American Diabetes Association

Table 1

Multiple linear regression analysis for associations of vitamin D with measures of insulin sensitivity/resistance and β-cell function

Outcome per unit increase in baseline 25(OH)D	Model 1*			Model 2†			Model 3‡
Outcome per unit increase in baseline 25(OH)D	β (95% CI)	P	R²§	β (95% CI)	P	R²§	β (95% CI)	P	R²§
Insulin sensitivity/resistance measures
IS-OGTT‖	0.009 (0.007–0.011)	<0.0001	0.10	0.008 (0.005–0.010)	<0.0001	0.15	0.004 (0.002–0.007)	0.0003	0.29
HOMA-IR‖	−0.010 (−0.012 to −0.007)	<0.0001	0.11	−0.008 (−0.010 to −0.005)	<0.0001	0.15	−0.003 (−0.006 to −0.001)	0.007	0.35
Beta-cell Function measures
IGI/IR‖	0.008 (0.005–0.011)	<0.0001	0.12	0.007(0.004–0.011)	0.0001	0.12	0.004 (0.0004–0.008)	0.03	0.19
ISSI-2‖	0.005 (0.003–0.006)	<0.0001	0.15	0.004 (0.003–0.006)	<0.0001	0.16	0.003 (0.001–0.005)	0.001	0.23

Outcome per unit increase in baseline 25(OH)D	Model 1*			Model 2†			Model 3‡
Outcome per unit increase in baseline 25(OH)D	β (95% CI)	P	R²§	β (95% CI)	P	R²§	β (95% CI)	P	R²§
Insulin sensitivity/resistance measures
IS-OGTT‖	0.009 (0.007–0.011)	<0.0001	0.10	0.008 (0.005–0.010)	<0.0001	0.15	0.004 (0.002–0.007)	0.0003	0.29
HOMA-IR‖	−0.010 (−0.012 to −0.007)	<0.0001	0.11	−0.008 (−0.010 to −0.005)	<0.0001	0.15	−0.003 (−0.006 to −0.001)	0.007	0.35
Beta-cell Function measures
IGI/IR‖	0.008 (0.005–0.011)	<0.0001	0.12	0.007(0.004–0.011)	0.0001	0.12	0.004 (0.0004–0.008)	0.03	0.19
ISSI-2‖	0.005 (0.003–0.006)	<0.0001	0.15	0.004 (0.003–0.006)	<0.0001	0.16	0.003 (0.001–0.005)	0.001	0.23

*Model 1: adjusted for age, sex, season, ethnicity.

†Model 2: adjusted as in model 1 plus supplements, total physical activity, parathyroid hormone.

‡Model 3: adjusted as in model 2 plus BMI.

§R² is the coefficient of determination for the model.

‖Log transformations.