Table 1.
Association of A1C levels with 25(OH)D status and other variables*
| Overall | Age group (years) |
Self-reported history of diabetes |
||||
|---|---|---|---|---|---|---|
| 18–34 | 35–74 | ≥75 | Yes | No | ||
| n | 9,773 | 3,525 | 5,138 | 1,110 | 899 | 8,874 |
| Vitamin D (ng/ml) | −0.0016 (0.08) | 0.0008 (0.40) | −0.0035 (0.0045) | 0.0012 (0.63) | 0.0013 (0.90) | −0.0014 (0.0282) |
| Race/ethnicity | ||||||
| Black, non-Hispanic | 0.2169 (<0.0001) | 0.1440 (<0.0001) | 0.2825 (<0.0001) | 0.0782 (0.28) | 0.7571 (<0.0001) | 0.1607 (<0.0001) |
| Mexican-American | 0.2331 (<0.0001) | 0.1416 (0.0002) | 0.3245 (<0.0001) | 0.1817 (0.0074) | 0.7937 (<0.0001) | 0.1802 (<0.0001) |
| Other Hispanic | 0.2687 (0.0009) | 0.0570 (0.34) | 0.3817 (0.0003) | 0.6067 (0.16) | 0.9423 (0.15) | 0.1431 (0.0029) |
| Other race† | 0.1101 (0.0009) | 0.1461 (0.0008) | 0.0719 (0.08) | 0.3299 (0.0102) | −0.1996 (0.31) | 0.1334 (<0.0001) |
| Non-Hispanic Caucasian | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
| Female‡ | −0.0634 (0.0001) | −0.0896 (0.0002) | −0.0569 (0.0086) | −0.0062 (0.83) | −0.0999 (0.51) | −0.0597 (<0.0001) |
| BMI (kg/m2) | 0.0146 (<0.0001) | 0.0100 (<0.0001) | 0.0150 (<0.0001) | 0.0145 (0.0067) | −0.0095 (0.36) | 0.0159 (<0.0001) |
| Self-reported history of diabetes§ | 1.6237 (<0.0001) | 2.3946 (<0.0001) | 1.6397 (<0.0001) | 1.0802 (<0.0001) | N/A | N/A |
| PTH (ng/ml) | −0.0019 (0.0002) | −0.0004 (0.45) | −0.0028 (0.0002) | <−0.0001 (0.95) | −0.0085 (<0.0001) | −0.0007 (0.0176) |
| Age (years) | 0.0101 (<0.0001) | 0.0096 (<0.0001) | 0.0105 (<0.0001) | 0.0044 (0.46) | −0.0164 (0.0037) | 0.0110 (<0.0001) |
| Vigorous physical activity in last 30 days‖ | −0.0272 (0.06) | −0.0057 (0.75) | −0.0387 (0.07) | −0.1427 (0.0137) | −0.1091 (0.71) | −0.0242 (0.0366) |
| Dietary supplement¶ | −0.0850 (<0.0001) | −0.0461 (0.05) | −0.1121 (<0.0001) | −0.0569 (0.18) | −0.4260 (0.0073) | −0.0591 (0.0006) |
Data are parameter estimates (P values). Note: Self-reported history of diabetes means that the participant answered “yes” to the question, “Have you ever been told by a doctor that you have diabetes or sugar diabetes?” or reported current use of insulin or an oral antihyperglycemic medication.
*Model: A1C = β1 25(OH)D + β2 race + β3 sex + β4 BMI + β5 diabetes + β6 PTH + β7 age + β8 physical activity + β9 dietary supplement use.
†Including “multi-racial”.
‡Versus male;
§versus no history;
‖yes versus no;
¶versus no dietary supplement use. N/A, not applicable.