Table 1.
Characteristics* by Incident AMD Status and Tertiles of 25(OH)D Concentrations (N = 1225): the ARIC Study
|
Characteristics |
N |
AMD Incidence From Visit 3 to Visit 5 |
Tertiles of 25(OH)D |
R
(P
Value)† |
|||
|
No (n
= 1086) |
Yes (n
= 139) |
Tertile 1 (10.8–53.6) |
Tertile 2 (53.7–69.3) |
Tertile 3 (69.4–173) |
|||
| Season-adjusted serum 25(OH)D, nM, mean (SD) | 1225 | 63 (20.3) | 64 (18.7) | 43 (8.7) | 62 (4.6) | 85 (14.2)‡ | NA |
| Prevalent early AMD at visit 3, n (%) | 19 | 14 (1) | 5 (4)‡ | 5 (1) | 8 (2) | 6 (2) | – |
| Incident AMD, early or late, n (%) | 139 | 0 (0) | 139 (100)‡ | 47 (12) | 48 (12) | 44 (11) | – |
| Demographics | |||||||
| Age, y, mean (SD) | 1225 | 55 (5.0) | 58 (4.9)‡ | 55 (4.9) | 56 (4.9) | 56 (5.3)‡ | 0.07 (0.016) |
| Sex, n (% women) | 711 | 633 (58) | 78 (56) | 274 (67) | 233 (57) | 204 (50)‡ | – |
| Race, n (% Caucasian) | 1029 | 896 (83) | 133 (96)‡ | 272 (67) | 366 (90) | 391 (96)‡ | – |
| Field center, n (%) | – | ||||||
| Forsyth County, NC | 135 | 116 (11) | 19 (14)‡ | 39 (10) | 43 (11) | 53 (13)‡ | |
| Jackson, MS | 185 | 179 (17) | 6 (4) | 127 (31) | 41 (10) | 17 (4) | |
| Minneapolis, MN | 430 | 384 (35) | 46 (33) | 117 (29) | 153 (37) | 160 (39) | |
| Washington County, MD | 475 | 407 (37) | 68 (49) | 125 (30) | 172 (42) | 178 (44) | |
| Education, visit 1§, n (%) | – | ||||||
| Basic or 0 years | 144 | 128 (12) | 16 (12) | 55 (14) | 51 (12) | 38 (9) | |
| Intermediate | 545 | 482 (44) | 63 (45) | 168 (41) | 178 (44) | 199 (49) | |
| Advanced | 536 | 476 (44) | 60 (43) | 185 (45) | 180 (44) | 171 (42) | |
| Health and lifestyle characteristics | |||||||
| Health insurance, n (% yes) | 1161 | 1031 (95) | 130 (94) | 377 (92) | 393 (96) | 391 (96)‡ | – |
| Smoking status, n (%) | – | ||||||
| Current | 178 | 160 (15) | 18 (13)‡ | 67 (16) | 54 (13) | 57 (14)‡ | |
| Former | 463 | 396 (36) | 67 (48) | 123 (30) | 154 (38) | 186 (46) | |
| Never | 584 | 530 (49) | 54 (39) | 218 (54) | 201 (49) | 165 (40) | |
| Drinking status, n (%) | – | ||||||
| Current | 814 | 716 (66) | 98 (71) | 239 (59) | 280 (68) | 295 (72)‡ | |
| Former | 178 | 157 (14) | 21 (15) | 65 (16) | 52 (13) | 61 (15) | |
| Never | 233 | 213 (20) | 20 (14) | 104 (25) | 77 (19) | 52 (13) | |
| Waist circumference, cm, mean (SD) | 1225 | 96 (13.7) | 98 (11.8) | 99 (15.4) | 97 (12.4) | 93 (12.0)‡ | −0.14 (<0.001) |
| Waist to hip ratio, mean (SD) | 1225 | 0.91 (0.08) | 0.93 (0.07)‡ | 0.91 (0.08) | 0.92 (0.08) | 0.91 (0.08)‡ | −0.01 (0.713) |
| BMI category, kg/m2, n (%) | −0.20 (<0.001) | ||||||
| Under/normal weight (<25 kg/m2) | 378 | 341 (31) | 37 (27) | 108 (27) | 108 (26) | 162 (40)‡ | |
| Overweight (25–30 kg/m2) | 536 | 468 (43) | 68 (49) | 164 (40) | 192 (47) | 180 (44) | |
