The association of objectively measured physical activity and sedentary behavior with skeletal muscle strength and muscle power in older adults: A systematic review and meta-analysis

Investigating age-related differences in muscles of Kazakh horse through transcriptome analysis

This study conducted transcriptome sequencing on the skeletal muscles of three different anatomical locations across various growth stages to investigate the impact of ages on crucial candidate genes and molecular mechanisms associated with muscle development in Kazakh horses. Sixteen Kazakh horses were selected, and they were divided into four age groups, each with four biological replicates. Tissue samples from the longest dorsal muscle, abdominal muscle, and diaphragm muscle were collected for analysis. The results revealed differential mRNA expression in the longest dorsal muscle between the eight-month group (Group O) and the 10-year group (Group F), with 434 up-regulated and 322 down-regulated genes. In the abdominal muscle, there were 125 up-regulated and 127 down-regulated genes, while in the diaphragm muscle, there were 73 up-regulated and 70 down-regulated genes. In this study, GO enrichment analysis focused on biological processes. KEGG pathway analysis highlighted the Oxidative Phosphorylation pathway for the longest dorsal muscle, annotating 37 differentially expressed genes (DEGs), including ATP5PF, NDUFB8, and ATP5MG, all of which were down-regulated. For the abdominal muscle, the ECM-receptor interaction pathway was enriched, annotating 7 DEGs such as COL4A2, COL4A1, and ITGA5. In the diaphragm muscle, the Hippo signaling pathway was enriched, annotating 6 DEGs, including SERPINE1, RASSF1, and FZD10. This study provides robust data support and a theoretical foundation for a comprehensive understanding of the influence of age on skeletal muscle development in horses.

The Effects of Load, Crank Position, and Sex on the Biomechanics and Performance during an Upper Body Wingate Anaerobic Test

INTRODUCTION

The upper body Wingate Anaerobic Test (WAnT) is a 30-s maximal effort sprint against a set load (percentage of body mass). However, there is no consensus on the optimal load and no differential values for males and females, even when there are well-studied anatomical and physiological differences in muscle mass for the upper body. Our goal was to describe the effects of load, sex, and crank position on the kinetics, kinematics, and performance of the upper body WAnT.

METHODS

Eighteen participants (9 females) performed three WAnTs at 3%, 4%, and 5% of body mass. Arm crank forces, 2D kinematics, and performance variables were recorded during each WAnT.

RESULTS

Our results showed an increase of ~49% effective force, ~36% peak power, ~5° neck flexion, and ~30° shoulder flexion from 3% to 5% load ( P < 0.05). Mean power and anaerobic capacity decreased by 15%, with no changes in fatigue index ( P < 0.05). The positions of higher force efficiency were at 12 and 6 o'clock. The least force efficiency occurred at 3 o'clock ( P < 0.05). Sex differences showed that males produced 97% more effective force and 109% greater mean power than females, with 11.7% more force efficiency ( P < 0.001). Males had 16° more head/neck flexion than females, and females had greater elbow joint variability with 17° more wrist extension at higher loads. Males cycled ~32% faster at 3% versus 5% WAnT load with a 65% higher angular velocity than females. Grip strength, maximal voluntary isometric contraction, mass, and height positively correlated with peak and mean power ( P < 0.001).

CONCLUSIONS

In conclusion, load, sex, and crank position have a significant impact on performance of the WAnT. These factors should be considered when developing and implementing an upper body WAnT.

Association between handgrip strength and physical activity: A nationwide population-based study in Korea

BACKGROUND

This study investigated the association between handgrip strength (HGS) and physical activity (PA) at different levels in Korean adults for the purpose of providing direction for increasing HGS, which represents muscular strength, and increasing understanding of PA and HGS.

METHODS

This study targeted adults aged ≥30 years from the Korean National Health and Nutrition Examination Survey (2014-2019), including 31,888 participants for analysis. HGS was defined as the maximum value of the three measurements of the dominant hand. PA was defined as an activity that causes shortness of breath or a fast heartbeat. Data were weighted according to survey district and household data; p < .05 was considered statistically significant.

RESULTS

In men, HGS in those aged 30-64 years was significantly associated with high-intensity PA and in those aged ≥65 years was associated with moderate-intensity PA. In women, HGS in those aged 30-64 years was also significantly associated with high-intensity PA, and in those aged ≥65 years, it was significantly associated with both moderate- and high-intensity PA. Moreover, compared to participants who did not participate in weight training, those who participated showed higher HGS in both sexes.

CONCLUSIONS

This study demonstrated age- and sex-specific characteristics of the association between HGS and PA in Koreans. The findings suggest the importance of managing health by considering differences in age- and sex-related PA. In particular, this study suggests that adequate PA is necessary despite its importance of PA for elderly individuals.

Daily physical activity in older adults across levels of care: the HUNT Trondheim 70 + study

BACKGROUND

Physical activity (PA) is imperative for healthy ageing and is a modifiable lifestyle factor. Accurate, clinically meaningful estimates of daily PA among older adults can inform targeted interventions to maintain function and independence. This study describes daily PA in older adults across levels of care as a first step contributing to the limited evidence on potential associations between PA and the use of care services.

METHODS

This study used data from the Trondheim 70 + cohort in the population-based Norwegian HUNT Study. In total, 1042 participants aged 70 years or older with valid activity data were included. PA was assessed using two accelerometers over 7 consecutive days and was classified into PA (walking, standing, running, and cycling) and sedentary behavior (sitting and lying). Data on received care services were retrieved from municipal registers and participants were classified into four levels of care: 1) independently living (81.9%), 2) independently living with low-level home care services (6.5%), 3) recipients of home care services (6.0%), and 4) nursing home residents (5.7%). Time spent in the activity types and duration of bouts are presented across levels of care.

RESULTS

Participants mean age was 77.5 years (range: 70.1-105.4, 55% female) and PA was lower with higher age. Across levels of care, significant group differences were found in the total time spent in PA, particularly in walking and standing. Daily PA, duration of active bouts, and number of daily walking bouts were lower for participants receiving higher levels of care. Standing was the dominant type of PA and walking appeared predominantly in short bouts at all care levels.

CONCLUSIONS

This is the first population-based study using device-measured PA to describe daily PA across levels of care. The results showed that low-intensity activities constitute the primary component of everyday PA, advocating for placing greater emphasis on the significant role these activities play in maintaining daily PA at older age. Furthermore, the study demonstrated that activity types and bout durations are related to the ability to live independently among older adults. Overall, these findings can contribute to better target interventions to maintain function and independence in older adults.

Instruments for measuring the neuromuscular function domain of vitality capacity in older persons: an umbrella review

PURPOSE

Recently, handgrip, knee extensor and respiratory muscle strength were proposed as candidate biomarkers to assess the neuromuscular function of vitality capacity in older persons. This umbrella review aims to provide an overview of the available instruments and their measurement properties to assess these biomarkers.

METHODS

The databases PubMed, Web of Science and Embase were systematically screened for systematic reviews and meta-analyses reporting on handgrip, knee extensor or respiratory muscle strength assessments, resulting in 7,555 articles. The COSMIN checklist was used to appraise psychometric properties and the AMSTAR for assessing methodological quality.

RESULTS

Twenty-seven systematic reviews were included in this study. Some of the identified reviews described the psychometric properties of the assessment tools. We found five assessment tools that can be used to measure neuromuscular function in the context of healthy ageing. Those are the handheld dynamometer for handgrip strength, the dynamometer for knee extensor strength and regarding respiratory muscle strength, the sniff nasal inspiratory pressure, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP).

CONCLUSION

The handheld dynamometer for hand grip strength, the dynamometer for knee extensor strength, sniff nasal inspiratory pressure, MIP and MEP were identified. Therefore, these assessments could be used to identify community-dwelling older adults at risk for a declined neuromuscular function in the context of vitality capacity.

Associations between accelerometer-measured physical activity and sedentary behaviour with physical function among older women: a cross-sectional study

BACKGROUND

This study aimed to investigate the relationships between accelerometer-measured physical activity (PA) and sedentary behaviour (SB) with physical function (PF) among older Chinese women in the community.

METHODS

The present study comprised 1,113 community-dwelling older females, with an average age of 65 ± 2 years. We employed a linear regression analysis to investigate the relationship between patterns of PA and SB with PF. PA variables consisted of total PA time, bouted PA time (a continuous PA that lasts equal to or more than 10 min), and sporadic PA time (a continuous PA that lasts less than 10 min). SB variables included total SB time, 30-min bout of SB (a continuous SB that lasts equal to or more than 30 min), and 60-min bout of SB (a continuous SB that lasts equal to or more than 60 min). PF variables comprised handgrip strength (HGS), one-legged stance test with eyes closed (OLSTEC), usual walking speed (UWS), maximum walking speed (MWS) and chair-stand time (CT). To explore the joint effects of moderate-to-vigorous-intensity PA (MVPA) and SB on PF, we divided the duration of SB and MVPA participation in older women into different combinations: low MVPA & high SB, low MVPA & low SB, high MVPA & high SB, high MVPA & low SB.

RESULTS

The study revealed a significant association between 30-min bout of SB and CT, which remained after adjusting for total MVPA time (P = 0.021). Both total MVPA and bouted MVPA were found to be positively associated with better UWS, MWS, CT, and PF Z-score. When the combination of low MVPA & high SB was used as a reference, the regression coefficients for PF ascended by 1.32 (P < 0.001) in the high MVPA & high SB group and by 1.13 (P < 0.001) in the high MVPA & low SB group.

