Table 1. Demographic and basic characteristics from NHANES 2005–2008 (Unweighted n=842, Weighted N=12 214 485)a.
| Characteristics | No retinopathy | Mild NPR | Severe NPR/proliferative retinopathy | P-value |
|---|---|---|---|---|
| Unweighted, n | 541 | 195 | 106 | |
| Age (years) | 60.63±5.50 | 63.25±0.99 | 60.86±1.24 | 0.108 |
| Gender, n (%) | 0.006b | |||
| Male | 253 (43.2%) | 114 (56.9%) | 51 (51.8%) | |
| Female | 288 (56.8%) | 81 (43.1%) | 55 (48.2%) | |
| Ethnicity, n (%) | 0.004b | |||
| Non-Hispanic White | 231 (66.2%) | 82 (67.3%) | 26 (54.3%) | |
| Non-Hispanic Black | 141 (14.3%) | 57 (16.9%) | 48 (30.6%) | |
| Mexican American | 105 (7.5%) | 36 (7.3%) | 22 (10%) | |
| Other Hispanic | 47 (5.1%) | 16 (7.1%) | 8 (2.4%) | |
| Other | 17 (6.8%) | 4 (1.5%) | 2 (2.8%) | |
| Education, n (%) | 0.953 | |||
| Less than 9th grade | 106 (13.3%) | 50 (15.7%) | 22 (14.0%) | |
| Grades 9–12 | 244 (43.3%) | 81 (42.5%) | 49 (43.7%) | |
| College or above | 191 (43.4%) | 64 (41.9%) | 35 (42.3%) | |
| Poverty income ratio | 2.86±0.09 | 2.67±0.15 | 2.87±0.22 | 0.491 |
| Duration of diabetes (years) | 7.53±0.41 | 14.41±0.83 | 18.20±1.33 | 1.028E−8b |
| Smoking, n (%) | 0.090 | |||
| Current smoker | 83 (14.7%) | 39 (20.7%) | 11 (9.6%) | |
| Former smoker | 211 (38.8%) | 70 (33.9%) | 37 (29.6%) | |
| Non-smoking | 246 (46.4%) | 86 (45.4%) | 58 (60.8%) | |
| Overweight, n (%) | 0.942 | |||
| Yes | 467 (88.2%) | 196 (89.0%) | 90 (88.0%) | |
| No | 66 (11.8%) | 26 (11.0%) | 15 (12.0%) | |
| Hypertension, n (%) | 0.712 | |||
| Yes | 327 (89.2%) | 115 (88.0%) | 69 (83.8%) | |
| No | 44 (10.8%) | 19 (12.0%) | 9 (16.2%) | |
| Vitamin D deficiency, n (%) | 0.286 | |||
| Yes | 228 (36.6%) | 85 (43.5%) | 63 (49.0%) | |
| No | 279 (63.4%) | 92 (56.5%) | 39 (51.0%) | |
| HbA1C poor control, n (%) | 3.202 E−8b | |||
| Yes | 119 (33.1%) | 122 (65.3%) | 81 (71.6%) | |
| No | 342 (66.9%) | 73 (34.7%) | 25 (28.4%) | |
| HbA1C (%) | 6.78±0.07 | 7.64±0.15 | 8.21±0.24 | 6.328 E−7b |
| Triglyceride (mmol l−1) | 2.25±0.25 | 1.72±0.10 | 2.22±0.32 | 0.114 |
| Total cholesterol (mmol l−1) | 4.82±0.08 | 4.61±0.11 | 4.79±0.20 | 0.226 |
| HDL (mmol l−1) | 1.25±0.02 | 1.28±0.02 | 1.25±0.06 | 0.586 |
| LDL (mmol l−1) | 2.53±0.05 | 2.55±0.12 | 2.64±0.21 | 0.833 |
| Vitamin D supplement (mcg) | 12.08±0.60 | 14.47±2.61 | 13.78±3.39 | 0.682 |
| Calcium supplement (mg) | 410.89±39.94 | 371.33±51.49 | 477.54±119.91 | 0.730 |
Abbreviations: NHANES, National Health and Nutrition Examination Survey; NPR, non-proliferative retinopathy.
Values are mean±s.e. for continuous variables or unweighted counts (weighted %) for categorical variables. A P-value displays in scientific notation if P<0.0005.
a
Data are weighted according to the National Health and Nutrition Examination Survey protocol.
b
Significant difference among the 3 levels of retinopathy, P<0.05.