Table 1.
Baseline characteristics of the participants by the quartile of MMA levels
| Total (n = 573) | Quartile 1 (n = 143) | Quartile 2 (n = 146) | Quartile 3 (n = 142) | Quartile 4 (n = 142) | P | |
|---|---|---|---|---|---|---|
| Age (year) | 71 (65–80) | 67 (63–72) | 72 (64.75-80) | 73 (66–80) | 74 (67.75-80) | < 0.001 |
| Male (%) | 52.4 | 53.8 | 54.1 | 52.1 | 49.3 | 0.259 |
| Education | ||||||
| Less than 9th grade (%) | 16.4 | 16.8 | 16.4 | 14.8 | 17.6 | |
| 9 − 11th grade (%) | 17.1 | 14 | 17.1 | 19 | 18.3 | |
| High school graduate (%) | 24.6 | 26.6 | 23.3 | 22.5 | 26.1 | |
| College or AA degree (%) | 25 | 25.9 | 24 | 25.4 | 24.6 | |
| College graduate or above (%) | 16.9 | 16.8 | 19.2 | 18.3 | 13.4 | |
| Smoke (%) | 37 | 40.7 | 34.5 | 36 | 36.6 | < 0.001 |
| Drink (%) | 64.2 | 69.6 | 60.6 | 62.5 | 64.2 | < 0.001 |
| Hypertension (%) | 75.3 | 74.8 | 78.1 | 70.4 | 77.5 | < 0.001 |
| Diabetes (%) | 41.2 | 44.1 | 39 | 40.1 | 40.8 | < 0.001 |
| BMI (kg/m2) | 28.12 (24.25–32.65) | 28.05 (24.75–32.3) | 28.66 (25.41–33.29) | 27.59 (23.6-32.47) | 28.17 (24.38–32.5) | 0.295 |
| GNRI | 104.18 (100.1-107.29) | 105.53 (101.87-108.54) | 105.4 (102.66-107.43) | 104.32 (100.87-107.31) | 103.34 (99.72-106.98) | 0.006 |
| < 82 (%) | 10.5 | 2.1 | 3.4 | 4.2 | 4.9 | |
| 82–92 (%) | 1.1 | 0.7 | 2.8 | 1.4 | ||
| 92–98 (%) | 5.8 | 6.3 | 2.7 | 4.2 | 12 | |
| > 98 (%) | 82.5 | 91.6 | 93.2 | 88.7 | 81.7 | |
| Hemoglobin (g/dl) | 13.5 (12.5–14.5) | 13.7 (13-14.7) | 13.61 ± 1.42 | 13.45 ± 1.54 | 13.09 ± 1.82 | 0.001 |
| Anemia (%) | 10.5 | 4.2 | 7.5 | 12 | 17.6 | 0.001 |
| RDW (%) | 13.7 (13-14.6) | 13.5 (12.8–14.3) | 13.6 (13-14.4) | 13.6 (13-14.53) | 14.05 (13.3–14.9) | 0.002 |
| Albumin (g/l) | 42 (39–43) | 42 (40–44) | 42 (40–43) | 41 (39–43) | 41 (38–43) | 0.013 |
| Cholesterol (mmol/l) | 4.66 (3.91–5.61) | 4.68 (3.83–5.82) | 4.62 (3.85–5.72) | 4.66 (4.01–5.33) | 4.79 ± 1.19 | 0.945 |
| Triglyceride (mmol/l) | 1.55 (1.04–2.43) | 1.49 (0.85–2.41) | 1.59 (1-2.39) | 1.52 (1.11–2.44) | 1.62 (1.12–2.44) | 0.378 |
| BUN (mmol/l) | 11 (6.07-17) | 8.57 (4.64-13) | 9 (5.71-16) | 12 (7.5–19.5) | 15 (8.48-25) | < 0.001 |
| Creatinine (mmol/l) | 90.17 (71.6-117.57) | 74.26 (63.65–87.52) | 89.73 (72.49-108.95) | 99.89 (79.12-123.76) | 110.06 (81.11-179.23) | < 0.001 |
| Uric acid (mg/dl) | 5.9 (4.9–7.2) | 5.4 (4.6–6.6) | 5.8 (5–7) | 5.9 (5.1–7.2) | 6.45 (4.9–7.8) | < 0.001 |
| Vitamin D3 (nmol/l) | 61.3 (41.64–85.05) | 58.93 (39.7-77.94) | 65.27 (41.72–85.45) | 64.75 (46.15–88.78) | 58.45 (38.9–89.9) | 0.178 |
| Vitamin B12 (pg/ml) | 556 (386–775) | 638 (403.5–850) | 617 (462–812) | 552.5 (384-780.25) | 462 (318.5–643) | < 0.001 |
| Folate (ng/ml) | 549.5 (404–787) | 498.5 (369.75-671.25) | 596 (415–848) | 589.5 (415.5–799) | 556 (422.5–830) | 0.021 |
| CERAD-WL | 18 (14–21) | 19 (14–22) | 18 (14.75-21) | 17 (14–21) | 16.5 (13–20) | 0.022 |
| CERAD-DR | 6 (4–7) | 6 (4–7) | 6 (4–7) | 5 (3–7) | 5 (3–7) | 0.181 |
| Animal frequency test | 15 (11–18) | 15.31 ± 5.35 | 15 (11.75-18) | 15 (11–19) | 14 (10–18) | 0.047 |
| DSST | 38 (24–49) | 38.97 ± 18.12 | 39.36 ± 18.18 | 35.73 ± 19.41 | 32 (19.75-44) | 0.001 |
| Methylmalonic acid | 194 (141.5–283) | 115 (100–129) | 168 (153–183) | 221.5 (204-244.25) | 397.5 (329.5-536.5) | < 0.001 |
AF, Animal Fluency test; CERAD-WL, Consortium to Establish a Registry for Alzheimer’s Disease Word Learning test; CERAD-DR, Consortium to Establish a Registry for Alzheimer’s Disease Delayed Recall test; DSST, Digit Symbol Substitution test; CKD, chronic kidney disease; BMI, body mass index; GNRI, geriatric nutritional risk index; RDW, red blood cell distribution width; BUN, blood urea nitrogen