CONCLUSIONS

A significant association was observed between poorer lower limb function and prolonged, uninterrupted SB in older women, rather than with the total SB time. Concurrently, the insufficient engagement in MVPA may also be a crucial factor contributing to poorer PF in older women. Engaging in longer durations and higher intensity of PA, such as bouts of MVPA lasting a minimum of 10 min or longer, may contribute to better PF.

Adherence to Mediterranean, Dietary Approaches to Stop Hypertension and Healthy Eating Indices are associated with lower risk of disability among Puerto Rican adults from the longitudinal Boston Puerto Rican Health Study

BACKGROUND

Emerging evidence suggests that poor dietary quality is an important risk factor for disability. However, few studies have compared adherence to dietary patterns with disability and none among Puerto Rican adults.

OBJECTIVES

This study was designed to examine relationships between 3 dietary patterns-including Dietary Approaches to Stop Hypertension (DASH), Mediterranean dietary score (MeDS), and Healthy Eating Index (HEI)-2010-and ∼6-y incidence of activities of daily living (ADL) and instrumental activities of daily living (IADL) disability and to assess potential mediation by handgrip strength.

METHODS

Data are from the Boston Puerto Rican Health Study, a longitudinal cohort of Puerto Rican adults aged 45-75 y (N = 1502). Adherence to dietary pattern variables were derived from food frequency questionnaire (FFQ) data averaged at baseline and ∼2 y. Handgrip strength was assessed at baseline. Cox proportional hazards models were used to assess longitudinal associations between DASH, MeDS, and HEI-2010 and incident ∼6-y ADL (and subscales) and IADL disability. Mediation by handgrip strength was also tested.

RESULTS

Participants with higher adherence DASH had lower risk of ADL, ADL mobility, and ADL manual dexterity disabilities (hazards ratio [HR]: 0.96; 95% confidence interval [CI]: 0.91, 0.98; HR: 0.96; 95% CI: 0.92, 0.99; and HR: 0.95; 95% CI: 0.92, 0.98, respectively). Higher adherence to MeDS was associated with lower risk of ADL and ADL mobility disabilities (HR: 0.89; 95% CI: 0.81, 0.98; HR: 0.90; 95% CI: 0.82, 1.00), and higher adherence to HEI with lower risk of ADL manual dexterity (HR: 0.98; 95% CI: 0.97, 0.99) in fully adjusted models. Only DASH tended to be associated with IADL (HR: 0.97; 95% CI: 0.94, 1.00). Baseline handgrip strength was a mediator between HEI and ADL manual dexterity (23.7% of the indirect effect was explained through handgrip strength).

CONCLUSIONS

Higher adherence to a healthy diet pattern may decrease risk of disability and may be an important prevention strategy for ADL and IADL disability associated with aging.

Cross-sectional interactive associations of physical activity and sedentary behaviour with physical capacity across adulthood

BACKGROUND

The way physical activity (PA) and sedentary behaviour (SB) independently and interactively modify the age-related decline in physical capacity remains poorly understood. This cross-sectional study investigated the independent and interactive associations of PA and SB with physical function and performance throughout the adult life course.

METHODS

Data from 499 community-dwelling adults (63% female) aged 20-92 years, involved in the INSPIRE Human Translational Cohort, were used in this cross-sectional study. Daily time spent on moderate-to-vigorous PA (MVPA, min/day) and SB (h/day) was measured with activPAL triaxial accelerometers. Physical function and performance were assessed through the measurement of the 4-m usual gait speed (m/s), handgrip strength (kg), lower-limb strength (isokinetic knee extension torque, N·m), estimated lower-limb power (five-time chair-rise test performance, s) and cardiorespiratory fitness (V̇O2max, mL/kg/min). Confounder-adjusted multiple linear and curvilinear regressions were performed to investigate how MVPA, SB and their interactions were associated with the physical outcomes (all square root-transformed except gait speed) throughout the adulthood spectrum.

RESULTS

Interaction analyses revealed that the combination of higher levels of MVPA with lower levels of SB favourably reshaped the negative relationship between handgrip strength and age (age2 × SB × MVPA: B = -7E-08, SE = 3E-08, P < 0.05). In addition, higher levels of MVPA were independently associated with an improved age-related profile in gait speed (age2 × MVPA: B = 3E-06, SE = 1E-06, P < 0.05), chair-rise performance (age × MVPA: B = -9E-05, SE = 4E-05, P < 0.05) and V̇O2max (MVPA at 21 years: B = 3E-02, SE = 7E-03, P < 0.05; age × MVPA: B = -5E-04, SE = 2E-04, P < 0.05). Conversely, the detrimental association of age with lower-limb muscle strength (age × SB: B = -1E-04, SE = 6E-05, P < 0.05) and chair-rise performance (age × SB: B = 1E-05, SE = 7E-06, P < 0.05) was exacerbated with increasing duration of SB, independently of MVPA. Supplementary analyses further revealed that some of these associations were age and sex specific.

CONCLUSIONS

This cross-sectional study demonstrated that reduced sedentary time and increased activity duration were independently and synergistically associated with an attenuated age-related loss in physical capacity. These findings need to be confirmed with longitudinal data but encourage both adopting an active lifestyle and reducing sedentary time as preventive measures against physical aging.

Are accelerometer-measured sitting and physical activity times associated with muscle mass and strength in healthy young adults in the UAE?

Background

A high prevalence of obesity, sedentary behavior, and physical inactivity could affect muscle mass and strength in young adults in the United Arab Emirates (UAE). Therefore, we investigated the association of sex, body mass index (BMI), and accelerometer-measured sitting and physical activity (PA) times with skeletal muscle mass index (SMI), hand grip, and thigh muscle strength in healthy young adults in the UAE.

Methods

In this cross-sectional study, 156 healthy young adults (age 21.68 ± 3.01 years, BMI 25.40 ± 4.79 kg/m2, 52.6 % women) were included. BMI and muscle mass were recorded using a bioelectrical impedance analyzer. Maximum hand grip strength and thigh muscle torque were assessed using the Jamar-smart hand-dynamometer and Biodex System-4-Pro, respectively. Participants wore a triaxial Fibion accelerometer on their anterior thigh for >10 h per day for 4-7 days to measure their sitting and PA times. Multiple linear regression analyses were used.

Results

Participants spent most of their time sitting (11.37 ± 1.10 h), followed by standing (2.92 ± 0.86 h), walking (1.58 ± 0.55 h), and vigorous intensity PA (4.79 ± 5.85 min) per 16-h day. Sex (p < 0.001) and BMI (p < 0.001) were negatively associated with all muscle mass and strength variables. Men had more muscle mass and strength than women. As BMI increased, muscle mass and muscle strength decreased. Accelerometer-measured sitting and walking times were negatively associated with concentric hamstrings (p = 0.044) and quadriceps torques (p = 0.031), respectively.

Conclusion

Sex, BMI, and accelerometer-measured sitting and walking times were associated with muscle mass and/or muscle strength in healthy young adults. Women and those with a high BMI need interventions to improve their muscle mass and strength. The paradox regarding the association of PA with muscle mass and strength in younger adults may be due to possible influences from other factors (e.g., resistance training, dietary intakes, etc.) superseding that of accelerometer-measured PA.

Longitudinal association of grip strength with cardiovascular and all-cause mortality in older urban Lithuanian population

BACKGROUND

Ageing populations experience greater risks associated with health and survival. It increases the relevance of identifying variables associated with mortality. Grip strength (GS) has been identified as an important biomarker for all cause and cardiovascular mortality, however, its prognostic value has not been studied in Lithuania. The aim of the present study is to evaluate the relationship of GS to vital status in a representative sample of the Lithuanian 45-72-year-old urban population during the period of 12 years of follow-up and to explore associations of GS with all-cause mortality and mortality from cardiovascular diseases (CVD).

METHODS

Within the framework of the international study Health, Alcohol and Psychosocial Factors in Eastern Europe (HAPIEE) 7,115 men and women 45-72 years of age were examined in the baseline survey (2006 to 2008). Data from the Official Lithuanian Mortality Register were used to evaluate CVD and all-cause mortality from follow-up till 2020. Cox proportional hazards regression was used, and four models for all-cause and CVD mortality were assessed.

RESULTS

The mean GS was significantly higher among survivors' men and women as compared to individuals deceased from CVD and other causes of death. In survivor men and women groups, minimal values of GS in all terciles were higher as compared to all three deceased groups. In both men and women groups, the lowest GS (1st tercile) was associated with a significantly higher risk of all-cause and CVD mortality as compared to the highest levels of GS (3rd tercile) in three Cox regression models. In both men and women were found to have a 1.34- and 1.35-fold higher risk of all-cause mortality, respectively, at lower GS, but no significant difference in the risk of CVD mortality. When GS was treated in all models as decrement per 1 kg and decrement per 1 SD, in both men and women, the risk of all-cause mortality significantly increased with decreasing of GS.

CONCLUSIONS

The mean GS was significantly higher among survivors' men and women as compared to deceased from CVD and other causes of death. Risk of all-cause mortality significantly increased with decreasing of GS.

Exercise as a falls prevention strategy in the care of older people

Older people who sustain a fall may experience a range of adverse outcomes, such as distress, injury and loss of independence. Falls increase the risk of frailty and frailty increases the risk of falls. Regular exercise is a pillar of falls prevention and can have extensive benefits for older people's health, well-being and ability to undertake activities they enjoy. As part of the multidisciplinary team, nurses have a pivotal role in implementing exercise-based falls prevention strategies for older people and in encouraging their patients to exercise. This article discusses exercise as a falls prevention strategy in hospital and in the community and supports nurses to develop their knowledge and confidence in promoting exercise in older people.

