Table 3. Multiple logistic regression analysis of hypovitaminosis D associated with sleep characteristics in shift workers.
| Outcomes | Category | n (%) | 25(OH)D < 20 ng/mL | |||
|---|---|---|---|---|---|---|
| OR crude | p | OR adjusted | p * | |||
| Total sleep time | > 6 hours | 56 (68.3) | 1.00 | 1.00 | 0.358 | |
| ≤ 6 hours | 26 (31.7) | 1.71 (0.89–2.45) | 0.288 | 1.63 (0.74–2.13) | ||
| Sleep latency | < 30 min | 70 (85.4) | 70 (85.4) | 1.00 | 0.098 | |
| ≥ 30 min | 23 (14.6) | 2.68 (0.77–3.35) | 0.121 | 2.94 (0.80–3.70) | ||
| Sleep efficiency | > 85% | 56 (68.3) | 1.00 | 1.00 | 0.016 | |
| ≤ 85% | 26 (31.7) | 4.41 (2.83–7.62) | 0.005 | 3.68 (1.95–5.53) | ||
| Sleep apnea a | AHI < 5/h | 11 (13.4) | 1.00 | 1.00 | ||
| AHI 5–14/h | 34 (41.5) | 0.30 (0.08–1.11) | 0.073 | 0.25 (0.06–1.71) | 0.25 (0.06–1.71) | |
| AHI 15–30/h | 27 (32.9) | 1.48 (0.43–2.38) | 0.407 | 1.56 (0.58–2.23) | 0.295 | |
| AHI > 30/h | 10 (12.2) | 0.97 (0.39–2.13) | 0.971 | 0.98 (0.53–1.59) | 0.239 | |
| Arterial oxygen saturation | > 90% | 20 (24.4) | 1.00 | 1.00 | 0.020 | |
| < 90% | 62 (75.6) | 4.18 (2.87–5.36) | 0.041 | 5.35 (3.37–6.12) | ||
| Microarousal index | < P50 | 42 (51.2) | 1.00 | 1.00 | 0.018 | |
| > P50 | 40 (48.8) | 2.72 (1.03–4.56) | 0.048 | 3.85 (1.26–5.63) | ||
a
Multinomial logistic regression performed; p *: value for the Wald test.
OR crude : value estimated by the univariate analysis; OR adjusted : value adjusted for age, body fat, and seasonality.
Abbreviations: OR: odds ratio; P50: 50th percentile; AHI: apnea-hypopnea index