02118.66 ± 31.120.0003
TSH (mIU/L) (mean ± SD)3.15 ± 3.332.96 ± 2.422.6 ± 1.992.52 ± 1.460.0001
FT4 (pmol/L) (mean ± SD)15.44 ± 2.7316.09 ± 10.4215.9 ± 4.6715.69 ± 2.360.81
C.Ca (mmol/L) (mean ± SD)2.3 ± 0.152.32 ± 0.132.32 ± 0.122.34 ± 0.100.043
Male, N (%)56 (30.4%)237 (43.3%)67 (37.9%)37 (40.2%)0.019
Female, N (%)128 (69.6%)310 (56.7%)110 (62.1%)55 (59.8%)
T1DM, N (%)71 (38.6%)209 (38.2%)37 (20.9%)21 (22.8%)0.000017
T2DM, N (%)113 (61.4%)338 (61.8%)140 (79.1%)71 (77.2%)

 

Table 3. Mean Change of Vitamin D Levels and HbA1c at Follow-Up
 
Vitamin DnVitamin D baseline (mean ± SD)HbA1c baseline (mean ± SD)Vitamin D follow-up (mean ± SD)HbA1c follow-up (mean ± SD)Mean change vitamin D (P value)Mean change HbA1c (P value
HbA1c: glycated hemoglobin.
< 2018414.17 ± 3.8910.62 ± 2.4568.11 ± 29.027.63 ± 1.61+53.94 (0.0001)-2.99 (0.0001)
≥ 20 and < 5054733.58 ± 8.2310.86 ± 2.674.46 ± 25.847.89 ± 1.7+40.88 (0.0001)-2.97 (0.0001)
≥ 50 and < 7517760.33 ± 7.039.93 ± 2.5692.27 ± 20.027.37 ± 1.39+31.94 (0.0001)-2.56 (0.0001)
≥ 759291.75 ± 15.149.81 ± 2.52118.66 ± 31.127.4 ± 1.16+26.91 (0.0001)-2.41 (0.0001)

 

Table 4. Coefficient of Correlation Between Groups
 
Vitamin DnVitamin D follow-up (mean ± SD)HbA1c post-supplementation (mean ± SD)Coefficient of correlationP value
HbA1c: glycated hemoglobin.
≥ 20 and < 5016441.34 ± 5.357.95 ± 1.70-0.020.79
≥ 50 and < 7528862.94 ± 7.338.03 ± 1.8400.97
≥ 75548101.5 ± 22.837.46 ± 1.39-0.10.02