Association of life-space with light-intensity and moderate to vigorous-intensity physical activity in older adults using daycare rehabilitation facilities

BACKGROUND

The use of assistive devices and the presence of caregivers in the living space of older people using daycare rehabilitation facilities may increase their physical activity. However, the exact relationship between these factors and physical activity has not been well established.

OBJECTIVE

We aimed to examine whether assistive devices and caregivers were life-space factors associated with light-intensity physical activity (LPA) and moderate to vigorous-intensity physical activity (MVPA) among daycare rehabilitation facility users.

METHODS

Forty-seven daycare rehabilitation facility users were recruited (mean age: 76.5 ± 8.6 years; men: 16; women: 31). LPA and MVPA were measured using accelerometers and averaged over 7 days. Life-space assessment (LSA) and the Geriatric Depression Scale score were assessed. The LSA includes composite life-space, maximal life-space (LS-M), life-space using equipment (LS-E), and independent life-space. Grip strength and maximum gait speed were measured two times, and the best results were used.

RESULTS

Multiple regression analysis showed that LPA was significantly associated with sex (β = 0.773), grip strength (β = 0.434), and LS-M (β = 0.325), whereas MVPA was significantly associated with age (β = -0.421) and LS-E (β = 0.455).

CONCLUSION

A close association was found between LS-M and LS-E and the intensity of physical activity in older people who used daycare rehabilitation facilities.

Association Between Typologies of Sedentary Behavior and Muscle Strength, Gait Speed, and Balance in Community-Dwelling Older Adults

Knowledge of how the different types of sedentary behaviors (SB) are associated with functional limitations can guide professionals who work with older adults on better recommendations about the amount of daily time that should be encouraged in each type of SB. The objective was to estimate the associations between two SB typologies (SB television [TV] and SB computer/internet) and the presence of handgrip strength, lower limb strength, gait speed, and balance limitations in Brazilian community-dwelling older adults. This is a cross-sectional study with 1,298 community-dwelling older adults (≥60 years). SB was assessed by self-reporting daily time spent watching TV or using computer/internet (categorized into <2, 3-4, and ≥5 hr/day). Outcomes were handgrip strength, lower limb strength, gait speed, and balance limitations considering referenced cutoff points. Older adults in SB TV ≥5 hr/day had 1.75 (95% confidence interval [CI] [1.07, 2.86]) and 1.88 (95% CI [1.02, 3.46]) times more chances of handgrip strength and gait speed limitations, respectively. On the other hand, those who spent 3-4 and ≥5 hr/day in SB computer/internet had 0.45 (95% CI [0.20, 0.99]) and 0.37 (95% CI [0.15, 0.93]) had less chances of lower limb strength and balance limitations, respectively. In conclusion, functional limitations would be associated differently depending on the type of SB in the older adults sampled.

Powerpenia Should be Considered a Biomarker of Healthy Aging

To identify biomarkers that precede the decline of human function and independence during the lifespan, two important concepts have been introduced in recent decades: sarcopenia and dynapenia. While the former is originally focused on skeletal muscle loss, the latter is on maximal strength loss. Although the dynapenia concept implies the inclusion of skeletal muscle power, in practical terms, this has not been specifically addressed. For instance, only 2 out of 220 studies published between 2008 and 2023 have directly measured muscle power to classify individuals with dynapenia. As previous studies have shown a greater relevance of skeletal muscle power in healthy aging, we hereby propose the introduction of the term "powerpenia" to specifically reflect the loss of skeletal muscle power along lifespan, but also with disease and/or physical inactivity. Together with sarcopenia and dynapenia, we contend that powerpenia should be considered a biomarker of healthy aging.

The relationship between sarcopenia and metabolic dysfunction-associated fatty liver disease among the young and middle-aged populations

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) has been proposed as a new term for diagnosing fatty liver disease, which is considered to be a multi-systemic disease with multiple extrahepatic manifestations, including sarcopenia. The link between sarcopenia and MAFLD remains uncertain, especially among young and middle-aged adults. Thus, we examined the relationship between MAFLD and sarcopenia in young and middle-aged individuals in this study.

METHODS

A total of 2214 individuals with laboratory tests, dual-energy X-ray absorptiometry and ultrasound transient elastography from NHANES 2017-2018 were selected for this study. MAFLD was diagnosed as fatty liver disease with any one of the situations: overweight/obesity, diabetes mellitus, presence of metabolic dysregulation. Sarcopenia was defined by appendicular lean mass adjusted for body mass index (BMI). Multivariable logistic regression and restricted cubic spline (RCS) model were applied to explore the relationship between MAFLD and sarcopenia, and the mediation analyses were also conducted. Moreover, subgroup analyses stratified by BMI and lifestyles were done.

RESULTS

The prevalence of MAFLD was 47.85%, and nearly 8.05% of participants had sarcopenia. The prevalence of sarcopenia was higher in participants with MAFLD (12.75%; 95% CI 10.18-15.31%) than in the non-MAFLD (3.73%; 95% CI 2.16-5.31%). MAFLD was significantly positively associated with sarcopenia after adjustments [OR = 2.87 (95% CI: 1.62-5.09)]. Moreover, significant positive associations were observed between liver fibrosis and sarcopenia prevalence in MAFLD patients (OR = 2.16; 95% CI 1.13-4.15). The RCS curve revealed that MAFLD was linearly associated with sarcopenia. The relationship between the MAFLD and sarcopenia were mediated by C-reactive protein (mediation proportion: 15.9%) and high-density lipoprotein cholesterol (mediation proportion: 18.9%). Subgroup analyses confirmed the association between MAFLD and sarcopenia differed in different lifestyle groups.

CONCLUSIONS

Both MAFLD prevalence and severity was significantly associated with sarcopenia. Thus, clinicians should advise comorbidity screening and lifestyle changes to young and middle-aged patients.

Differential association between physical activity behaviours and dynapenia by comorbid diseases in community-dwelling Korean older adults

BACKGROUND

Physical activity (PA) behaviours and comorbid diseases are associated with muscle strength. However, the association between dynapenia and detailed PA behaviours, including participation in aerobic and resistance exercises and sedentary behaviour (SB), in relation to comorbid diseases has not yet been investigated. Using nationwide data, this study aimed to evaluate the independent association of dynapenia with detailed PA behaviour (participation in aerobic and resistance exercises and SB), and assess the differential associations of detailed PA behaviour with dynapenia according to comorbid diseases with prevalent sarcopenia.

METHODS

A total of 7,558 community-dwelling older adults aged ≥ 65 years who were included in the Korea National Health and Nutrition Examination Survey from 2014 to 2019 were included in the present study. Cross-sectional associations between PA behaviours (participation in aerobic exercise, participation in resistance exercise, and SB) and dynapenia were analysed using complex-sample multivariable-adjusted logistic regression models according to the type of comorbid disease (cardiovascular disease [CVD], diabetes mellitus [DM], and chronic lung disease [CLD]).

RESULTS

Sufficient aerobic exercise, sufficient resistance exercise, and low sedentary time of < 420 min/day showed independent negative associations with dynapenia (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.60-0.83; OR, 0.54; 95% CI, 0.42-0.69; and OR, 0.84; 95% CI, 0.72-0.97, respectively). Among the participants with CVD or CLD, the associations of sufficient resistance exercise (OR, 0.46; 95% CI, 0.26-0.82 and OR, 0.51; 95% CI, 0.35-0.75 for CVD and CLD, respectively) and low sedentary time (OR, 0.66; 95% CI, 0.45-0.98 and OR, 0.71; 95% CI, 0.55-0.93 for CVD and CLD, respectively) with dynapenia were significant, whereas the association of sufficient aerobic exercise with dynapenia was insignificant. Meanwhile, in participants with DM, sufficient aerobic exercise (OR, 0.70; 95% CI, 0.52-0.94) and sufficient resistance exercise (OR, 0.45; 95% CI, 0.29-0.70) were independently associated with dynapenia, whereas no association between SB and dynapenia was found.

CONCLUSION

We observed an independent inverse association between PA behaviours and dynapenia. Disease-specific associations between each PA behaviour (sufficient aerobic exercise, sufficient resistance exercise, and low sedentary time) and dynapenia differed in the older adults. Therefore, these differences should be acknowledged during interventions for this population.

Association of the Combination of Moderate-to-Vigorous Physical Activity and Sleep Quality with Physical Frailty

BACKGROUND

The association of the individual and combined effects of moderate-to-vigorous physical activity (MVPA) and sleep quality with physical frailty in community-dwelling older adults is still unknown.

SUBJECTS AND METHODS

A cross-sectional study was conducted with a sample of older adults who had not required nursing care or support services. Physical frailty was assessed using Liu's definition based on Fried's concept. MVPA was measured by a triaxial accelerometer, and individuals who met either moderate physical activity (MPA) for ≥300 min/week, vigorous physical activity (VPA) for ≥150 min/week, or both were defined as "MVA+". "SLP+" was defined as a Pittsburgh Sleep Quality Index score of <5.5 points.

RESULTS

A total of 811 participants were included in the final analysis. After adjusting for the multivariable confounding factors, the odds ratios (ORs) and 95% confidence intervals (CIs) for physical pre-frailty and frailty in the MVA-SLP+ (OR, 2.56; 95%CI, 1.80-3.62) and the MVA-SLP- group (OR, 3.97; 95%CI, 2.33-6.74) were significantly higher compared with the MVA+SLP+ group.

