Background
Methods
Systematic review protocol
Eligibility criteria
Data extraction and quality assessment
Data analysis
Results
Studies retrieved
Study quality assessment
Criterion | Watson et al. 2006 [35] | Colberg et al. 2008 [36] | Devore et al. 2009 [37] | Baker et al. 2010 [38] | Yanagawa et al. 2011 [39] | Lehtisalo et al. 2016 [40] | |
---|---|---|---|---|---|---|---|
Study Design | RCT | CS | CS | LS | RCT | NRCT | RCT |
Eligibility Criteria | Y | Y | Y | Y | Y | Y | Y |
Random allocation | Y | N/A | N/A | N/A | Y | N | Y |
Concealed allocation | N | N/A | N/A | N/A | N | N | N |
Group baseline similarity | Y | N | N | N | Y | Y | Y |
Blinding of subjects | N | N/A | N/A | N/A | N | N | N |
Blinding of therapists | N | N/A | N/A | N/A | Y | N | N |
Blinding of assessors | N | N/A | N/A | N/A | N | N | N |
Measures of one key outcome in at least 85% of participants | Y | Y | Y | Y | Y | Y | Y |
At least one key outcomes analyzed with ‘intention to treat’ | N | N | N | N | Y | N | N |
Point measures, and measures of variability for at least one key outcome | Y | Y | Y | Y | Y | Y | Y |
Between group statistical comparisons reported for at least one key outcome | Y | Y | Y | Y | Y | Y | Y |
Full supervision of exercise intervention | Y | N | N | N | Y | Y | Y |
Final score (/ 12) | 7 | 4 | 4 | 4 | 9 | 6 | 7 |
Study design and participant characteristics
Citation | Inclusion criteria | Condition (N) | Age, years (SD) | % Female | Medications |
---|---|---|---|---|---|
Watson et al. 2006 [35] | Glucose tolerance criteria for prediabetes 7.8 mmol/L ≥ 2-h glucose <11.1 mmol/L) Normal cognitive assessment | Exercise group: exercise plus AHAS2ED (15) BMI: 24.7 ± 3.2 kg/m2 Control group: AHAS1ED (13) BMI:26.7 ± 4.3 kg/m2 | 58.0 ± 9.7 60.6 ± 9.0 | Not reported | Not reported |
Colberg et al. 2008 [36] | American Diabetes Association criteria for the diagnosis of type 2 diabetes. Cutoff point for MMSE score > 24 and SLUMS <20 for high school educated, <15 for less educated | Diabetes group (74) HbA1c, % 6.6 ± 0.2 Control group (71) HbA1c, % 5.2 ± 0.0 | 55.5 ± 1.0 57.5 ± 1.3 | 66.2 | Not reported |
Devore et al. 2009 [37] | American Diabetes Association criteria for diagnosis of type 2 diabetes Diabetes duration: 1–15 year Telephone Interview for Cognitive Status (modified forms of the Mini-Mental State Examination | High physical activity group (512) BMI (43%) ≥ 30 kg/m2 Moderate physical activity group (520) BMI (33%) ≥ 30 kg/m2 Low physical activity group (518) BMI (32%) ≥ 30 kg/m2 No control group | 74.0 ± 2.3 74.0 ± 2.4 74.0 ± 2.3 | 100 | Insulin therapy Oral hypoglycemia Anti-hypertension/ anti-hypoglycemia |
Baker et al. 2010 [38] | Glucose tolerance criteria for prediabetes (7.8 mmol/L ≥ 2-h glucose <11.1 mmol/L) and for diagnosed type 2 diabetes (2-h glucose ≥1.1 mmol/L) Normal cognitive assessment | Exercise group: aerobic exercise (19), 2-h OGTT glucose levels:184 ± 46 mg/dL BMI:30.6 ± 3.9 kg/m2 Control group: stretching (9) 2-h OGTT glucose levels: 163 ± 31.8 mg/dL BMI: 30.1 ± 7.3 kg/m2 | 71.0 ± 7.5 66.0 ± 6.0 | 64.3 | Anti-hypertension |
Yanagawa et al. 2011 [39] | World Health Organization criteria for diagnosis of type 2 diabetes euglycemic clamp) Normal cognitive assessment | Exercise group (9) HbA1c, % 7.29 ± 0.56 BMI: 23.31 ± 2.80 kg/m2 Control group: walking (7) HbA1c, % 7.14 ± 0.61 BMI: 22.31 ± 2.03 kg/m2 | 71.6 ± 3.8 70.1 ± 3.7 | 31.2 | Not reported |
Lehtisalo et al. 2016 [40] | Glucose tolerance criteria for prediabetes 7.8 mmol/L ≥ 2-h glucose <11.1 mmol/L Normal cognitive assessment | Exercise group: Mixing exercise (364) Control group: Health advice (158) | 55.1 ± 6.8 55.3 ± 7.8 | 67.1 | Not reported |
Measures of glucose homeostasis and insulin resistance
Measures of body composition
Neuropsychological assessment
Intervention characteristics
Citation | Intervention modality | Intensity | Volume (minutes) | Frequency (days/week) | Duration (weeks) | Control condition |
---|---|---|---|---|---|---|
