Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults

The effect of vitamin D supplementation on lower-extremity power and function in older adults: a randomized controlled trial

Background

The effect of vitamin D supplementation on muscle function in older adults has been tested in randomized trials with mixed results, which may be due to differences in the study participant characteristics, including baseline vitamin D status. The results of 2 meta-analyses of randomized trials suggested a beneficial effect of vitamin D supplementation on muscle function in older adults with low baseline serum 25-hydroxyvitamin D [25(OH)D].

Objectives

We aimed to test the effect of 12 mo of vitamin D supplementation on lower-extremity power and function in older community-dwelling adults screened for low serum 25(OH)D.

Methods

This was a single-center, double-blind, randomized, placebo-controlled trial that included 100 community-dwelling men and women ≥60 y old who had serum 25(OH)D ≤20 ng/mL at screening and a mean ± SD serum 25(OH)D of 20.2 ± 6.7 ng/mL at baseline. Participants were randomly assigned to 800 IU vitamin D3/d (intervention) or placebo. Those in the intervention group whose serum 25(OH)D was <28 ng/mL after 4 mo were given an additional 800 IU vitamin D3/d, whereas all other participants received placebo as an additional pill.

Results

After 12 mo, the mean ± SD serum 25(OH)D was 32.5 ± 5.1 ng/mL in the intervention group and 19.8 ± 7.3 ng/mL in the control group (treatment × time P < 0.001). The change in leg press power, function, and strength did not differ between the 2 groups over 12 mo (all treatment × time P ≥ 0.60), nor did the change in lean mass (treatment × time P ≥ 0.89).

Conclusion

Increasing serum 25(OH)D to >32 ng/mL (on average) over 12 mo did not affect lower-extremity power, strength, or lean mass in older community-dwelling adults. This trial was registered at clinicaltrials.gov as NCT02293187.

Serum 25-hydroxyvitamin D levels and incident falls in older women

Three hundred eighty-seven home-dwelling older women were divided into quartiles based on mean serum 25-hydroxyvitamin D (S-25(OH)D) levels. The rates of falls and fallers were about 40% lower in the highest S-25(OH)D quartile compared to the lowest despite no differences in physical functioning, suggesting that S-25(OH)D levels may modulate individual fall risk.

INTRODUCTION

Vitamin D supplementation of 800 IU did not reduce falls in our previous 2-year vitamin D and exercise RCT in 70-80 year old women. Given large individual variation in individual responses, we assessed here effects of S-25(OH)D levels on fall incidence.

METHODS

Irrespective of original group allocation, data from 387 women were explored in quartiles by mean S-25(OH)D levels over 6-24 months; means (SD) were 59.3 (7.2), 74.5 (3.3), 85.7 (3.5), and 105.3 (10.9) nmol/L. Falls were recorded monthly with diaries. Physical functioning and bone density were assessed annually. Negative binomial regression was used to assess incidence rate ratios (IRRs) for falls and Cox-regression to assess hazard ratios (HR) for fallers. Generalized linear models were used to test between-quartile differences in physical functioning and bone density with the lowest quartile as reference.

RESULTS

There were 37% fewer falls in the highest quartile, while the two middle quartiles did not differ from reference. The respective IRRs (95% CI) for falls were 0.63 (0.44 to 0.90), 0.78 (0.55 to 1.10), and 0.87 (0.62 to 1.22), indicating lower falls incidence with increasing mean S-25(OH)D levels. There were 42% fewer fallers (HR 0.58; 040 to 0.83) in the highest quartile compared to reference. Physical functioning did not differ between quartiles.

CONCLUSIONS

Falls and faller rates were about 40% lower in the highest S-25(OH)D quartile despite similar physical functioning in all quartiles. Prevalent S-25(OH)D levels may influence individual fall risk. Individual responses to vitamin D treatment should be considered in falls prevention.

A 2-Year Follow-Up After a 2-Year RCT with Vitamin D and Exercise: Effects on Falls, Injurious Falls and Physical Functioning Among Older Women

Background

Both exercise and vitamin D are recommended means to prevent falls among older adults, but their combined effects on fall-induced injuries are scarcely studied.

Methods

A 2-year follow-up of a previous 2-year randomized controlled trial with vitamin D and exercise (Ex) of 409 older home-dwelling women using a factorial 2 × 2 design (D⁻Ex⁻, D⁺Ex⁻, D⁻Ex⁺, D⁺Ex⁺). Besides monthly fall diaries, femoral neck bone mineral density (fn-BMD), and physical functioning were assessed at 1 and 2 years after the intervention.

Results

After the intervention, S-25OHD concentrations declined to baseline levels in both supplement groups. The groups did not differ for change in fn-BMD or physical functioning, except for leg extensor muscle strength, which remained about 10% greater in the exercise groups compared with the reference group (D⁻Ex⁻). There were no between-group differences in the rate of all falls, but medically attended injurious falls reduced in D⁺Ex⁻ and D⁻Ex⁺ groups compared with D⁻Ex⁻. However, all former treatment groups had less medically attended injured fallers, HRs (95% CI) being 0.62 (0.39–1.00) for D⁺Ex⁻, 0.46 (0.28–0.76) for D⁻Ex⁺, and 0.55 (0.34–0.88) for D⁺Ex⁺, compared with D⁻Ex⁻.

Conclusions

Exercise-induced benefits in physical functioning partly remained 2 years after cessation of supervised training. Although there was no difference in the rate of all falls, former exercise groups continued to have lower rate of medically attended injured fallers compared with referents even 2 years after the intervention. Vitamin D without exercise was associated with less injurious falls with no difference in physical functioning.

