TABLE 1.
Candidate variables and baseline characteristics of the participants.
| Variables | Total | Robust | Pre-frail | Frail | P-value | P-value* | P-value** | P-value*** |
| Sex | 0.152 | 0.935 | 0.063 | 0.060 | ||||
| Male | 338 (64.1%) | 170 (65.1%) | 148 (65.5%) | 20 (50.0%) | ||||
| Female | 189 (35.9%) | 91 (34.9%) | 78 (34.5%) | 20 (50.0%) | ||||
| Age | 72.2 ± 5.0 | 71.8 ± 4.7 | 72.1 ± 5.1 | 75.2 ± 5.3 | < 0.001 | 0.452 | < 0.001 | < 0.001 |
| Race | 0.508 | 0.228 | 0.536 | 0.211 | ||||
| Mexican American | 46 (8.7%) | 23 (8.8%) | 22 (9.7%) | 1 (2.5%) | ||||
| Non-Hispanic Black | 36 (6.8%) | 14 (5.4%) | 20 (8.8%) | 2 (5.0%) | ||||
| Non-Hispanic White | 356 (67.6%) | 177 (67.8%) | 149 (65.9%) | 30 (75.0%) | ||||
| Other Hispanic | 73 (13.9%) | 37 (14.2%) | 29 (12.8%) | 7 (17.5%) | ||||
| Other race | 16 (3.0%) | 10 (3.8%) | 6 (2.7%) | 0 (0.0%) | ||||
| Education | 0.152 | 0.217 | 0.042 | 0.175 | ||||
| Non-received higher education | 312 (59.2%) | 170 (65.1%) | 148 (65.5%) | 20 (50.0%) | ||||
| Received higher education | 215 (40.8%) | 91 (34.9%) | 78 (34.5%) | 20 (50.0%) | ||||
| Income | 0.049 | 0.131 | 0.024 | 0.153 | ||||
| Earning less than $1000,000 | 485 (92.0%) | 234 (89.7%) | 211 (93.4%) | 40 (100.0%) | ||||
| Earning more than or equal to $1000,000 | 42 (8.0%) | 27 (10.3%) | 15 (6.6%) | 0 (0.0%) | ||||
| Smoking | < 0.001 | 0.001 | < 0.001 | 0.082 | ||||
| Every day | 74 (14.0%) | 20 (7.7%) | 43 (19.0%) | 11 (27.5%) | ||||
| Some days | 11 (2.1%) | 6 (2.3%) | 3 (1.3%) | 2 (5.0%) | ||||
| Not at all | 442 (83.9%) | 235 (90.0%) | 180 (79.6%) | 27 (67.5%) | ||||
| Alcohol use | 0.532 | 0.394 | 0.359 | 0.648 | ||||
| Yes | 431 (81.8%) | 218 (83.5%) | 182 (80.5%) | 31 (77.5%) | ||||
| No | 96 (18.2%) | 43 (16.5%) | 44 (19.5%) | 9 (22.5%) | ||||
| BMI (kg/M2) | 28.0 ± 5.3 | 27.2 ± 4.5 | 28.8 ± 5.6 | 28.3 ± 6.7 | 0.002 | 0.001 | 0.209 | 0.550 |
| Albumin, urine (μg/mL) | 75.4 ± 445.8 | 42.5 ± 172.2 | 65.9 ± 240.1 | 343.5 ± 1438.2 | < 0.001 | 0.559 | < 0.001 | < 0.001 |
| Creatinine, urine (mg/dL) | 113.1 ± 65.2 | 110.9 ± 64.2 | 114.5 ± 66.0 | 120.2 ± 67.2 | 0.647 | 0.543 | 0.403 | 0.614 |
| ALT (U/L) | 22.2 ± 18.9 | 21.3 ± 11.1 | 23.6 ± 26.1 | 20.4 ± 8.9 | 0.332 | 0.179 | 0.785 | 0.326 |
| AST (U/L) | 25.4 ± 15.3 | 24.6 ± 8.1 | 26.8 ± 21.5 | 23.1 ± 7.3 | 0.172 | 0.111 | 0.569 | 0.160 |
| GGT (U/L) | 27.3 ± 26.5 | 24.5 ± 22.8 | 29.7 ± 28.7 | 32.0 ± 33.7 | 0.047 | 0.029 | 0.092 | 0.608 |
| LDH (U/L) | 136.6 ± 27.4 | 136.0 ± 25.2 | 136.4 ± 30.1 | 141.0 ± 26.3 | 0.556 | 0.864 | 0.281 | 0.328 |
| ALP (U/L) | 70.3 ± 24.0 | 69.0 ± 24.8 | 70.2 ± 21.5 | 79.5 ± 29.8 | 0.034 | 0.557 | 0.009 | 0.024 |
| BUN (mmol/L) | 5.8 ± 2.5 | 5.6 ± 2.0 | 5.7 ± 2.4 | 7.4 ± 4.4 | < 0.001 | 0.545 | < 0.001 | < 0.001 |
| Total calcium (mmol/L) | 2.4 ± 0.1 | 2.4 ± 0.1 | 2.4 ± 0.1 | 2.4 ± 0.1 | 0.693 | 0.590 | 0.437 | 0.628 |
