Characteristics of studies included in the meta-analysis for Alzheimer’s disease
| First author; year and country | Cohort and sample source | Sex; % women | Baseline age (mean (SD) or range) | Follow-up time (SD) and rate (%) | AD criteria | Sample size | Incident case | PA type | Amount of PA (unit) | Adjusted confounders | Multi-adjusted RR (95% CI) |
| For qualitative and quantitative analysis | |||||||||||
| Scarmeas6 ;2009; USA | WHICAP; community dwelling elders | C; 69% | 77.2 (6.6) | 5.4 (3.3); 85% | NINCDS-ADRDA criteria | 520 | 71 | LTPA | Median 0 hours/week | Cohort, age, sex, ethnicity, education, APOE status, caloric intake, BMI, smoking status, depression, leisure activities, a comorbidity index and baseline CDR score | 1 (reference) |
| 650 | 84 | Median 0.1 hours/week of vigorous, 0.8 hours/week of moderate or 1.3 hours/week of light PA, or a combination thereof | 0.71 (0.51 to 0.98) | ||||||||
| 710 | 69 | Median 1.3 hours/week of vigorous, 2.4 hours/week of moderate or 3.8 hours/week of light PA, or a combination thereof | 0.63 (0.45 to 0.90) | ||||||||
| Ravaglia14 ;2008; Italy | CSBA; population based study | C; 53.5% | 73.2 (6.0) | 3.9 (0.7); 94% | NINCDS-ADRDA criteria | 250 | 21 | Mixed PA | <4774 kcal/week | Age, gender, education, and APOE genotype, cardiovascular disease, hypertension and hyperhomocysteinaemia, basic activities of daily living motor disability | 1 (reference) |
| 249 | 20 | 4774–8090 kcal/week | 0.95 (0.50 to 1.80) | ||||||||
| 250 | 13 | >8090 kcal/week | 0.70 (0.33 to 1.49) | ||||||||
| Podewils15 ;2005; USA | CHCS; community dwelling elders | C; 59.1% | 74.8 (4.9) | 5.2; 94% | NINCDS-ADRDA criteria | 844 | 69 | LTPA | <248 kcal/week | Age, educational level, gender, ethnicity, APOE4, baseline 3MSE score, MRI white matter grade score, ADL impairment, IADL impairment, LSN score and social support score | 1 (reference) |
| 5.4; 94% | 842 | 70 | 248–742 kcal/week | 1.07 (0.73 to 1.57) | |||||||
| 5.5; 94% | 844 | 58 | 743–1657 kcal/week | 0.92 (0.62 to 1.39) | |||||||
| 5.6; 94% | 843 | 48 | >1657 kcal/week | 0.70 (0.44 to 1.13) | |||||||
| Laurin7; 2001; Canada | CSHA; community dwelling elders | C; 60% | 65 (+) | 5; 72% | NINCDS-ADRDA criteria | 1183 | 80 | LTPA | No regular PA | Age, sex and educational level | 1 (reference) |
| 506 | 21 | Other types | C: 0.67 (0.39 to 1.14) W: 0.70 (0.33 to 1.49) M: 0.87 (0.26 to 2.90) | ||||||||
| 1412 | 52 | ≥3 times/week at an intensity equal to walking (based on the MET table, the MET of ordinary walking=2.5 METs) | C: 0.67 (0.46 to 0.98) W: 0.87 (0.51 to 1.48) M: 0.61 (0.25 to 1.50) | ||||||||
| 747 | 16 | ≥3 times/week at an intensity greater than walking | C: 0.50 (0.28 to 0.90) W: 0.27 (0.08 to 0.90) M: 0.73 (0.27 to 1.98) | ||||||||
| Only for qualitative meta-analysis | |||||||||||
| Neergaard10; 2016; Denmark | PERF I study; RCT database | W; 100% | 70.1–75.1 (4.9–6.4) | 11.9 (3.9); 94% | ICD10 | 1550 | 81 | Mixed PA | None | Age, education, BMI, smoking, alcohol, vascular factors and neural disorders | 1 (reference) |
| 1097 | 48 | Once/week | 0.84 (0.58 to 1.20) | ||||||||
| 674 | 35 | Twice/week | 0.99 (0.66 to 1.47) | ||||||||
| 1849 | 86 | 3+ times/week | 1.00 (0.73 to 1.37) | ||||||||
| Andel8; 2008; Sweden | STR; National Swedish twin registry | C; 61% | 48.1 (5.0) | 31.3; 70% | NINCDS-ADRDA criteria | 357 | 35 | LTPA | Hardly any exercise | Age, gender, education, smoking, alcohol consumption, portion of fruits and vegetables in diet, BMI and angina pectoris | 1 (reference) |
| 31.5; 70% | 2217 | 138 | Light exercise such as walking or light gardening | 0.64 (0.41 to 1.00) | |||||||
| 31.6; 70% | 299 | 6 | Regular exercise involving sports | 0.34 (0.14 to 0.86) | |||||||
| 31.4; 70% | 223 | 18 | Hard physical training | 0.65 (0.33 to 1.29) | |||||||
| Akbaraly37; 2009; France | Three City Study; population based study | C; 61% | 73.6–78 (5.3–5.7) | 4 (maximum); 92.3% | NINCDS-ADRDA criteria | 2591 | 97 | Mixed PA | Low (score<2) | Gender, educational level, occupational grade, study centre, marital status, hypertension, diabetes, vascular diseases history, hypercholesterolaemia, depressive symptoms, APOE genotype, incapacity in daily life activity, and cognitive impairment assessed by MMSE | 1 (reference) |
| 1373 | Mild (score=2) | 0.87 (0.50 to 1.51) | |||||||||
| 1734 | High (score>2) | 1.29 (0.80 to 2.09) | |||||||||
| Abbott9;2004; USA | HAAS; population based study | M; 100% | 84 (75–98) | 4.7; NA | NINCDS-ADRDA criteria | 600 | 30 | Leisure time walking | <0.25 miles/day | Age, APOE4, baseline CASI score, decline in PA since mid-adulthood, physical performance score, education, BMI, childhood years spent living in Japan, status as a skilled professional, hypertension, diabetes, prevalent coronary heart disease, and total and HDL cholesterol | 2.21 (1.06 to 4.57) |
| 769 | 39 | 0.25–1 miles/day | 1.86 (0.91 to 3.79) | ||||||||
| 433 | 21 | 1–2 miles/day | 1.88 (0.87 to 4.04) | ||||||||
| 455 | 11 | >2 miles/day | 1 (reference) | ||||||||
3MSE, Modified Mini-Mental State Examination; ADL, activities of daily living; APOE, apolipoprotein E; BMI, body mass index; C, combined; CASI, Cognitive Abilities Screening Instrument; CDR, Clinical Dementia Rating; CHCS, Cardiovascular Health Cognition Study; CSBA, Conselice Study of Brain Ageing; CSHA, Canadian Study of Health and Ageing; HAAS, Honolulu–Asia Ageing Study; HDL, high density lipoprotein; IADL, instrumental activities of daily living; ICD10, International Classification of Diseases,10th revision; LSN, Lubben Social Network; LTPA, leisure time physical activity; MET, metabolic equivalent of task; MMSE, Mini-Mental State Examination; NA, not accessible; NINCDS-ADRDA, National Institute of Neurological Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association; O, original result; PA, physical activity; PERF I, Prospective Epidemiologic Risk Factor; RCT, randomised controlled trial; STR, Swedish Twin Registry; T, result after data transformation; WHICAP, Washington Heights-Inwood Columbia Ageing Project.