Table 2.
Baseline characteristics of 641 Health ABC participants with chronic kidney disease
| All | Bone turnover | ||
|---|---|---|---|
| Non-low | Lowa | ||
| No. | 641 | 538 | 103 |
| Age, mean (SD), y | 75 (3) | 75 (3) | 76 (3) |
| Female, n (%) | 313 (49) | 266 (49) | 47 (46) |
| Race | |||
| White, n (%) | 402 (63) | 332 (62) | 70 (68) |
| Black, n (%) | 239 (37) | 206 (38) | 33 (32) |
| Site | |||
| Memphis, n( %) | 319 (50) | 269 (50) | 50 (49) |
| Pittsburgh, n (%) | 322 (50) | 269 (50) | 53 (52) |
| Education | |||
| < High school, n (%) | 150 (24) | 126 (24) | 24 (23) |
| High school graduate, n (%) | 212 (33) | 176 (33) | 36 (35) |
| Postsecondary, n (%) | 277 (43) | 234 (44) | 43 (42) |
| SBP, mean (SD), mm Hg | 136 (23) | 137 (24) | 133 (19) |
| DBP, mean (SD), mm Hg | 70 (12) | 71 (12) | 68 (10) |
| Current smoker, n (%) | 74 (12) | 58 (10) | 18 (18) |
| BMI, mean (SD), kg/m2 | 28.1 (4.9) | 28.3 (5.0) | 27.0 (4.4) |
| Current drinker, n (%) | 293 (46) | 240 (45) | 53 (52) |
| Physical activity, median (25th, 75th percentile), kcal/kg/wk | 0 (0, 5) | 0 (0, 5) | 0 (0, 7.5) |
| Diabetes, n (%) | 283 (44) | 239 (44) | 44 (43) |
| Hypertension, n (%) | 538 (84) | 460 (86) | 78 (76) |
| Antihypertensive use, n (%) | 444 (69) | 385 (72) | 59 (57) |
| Vitamin D supplement, n (%) | 53 (8) | 46 (9) | 7 (7) |
| Any osteoporosis drugs, n (%) | 0 | 0 | 0 |
| Diuretics use, n (%) | 260 (41) | 231 (43) | 29 (28) |
| eGFR, mean (SD), mL/min/1.73 m2 | 48 (10) | 47 (10) | 53 (6) |
| UACR, median (25th, 75th percentile), mg/g | 11 (5, 37) | 12 (5, 38) | 9 (5, 35) |
| Prevalent osteoporosis | |||
| Definite, n (%) | 16 (3) | 13 (3) | 3 (3) |
| Possible, n (%) | 27 (4) | 19 (4) | 8 (8) |
| Hip BMD score < –2.5, n (%) | 37 (6) | 31 (6) | 6 (6) |
| 25-hydroxyvitamin D, mean (SD) | 25.7 (12.4) | 25.4 (12.8) | 27.1 (10.5) |
| FGF-23, median (25th, 75th percentile) | 55 (42, 73) | 60 (45, 77) | 42 (35, 49) |
| α-Klotho, median (25th, 75th percentile) | 589 (457, 756) | 544 (432, 714) | 756 (663, 873) |
| PTH, median (25th, 75th percentile) | 39 (29, 56) | 43 (32, 61) | 27 (21, 33) |
Abbreviations: BMD, bone mineral density; BMI, body mass index; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; FGF, fibroblast growth factor; Health ABC, Health Aging and Body Composition Study; PTH, parathyroid hormone; SBP, systolic blood pressure; UACR, urine albumin-to-creatinine ratio.
aLow bone turnover = low FGF-23, high α-Klotho, and low PTH.