Table 6. Studies Included in Highest-Scoring Systematic Reviews, Sorted by Length of Observation Period.
| Author, Year (Location) | No. of Subjects (Dementia Cases) | Mean Age (Years) at Baseline (SD) | Mean Baseline B12 (SD) | Mean Baseline Hcy (SD) | Hcy as a Predictor for Dementia (Adjusted) (95% CI) | Hcy as a Predictor for AD (Adjusted) (95% CI) | Adjustment Factors | Obs. Period (Years) |
|---|---|---|---|---|---|---|---|---|
| Zylberstein et al, 2011 (33) (Sweden) | 1,368 (151) | 46.8 (no SD) (all women) | 397 pmol/L (138) | 11.8 μmol/L (4.6) | Highest vs lowest Hcy quintile: HR, 1.7 (1.1–2.6) |
Highest vs lowest Hcy quintile: HR, 2.13 (1.22–3.73) |
Age, creatinine, vitamin B12, education, and other risk factors | 30 |
| Seshadri et al, 2002 (34) (USA) | 1,092 (111) | Men 76 (5) Women 77 (6) |
416 pg/mL (209) | 13.1 μmol/L (6.3) | Hcy as a continuous variable: RR, 1.3 (1.1–1.5) |
Hcy as a continuous variable: RR 1.4 (1.1–1.7) |
Age, sex | 8 |
| Kivipelto et al, 2009 (35) (Sweden) | 228 (83) | 81.0 (4.6) | 317 pmol/L (138) | 18.6 μmol/L (10.7) | Hcy as a continuous variable: RR, 1.01 (1.00–1.02) |
Hcy as a continuous variable: RR, 1.01 (1.00–1.03) |
Age, sex, education | 6.7 |
| Nurk et al, 2005 (36) (Norway) | 2,189 (235) | 72.0 (no SD) at follow-up, all patients were eligible between 65–67 years | 347 pmol/L (341–354) | 11.5 μmol/L (11.3–11.6) | Highest vs lowest Hcy quintile: OR, 2.34 (1.39–3.91) |
NR | Sex, APOE genotype, education, CVD, HBP, depression score | 6 |
| Luchsinger et al, 2004 (37) (USA) | 679 (109) | 76.2 (5.7) | NR | Cut-off value: > 15.6 μmol/L | NR | Highest vs lowest Hcy quartile: HR, 1.4 (0.8–2.4) |
Age, sex, education, APOE genotype | 4.7 |
| Haan et al, 2007 (38) (USA) | 1,779 (62) | 60–101 years (mean NR) | 334 pmol/L (150) | 10.8 μmol/L (6.5) | Highest vs lowest Hcy tertile: HR, 2.39 (1.11–5.16) |
NR | Vitamin B12, education | 4.5 |
| Ravaglia et al, 2005 (39) (Italy) | 816 (112) | 73.6 (6.3) | NR | 259 pmol/L (95% CI, 94–708) | Hcy >15 μmol/L: HR, 2.08 (1.31–3.30) |
Hcy >15 μmol/L: HR, 2.11 (1.19–3.76) |
Age, sex, education, APOE genotype, stroke, creatinine, folate, B12 | 4 |
| Wang et al, 2001 (40) (Sweden) | 370 (78) | >75 (mean NR) | Cut-off value: B12 < 150 pmol/L |
NR | Vitamin B12: RR, 1.3 (0.7–2.3) |
Vitamin B12: RR, 1.6 (0.9–2.8) |
Age, sex, education | 3 |
| Kalmijn et al, 1999 (41) (Nether-lands) | 702 (110) | 67.7 (7.1) | NR | 15.6 μmol/L (SE, 0.35) | Highest vs lowest Hcy tertile: OR, 1.30 (0.50–3.38) |
NR | Age, sex, education | 2.6 |
| Kim et al, 2008 (42) (South Korea) | 518 (45) | 71.6 (4.9) | 382 pmol/L (148) | 12.3 μmol/L (5.2) | Highest vs lowest Hcy quintile: OR, 1.10 (0.86–1.40) |
NR | Age, sex, education | 2.4 |
| Rowan et al, 2007 (43) (UK) | 126 (26) | 79.4 (IQR, 77.3–82.8) post-stroke | 264 pmol/L (169) | 16.0 μmol/L (5.1) | Unclear if it was adjusted Hcy as a continuous variable: OR, 1.04 (0.96–1.14) |
NR | N/A | 2 |
Abbreviations: APOE, apolipoprotein E; CI, confidence interval; CVD, cardiovascular disease; Hcy, homocysteine; HBP, high blood pressure; HR, hazard ratio; IQR, interquartiile range;
N/A, not applicable; No., number; NR, not reported; Obs, observation; OR, odds ratio; RR, relative risk; SD, standard deviation; SE, standard error; vs, versus.