CONCLUSION

Community-dwelling older adults who did not meet the MVPA criteria, regardless of sleep quality, had a higher prevalence of physical frailty.

Sedentary behavior and the combination of physical activity associated with dementia, functional disability, and mortality: A cohort study of 90,471 older adults in Japan

OBJECTIVE

To examine the associations of sedentary behavior (SB) and the combination of moderate-to-vigorous intensity physical activity (MVPA) with dementia, functional disability, and mortality in older adults, and the heterogeneity in different subpopulations.

METHODS

Nation-wide cohort with 90,471 individuals aged ≥65 years in Japan. SB (<3, 3-<8, and ≥ 8 h per day [h/d]) and MVPA (0, 0 < MVPA<1, and ≥ 1 h/d) were measured in 2016. Long-term care registry-based incidence of outcomes was ascertained through 2021. Cox proportional hazard models were performed.

RESULTS

Compared with SB < 3 h/d group, SB ≥ 8 h/d was associated with higher risks of dementia, functional disability, and mortality with hazard ratios (95% confidence interval) of 1.36 (1.22-1.52), 1.32 (1.19-1.48), and 1.31 (1.18-1.45). The combination of MVPA and SB demonstrated a dose-respond trend of increasing risks of dementia, functional disability, and mortality with increased SB and decreased MVPA, where participants who spent no MVPA with SB ≥ 8 h/d had the highest risks. High MVPA attenuated but didn't eliminate the risks. Participants who spent MVPA≥1 h/d with SB ≥ 8 h/d had comparable risks to those who spent no MVPA with SB < 3 h/d. No heterogeneity was found by MVPA levels, sex, education, comorbidity, and depression conditions.

CONCLUSIONS

Prolonged daily SB was associated with higher risks of dementia, functional disability, and mortality in older adults, regardless of MVPA, sex, education, and chronic conditions. Individuals with high MVPA also face considerable risks when engaging in high SB. High MVPA with high SB revealed a comparable risk to no MVPA with low SB.

Muscle strength and non-alcoholic fatty liver disease/metabolic-associated fatty liver disease

This editorial comments on an article published in a recent issue of World Journal of Gastroenterology, entitled “Association of low muscle strength with metabolic dysfunction-associated fatty liver disease: A nationwide study”. We focused on the association between muscle strength and the incidence of non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD), as well as the mechanisms underlying the correlation and related clinical applications. NAFLD, which is now redefined as MAFLD, is one of the most common chronic liver diseases globally with an increasing prevalence and is characterized by malnutrition, which may contribute to decreased muscle strength. Reduction of muscle strength reportedly has a pathogenesis similar to that of NAFLD/ MAFLD, including insulin resistance, inflammation, sedentary behavior, as well as insufficient vitamin D. Multiple studies have focused on the relationship between sarcopenia or muscle strength and NAFLD. However, studies investigating the relationship between muscle strength and MAFLD are limited. Owing to the shortage of specific medications for NAFLD/MAFLD treatment, early detection is essential. Furthermore, the relationship between muscle strength and NAFLD/MAFLD suggests that improvements in muscle strength may have an impact on disease prevention and may provide novel insights into treatments including dietary therapy, as well as tailored physical activity.

Association of physical behaviours with sarcopenia in older adults: a systematic review and meta-analysis of observational studies

BACKGROUND

Physical behaviours (ie, physical activity and sedentary behaviour) might have a role in the development of sarcopenia, although the evidence is unclear. We aimed to explore the association of total and intensity-specific levels of physical activity and sedentary behaviour with sarcopenia and its components (ie, muscle mass, muscle strength, and physical performance) in older adults.

METHODS

We conducted a systematic review and meta-analysis and searched MEDLINE (via PubMed), Scopus, and Web of Science from inception to July 26, 2022, for peer-reviewed, observational studies or baseline data from randomised clinical trials conducted in older adults (ie, individual age ≥60 years or mean age ≥65 years) and published in English that reported on the association of physical activity or sedentary behaviour or both with sarcopenia (or its determinants: muscle mass or strength, and physical performance). Physical activity and sedentary behaviour were measured by any method. The main outcome was sarcopenia, which could be diagnosed by any means. Estimates were extracted and pooled using Bayesian meta-analytic models and publication bias was assessed using the Egger's test. This study is registered with PROSPERO, CRD42022315865.

FINDINGS

We identified 15 766 records, of which 124 studies (230 174 older adults; 121 301 [52·7%] were female and 108 873 [47·3%] were male) were included in the systematic review. 86 studies were subsequently included in the meta-analysis. Higher levels of total physical activity were inversely associated with sarcopenia both cross-sectionally (21 studies, n=59 572; odds ratio 0·49, 95% credible interval 0·37-0·62) and longitudinally (four studies, n=7545; 0·51, 0·27-0·94). A protective association was also identified for moderate-to-vigorous physical activity in cross-sectional research (five studies, n=6787; 0·85, 0·71-0·99), whereas no association was identified for the remaining physical behaviours (ie, steps, light physical activity, or sedentary behaviour).

INTERPRETATION

Total and moderate-to-vigorous physical activity are inversely associated with sarcopenia. These findings might support the importance of moderate-to-vigorous, rather than light, intensity physical activity-based interventions to prevent sarcopenia.

FUNDING

None.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Physical activity, sedentary behavior, and the risk of frailty and falling: A Mendelian randomization study

BACKGROUND

Due to inconclusive evidence from observational studies regarding the impact of physical activity (PA) and sedentary behavior on frailty and falling risk, we conducted a two-sample Mendelian randomization analysis to investigate the causal associations between PA, sedentary behavior, and frailty and falls.

METHODS

We extracted summary data from genome-wide association studies conducted among individuals of European ancestry, encompassing PA (n = 90 667-608 595), sedentary behavior (n = 372 609-526 725), frailty index (n = 175 226), and falling risk (n = 451 179). Single nucleotide polymorphisms associated with accelerometer assessed fraction >425 milligravities, self-reported vigorous activity, moderate to vigorous physical acticity (MVPA), leisure screen time (LST), and sedentary behavior at work were taken as instrumental variables. The causal effects were primarily estimated using inverse variance weighted methods, complemented by several sensitivity and validation analyses.

RESULTS

Genetically predicted higher levels of PA were significantly associated with a reduction in the frailty index (accelerometer assessed fraction >425 milligravities: β = -0.25, 95% CI = -0.36 to -0.14, p = 1.27 × 10-5 ; self-reported vigorous activity: β = -0.13, 95% CI = -0.20 to -0.05, p = 7.9 × 10-4 ; MVPA: β = -0.28, 95% CI = -0.40 to -0.16, p = 9.9 × 10-6 ). Besides, LST was significantly associated with higher frailty index (β = 0.18, 95% CI = 0.14-0.22, p = 5.2 × 10-20 ) and higher odds of falling (OR = 1.13, CI = 1.07-1.19, p = 6.9 × 10-6 ). These findings remained consistent throughout sensitivity and validation analyses.

CONCLUSIONS

Our study offers evidence supporting a causal relationship between PA and a reduced risk of frailty. Furthermore, it underscores the association between prolonged LST and an elevated risk of frailty and falls. Therefore, promoting PA and reducing sedentary behavior may be an effective strategy in primary frailty and falls prevention.

Seven knowledge gaps in modern biogerontology

About a year ago, members of the editorial board of Biogerontology were requested to respond to a query by the editor-in-chief of the journal as to what one question within their field of ageing research still needs to be asked and answered. This editorial is inspired by the wide range and variety of questions, ideas, comments and suggestions received in response to that query. The seven knowledge gaps identified in this article are arranged into three main categories: evolutionary aspects of longevity, biological survival and death aspects, and heterogeneity in the progression and phenotype of ageing. This is not an exhaustive and exclusive list, and may be modified and expanded. Implications of these knowledge gaps, especially in the context of ongoing attempts to develop effective interventions in ageing and longevity are also discussed.

Preoperative physical activity is associated with prognosis in patients with esophageal cancer undergoing thoracoscopic-laparoscopic esophagectomy after neoadjuvant chemotherapy

OBJECTIVE

This study examined the association between a single preoperative physiotherapy session during neoadjuvant chemotherapy and physical function and that between preoperative physical activity and prognosis.

METHODS

In this retrospective, single-center, observational study, we evaluated data from 234 patients scheduled for neoadjuvant chemotherapy and thoracoscopic-laparoscopic esophagectomy who underwent a single preoperative physiotherapy session. The five-repetition sit-to-stand test was performed before and after neoadjuvant chemotherapy. After neoadjuvant chemotherapy, patients were classified into high- and low-physical activity groups based on preoperative physical activity. To examine the association between preoperative physiotherapy and changes in physical function, a multivariate regression analysis was performed. The Cox proportional hazards model was used to investigate the association between preoperative physical activity and overall survival.

RESULTS

The median percentage change in the five-repetition sit-to-stand test score was - 3.36%. In the multivariate regression analysis, the regression coefficient of the constant term was - 23.93 (95% confidence interval - 45.31 to - 2.56; P = 0.028). Low physical activity was significantly associated with overall survival after adjustment for confounding factors (P = 0.040).

CONCLUSIONS

This study demonstrated that a single preoperative physiotherapy session during neoadjuvant chemotherapy improves physical function, and preoperative physical activity is significantly associated with prognosis.