| Creatinine, serum (μmol/L) | 90.0 ± 42.5 | 86.3 ± 23.3 | 88.7 ± 27.6 | 121.9 ± 123.2 | < 0.001 | 0.525 | < 0.001 | < 0.001 |
| Glucose, serum (mmol/L) | 6.1 ± 1.9 | 6.0 ± 1.8 | 6.1 ± 1.9 | 6.7 ± 2.1 | 0.149 | 0.595 | 0.051 | 0.099 |
| Chloride (mmol/L) | 103.5 ± 3.3 | 103.7 ± 3.2 | 103.4 ± 3.1 | 103.4 ± 4.2 | 0.682 | 0.395 | 0.684 | 0.962 |
| Iron, refrigerated (μmol/L) | 15.9 ± 5.5 | 16.5 ± 5.5 | 15.7 ± 4.8 | 13.2 ± 8.0 | 0.001 | 0.092 | < 0.001 | 0.007 |
| Phosphorus (mmol/L) | 1.2 ± 0.2 | 1.2 ± 0.2 | 1.2 ± 0.2 | 1.2 ± 0.2 | 0.046 | 0.951 | 0.015 | 0.018 |
| Uric acid (μmol/L) | 352.0 ± 86.3 | 347.0 ± 83.8 | 355.7 ± 83.6 | 363.7 ± 113.7 | 0.364 | 0.269 | 0.254 | 0.587 |
| Sodium (mmol/L) | 139.6 ± 2.5 | 139.6 ± 2.6 | 139.6 ± 2.5 | 139.9 ± 1.9 | 0.681 | 0.767 | 0.383 | 0.480 |
| Potassium (mmol/L) | 4.1 ± 0.4 | 4.1 ± 0.4 | 4.1 ± 0.4 | 4.2 ± 0.5 | 0.596 | 0.554 | 0.512 | 0.336 |
| Albumin, serum (g/L) | 139.6 ± 2.5 | 41.9 ± 2.7 | 41.8 ± 2.8 | 40.8 ± 3.6 | 0.057 | 0.549 | 0.017 | 0.040 |
| Globulin, serum (g/L) | 29.2 ± 4.9 | 29.1 ± 4.7 | 29.2 ± 4.8 | 30.1 ± 5.8 | 0.426 | 0.828 | 0.193 | 0.241 |
| HDL-Cholesterol (mmol/L) | 1.4 ± 0.4 | 1.5 ± 0.4 | 1.4 ± 0.4 | 1.4 ± 0.3 | 0.142 | 0.057 | 0.321 | 0.980 |
| Triglyceride (mmol/L) | 1.4 ± 0.7 | 1.3 ± 0.6 | 1.5 ± 0.8 | 1.4 ± 0.7 | 0.071 | 0.022 | 0.588 | 0.495 |
| LDL-cholesterol (mmol/L) | 2.8 ± 1.0 | 2.9 ± 1.0 | 2.7 ± 1.0 | 2.4 ± 0.9 | 0.007 | 0.045 | 0.004 | 0.078 |
| 25-hydroxyvitamin D3 (nmol/L) | 65.7 ± 28.0 | 70.0 ± 27.9 | 62.2 ± 27.5 | 57.1 ± 27.1 | 0.001 | 0.002 | 0.006 | 0.284 |
% for: Sex Race Education Income Smoking Alcohol-use. P-value was calculated by Chi-square test. Mean ± SD for: Age BMI (kg/m2) Albumin, urine (μg/mL); Creatinine, urine (mg/dL); ALT (U/L); AST (U/L); ALP (U/L); BUN (mmol/L); Total calcium (mmol/L); Creatinine, serum (μmol/L) GGT (U/L); Glucose, serum (mmol/L); Iron, refrigerated (μmol/L) LDH (U/L); Phosphorus (mmol/L); Uric acid (μmol/L); Potassium (mmol/L) Chloride (mmol/L); Globulin, serum (g/L); HDL-Cholesterol (mmol/L); Triglyceride (mmol/L); LDL-cholesterol (mmol/L) Albumin, serum (g/L) Sodium (mmol/L); 25-hydroxyvitamin D3 (nmol/L). P-value was calculated by weighted linear regression model. P-value*: P-value for Robust-Pre-frail based on Fisher’s Least Significant Difference (LSD) post hoc test. P-value**: P-value for Robust-Frail based on Fisher’s Least Significant Difference (LSD) post hoc test. P-value***: P-value for Pre-frail-Frail based on Fisher’s Least Significant Difference (LSD) post hoc test. BMI, body mass index; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; BUN, blood urea nitrogen; GGT, gamma glutamyl transferase; LDH, lactate dehydrogenase; HDL, high-density lipoprotein; LDL, low-density lipoprotein.