Table 4. Standardized β coefficients between serum 25-hydroxyvitamin D3 and ln(HOMA-IR) and ln(HOMA-β) in the study population.
| Ln(HOMA-IR) | Ln(HOMA-β) | |||
| Overall (N = 480) | ||||
| Serum 25-hydroxyvitamin D3, ng/mL | ||||
| Adjusted standardized β coefficient (95% CI), model 1 | −0.11 (−0.17 to −0.04) | P = 0.001 | −0.06 (−0.11 to 0.001) | P = 0.06 |
| Adjusted standardized β coefficient (95% CI), model 2 | −0.11 (−0.17 to −0.04) | P = 0.002 | −0.05 (−0.11 to 0.01) | P = 0.12 |
| Adjusted standardized β coefficient (95% CI), model 3 | −0.08 (−0.14 to −0.02) | P = 0.006 | −0.03 (−0.08 to 0.03) | P = 0.31 |
| Normo-to-prediabetic (N = 445) | ||||
| Serum 25-hydroxyvitamin D3, ng/mL | ||||
| Adjusted standardized β coefficient (95% CI), model 1 | −0.11 (−0.17 to −0.04) | P = 0.001 | −0.07 (−0.12 to −0.01) | P = 0.02 |
| Adjusted standardized β coefficient (95% CI), model 2 | −0.10 (−0.17 to −0.03) | P = 0.003 | −0.06 (−0.12 to 0.0002) | P = 0.05 |
| Adjusted standardized β coefficient (95% CI), model 3 | −0.08 (−0.14 to −0.02) | P = 0.005 | −0.04 (−0.09 to 0.01) | P = 0.11 |
| Non-obese, normo-to-prediabetic (N = 303) | ||||
| Serum 25-hydroxyvitamin D3, ng/mL | ||||
| Adjusted standardized β coefficient (95% CI), model 1 | −0.08 (−0.15 to −0.02) | P = 0.02 | −0.05 (−0.11 to 0.01) | P = 0.09 |
| Adjusted standardized β coefficient (95% CI), model 2 | −0.08 (−0.15 to −0.01) | P = 0.03 | −0.04 (−0.10 to 0.02) | P = 0.22 |
| Adjusted standardized β coefficient (95% CI), model 3 | −0.07 (−0.14 to −0.01) | P = 0.03 | −0.04 (−0.10 to 0.02) | P = 0.24 |
| Obese, normo-to-prediabetic (N = 142) | ||||
| Serum 25-hydroxyvitamin D3, ng/mL | ||||
| Adjusted standardized β coefficient (95% CI), model 1 | −0.09 (−0.20 to 0.02) | P = 0.10 | −0.05 (−0.15 to 0.05) | P = 0.32 |
| Adjusted standardized β coefficient (95% CI), model 2 | −0.10 (−0.22 to 0.01) | P = 0.08 | −0.05 (−0.16 to 0.05) | P = 0.29 |
| Adjusted standardized β coefficient (95% CI), model 3 | −0.09 (−0.19 to 0.02) | P = 0.11 | −0.04 (−0.14 to 0.05) | P = 0.39 |
CI, confidence interval; HOMA-IR, homeostasis model assessment of insulin resistance; HOMA-β, homeostasis model assessment of β-cell function.
Normo-to-prediabetes was defined as a fasting plasma glucose level <126 mg/dL and a HbA1c level <6.5% [reference 24].
Obesity was defined as a body mass index ≥25 kg/m2 [reference 25].
Three different linear regression models were used to examine the standardized β coefficient: model 1 adjusted for age, sex, and months of blood sample collection; model 2 adjusted for the same covariates used in model 1, in addition to smoking habits, estimated glomerular filtration rate, work status, exercise habits, alcohol intake, protein intake, fat intake, and total dietary fiber intake; model 3 adjusted for the same covariates used in model 2, in addition to body mass index.