Alterations in neuromuscular junction morphology with ageing and endurance training modulate neuromuscular transmission and myofibre composition

Both ageing and exercise training affect the neuromuscular junction (NMJ) structure. Morphological alterations in the NMJ have been considered to influence neuromuscular transmission and myofibre properties, but the direct link between the morphology and function has yet to be established. We measured the neuromuscular transmission, myofibre composition and NMJ structure of 5-month-old (young) and 24-month-old untrained (aged control) and trained (aged trained) mice. Aged trained mice were subjected to 2 months of endurance training before the measurement. Neuromuscular transmission was evaluated in vivo as the ratio of ankle plantar flexion torque evoked by the sciatic nerve stimulation to that by direct muscle stimulation. The torque ratio was significantly lower in aged mice than in young and aged trained mice at high-frequency stimulations, showing a significant positive correlation with voluntary grip strength. The degree of pre- to post-synaptic overlap of the NMJ was also significantly lower in aged mice and positively correlated with the torque ratio. We also found that the proportion of fast-twitch fibres in the soleus muscle decreased with age, and that age-related denervation occurred preferentially in fast-twitch fibres. Age-related denervation and a shift in myofibre composition were partially prevented by endurance training. These results suggest that age-related deterioration of the NMJ structure impairs neuromuscular transmission and alters myofibre composition, but these alterations can be prevented by structural amelioration of NMJ with endurance training. Our findings highlight the importance of the NMJ as a major determinant of age-related deterioration of skeletal muscles and the clinical significance of endurance training as a countermeasure. KEY POINTS: The neuromuscular junction (NMJ) plays an essential role in neuromuscular transmission and the maintenance of myofibre properties. We show that neuromuscular transmission is impaired with ageing but recovered by endurance training, which contributes to alterations in voluntary strength. Neuromuscular transmission is associated with the degree of pre- to post-synaptic overlap of the NMJ. Age-related denervation of fast-twitch fibres and a shift in myofibre composition toward a slower phenotype are partially prevented by endurance training. Our study provides substantial evidence that age-related and exercise-induced alterations in neuromuscular transmission and myofibre properties are associated with morphological changes in the NMJ.

Longitudinal analysis of physical function in older adults: The effects of physical inactivity and exercise training

Lack of exercise contributes to systemic inflammation and is a major cause of chronic disease. The long-term impact of initiating and sustaining exercise in late life, as opposed to sustaining a sedentary lifestyle, on whole-body health measures such as physical performance is not well known. This is an exploratory study to compare changes in physical performance among older adults initiating exercise late in life versus inactive older adults. Data from two observational cohorts were included in this analysis, representing two activity groups. The Active group cohort comprises older adults (n = 318; age 72.5 ± 7.2 years) enrolled in a supervised exercise program, "Gerofit." The inactive group comprises older adults (n = 146; age 74.5 ± 5.5 years) from the Italian study "Act on Ageing" (AOA) who self-reported being inactive. Participants in both groups completed physical performance battery at baseline and 1-year including: 6-min walk test, 30-s chair stand, and timed up-and-go. Two-sample t-tests measured differences between Gerofit and AOA at baseline and 1-year across all measures. Significant between-group effects were seen for all performance measures (ps = 0.001). The AOA group declined across all measures from baseline to 1 year (range -18% to -24% change). The Gerofit group experienced significant gains in function for all measures (range +10% to +31% change). Older adults who initiated routine, sustained exercise were protected from age-related declines in physical performance, while those who remained sedentary suffered cumulative deficits across strength, aerobic endurance, and mobility. Interventions to reduce sedentary behaviors and increase physical activity are both important to promote multi-system, whole-body health.

Association of Sedentary Lifestyle with All-Cause and Cause-Specific Mortality in Adults with Reduced Kidney Function

Key Points

Nearly half of individuals with reduced kidney function had sedentary lifestyle, defined as more than 6 hours of sitting a day. Non-Hispanic White individuals and individuals with younger age, obesity, and with diabetes were more likely to have sedentary lifestyles. Spending more than 6 hours a day sedentary increases the future risk of death from all causes and cardiovascular diseases in individuals with reduced kidney function.

Background

Individuals with CKD tend to have sedentary behavior and decreased physical activity; both are independent predictors of mortality in general population. While physical inactivity correlates to adverse health outcomes in patients with reduced kidney function, it is unclear whether this relationship remains significant for sedentary behavior. Our study purpose was to evaluate the association of sedentary lifestyle with mortality risk in individuals with renal insufficiency.

Methods

The study population were adult participants of 2007–2016 National Health and Nutrition Examination Survey with eGFR <60 ml/min per 1.73 m2 or self-reporting receiving dialysis (N =1419). Sedentary lifestyle was defined as sedentary time >6 hours per day. Outcome of interest was all-cause and cardiovascular disease (CVD)–related or cancer-related mortality.

Results

We observed that non-Hispanic White individuals and individuals with younger age and higher educational level were more likely to have sedentary lifestyle. During a median follow-up of 99 (interquartile range, 70–128) months, a total of 458 participants died (3.98 deaths per 1000 person-months); 120 died from CVD and 92 from cancer, respectively. The crude analysis showed that individuals with sedentary lifestyle have higher risk of all-cause and CVD-related but not cancer-related mortality compared with the nonsedentary population. After adjusting for potential confounders, we showed that all-cause mortality and CVD-related mortality were 1.64-fold (95% confidence interval, 1.26 to 2.12) and 1.66-fold (95% confidence interval, 1.03 to 2.67) higher, respectively, in the sedentary population compared with the nonsedentary population. Similar results were observed in the sensitive analyses, in which we excluded individuals with dialysis, eGFR <15 ml/min per 1.73 m2, or mobility disability.

Conclusions

Our findings suggest that sedentary lifestyle correlated to greater risk of all-cause and CVD-related mortality among individuals with reduced kidney function. Interventions targeting the individuals with risky behaviors may have practical importance for public health.

Effects of aerobic and combined aerobic-resistance exercise on motor function in sedentary older adults: A randomized clinical trial

BACKGROUND

Sedentary behavior is widespread among older adults and accelerates the decline of motor function. Nevertheless, there is insufficient evidence concerning the effectiveness of regular exercise in enhancing the same in sedentary older adults.

OBJECTIVE

To compare the effects of 24 weeks of aerobic and combined aerobic-resistance exercise on the motor function of sedentary older adults.

METHODS

Sixty healthy sedentary older (65-80 years) were randomly enrolled. Participants were randomly divided into 3 groups (1:1:1): aerobic exercise group (AEG), combined aerobic-resistance exercise group (CEG), and health education group (HEG). The training group underwent a five-day-a-week regimen, with each session lasting for 40 minutes (including 10 min warm-up and cool-down). HEG received only monthly health lectures. We assessed lower limb muscle strength (30-second sit-to-stand ability), single-dual task gait, static and dynamic balance functions at baseline and after 24 weeks of intervention using per-protocol analysis.

RESULTS

Among 60 elderly healthy who were randomized (mean age 70.59 ± 3.31 years; 28 women (46%)), 42 (70%) completed the evaluation after 24 weeks. Both the aerobic exercise and combined aerobic-resistance exercise groups exhibited improved 30-second sit-to-stand ability, static balance in closed-eye standing mode, and dynamic balance (P< 0.05). However, there were no statistically significant changes in the single-task gait parameters of stride length, stride width, and stride speed (P> 0.05). Additionally, compared to the aerobic exercise group, the combined exercise group showed an increase in dual-task gait speed and medial and lateral dynamic stability indices (P< 0.05).

CONCLUSION

Both the aerobic exercise and combined aerobic-resistance exercise programs are effective in enhancing lower limb muscle strength, dynamic balance, and static balance while standing with eyes closed in sedentary older adults. Furthermore, the combined aerobic-resistance exercise program is more effective in improving dual-task gait speed as well as medial and lateral dynamic balance.

The association between sedentary behaviour and sarcopenia in older adults: a systematic review and meta-analysis

BACKGROUND

Sedentary behaviour is considered to contribute to sarcopenia when combined with physical inactivity. Whether sedentary behaviour is independently associated with sarcopenia remains controversial. The aim of this study is to explore the association between sedentary behaviour and sarcopenia in older adults in community and long-term care facility settings.

METHODS

Eight electronic databases including MEDLINE, PsycINFO, Wanfang were searched from inception until August 2023. The review included cross-sectional and longitudinal studies concerning the association between sedentary behaviour and sarcopenia among participants over 60 years old. Evidence was pooled by both random-effects meta-analysis and narrative synthesis. Subgroup analyses explored variation according to adjustment of physical activity, settings, and measurements of sedentary behaviour and sarcopenia. Quality assessment for individual studies was performed with the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.

RESULTS

Seventeen articles (16 cross-sectional studies and 1 longitudinal study) of 25,788 participants from community or long-term care facility settings were included. The overall quality of the included studies was rated high. Meta-analysis of 14 cross-sectional studies showed that sedentary behaviour was independently positively associated with sarcopenia: pooled odd ratio 1.36 (95% confidence interval, 1.18-1.58). The independent positive association remained in subgroup analyses by adjustment of physical activity, settings, and measurements of sedentary behaviour and sarcopenia. The narrative analysis corroborated the findings of the meta-analysis and provided additional evidence suggesting that interruptions in sedentary periods were linked to a decreased likelihood of developing sarcopenia.

CONCLUSIONS

The findings support the hypothesis that sedentary behaviour is independently positively associated with sarcopenia in older adults, providing vital indications for the development of strategies to prevent sarcopenia.

SYSTEMATIC REVIEW REGISTRATION

The systematic review protocol has been registered with the PROSPERO database (CRD42022311399).

