Effects of intensity, frequency, and time window of exercise on sleep quality among community-dwelling adults aged 65-86 years.

BACKGROUND: Although the effects of exercise training (ET) on sleep problem have been reported, the effects according to the components of exercise, including intensity, frequency, and time window, are unknown. Thus, in this study, we aimed to assess the effects of ET on sleep quality in community-dwelling older adults with sleep problems. METHODS: We evaluated individuals aged ≥65 years whose Pittsburgh sleep quality index was >5 points at baseline. The participants were allocated to either the control group or the ET group and underwent interval walking training (IWT) for 5 months. Information regarding intensity, frequency, and time window of ET were obtained using a waist-worn accelerometer. RESULTS: Overall, 63 participants (24 men [mean ± standard deviation age: 75.1 ± 4.6 years] and 39 women [74.7 ± 5.2 years]) and 65 participants (24 men [75.2 ± 4.0 years] and 41 women [73.6 ± 4.2 years]) were included in the ET and control groups, respectively. The change in Pittsburgh sleep quality index was not significantly different between the two groups for both sexes. In the ET group, women who exercised 3-8 h before bedtime, men who did ET > 8 h before bedtime and more than 1 h after waking up, and men who did ET ≥ 5.05 days/week experienced significant improvements compared to the baseline. CONCLUSIONS: IWT does not significantly improve sleep quality. To obtain improvements in sleep quality, it might be necessary to consider the time window of performing ET for both sexes and ET frequency for men.

Effect of high-intensity interval walking on microvascular endothelial function among community-dwelling older people.

AIM: To investigate the effects of high-intensity interval exercise training on microvascular endothelial function among community-dwelling older people. METHODS: We analyzed the data from a nonrandomized controlled trial. This study's participants were 48 men (aged 75 ± 5 years; exercise training group, n = 24; control group, n = 24) and 83 women (aged 75 ± 4 years; exercise training group, n = 36; control group, n = 47). The exercise training group underwent a high-intensity interval walking training for 5 months. RESULTS: In the exercise group, 100% and 91.7% of men and women, respectively, achieved brisk walking times ≥50 min/week. The change in the reactive hyperemia index significantly differed between the groups of men, whereas that in the control group was not significant; however, a significant increase was observed in the exercise training group. Among women, changes in the reactive hyperemia index were not significant in either group; however, for women in the exercise training group, these changes negatively and positively correlated with the change in body mass index (Spearman's rho = -0.342; P = 0.041) and baseline body mass index (rho = 0.362, P = 0.030), respectively. Additionally, the distribution of body mass index was broader in women than in men. CONCLUSIONS: Interval walking training increased the reactive hyperemia index in men rather than in women. A higher variation in baseline body mass index may be associated with no statistical increase in reactive hyperemia index in women. Geriatr Gerontol Int 2023; 23: 103-110.

Effects of interval-walking training on blood pressure in community-dwelling Japanese older adults.

BACKGROUND: The hypotensive effects of high-intensity interval training have been reported; however, studies on older adults are few. This study aimed to examine whether interval-walking training (IWT), a home-based program of high-intensity interval training, reduces blood pressure (BP) levels when compared with a non-intervention group in community-dwelling older adults. METHODS: An intervention study was conducted with 55 men (age, 75±5 years; IWT/control groups, N.=27/28) and 100 women (75±5 years; N.=47/53). The IWT regimen was as follows: fast (high-intensity) walking at 70-85% of the peak aerobic capacity and normal (light-intensity) walking at approximately 40% of the peak aerobic capacity for 3 min each, ≥5 times/walking day, and ≥4 days/week for 5 months. Systolic, diastolic, and mean arterial BPs (SBP, DBP, and MAP, respectively) were measured in the supine posture. RESULTS: The mean baseline SBP/DBP was 132/78 mmHg in men and 131/72 mmHg in women. Five-month changes in SBP, DBP, or MAP did not significantly differ between the IWT and control groups in either sex. The weekly fast-walking time in the IWT group was negatively correlated with changes in DBP (Spearman's ρ=-0.383, P=0.049) and MAP (ρ=-0.444, P=0.021) only in men. CONCLUSIONS: Though present findings did not indicate significant hypotensive effects of IWT in community-dwelling older adults, men with longer fast-walking times experienced greater BP decreases. Further studies with sufficient sample sizes are needed to determine the factors modulating the effects of the proposed training program.

Effects of strengthening the hip flexor muscles on walking ability and the locomotive syndrome rank test: An intervention study.