Watson et al. 2006 [35] | Aerobic exercise plus Diet control Supervised | 50% of HRR over 12 weeks increasing to 70% of HRR from 13 to 26 weeks | 60 | 3 | 52 | Stretching plus diet |
Baker et al. 2010 [38] | Aerobic exercise, treadmill Supervised | Workload gradually increased to 75–85% of HRR over 1–6 weeks | 45–60 | 4 | 26 | Stretching or balance |
Yanagawa et al. 2011 [39] | Aerobic exercise (JOBA) Supervised | 55–69% heart rate reserve, or 40–59% of VO2peak | 45 | 4 | 12 | Usual level of activity |
Lehtisalo et al. 2016 [40] | Brisk walking, skiing, jogging, swimming, bicycling, gymnastics, resistance training, and ball games Supervised | Moderate-vigorous | 30 | 7 | 156 | No any exercise health advice |
Citation | Physical activity assessment method | Physical activity category a | ||
---|---|---|---|---|
Low active | Moderate active | High active | ||
Colberg et al. 2008 [36] | Modified (diabetes) a version of the HAPAQ (One-year recall) |
Regular exercise, % 55.4
b
Days of exercise/week 2.2 ± 0.3 City blocks walked/day1.2 ± 1.5 Stairs climbed/day flights 0.5 ± 0.6 Usual walking pace 2.0 ± 0.1 Usual exertion 0.9 ± 0.2
Weekday, hours/day
Vigorous activity 0.8 ± 0.2 Moderate activity 3.0 ± 0.3 Light activity 5.5 ± 0.4 Sit activity 7.1 ± 0.5 Sleep/recline activity 7.6 ± 0.2
Weekend, hours/day
Vigorous activity 1.0 ± 0.2 Moderate activity 3.2 ± 0.3 Light activity 4.5 ± 0.3 Sit activity 7.1 ± 0.4 Sleep/recline activity 8.2 ± 0.2 |
Regular exercise, % 71.8
b
Days of exercise/week 2.2 ± 0.3 City blocks walked/day 0.3 ± 2.4 Stairs climbed/day flights 0.6 ± 0.8 Usual walking pace 0.5 ± 0.1 Usual exertion 4.3 ± 0.2
Weekday, hours/day
Vigorous activity 0.8 ± 0.1 Moderate activity 3.2 ± 0.4 Light activity 6.9 ± 0.3 Sit activity 5.4 ± 0.4 Sleep/recline activity 7.6 ± 0.2
Weekend, hours/day
Vigorous activity 0.2 ± 0.2 Moderate activity 4.2 ± 0.3 Light activity 5.4 ± 0.3 Sit activity 5.3 ± 0.4 Sleep/recline activity 7.9 ± 0.2 | |
Devore et al. 2009 [37] | SAPAQ-CS SAPAQ-PS | 3.38 (0.13–6.76) | 10.70 (6.77–15.50) | 24.39 (15.54–112.23) |
Training modality
Exercise dose and intensity
Control conditions
Outcome measurement
Executive function/attention
Aerobic exercise vs. non-exercise controls
Citation | Outcome measurement | Results | Calculation | Statistics | |||
---|---|---|---|---|---|---|---|
Domain | Method | Group | Pre-exercise (Mean ± SD) | Post-exercise (Mean ± SD) | Between group Effect size (95%, CIs) | Between group p-value | |
Watson et al. 2006 [35] | Memory Attention/Executive function | SR BVR TMT | AE CO AE CO AE CO | 6.30 ± 1.15* 6.25 ± 1.10* Not reported Not reported Not reported Not reported | 3.65 ± 1.15* 5.05 ± 1.15* Not reported Not reported Not reported Not reported | 1.35 (0.48, 2.22) Unable to be calculated Unable to be calculated | 0.01 Not significant Not significant |
Baker et al. 2010 [38] | Information processing and executive function Memory | VF TMTB TS SCWI SOPT SR LR | AE CO AE CO AE CO AE CO AE CO AE CO AE CO | Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported | Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported | Unable to be calculated Unable to be calculated Unable to be calculated Unable to be calculated Unable to be calculated Unable to be calculated Unable to be calculated | 0.11 0.04 0.03 0.04 0.10 Not significant Not significant |
Yanagawa et al. 2011 [39] | Memory Information processing and executive function Global cognitive function | WLIM WLDM WAIS-DST TMTA Stroop TMTB MMSE | AE CO AE CO AE CO AE CO AE CO AE CO AE CO | Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported | Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported | 0.59 (−0.42, 0.60) 0.08 (−0.90, 1.07) 0.38 (−0.62, 1.38) 0.46 (−0.54, 1.46) 0.14 (−0.84, 1.13) 0.60 (−0.41, 0.41) 0.02 (−0.97, 1.00) | 0.31 1.00 0.79 0.53 0.27 0.27 0.96 |
Lehtisalo et al. 2016 [40] | Overall cognitive performance Executive function | CERAD TMTB | AE CO AE CO | 8.3 ± 9 Not reported 48.6 ± 9.6 Not reported | Unable to be calculated Unable to be calculated | Unable to be calculated Unable to be calculated | Not significant Not significant |
Memory