Moderating Effect of Grip Strength in the Association between Diabetes Mellitus and Depressive Symptomatology

Diabetes mellitus and depression rank among the leading causes of disease burden and are present in the top ten causes of disability-adjusted life years worldwide. Numerous studies have shown that both depression and diabetes have a detrimental effect on the quality of life, and when they coexist, the effect is considerably worse. This study aimed to analyse how grip strength moderates the relationship between diabetes and depressive symptoms among middle-aged and older adults. In total, 41,701 participants (18,003 men) in wave 8 of the cross-sectional population-based Survey of Health, Ageing, and Retirement in Europe (2019/2020) data were studied. A dynamometer was used to test grip strength twice on each hand. Depressive symptoms were measured using the 12-item EURO-D scale. The relationship between diabetes and depressive symptoms is negatively moderated by grip strength (male: B = -0.03, 95% CI = -0.04, -0.03; female: B = -0.06, 95% CI = -0.07, -0.06). Furthermore, the significant zone grip strength moderation values for males and females were less than 48.7 kg and 38.9 kg, respectively. Muscular strength was a moderator of depressive symptoms, attenuating its association with diabetes. This supports the premise that physical activity, namely muscle-strengthening exercises, should be included in diabetes treatment programs.

Correlates of physical activity levels, muscle strength, working memory, and cognitive function in older adults

Objective

To explore the relationship between physical activity level, muscle strength, working memory and cognitive function in older adults.

Methods

A cross-sectional research design was employed to recruit 120 older adults individuals aged 70 and above. Participants were asked to complete the International Physical Activity Questionnaire-Short Form and the Montreal Cognitive Assessment Scale. Data on variables such as grip strength and performance on the N-back task were collected. Data analysis involved the use of independent samples t-tests, χ2 tests, linear regression analysis, Pearson correlation analysis, and one-way analysis of variance (ANOVA).

Results

The detection rate of cognitive dysfunction in older adults was 53.211%; 1-back correct rate had an explanatory power of 11.6% for the cognitive function scores of older adults (R2 = 0.116, p < 0.001); grip strength showed a significant positive correlation with 1-back correct rate (r = 0.417, p < 0.001), and was significantly correlated with the 0-back response time (r = -0.478), 1 -back response time (r = -0.441) were significantly negatively correlated (p < 0.001); physical activity level was significantly positively correlated with grip strength (r = 0.559, p < 0.001), and the difference in grip strength among older adults with different physical activity levels was statistically significant (F = 19.685, p < 0.001).

Conclusion

Physical activity level, muscle strength, working memory, and cognitive function are closely related in older adults, and the relational pathway of physical activity → muscle strength → working memory → cognitive function may serve as a useful addition to promote the field of cognitive research in older adults. To identify and prevent cognitive decline in older adults, physical activity questionnaires, grip strength tests, and 1-back task tests can be extended to nursing homes and communities.

The Mediating Role of Sarcopenia in the Association between Physical Activity and Falls among Chinese Older Adults: A Cross-Sectional Study

Physical inactivity and sarcopenia are potentially modifiable risk factors for falls in older adults, but the strength of the association between physical activity (PA), sarcopenia, and falls in Chinese older adults is unclear. This study sought to investigate the potential mediation mechanism relationship in the connection between PA, sarcopenia, including its elements (muscle strength, physical performance, and skeletal muscle mass), and falls among Chinese older people. The subjects were 3592 community-dwelling Chinese aged 60 or over, selected from the China Health and Retirement Longitudinal Study (CHARLS). PA was evaluated through the International Physical Activity Questionnaire (IPAQ), and sarcopenia was determined through the Asian Working Group on Sarcopenia (AWGS) 2019 guidelines. We employed logistic regression to explore the link between physical activity, sarcopenia, and falls. Additionally, we applied Karlson, Holm and Breen's (KHB) method to estimate two different mediation models. The results demonstrated that PA lowers the risk of falls [odds ratio (OR) 0.54, 95% confidence interval (CI) 0.48-0.61], whereas sarcopenia increases the risk of falls (OR 1.34, 95% CI 1.16-1.55). Sarcopenia mediated the association between PA and falls, explaining a total of 2.69% of the association (indirect effect = -0.02). PA also had a significant mediating effect on the association between sarcopenia and falls, explaining a total of 20.12% of the association (indirect effect = 0.06). The proportion mediated by sarcopenia was 2.69% for PA and falls (indirect effect = -0.02). Our findings suggest that PA and sarcopenia have a direct effect on falls as well as an indirect effect through each other. Enhancing PA levels and preventing sarcopenia may help prevent falls in older adults.

Association of Physical Activity and Exercise with Physical Performance and Muscle Mass in Older Adults: Results from the Longevity Check-Up (Lookup) 7+ Project

Regular engagement in physical activity (PA) or physical exercise (PE) is effective at improving physical performance and body composition in older adults. Less is known about the benefits that may be obtained through combining PA with PE and whether the effects of activity habits differ between men and women. This study cross-sectionally investigated the association of PA and/or PE with physical performance and anthropometric measures in a large and relatively unselected sample of older adults enrolled in the Longevity Check-up (Lookup) 7+ project. Participants were individuals 65 years and older living in the community who were recruited in unconventional settings across Italy. Adherence to PA or PE was operationalized as involvement in light walking or various types of exercise, respectively, at least twice weekly for a minimum of 30 min per session throughout the last 12 months. Physical performance measures included handgrip strength and five-time sit-to-stand (5STS) tests. Lower-limb muscle power and appendicular skeletal muscle mass (ASM) were estimated through validated equations. We analyzed data of 4119 participants, of whom 2222 (53.4%) were women. The mean age was 72.8 ± 5.8 years in men and 72.1 ± 5.4 years in women. Regular engagement in PA + PE was reported by 139 (7.3%) men and 100 (4.5%) women. Results indicated that regular walking activity and/or PE were significantly associated with better physical performance and greater ASM with sex-specific patterns. Associations were also influenced by the type of activity, physical performance assessment tool, and anthropometric parameters. Men engaged in PA + PE performed better on the 5STS test and had greater handgrip strength, ASM, and relative and specific muscle power than those practicing either PA or PE. In women, the combination of PA and PE was associated with greater handgrip strength. The findings of this study indicate that older adults regularly practicing PA + PE had better physical performance than those who only engaged in either modality. In men, the combination of PA and PE was also associated with greater ASM.

Association between hearing status and social participation in Japanese older adults: A cross-sectional study from the Japan gerontological evaluation study

PURPOSE

Hearing is known to decline with age. As sensitivity to speech declines, conversation becomes more difficult and social interactions are affected, resulting in increased risk of cognitive decline. This study aimed to examine the relationship between hearing status and social participation.

MATERIALS AND METHODS

The study included 21,117 adults aged 65 years or older who responded to a survey in 2019. The survey asked participants about their hearing status and how frequently they participated in certain social activities.

RESULTS

The analysis of the relationship between degree of hearing and social activity showed lower hearing status odds ratios for those who participated more frequently in social activities compared to those who participated less frequently. The odds ratios were as follows, hobby clubs (OR 0.81, 95%CI 0.78-0.84), activities such as teaching skills or passing on experiences to others (OR 0.69, 95%CI 0.65-0.75), and meeting with friends (OR 0.77, 95%CI 0.74-0.79). Compared to those who did not participate in social activities, those who participated in three or more types of groups had significantly lower hearing impairment (OR 0.75, 95% CI 0.72-0.79).

CONCLUSION

Hearing impairment was shown to inhibit participation in activities, including those that require communication with multiple people or smooth communication, those that involve a wide range of ages, and those that involve work and movement. Hearing impairment should be identified and addressed in its early stages to prevent its negative impact on social participation.

Effects of an educational intervention on frailty status, physical function, physical activity, sleep patterns, and nutritional status of older adults with frailty or pre-frailty: the FRAGSALUD study

Introduction

The prevalence of frailty is increasing worldwide, emphasizing the importance of prioritizing healthy ageing. To address this, cost-effective and minimally supervised interventions are being sought. This study aimed to assess the impact of an educational program on frailty status, physical function, physical activity, sleep patterns, and nutritional status in community-dwelling older adults with at least 1 Fried's frailty criteria.

Methods

A 6-month multicentre randomized controlled trial was conducted from March 2022 to February 2023 in 14 health centres located in Cadiz and Malaga, Spain. The educational intervention consisted of 4 group sessions and 6 follow-up phone calls spread over 6 months. The program focused on educating participants about frailty and its impact on health, providing guidelines for physical activity, healthy dietary habits, cognitive training, psychological well-being and social activities. A total of 163 participants, divided into control (n = 80) and educational groups (n = 83) were assessed before and after the intervention.

Results

The results showed a significant group-time interaction in the physical function evaluated with a large effect on Short Physical Performance Battery score (η2p = 0.179, -0.1 [-1.2-1.0] points for control group vs. 1.0 [0.0-3.0] points for educational group, p < 0.001), and an effect on the 4-meter gait test ((η2p = 0.122, 0.5 [0.1-0.0] s for control group vs. -0.4 [-0.5- -0.3] s for educational group, p < 0.001), and the 5-repetition sit-to-stand test (η2p = 0.136, 1.0 [0.0-1.2] s for control group vs. -4.3 [-7.0- -2.3] for educational group, p < 0.001). Additionally, the use of accelerometers to assess physical activity, inactivity, and sleep patterns revealed a significant small effect in the number of awakenings at night ((η2p = 0.040, 1.1 [-0.5-3.4] awakenings for control group vs. 0.0 [-2.2-0.0] awakenings for educational group, p = 0.009). The findings also highlighted a significant medium effect regarding malnutrition risk, which was assessed using the Mini-Nutritional Assessment score (η2p = 0.088, -0.7 [-2.3-1.5] points for control group vs. 1.5 [-0.5-3.0] points for educational group, p < 0.001).

