Table 3.
Adjusted OR and 95 % CIs for diabetic retinopathy by vitamin D status stratified by age, sex, race, duration of diabetes, and HbA1c levels among Caucasian and African American ARIC study participants classified as having diabetes, with gradable eye photo at visit 3 (1993–95), and available serum 25(OH)D concentrations at visit 2 (1990–92) (N = 1339)
| Vitamin D status assessed with serum 25(OH)D concentrations (nmol/L) | ||||||
|---|---|---|---|---|---|---|
| <30 deficient | 30 to <50 inadequate | 50 to <75 adequate | ≥75 adequate | p trend* | Continuous, per 10 nmol/L | |
| Age group | ||||||
| 47 to 54 years (n = 471) | ||||||
| #with DR/# in group | 8/40 | 40/172 | 33/195 | 10/64 | ||
| Adjusted OR (95 % CI)a | 1 | 1.20 (0.42–3.44) | 0.90 (0.31–2.64) | 1.44 (0.39–5.25) | 0.800 | 1.02 (0.87–1.20) |
| 55–59 years (n = 356) | ||||||
| #with DR/# in group | 6/26 | 24/124 | 30/147 | 7/59 | ||
| Adjusted OR (95 % CI) | 1 | 0.84 (0.23–3.04) | 1.12 (0.31–4.08) | 0.88 (0.19–4.07) | 0.686 | 0.96 (0.80–1.16) |
| 60–64 years (n = 332) | ||||||
| #with DR/# in group | 9/19 | 30/103 | 35/149 | 5/61 | ||
| Adjusted OR (95 % CI) | 1 | 0.43 (0.14–1.36) | 0.39 (0.12–1.20) | 0.10 (0.02–0.45) | 0.011 | 0.80 (0.68–0.95) |
| 65 to 68 years (n = 180) | ||||||
| #with DR/# in group | 5/11 | 17/55 | 17/86 | 4/28 | ||
| Adjusted OR (95 % CI) | 1 | 0.64 (0.13–3.09) | 0.38 (0.08–1.81) | 0.27 (0.04–1.69) | 0.203 | 0.86 (0.68–1.08) |
| p for interaction | 0.372 | |||||
| Sex | ||||||
| Men (n = 629) | ||||||
| #with DR/# in group | 5/18 | 38/161 | 64/323 | 12/127 | ||
| Adjusted OR (95 % CI) | 1 | 0.67 (0.19–2.36) | 0.52 (0.15–1.79) | 0.23 (0.06–0.89) | 0.019 | 0.85 (0.75–0.97) |
| Women (n = 710) | ||||||
| #with DR/# in group | 23/78 | 73/293 | 51/254 | 14/85 | ||
| Adjusted OR (95 % CI) | 1 | 0.80 (0.41–1.59) | 0.68 (0.33–1.38) | 0.78 (0.31–1.97) | 0.262 | 0.93 (0.82–1.05) |
| p for interaction | 0.320 | |||||
| Race | ||||||
| Caucasian (n = 906) | ||||||
| #with DR/# in group | 10/38 | 55/249 | 73/428 | 23/191 | ||
| Adjusted OR (95 % CI) | 1 | 0.72 (0.29–1.81) | 0.52 (0.21–1.28) | 0.40 (0.15–1.07) | 0.072 | 0.91 (0.82–1.01) |
| African American (n = 433) | ||||||
| #with DR/# in group | 18/58 | 56/205 | 42/149 | 3/21 | ||
| Adjusted OR (95 % CI) | 1 | 0.89 (0.42–1.89) | 0.98 (0.45–2.16) | 0.45 (0.10–2.15) | 0.268 | 0.91 (0.77–1.08) |
| p for interaction | 0.555 | |||||
| Duration of diabetes, | ||||||
| <6 years (n = 593) | ||||||
| #with DR/# in group | 5/44 | 13/195 | 15/256 | 1/98 | ||
| Adjusted OR (95 % CI) | 1 | 0.53 (0.17–1.60) | 0.48 (0.16–1.45) | 0.08 (0.01–0.72) | 0.014 | 0.77 (0.62–0.95) |
| ≥6 years (n = 746) | ||||||
| #with DR/# in group | 23/52 | 98/259 | 100/321 | 25/114 | ||
| Adjusted OR (95 % CI) | 1 | 0.99 (0.50–1.95) | 0.84 (0.43–1.65) | 0.68 (0.30–1.52) | 0.219 | 0.94 (0.85–1.04) |
| p for interaction | 0.417 | |||||
| HBA1c levels | ||||||
| ≤7 % (adequate control) (n = 756) | ||||||
| #with DR/# in group | 5/47 | 21/241 | 16/326 | 4/142 | ||
| Adjusted OR (95 % CI) | 1 | 0.75 (0.26–2.13) | 0.44 (0.15–1.29) | 0.26 (0.06–1.07) | 0.091 | 0.86 (0.73–1.02) |
| >7 % (inadequate control) (n = 583) | ||||||
| #with DR/# in group | 23/49 | 90/213 | 99/251 | 22/70 | ||
| Adjusted OR (95 % CI) | 1 | 0.93 (0.47–1.83) | 0.89 (0.45–1.77) | 0.65 (0.28–1.51) | 0.163 | 0.93 (0.83–1.03) |
| p for interaction | 0.290 | |||||
* p for trend calculated using serum 25(OH)D as a continuous variable
aModel adjusted for race, duration of diabetes, HbA1c (continuous), and hypertension status. Strata of HbA1c are further adjusted for continuous levels of HBA1c