Table 1.
Baseline Characteristics by BMI Sextiles (World Health Organization Classification)
| Characteristic | BMI, kg/m2 |
P | |||||
|---|---|---|---|---|---|---|---|
| <18.5 | 18.5-<25 | 25-<30 | 30-<35 | 35-<40 | ≥40 | ||
| Patients | 1,059 (1.1%) | 20,357 (21.2%) | 33,212 (34.5%) | 22,996 (23.9%) | 10,945 (11.4%) | 7,578 (7.9%) | <0.001 |
| Age, y | 43.3 (22.8) | 48.7 (20.0) | 52.0 (16.5) | 51.4 (15.2) | 49.2 (14.6) | 45.5 (14.1) | <0.001 |
| Women | 773 (73.0%) | 13,231 (65.0%) | 19,842 (59.7%) | 14,698 (63.9%) | 7,671 (70.1%) | 5,649 (74.5%) | <0.001 |
| Race/ethnicity | |||||||
| Black | 332 (31.3%) | 5,879 (28.9%) | 10,670 (32.1%) | 8,369 (36.4%) | 4,264 (39.0%) | 3,186 (42.0%) | <0.001 |
| Hispanic | 320 (30.2%) | 6,687 (32.9%) | 12,106 (36.5%) | 8,535 (37.1%) | 3,965 (36.2%) | 2,722 (35.9%) | |
| Asian/other race | 249 (23.5%) | 4,668 (22.9%) | 6,623 (19.9%) | 3,818 (16.6%) | 1,679 (15.3%) | 1,031 (13.6%) | |
| White | 158 (14.9%) | 3,123 (15.3%) | 3,813 (11.5%) | 2,274 (9.9%) | 1,037 (9.5%) | 639 (8.4%) | |
| Insurance | |||||||
| Commercial | 586 (55.3%) | 12,112 (59.5%) | 20,570 (61.9%) | 14,445 (62.8%) | 6,877 (62.8%) | 4,695 (62.0%) | <0.001 |
| Medicare | 180 (17.0%) | 3,418 (16.8%) | 5,264 (15.8%) | 3,255 (14.2%) | 1,345 (12.3%) | 749 (9.9%) | |
| Medicaid | 237 (22.4%) | 3,795 (18.6%) | 5,763 (17.4%) | 4,217 (18.3%) | 2,197 (20.1%) | 1,799 (23.7%) | |
| Self-pay | 56 (5.3%) | 1,032 (5.1%) | 1,615 (4.9%) | 1,079 (4.7%) | 526 (4.8%) | 335 (4.4%) | |
| Median income by zip code | |||||||
| <$30,000 | 193 (18.2%) | 3,585 (17.6%) | 6,528 (19.7%) | 4,844 (21.1%) | 2,463 (22.5%) | 2,000 (26.4%) | <0.001 |
| $30,000-$49,999 | 476 (45.0%) | 8,965 (44.0%) | 15,345 (46.2%) | 10,897 (47.4%) | 5,187 (47.4%) | 3,452 (45.6%) | |
| $50,000-$69,999 | 164 (15.5%) | 3,436 (16.9%) | 5,333 (16.1%) | 3,468 (15.1%) | 1,598 (14.6%) | 949 (12.5%) | |
| $70,000 | 84 (7.9%) | 1,710 (8.4%) | 2,344 (7.1%) | 1,416 (6.2%) | 635 (5.8%) | 374 (4.9%) | |
| Not specified | 142 (13.4%) | 2,661 (13.1%) | 3,662 (11.0%) | 2,371 (10.3%) | 1,062 (9.7%) | 803 (10.6%) | |
| Baseline diagnoses | |||||||
| Hypertension | 261 (24.6%) | 7,084 (34.8%) | 15,715 (47.3%) | 12,430 (54.1%) | 6,253 (57.1%) | 4,306 (56.8%) | <0.001 |
| Diabetes | 90 (8.5%) | 3,236 (15.9%) | 7,872 (23.7%) | 6,989 (30.4%) | 3,761 (34.4%) | 2,745 (36.2%) | <0.001 |
| Coronary artery disease | 64 (6.0%) | 1,382 (6.8%) | 2,755 (8.3%) | 1,892 (8.2%) | 842 (7.7%) | 495 (6.5%) | <0.001 |
| Baseline laboratory values | |||||||
| eGFR,a mL/min/1.73 m2 | 101.3 (29.5) | 92.5 (25.6) | 88.4 (23.3) | 88.5 (23.3) | 90.9 (23.7) | 95.6 (23.9) | <0.001 |
| eGFR < 60 mL/min/1.73 m2 | 98 (9.3%) | 2,106 (10.4%) | 3,642 (11.0%) | 2,476 (10.8%) | 1,030 (9.4%) | 552 (7.3%) | <0.001 |
| Serum bicarbonate,b mEq/L | 25.4 (2.6) | 25.6 (2.6) | 25.6 (2.5) | 25.5 (2.6) | 25.3 (2.6) | 25.4 (2.6) | <0.001 |
| Serum urea nitrogen,c mg/dL (n = 86,673) | 14.2 (6.0) | 14.8 (6.1) | 15.0 (5.6) | 14.9 (5.7) | 14.7 (5.8) | 14.2 (5.6) | <0.001 |
Note: Values expressed as number (percent) or continuous variables as mean (standard deviation).
Abbreviations: BMI, body mass index; eGFR, estimated glomerular filtration rate.
a
Calculated using Chronic Kidney Disease Epidemiology Collaboration creatinine equation.
b
Conversion to SI units (mmol/L): 1 mEq/L = 1 mmol/L.
c
Conversion to SI units (mmol/L): 1 mg/dL = 0.357 mmol/L.