Table 1.
Baseline Characteristics of National Health and Nutrition Examination Survey (NHANES) III Participants with Chronic Kidney Disease Stages 3 or 4, Overall and by Race/Ethnicity
| Characteristic | All (n=1123) % |
Non-Hispanic Blacks (n=351) % |
Non-Hispanic Whites (n=772) % |
P-value |
|---|---|---|---|---|
| Mean age in years (SD) | 73.3 (11.8) | 68.01 (10.2) | 74.7 (11.2) | 0.04 |
| 20-49 | 3.9 | 6.2 | 3.4 | |
| 50-70 | 27.4 | 48.0 | 22.0 | |
| >70 | 68.7 | 45.8 | 74.6 | |
| Male sex | 42.9 | 47.5 | 41.8 | 0.15 |
| *Poverty Income Ratio | <0.0001 | |||
| ≤1 | 18.1 | 40.7 | 12.3 | |
| >1 to ≤2 | 32.3 | 29.9 | 32.8 | |
| >2 to ≤3 | 19.7 | 14.7 | 21.0 | |
| >3 to ≤4 | 13.7 | 9.0 | 14.9 | |
| >4 | 16.2 | 5.6 | 19.0 | |
| Level of Education | <0.0001 | |||
| High School or less | 50.9 | 68.8 | 46.4 | |
| Some College | 37.1 | 26.6 | 39.8 | |
| College or greater | 11.9 | 4.6 | 13.8 | |
| Diabetes (yes) | 18.4 | 33.3 | 14.6 | 0.0001 |
| Hypertension (yes) | 80.4 | 89.3 | 78.1 | 0.001 |
| Estimated GFR, median in ml/min per 1.73m2 (IQR) | 50.6 (43.9-55.5) | 50.1 (41.0-55.3) | 50.8 (44.6-55.5) | 0.02 |
| Albuminuria (≥30 mg/g) | 30.4% | 46.3% | 26.3% | 0.03 |
| Total Calories >2000 Kilocalories/day | 20.8% | 15.3% | 22.2% | 0.06 |
| Potential Renal Acid Load, median in mEq/day (IQR) | 46.3 (34.7-58.4) | 50.4 (39.7-66.8) | 43.9 (32.3-56.0) | 0.001 |
| Body Mass Index, median in kg/m2 (IQR) | 27.4 (24.1-30.9) | 27.8 (25.2-31.6) | 26.8 (23.9-30.4) | 0.05 |
| Body Surface Area, median in m2 (IQR) | 1.86 (1.69-2.04) | 1.95 (1.71-2.07) | 1.83 (1.67-1.99) | 0.05 |
| Net Acid Excretion, median in mEq/day (IQR) | 46.3 (34.6-58.4) | 50.9 (40.4-66.8) | 44.2 (31.9-56.9) | 0.007 |
*
Chronic kidney disease defined using Modification of Diet in Renal Disease study equation to estimate glomerular filtration rate. Poverty income ratio is the ratio of family income to federal poverty threshold. Hypertension was defined by self-report, average systolic blood pressure ≥140 or average diastolic blood pressure ≥90 mmHg, or use of medications. Diabetes was defined by self-report or measured hemoglobin A1c ≥6.5%.
Abbreviations: SD, standard deviation; GFR, glomerular filtration rate; IQR, interquartile range