Effect of a 24-Month Physical Activity Intervention vs Health Education on Cognitive Outcomes in Sedentary Older Adults: The LIFE Randomized Trial.

IMPORTANCE: Epidemiological evidence suggests that physical activity benefits cognition, but results from randomized trials are limited and mixed. OBJECTIVE: To determine whether a 24-month physical activity program results in better cognitive function, lower risk of mild cognitive impairment (MCI) or dementia, or both, compared with a health education program. DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical trial, the Lifestyle Interventions and Independence for Elders (LIFE) study, enrolled 1635 community-living participants at 8 US centers from February 2010 until December 2011. Participants were sedentary adults aged 70 to 89 years who were at risk for mobility disability but able to walk 400 m. INTERVENTIONS: A structured, moderate-intensity physical activity program (n = 818) that included walking, resistance training, and flexibility exercises or a health education program (n = 817) of educational workshops and upper-extremity stretching. MAIN OUTCOMES AND MEASURES: Prespecified secondary outcomes of the LIFE study included cognitive function measured by the Digit Symbol Coding (DSC) task subtest of the Wechsler Adult Intelligence Scale (score range: 0-133; higher scores indicate better function) and the revised Hopkins Verbal Learning Test (HVLT-R; 12-item word list recall task) assessed in 1476 participants (90.3%). Tertiary outcomes included global and executive cognitive function and incident MCI or dementia at 24 months. RESULTS: At 24 months, DSC task and HVLT-R scores (adjusted for clinic site, sex, and baseline values) were not different between groups. The mean DSC task scores were 46.26 points for the physical activity group vs 46.28 for the health education group (mean difference, -0.01 points [95% CI, -0.80 to 0.77 points], P = .97). The mean HVLT-R delayed recall scores were 7.22 for the physical activity group vs 7.25 for the health education group (mean difference, -0.03 words [95% CI, -0.29 to 0.24 words], P = .84). No differences for any other cognitive or composite measures were observed. Participants in the physical activity group who were 80 years or older (n = 307) and those with poorer baseline physical performance (n = 328) had better changes in executive function composite scores compared with the health education group (P = .01 for interaction for both comparisons). Incident MCI or dementia occurred in 98 participants (13.2%) in the physical activity group and 91 participants (12.1%) in the health education group (odds ratio, 1.08 [95% CI, 0.80 to 1.46]). CONCLUSIONS AND RELEVANCE: Among sedentary older adults, a 24-month moderate-intensity physical activity program compared with a health education program did not result in improvements in global or domain-specific cognitive function. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01072500.

Effects of weight regain following intentional weight loss on glucoregulatory function in overweight and obese adults with pre-diabetes.

OBJECTIVE: To assess the extent to which initial, intentional weight loss-associated improvements in glucose tolerance and insulin action are diminished with weight regain. METHODS: 138 overweight and obese (BMI: 32.4±3.9kg/m(2)), adults (59.0±9.7 years), with pre-diabetes were followed through a 6-month weight loss intervention and subsequent 18-month weight maintenance period, or usual care control condition. Longitudinal change in weight (baseline, 6, 24 months) was used to classify individuals into weight pattern categories (Loser/Maintainer (LM), n= 50; Loser/Regainer (LR), n=51; and Weight Stable (WS), n=37). Fasting plasma glucose (FPG), insulin, and insulin resistance (HOMA-IR) were measured at baseline, 6, 12, 18 and 24 months and model adjusted changes, by weight pattern category, were assessed. RESULTS: LMs and LRs lost 8.3±4.7kg (8.7±4.5%) and 9.6±4.7kg (10.2±4.7%) during the first 6 months, respectively. LM continued to lose 1.1±3.4kg over the next 18 months (9.9±6.5% reduction from baseline; p<0.05), while LRs regained 6.5±3.7kg (3.3±5.3% reduction from baseline; p<0.05). Weight change was directly associated with change in all DM risk factors (all p<0.01). Notably, despite an absolute reduction in body weight (from baseline to 24 months) achieved in the LR group, 24-month changes in FPG, insulin, and HOMA-IR did not differ between WS and LR groups. Conversely, LM saw sustained improvements in all measured DM risk factors. CONCLUSIONS: Significant weight loss followed by weight loss maintenance is associated with sustained improvements in FPG, insulin, and HOMA-IR; conversely, even partial weight regain is associated with regression of initial improvements in these risk factors towards baseline values.

Relationship of weekly activity minutes to metabolic syndrome in prediabetes: the healthy living partnerships to prevent diabetes.

BACKGROUND: Physical inactivity contributes to metabolic syndrome (MetS) in overweight/obesity. However, little is known about this relationship in prediabetes. METHODS: The study purpose is to examine relationships between physical activity (PA) and MetS in prediabetes. The Healthy Living Partnerships to Prevent Diabetes tested a community translation of the Diabetes Prevention Program (DPP). Three hundred one overweight/obese prediabetics provided walking minutes/week (WM) and total activity minutes/week (AM) via the International Physical Activity Questionnaire. MetS was at least 3 of waist (men ≥ 102 cm, women ≥ 88 cm), triglycerides (≥150 mg·dl), blood pressure (≥130·85 mm Hg), glucose (≥100 mg·dl), and HDL (men < 40 mg·dl, women < 50 mg·dl). RESULTS: The sample was 57.5% female, 26.7% nonwhite/Hispanic, 57.9 ± 9.5 years and had a body mass index (BMI) 32.7 ± 4 kg·m². Sixty percent had MetS. Eighteen percent with MetS reported at least 150 AM compared with 29.8% of those without MetS. The odds of MetS was lower with greater AM (P(trend) = .041) and WM (P(trend) = .024). Odds of MetS with 0 WM were 2.08 (P = .046) and with no AM were 2.78 (P = .009) times those meeting goal. One hour additional WM led to 15 times lower MetS odds. CONCLUSIONS: Meeting PA goals reduced MetS odds in this sample, which supported PA for prediabetes to prevent MetS.