Discussion

Thus, the 6-month educational program effectively improved physical function, sleep patterns, and nutritional status compared to usual healthcare attendance in community-dwelling older adults with frailty or pre-frailty. These findings underscore the potential of minimally supervised interventions in promoting a healthy lifestyle in this vulnerable population.

Type 2 Diabetes Mellitus and Sarcopenia as Comorbid Chronic Diseases in Older Adults: Established and Emerging Treatments and Therapies

Type 2 diabetes mellitus (T2DM) and sarcopenia (low skeletal muscle mass and function) share a bidirectional relationship. The prevalence of these diseases increases with age and they share common risk factors. Skeletal muscle fat infiltration, commonly referred to as myosteatosis, may be a major contributor to both T2DM and sarcopenia in older adults via independent effects on insulin resistance and muscle health. Many strategies to manage T2DM result in energy restriction and subsequent weight loss, and this can lead to significant declines in muscle mass in the absence of resistance exercise, which is also a first-line treatment for sarcopenia. In this review, we highlight recent evidence on established treatments and emerging therapies targeting weight loss and muscle mass and function improvements in older adults with, or at risk of, T2DM and/or sarcopenia. This includes dietary, physical activity and exercise interventions, new generation incretin-based agonists and myostatin-based antagonists, and endoscopic bariatric therapies. We also highlight how digital health technologies and health literacy interventions can increase uptake of, and adherence to, established and emerging treatments and therapies in older adults with T2DM and/or sarcopenia.

Association between dietary patterns and subjective and objective measures of physical activity among Japanese adults aged 85 years and older: a cross-sectional study

A healthy diet and regular physical activity (PA) are delineated as healthy behaviours. Their implementation is associated with better health outcomes and improved quality of life. There is less evidence of a relationship between dietary patterns (DP) and PA, especially in adults aged ≥ 85. Hence, this cross-sectional study investigates the association between DP and PA in people of this age group, using the data from The Kawasaki Aging and Well-Being Project. Brief-type self-administered diet history questionnaire was used to estimate the intake of fifty-eight types of food. After energy adjustment, principal component analysis was performed to identify DP. PA was measured objectively using an accelerometer and subjectively using a questionnaire validated for this age group. Thousand participants (median age: 86·9 years, men: 49·9 %) were included in the analysis. Three major DP (DP1 'various foods', DP2 'red meats and coffee', DP3 'bread and processed meats') were identified. DP1 'various foods' was similar to DP previously named 'healthy' or 'prudent' and showed a positive association with PA time (PAT) as measured by accelerometer (B, 6·25; 95 % CI 0·13, 12·37) and relatively shorter sedentary behaviour (SB) time. DP2 'red meats and coffee' and DP3 'bread and processed meats' were negatively associated with PAT and positively associated with SB time. This study observed the relationship between diet and PA behaviours in adults aged ≥ 85, with healthier and more food-diverse DP associated with longer PAT and relatively unhealthy DP with shorter PAT.

Machine Learning Applications in Sarcopenia Detection and Management: A Comprehensive Survey

This extensive review examines sarcopenia, a condition characterized by a loss of muscle mass, stamina, and physical performance, with a particular emphasis on its detection and management using contemporary technologies. It highlights the lack of global agreement or standardization regarding the definition of sarcopenia and the various techniques used to measure muscle mass, stamina, and physical performance. The distinctive criteria employed by the European Working Group on Sarcopenia in Older People (EWGSOP) and the Asian Working Group for Sarcopenia (AWGSOP) for diagnosing sarcopenia are examined, emphasizing potential obstacles in comparing research results across studies. The paper delves into the use of machine learning techniques in sarcopenia detection and diagnosis, noting challenges such as data accessibility, data imbalance, and feature selection. It suggests that wearable devices, like activity trackers and smartwatches, could offer valuable insights into sarcopenia progression and aid individuals in monitoring and managing their condition. Additionally, the paper investigates the potential of blockchain technology and edge computing in healthcare data storage, discussing models and systems that leverage these technologies to secure patient data privacy and enhance personal health information management. However, it acknowledges the limitations of these models and systems, including inefficiencies in handling large volumes of medical data and the lack of dynamic selection capability. In conclusion, the paper provides a comprehensive summary of current sarcopenia research, emphasizing the potential of modern technologies in enhancing the detection and management of the condition while also highlighting the need for further research to address challenges in standardization, data management, and effective technology use.

Physical Activity in Community-Dwelling Older Adults: Which Real-World Accelerometry Measures Are Robust? A Systematic Review

Measurement of real-world physical activity (PA) data using accelerometry in older adults is informative and clinically relevant, but not without challenges. This review appraises the reliability and validity of accelerometry-based PA measures of older adults collected in real-world conditions. Eight electronic databases were systematically searched, with 13 manuscripts included. Intraclass correlation coefficient (ICC) for inter-rater reliability were: walking duration (0.94 to 0.95), lying duration (0.98 to 0.99), sitting duration (0.78 to 0.99) and standing duration (0.98 to 0.99). ICCs for relative reliability ranged from 0.24 to 0.82 for step counts and 0.48 to 0.86 for active calories. Absolute reliability ranged from 5864 to 10,832 steps and for active calories from 289 to 597 kcal. ICCs for responsiveness for step count were 0.02 to 0.41, and for active calories 0.07 to 0.93. Criterion validity for step count ranged from 0.83 to 0.98. Percentage of agreement for walking ranged from 63.6% to 94.5%; for lying 35.6% to 100%, sitting 79.2% to 100%, and standing 38.6% to 96.1%. Construct validity between step count and criteria for moderate-to-vigorous PA was rs = 0.68 and 0.72. Inter-rater reliability and criterion validity for walking, lying, sitting and standing duration are established. Criterion validity of step count is also established. Clinicians and researchers may use these measures with a limited degree of confidence. Further work is required to establish these properties and to extend the repertoire of PA measures beyond "volume" counts to include more nuanced outcomes such as intensity of movement and duration of postural transitions.

Effects of yoga on physical and psychological health among community-dwelling older adults: A systematic review and meta-analysis

OBJECTIVES

To synthesise and critically appraise the quality of existing evidence about the effects of yoga on physical and psychological outcomes among older adults.

DESIGN

A systematic review and meta-analysis.

PARTICIPANTS

Participants aged 60 and above.

MEASUREMENTS

Nine English and two Chinese electronic bibliographic databases, including MEDLINE OvidSP, PsycINFO, AMED, EMBASE, Global Health, PubMed, Scopus, CINAHL, Cochrane Library, Hyread and WanFang databases, were searched. Randomised controlled trials (RCT) of yoga on physical and psychological outcomes among older adults were included. Meta-analysis was conducted for outcomes studied in three or more studies, otherwise narrative synthesis was performed.

RESULTS

Fifteen studies were included for review. The results of meta-analysis after sensitivity analysis showed that yoga significantly improved balance (SMD = 0.81, 95% CI: 0.48-1.14, p < .001, II2  = 59%), flexibility (SMD = 0.38, 95% CI: 0.07-0.68, p = .020, II2 34%), muscle strength (SMD = 0.49, 95% CI: 0.18-0.79, p = .002, I2 43%) and depressive symptoms (SMD = 0.50, 95% CI = 0.09-0.91, p = .01, I2 0%). There was insufficient data for meta-analysis on gait and other psychological outcomes. Narrative synthesis suggested that yoga has positive effects on reducing anxiety, but its effects on improving gait and reducing stress among older adults were inconclusive.

CONCLUSION

The results of this review supported the beneficial effects of yoga on physical outcomes among older adults, but the heterogeneity across studies was relatively high. Evidence related to the effect on psychological outcomes was limited.

Low back pain in pregnant women: A necessary or an avoidable evil?

OBJECTIVES

The aim of this study was to determine the prevalence, the main features and the potential risk factors of LBP in pregnant women.

METHODS

This cross-sectional study included 173 pregnant women in the third trimester. Non-inclusion criteria were severe mental disability and known previous history of musculoskeletal diseases. The participants were categorised into two groups: women with pregnancy-related LBP and pain-free women. Demographic, socio-professional, clinical and obstetrical data were compared between the two groups using the appropriate statistical tests.

RESULTS

The mean age was 32.2 ± 5.4 years [17-45]. Among them, 108 (62.4%) reported one or more episodes of LBP during at least 7 days, mostly in the third semester (n = 71). The presence of LBP was significantly associated with history of LBP in previous pregnancies and jobs requiring prolonged standing. Active jobs and the presence of gestational complications were significantly more common in pain-free women. In the multivariate analysis, LBP was independently predicted by the history of LBP in previous pregnancies and the absence of gestational complications.

CONCLUSIONS

The association of LBP with gestational complications as a protective factor has not yet been reported in previous studies. These complications are a common cause of hospitalisation, which represents a period of relative rest during pregnancy. Our results revealed that history of LBP in previous pregnancies, sedentary lifestyle prior to pregnancy and prolonged standing are the main risk factors of LBP. In contrast, rest and avoidance of physical overstrain during pregnancy may be protective factors.

