Association between insulin resistance and objective measurement of physical activity in community-dwelling older adults without diabetes mellitus

Association between accelerometer-measured physical activity, glucose metabolism, and waist circumference in older adults

AIMS

To examine the association of physical activity (PA) and sedentary time (ST) with glucose metabolism according to waist circumference (WC) in older people.

METHODS

A population-based sample of 702 individuals (aged 67-70 years) wore wrist-worn accelerometers for two weeks and underwent an oral glucose tolerance test. The associations between moderate-to-vigorous (MVPA) and light (LPA) PA, ST, and glucose metabolism across the tertiles of WC were analysed using general linear regression.

RESULTS

Among highest WC tertile, LPA negatively associated with fasting insulin (β =  - 0.047, 95% CI - 0.082 to - 0.012), HOMA-IR (β =  - 0.098, 95% CI - 0.184 to - 0.012), and HOMA-β (β =  - 3.367, CI - 6.570 to - 0.783). ST associated with 120 min glucose (β = 0.140, CI 0.021 to 0.260). Among lowest WC tertile, MVPA negatively associated with 30 min insulin (β =  - 0.086, 95% CI - 0.168 to - 0.004) and 120 min insulin (β =  - 0.160, 95% CI - 0.257 to - 0.063) and positively associated with Matsuda index (β = 0.076, 95% CI 0.014 to 0.139). Light PA negatively associated with 120 min insulin (β =  - 0.054, 95% CI - 0.104 to - 0.005).

CONCLUSION

With the limitation of the cross-sectional study, reducing ST and increasing LPA may be beneficial for glucose metabolism among abdominally obese older adults. Lean older adults could benefit more from increasing MVPA.

Effect of various exercises on frailty among older adults with subjective cognitive concerns: a randomised controlled trial

BACKGROUND

Physical exercise has been linked to reduced frailty, but there is insufficient evidence of beneficial effects in community-dwelling older adults with subjective cognitive concerns.

OBJECTIVE

This study aimed to clarify the effects of physical exercise in this population.

DESIGN

Single-blind randomised controlled trial.

SETTING

Community sports centres.

PARTICIPANTS

Residents aged 65-85 years were screened using the Kihon checklist; those with subjective cognitive concerns were invited for eligibility assessment. In total, 415 community-dwelling older adults were enrolled and randomised.

METHODS

This trial investigated the effects of aerobic training (AT), resistance training (RT) and combined training (AT+RT) programs on reducing frailty. All participants were randomised into one of the three intervention groups or the control group. Participants in the intervention groups underwent a group training program and self-paced home training for 26 weeks. The control group received lectures about health promotion. A 95-item frailty index (FI) was utilised to determine the effects of training. Participants were followed up at weeks 26 and 52.

RESULTS

At baseline, mean age of all participants (47% women) was 72.3 ± 4.6 years, with a mean FI score of 0.3 ± 0.1. Compared with control group, AT improved total FI by 0.020 (CI -0.039 to -0.001, effect size -0.275) and the depression and anxiety component of FI by 0.051 (CI -0.084 to -0.018, effect size -0.469) at week 26, but the effects waned at week 52. No significant differences in FI were found in RT and AT+RT groups at weeks 26 and 52.

CONCLUSIONS

A 26-week AT reduced frailty modestly, especially in the depression and anxiety component, in older adults with subjective cognitive concerns.

Effect of Various Exercises on Intrinsic Capacity in Older Adults With Subjective Cognitive Concerns

OBJECTIVES

Physical activity is associated with improvement in overall health and well-being, but robust evidence with comprehensive assessment of general health is lacking. This study aimed to clarify the effects of physical activity on intrinsic capacity among community-dwelling older adults with subjective memory concerns.

DESIGN

A single-blind randomized controlled trial compared aerobic training (AT), resistance training (RT), and combined training (AT+RT) programs for improving general health evaluated by intrinsic capacity.

SETTING

Toyota, Japan.

PARTICIPANTS

Residents (65-85 years old) who screened positive for subjective memory concerns using the Kihon checklist were invited for eligibility assessment. In total, 415 community-dwelling older adults were enrolled and randomized into the AT, RT, AT+RT, and control groups.

METHODS

Participants in the intervention groups underwent a group training program and self-paced home training for 26 weeks. The control group received lectures about health promotion. Intrinsic capacity (IC), constructed based on locomotion, cognition, psychological function, and vitality domains, was used to assess general health at baseline, week 26, and week 52. Between-group differences were exhibited with Z-score change in individual domain and combination of all domains.

RESULTS

At baseline, mean age of all participants (47% women) was 72.3 ± 4.6 years, with a mean composited IC Z-score of -0.2 ± 0.5. Overall, AT and RT improved composite IC Z-scores by 0.17 (95% confidence interval [CI] 0.03-0.30) and 0.17 (95% CI 0.05-0.28) at week 26, respectively, but the beneficial effects waned at week 52. No significant differences in composite IC Z-scores were found in the AT+RT group at weeks 26 and 52.

CONCLUSIONS AND IMPLICATIONS

Twenty-six-week AT with self-paced home training and RT with self-paced home training improve IC among community-dwelling older adults with subjective memory concerns, but the benefits waned subsequently. It will be required to develop optimal interventions that have a continuous beneficial effect on IC among community-dwelling older adults.