| Obese (≥30 kg/m2) | 311 | 277 (26) | 34 (24) | 136 (33) | 109 (27) | 66 (16) | |
| Physical activity index visits 1 and 3, mean (SD) | 1179 | 3.1 (1.3) | 2.8 (1.4)‡ | 2.8 (1.3) | 3.0 (1.3) | 3.3 (1.2)‡ | 0.15 (<0.001) |
| Diastolic blood pressure, mm Hg, mean (SD) | 1225 | 72 (9.5) | 72 (9.4) | 72 (9.3) | 72 (9.7) | 72 (9.6) | 0.004 (0.887) |
| Systolic blood pressure, mm Hg, mean (SD) | 1225 | 118 (16.1) | 118 (14.7) | 118 (16.0) | 118 (15.0) | 118 (16.9) | −0.02 (0.497) |
| Hypertension, n (% yes)‖ | 305 | 273 (25) | 32 (23) | 118 (29) | 101 (25) | 86 (21)‡ | – |
| Total cholesterol, mg/dL, mean (SD) | 1222 | 208 (37.4) | 212 (38.1) | 208 (37.5) | 212 (40.3) | 206 (34.2) | 0.01 (0.780) |
| HDL, mg/dL, mean (SD) | 1218 | 51 (16.6) | 50 (14.8) | 51 (15.9) | 50 (16.1) | 51 (17.1) | −0.01 (0.786) |
| LDL, mg/dL, mean (SD) | 1198 | 131 (33.9) | 136 (35.1) | 132 (34.7) | 134 (36.0) | 129 (31.1) | −0.02 (0.511) |
| Triglycerides, mg/dL, mean (SD) | 1222 | 133 (84.2) | 132 (61.0) | 125 (76.5) | 140 (91.2) | 132 (76.6)‡ | 0.07 (0.019) |
| Glucose, mg/dL, mean (SD) | 1225 | 106 (27.0) | 104 (15.5) | 107 (28.4) | 107 (31.9) | 102 (13.8)‡ | −0.12 (<0.001) |
| Hormone use, among females, n (%) | – | ||||||
| Current estrogen user | 132 | 120 (22) | 12 (18) | 47 (20) | 33 (17) | 52 (28)‡ | |
| Current estrogen and progestin user | 93 | 82 (15) | 11 (16) | 23 (10) | 27 (14) | 43 (24) | |
| Never used hormones | 363 | 322 (59) | 41 (60) | 161 (67) | 125 (64) | 77 (42) | |
| Former hormone user | 29 | 25 (4) | 4 (6) | 9 (3) | 9 (5) | 11 (6) | |
Bolded values represent statistically significant results at a P value of <0.05 or smaller. NA, not applicable.
Characteristics assessed at visit 2 unless otherwise noted.
Spearman correlation coefficient and associated P value for the correlation between season-adjusted serum 25(OH)D and the respective continuous variable. Values are not shown (–) for categorical variables.
P value < 0.05 For continuous variables, t-tests or ANOVAs were used to compare means of characteristics between those with and without any incident AMD or across tertiles of 25(OH)D, respectively. For categorical variables, χ2 tests were used to compare proportions of characteristics between those with and without any incident AMD or across tertiles of 25(OH)D.
Education defined as basic or 0 years (≤11 years or less, i.e., high school with no degree or less), intermediate (12–16 years, i.e., high-school graduate or vocational school), or advanced (17–21 years, i.e., college or higher).
Average systolic blood pressure ≥140 mm Hg, or diastolic ≥90 mm Hg, or high blood pressure medication use in the past 2 weeks.