BACKGROUND: Locomotive syndrome is a state in which locomotive function is decreased due to musculoskeletal diseases. To extend a healthy lifespan, it is important to prevent falls and locomotive syndrome development accompanying aging by slowing the decline in walking ability. However, it is unclear whether hip flexor muscle strengthening improves walking ability and locomotive syndrome. This study aimed to examine the effect of hip flexor muscle strengthening on walking ability and the locomotive syndrome rank test. METHODS: Forty participants were enrolled. Before hip flexor muscle strengthening, maximum muscle strength on the exercised side was measured, and gait analysis and the two-step test were performed simultaneously. Participants were divided into a healthy group and a locomotive syndrome group based on the two-step test and were given hip flexor muscle training at least three days a week for six weeks. After completing the training, maximum muscle strength was measured and gait analysis was performed for all participants. The difference between the two-step test conducted pre- and post-training in the locomotive syndrome group was statistically analyzed. RESULTS: Twenty-two and 14 participants were included in the healthy and the locomotive syndrome groups, respectively. Hip flexion strength on the exercised side increased from 1.68 to 1.95 Nm/kg (p < 0.0001) and 1.04 to 1.21 Nm/kg (p = 0.0031) in the healthy and the locomotive syndrome groups, respectively. Step length, stride length and walking speed measured by gait analysis also increased in both groups. Consequently, the two-step test score improved from 1.17 to 1.30 (p = 0.0002) and the stage of locomotive syndrome improved in 9 participants (p = 0.041). CONCLUSIONS: Strengthening of the hip flexor muscles improved walking ability and the stage of locomotive syndrome. Therefore, strengthening of the hip flexor muscles is important for the prevention and improvement of locomotive syndrome.

Measurements of ionic concentrations along with endocochlear potential in wild-type and claudin 14 knockout mice.

OBJECTIVE: To examine whether the changes in endolymphatic ion concentrations were involved in hair cells degeneration in claudin-14 knockout (KO) mice (Cldn14-/-), we measured the endocochlear potential (EP) along with concentrations of K+, Na+, H+, or Ca2+ ([K]e, [Na]e, pHe, [Ca]e) in Cldn14-/-, in which hair cells were selectively damaged, and compared with measurements in wild type mice (Wt). METHODS: We used the Cldn14-/- from 3 weeks of age, in which the auditory brain responses (ABR) was severely diminished. Using double-barreled ion-selective microelectrodes, we measured [K]e, [Na]e, pHe, and [Ca]e in both Wt and Cldn14-/- at 8-10 weeks of age. RESULTS: (1) In Wt, the EP was +92mV. [K]e, [Na]e, pHe, and [Ca]e were 169mM, ∼1.0mM, 7.50, and 395nM, respectively. In the Cldn14-/-, the EP was +96mV. [K]e, [Na]e, pHe, and [Ca]e were 167mM, ∼1.0mM, 7.73, and 179nM, respectively. No significant differences in the above values were observed between Wt and Cldn14-/-. (2) A significant linear correlation between EP and [Ca]e (R=0.93) was observed for both Wt and Cldn14-/-, but no correlation was observed between EP and K+, Na+, or H+. CONCLUSION: These findings suggest that (1) the changes in endolymphatic ion concentrations might not be involved in hair cells degeneration in Cldn14-/-, (2) [Ca]e might be regulated by EP in both Wt and Cldn14-/-.

[Expected Duties of Pharmacists and Potential Needs of Physicians and Nurses on a Kaifukuki Rehabilitation Ward].

This study investigated the required duties of pharmacists in a kaifukuki rehabilitation ward from the viewpoint of the ward physicians and nurses. A questionnaire survey was distributed to 27 facilities with kaifukuki rehabilitation wards. The questionnaire examined which duties the physicians and nurses expected from pharmacists while on the ward (4 areas, 10 items), as well as the time required for pharmacists to carry out those duties. Multivariate analysis was used to investigate which types of work took the most time for pharmacists on kaifukuki rehabilitation wards. Responses were received from 43 physicians and 184 nurses who worked on the kaifukuki rehabilitation wards of 19 facilities. The results revealed that the essential duties performed by pharmacists were the management of medical supplies, instruction on the use of self-medicating drugs at the time of introduction, and monitoring drug side effects. Furthermore, some duties, such as the distribution of medicines and changing or suggesting new drugs, required pharmacists to spend extended time on the ward. The responses indicated that physicians and nurses recognized the necessity for pharmacists to perform ward duties along with their routine work. This study shows that physicians and nurses working in kaifukuki rehabilitation wards demand proactive participation from pharmacists in appropriate medical therapy, such as instruction in the administration of medications and assessment at the time of prescription changes.

Zebrafish mutants of the neuromuscular junction: swimming in the gene pool.