Aerobic exercise vs. non-exercise or aerobic exercise and diet restriction vs. diet restriction or high physical activity vs. low physical activity
Information processing speed
Global cognitive function
Aerobic exercise vs. non-exercise or higher physical activity vs. low physical activity
Citation | Assessment time point | Outcome measurements | Results | Statistics | |||
---|---|---|---|---|---|---|---|
Domain | Method | Group | Physical activity levels | Between group mean difference (95%, CIs) | p-value | ||
Colberg et al. 2008 [36] | Cross section study | Global cognitive function | MMSE SLUMS | AE CO AE CO AE CO | weekday light activity: 5.5 ± 0.4 weekday light activity: 6.9 ± 0.3 weekday moderate activity: 3.0 ± 0.3 weekday moderate activity: 3.2 ± 0.4 weekday light activity: 5.5 ± 0.4 weekday light activity: 6.9 ± 0.3 | Not reported Not reported Not reported | 0.04 <0.01 0.04 |
Devore et al. 2009 [37] | Cross section study | General cognitive function Memory | TICS score Global cognitive Score Immediate and delayed recalls | LPA MPA HPA LPA MPA HPA LPA MPA HPA | 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) | 0.37 (0.02, 0.72) 0.07 (0.01, 0.15) 0.06 (0.03, 0.1) | 0.03 (HPA versus LPA) 0.06 (HPA versus LPA) 0.20 (HPA versus LPA) |
Devore et al. 2009 [37] | Prospective study | General cognitive function Memory | TICS score Global cognitive Score Immediate and delayed recalls | LPA MPA HPA LPA MPA HPA LPA MPA HPA | 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) 3.38 (0.13–6.76) 10.70 (6.77–15.50) 24.39(15.54–112.23) | 0.21 (0.15, 0.57) 0.05 (0.03, 0.12) 0.07 (0.03, 0.16) | 0.20 (HPA versus LPA) 0.20 (HPA versus LPA) 0.20 (HPA versus LPA) |
Relationship between changes in measures of cognitive function and insulin resistance
Citation | Cognition | Insulin resistance measurement | Time since last exercise bout | Relationship | r | p-value | Comments |
---|---|---|---|---|---|---|---|
Watson et al. 2006 [35] | Delayed memory | Two-hour Oral glucose tolerance test insulin level (mmol/L) | 26 weeks | Change in delayed memory and change in two-hour Oral glucose tolerance test insulin level (mmol/L) | −0.52 | 0.047 | Exercise group (Aerobic exercise plus American Heart Association Step 2 Eucaloric Diet only |
Colberg et al. 2008 [36] | Global cognitive function | Insulin (IU/mL) | Not reported Not reported | Relationship between HOMA-IR and cognitive function Relationship between insulin level and cognitive function | −0.19 −0.18 | 0.02 0.03 | Diabetes exercise group |
Yanagawa et al. 2011 [39] | Delayed memory | Euglycemic Clamp (glucose infusion rate (mL/kg/min) Metabolic clearance rate(mL/kg/min) | 12 weeks | Change in word recall and change in glucose infusion rate Change in word recall and change in metabolic clearance rate | 0.64 0.575 | 0.024 0.051 | Horseback riding simulation equipment (JOBA) exercise group |
Relationship between changes in measures of cognitive function and glucose homeostasis
Citation | Cognition | Glucose level measurement | Time since last exercise bout | Relationship | r | P value | Comments |
---|---|---|---|---|---|---|---|
Yanagawa et al. 2011 [39] | Delayed memory Executive function | HbA1c (%) (glycosylated hemoglobin) Fasting glucose level (mg/dl) | 12 weeks 12 weeks | Change in word recall and change in HbA1c Change in word recall and change in metabolic clearance rate | −0.627 0.611 | 0.029 0.035 | Horseback riding simulation equipment (JOBA) exercise group |
The relationship between changes in measures of cognitive function and body composition
Citation | Cognition | Body composition measurement | Time since last exercise bout | Relationship | r | P value | Comments |
---|---|---|---|---|---|---|---|
Watson et al. 2006 [35] | Delayed memory | Intra-abdominal fat (cm2) | 26 weeks | Change in delayed memory and change in intra-abdominal fat (IAF) | Not reported −0.62 | Not reported 0.024 | Exercise group (exercise plus American Heart Association Step 2 Eucaloric Diet) Control group (stretching plus American Heart Association Step 1 Eucaloric Diet) |