Effects of a Multimodal Exercise Program on Physical Function, Falls, and Injuries in Older Women: A 2-Year Community-Based, Randomized Controlled Trial

OBJECTIVES

To investigate the effects of multimodal supervised exercise on physical functioning, falls, and related injuries in older women.

DESIGN

Two-year randomized controlled trial.

SETTING

Tampere, Finland.

PARTICIPANTS

Women aged 70 to 80 who had fallen in the previous year (n = 409).

INTERVENTION

Participants were randomly assigned to an exercise or control group (ClinicalTrial.gov NCT00986466). Exercisers participated in group exercise classes twice a week for 12 months and once a week for the subsequent 12 months and home exercises. Controls maintained their current physical activity.

MEASUREMENTS

Physical functioning assessed at baseline and at 6-month intervals during the intervention. Falls and related injuries monitored with fall diaries.

RESULTS

Intention-to-treat analyses showed that exercise led to significant improvements in physical functioning. Leg strength differed significantly between the groups (mean change: 14.1%, 95% confidence interval (CI) = 8.0 to 20.2 in exercisers; 1.6%, 95% CI = -4.5 to 7.7 in controls; P < .001). Chair stand time also differed significantly between groups (7.4%, 95% CI 3.8 to 10.8% in exercisers; 2.4%, 95% CI = -1.6 to 6.2) in controls; P = .02). Between-group differences were significant for fast walking speed (P = .003) and probability of completing the backward walking test (P < .001), favoring exercisers. Timed Up-and-Go and grip strength did not differ between groups. There was no difference in the total falls incidence rate ratio (IRR = 1.0, 95% CI = 0.79 to 1.26), but exercisers were less likely to have medically attended injurious falls (IRR = 0.45, 95% CI = 0.27 to 0.78; P = .004).

CONCLUSION

Twenty-four months of multimodal exercise enhanced physical functioning in women aged 70 to 80 with a history of falls. Although the total number of falls was not lower than in controls, the rate of medically attended injurious falls was more than 50% lower.

Study protocol for prevention of falls: a randomized controlled trial of effects of vitamin D and exercise on falls prevention

Background

Falls are the leading cause of unintentional injury and injury-related death among older people. In addition to physical activity, vitamin D also may affect balance and neuromuscular function. Low serum 25-hydroksivitamin D level increases the risk of bone loss, falls and fractures. Thus, an appropriate exercise program and sufficient vitamin D intake may significantly improve not only functional balance, but also balance confidence. Balance represents a complex motor skill determined by reaction time, muscle strength, and speed and coordination of movement.

Methods/Design

A 2-year randomized double-blind placebo-controlled vitamin D and open exercise trial of 409 home-dwelling women 70 to 80 years of age comprising four study arms: 1) exercise + vitamin D (800 IU/d), 2) exercise + placebo, 3) no exercise + vitamin D (800 IU/d), 4) no exercise + placebo. In addition to monthly fall diaries, general health status, life style, bone health, physical functioning, and vitamin D metabolism will be assessed. The primary outcomes are the rate of falls and fall-related injuries. Secondary outcomes include changes in neuromuscular functioning (e.g. body balance, muscle strength), ADL- and mobility functions, bone density and structure, cardiovascular risk factors, quality of life and fear of falling.

Discussion

The successful completion of this trial will provide evidence on the effectiveness of exercise and vitamin D for falls reduction.

Trial Registration

ClinicalTrial.gov -register (NCT00986466).

Validation of lower extremity performance tests for determining the mobility limitation levels in community-dwelling older women

BACKGROUND AND AIMS

Assessment of mobility status among community-dwelling older people is important for preventing further deterioration of mobility and identifying changes in mobility as early as possible. We attempted to identify the optimal cut-off values for eight lower extremity performance (LEP) tests in community-dwelling older women with mobility limitation (ML) levels.

METHODS

The ML levels of 433 community-dwelling older women, mean age 73.2 years (SD 5.7, range 65-93) were classified according to selfreports. ML levels were identified by face-to-face interviews and according to self-reported difficulty in walking one-quarter of a mile or climbing 10 steps without resting. The LEP tests comprised one-legged stance, tandem stance, functional reach, tandem walk, alternate step, five chair sit-to-stands, timed up-and-go (TUG) and usual gait speed. Receiver-operating characteristic curves were obtained for all scales to assess optimal cut-off values.

RESULTS

The optimal cut-off value of 6.52 (s) for the TUG test was shown by the highest sensitivity (74%) and specificity (71%) in the discrimination of no ML from moderate ML, whereas the optimal cut-off value of 1.05 (m/s) in the usual gait speed test showed the highest sensitivity (73%) and specificity (67%) in the discrimination of moderate ML from severe ML.

CONCLUSIONS

Among community-dwelling older women, TUG and usual gait speed had the highest sensitivity and specificity in discriminating ML levels.

Backward walking in Parkinson's disease

We walk backward on a daily basis, such as when backing away from the kitchen sink or stepping back from a curb as a swiftly moving bus passes. This task may be particularly difficult for individuals with Parkinson's disease (PD) who often fall as a result of moving or being perturbed in the backward direction. The aim of this study was to assess backward walking (BW) in individuals with PD. Both forward walking (FW) and BW were assessed in 78 people with idiopathic PD (H&Y range: 0.5-3) in the ON state, and 74 age- and sex-matched controls. In FW, those with PD had significantly shorter strides, lower swing percents, higher stance percents, and lower functional ambulation profiles than controls. Both groups walked significantly slower and with a wider base of support during BW than FW. Additionally, in BW those with PD walked significantly slower with shorter strides, lower swing percents, and higher double support and stance percents, and lower functional ambulation profiles compared with controls. Those with mild to moderate PD have impaired FW and BW, but differences between those with and without PD are more pronounced in BW.