This review provides an overview of zebrafish mutants with dysfunctional acetylcholine receptors or related proteins at the neuromuscular junction (NMJ). The NMJ, which has served as the classical model of the chemical synapse, uses acetylcholine as the neurotransmitter, and mutations of proteins involved in the signaling cascade lead to a variety of behavioral phenotypes. Mutants isolated after random chemical mutagenesis screening are summarized, and advances in the field resulting from these mutants are discussed.

Association between muscle mass and disability in performing instrumental activities of daily living (IADL) in community-dwelling elderly in Japan.

This study describes the association between low muscle mass and disability in performing IADL in elderly, community-dwelling Japanese subjects. Subjects were 1268 elderly, community-dwelling Japanese aged 65 years or older. Low muscle mass was defined by appendicular muscle mass index (AMI, weight [kg]/height [m(2)]), measured by bioelectrical impedance analysis (BIA). We classified "middle" AMI as a value 1-2 standard deviation (SD) below the young normal mean of AMI and "low" as more than 2 SD below the young normal mean. Examination of IADL was performed using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) questionnaire. In this study, 17.2% and 26.2% of elderly men and women, respectively, were classified as having low muscle mass. There was a significant association with age and the change from normal to middle to low muscle mass in both men and women. The prevalence of IADL disability also increased significantly as muscle mass decreased. After adjustment for age and BMI, low muscle mass was significantly associated with IADL disability in men and women. Furthermore, middle muscle mass was significantly associated with IADL disability in women. This study revealed that low muscle mass, defined as a value 2 SD below the mean of young adults, had a significant association with IADL disability in elderly Japanese. Interventions to prevent age-related losses in muscle mass may be an effective strategy to prevent IADL disability among the elderly.

Assessment of the best gait parameter in relation to bone status in community-dwelling young-old and old-old women in Japan.

Even if physical exercise contributes to bone health of the elderly, intense activities have the potential to worsen the risk of osteoporosis. This fact and the inevitable decrease of mobility with age increase the likelihood that the mobility parameter that best benefits bone health differs with age. The aim of this study was to objectively assess the gait parameter that most strongly influences bone health of young-old and old-old women. Subjects comprised 200 community-dwelling elderly women (132 young-old, 68 old-old) registered at welfare centers for the aged. Bone status was examined in the right heel by quantitative ultrasound (QUS) and indicated as stiffness index (SI). Gait parameters including usual and maximum walking speed (UWS and MWS, respectively), daily walking steps (DWS), obstacle-negotiating gait, and stair-climbing were examined objectively. Other bone-related physical factors (body components, handgrip strength, and masticatory function) were measured and adjusted while performing assessment. After adjustment for covariates, multiple linear regression analysis showed that MWS had the strongest association with SI in young-old women and DWS had the strongest association with SI in old-old women. To prevent osteoporosis, brisk walking exercise and engaging in movement in everyday life, respectively, should be advocated for young-old women and old-old women in Japan.

Factors associated with good self-rated health of non-disabled elderly living alone in Japan: a cross-sectional study.

BACKGROUND: Self-rated health (SRH) is reported as a reliable predictor of disability and mortality in the aged population and has been studied worldwide to enhance the quality of life of the elderly. Nowadays, the elderly living alone, a particular population at great risk of suffering physical and mental health problems, is increasing rapidly in Japan and could potentially make up the majority of the aged population. However, few data are available pertaining to SRH of this population. Given the fact that sufficient healthcare is provided to the disabled elderly whereas there is little support for non-disabled elderly, we designed this population-based survey to investigate SRH of non-disabled elderly living alone and to identify the factors associated with good SRH with the purpose of aiding health promotion for the elderly. METHODS: A cross-sectional study was conducted in a metropolitan suburb in Japan. Questionnaires pertaining to SRH and physical conditions, lifestyle factors, psychological status, and social activities, were distributed in October 2005 to individuals aged > or = 65 years and living alone. Response rate was 75.1%. Among these respondents, a total of 600 male and 2587 female respondents were identified as non-disabled elderly living alone and became our subjects. Multivariate logistic regression was used to identify the factors associated with good SRH and sex-specific effect was tested by stepwise logistic regression. RESULTS: Good SRH was reported by 69.8% of men and 73.8% of women. Multivariate logistic regression analysis showed that good SRH correlated with, in odds ratio sequence, "can go out alone to distant places", no depression, no weight loss, absence of self-rated chronic disease, good chewing ability, and good visual ability in men; whereas with "can go out alone to distant places", absence of self-rated chronic disease, no weight loss, no depression, no risk of falling, independent IADL, good chewing ability, good visual ability, and social integration (attend) in women. CONCLUSION: For the non-disabled elderly living alone, sex-appropriate support should be considered by health promotion systems from the view point of SRH. Overall, the ability to go out alone to distant places is crucial to SRH of both men and women.