Determinants of Activity Phenotype in Patients with Chronic Obstructive Pulmonary Disease

Introduction

Physical activity (PA) and sedentary behavior (SB) have attracted attention in chronic obstructive pulmonary disease (COPD), and there have been efforts to evaluate PA and SB separately. The factors associated with the characteristics of the four activity phenotypes defined by the durations of PA and SB are largely unknown. The aim of this study was to clarify the factors that could differentiate each activity phenotype.

Materials and Methods

Study subjects were outpatients with stable COPD who were ≥40 years of age. We investigated the influence of 26 different factors on the activity phenotypes of COPD and extracted the factors that showed significant differences among the four activity phenotypes.

Results

Two hundred sixteen patients were included in the analysis. Exercise capacity and dyspnea were determinants that distinguished the low PA groups from the high PA groups. The pulmonary function and desaturation during exercise were factors that distinguished the high PA with low SB group from the low PA with high SB group. BMI, grip strength, upper arm circumference and HbA1c were higher in the low PA and low SB group than in the low PA and high SB group.

Conclusion

These factors could be the determinants discriminating activity phenotypes of patients with COPD.

Habitual physical activity and sedentary behavior as predictors of dynapenia in older adults: a cross-sectional study

BACKGROUND

Dynapenia is a risk factor of mortality. Therefore, the development of low-cost and easy-to-apply tools is essential to optimize the health surveillance actions of older people.

OBJECTIVES

To compare the time spent on habitual physical activity (HPA) and sedentary behavior (SB) among dynapenic and non-dynapenic older adults and ascertain the predictive ability of these behaviors on outcome.

DESIGN AND SETTING

A cross-sectional population epidemiological survey was conducted involving 208 older adults.

METHODS

HPA and SB were quantified using the International Physical Activity Questionnaire, and dynapenia was identified by handgrip strength (women: 18.37 kgf; men: 26.75 kgf).

RESULTS

The prevalence was 24.50%. In both sexes, dynapenic individuals reported a HPA median time of 70.00 minutes/week (min/wk), while non-dynapenic women and men reported HPA median times of 240.00 and 280.00 min/wk, respectively (P < 0.05). For SB among dynapenic individuals, a median of 388.75 min/day was observed in women and 428.57 min/d in men. In contrast, non-dynapenic women and men had 291.42 and 274.28 min/day in SB (P < 0.05), respectively. The best cutoff HPA to discriminate the outcome was 150.00 min/wk in women (sensitivity: 73.30%; specificity: 60.67%) and 140.00 min/wk in men (sensitivity, 71.43%; specificity, 61.54%). The best cutoff SB was 381.43 min/day in women (sensitivity, 53.30%; specificity, 84.80%) and 351.43 min/day in men (sensitivity, 71.43%; specificity, 73.85%).

CONCLUSION

Older individuals with dynapenia spent less time on HPA and more time in SB. Furthermore, HPA was found to be a better discriminator of dynapenic individuals, and SB better discriminated non-dynapenic individuals.

The association between physical activity and fear of falling among community-dwelling older women in China: the mediating role of physical fitness

Background

This study aimed to explore the association between physical activity (PA) and fear of falling (FOF) and to determine whether this relationship was mediated by physical fitness (PF) in community-dwelling older women.

Methods

For this cross-sectional study, a total of 1,108 older women were recruited. Moderate-to-vigorous physical activity (MVPA) and light physical activity (LPA) were objectively measured by accelerometers. Physical fitness indicators including body mass index (BMI), forced vital capacity, choice reaction time, grip strength, sit and reach, and five times sit-to-stand were measured. FOF was evaluated by the Chinese version of the activities-specific balance confidence scale. A stepwise linear regression model analysis was used for mediation analysis, and bootstrap analysis was used to verify the mediation effects.

Result

The Pearson correlation coefficient results suggested that MVPA was significantly and negatively correlated with FOF while LPA was not correlated with FOF. Logistic regression analysis suggested a significant association between MVPA, BMI, forced vital capacity, choice reaction time, sit and reach, grip strength, five times sit-to-stand, and FOF. The mediation analysis showed a negative relationship between MVPA and FOF. BMI completely mediated the relationship between MVPA and FOF while sit and reach, five times sit-to-stand, and forced vital capacity partially mediated the relationship between MVPA and FOF.

Conclusion

Accumulation of more daily MVPA was associated with reducing the odds of FOF in community-dwelling older women. PF indicators fully or partially mediate the relationship between MVPA and FOF. Therefore, more intervention efforts should focus on the promotion of MVPA to improve PF and thus reduce FOF among older women.

Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study

BACKGROUND

The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults.

METHODS

A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011-2020). Functional disability was ascertained using the national database of Japan's Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants' waists.

RESULTS

During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability.

CONCLUSION

Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

Habitual Physical Activity and Dietary Profiles in Older Japanese Males with Normal-Weight Obesity

Normal-weight obesity is defined as having high body fat but a normal body mass index (BMI). This study examined whether there are differences in habitual physical activity and diet between individuals with normal-weight obesity and obese or non-obesity. This study included 143 males aged 65-75 years, and they were classified into the following three groups according to BMI and visceral fat area (VFA): obese group (n = 27 (BMI: ≥25 kg/m² and VFA: ≥100 cm²)), normal-weight obese group (n = 35 (BMI: <25 kg/m² and VFA: ≥100 cm²)) and non-obese group (n = 81 (BMI: <25 kg/m² and VFA < 100 cm²)). Lowered high-density lipoprotein cholesterol and elevated triglyceride and alanine transaminase were observed in the normal-weight obese group than in the non-obese group (all for p ≤ 0.04, effect size ≥ 0.50). No differences were found in physical activity and dietary habits between non-obese and normal-weight obese groups (all for p > 0.05). Although impaired lipid and liver function parameters were observed in older males with normal-weight obesity compared with older males with non-obesity, physical activity and dietary profiles in themselves were not shown these differences in the present study.

The association between selenium and bone health: a meta-analysis

Aims

Previous studies have suggested that selenium as a trace element is involved in bone health, but findings related to the specific effect of selenium on bone health remain inconclusive. Thus, we performed a meta-analysis by including all the relevant studies to elucidate the association between selenium status (dietary intake or serum selenium) and bone health indicators (bone mineral density (BMD), osteoporosis (OP), or fracture).

Methods

PubMed, Embase, and Cochrane Library were systematically searched to retrieve relevant articles published before 15 November 2022. Studies focusing on the correlation between selenium and BMD, OP, or fracture were included. Effect sizes included regression coefficient (β), weighted mean difference (WMD), and odds ratio (OR). According to heterogeneity, the fixed-effect or random-effect model was used to assess the association between selenium and bone health.

Results

From 748 non-duplicate publications, 19 studies were included. We found a significantly positive association between dietary selenium intake (β = 0.04, 95% confidence interval (CI) 0.00 to 0.07, p = 0.029) as well as serum selenium (β = 0.13, 95% CI 0.00 to 0.26, p = 0.046) and BMD. Consistently, those with higher selenium intake had a lower risk of OP (OR = 0.47, 95% CI 0.31 to 0.72, p = 0.001), and patients with OP had a significantly lower level of serum selenium than healthy controls (WMD = -2.01, 95% CI -3.91 to -0.12, p = 0.037). High dietary selenium intake was associated with a lower risk of hip fracture (OR = 0.44, 95% CI 0.37 to 0.52, p < 0.001).

Conclusion

Selenium was positively associated with BMD and inversely associated with OP; dietary selenium intake was negatively associated with hip fracture. The causality and therapeutic effect of selenium on OP needs to be investigated in future studies.

Physical Activity, Sedentary Behavior, and Type 2 Diabetes: Mendelian Randomization Analysis

Context

The causality and pathways of the associations between physical activity and inactivity and the risk of type 2 diabetes remain inconclusive.

Objective

We conducted an updated mendelian randomization (MR) study to explore the associations of moderate-to-vigorous physical activity (MVPA) and leisure screen time (LST) with type 2 diabetes mellitus (T2DM).

Methods

Genetic variants strongly associated with MVPA or LST with low linkage disequilibrium were selected as instrumental variables from a genome-wide meta-analysis including more than 600 000 individuals. Summary-level data on T2DM were obtained from the DIAbetes Genetics Replication And Meta-analysis consortium including 898 130 individuals. Data on possible intermediates (adiposity indicators, lean mass, glycemic traits, and inflammatory biomarkers) were extracted from large-scale genome-wide association studies (n = 21 758-681 275). Univariable and multivariable MR analyses were performed to estimate the total and direct effects of MVPA and LST on T2DM. Methylation MR analysis was performed for MVPA in relation to diabetes.

Results

The odds ratio of T2DM was 0.70 (95% CI, 0.55-0.88; P = .002) per unit increase in the log-odds ratio of having MVPA and 1.45 (95% CI, 1.30-1.62; P = 7.62 × 10-11) per SD increase in genetically predicted LST. These associations attenuated in multivariable MR analyses adjusted for genetically predicted waist-to-hip ratio, body mass index, lean mass, and circulating C-reactive protein. The association between genetically predicted MVPA and T2DM attenuated after adjusting for genetically predicted fasting insulin levels. Two physical activity-related methylation biomarkers (cg17332422 in ADAMTS2 and cg09531019) were associated with the risk of T2DM (P < .05).

Conclusion

The study suggests causal associations of MVPA and LST with T2DM that appear to be mediated by obesity, lean mass, and chronic low-grade inflammation.

Impact of physical activity levels on the ability to maintain static trunk posture in older adults

PROPOSE

to assess the impact of physical activity (PA) levels on sitting posture in the older adults.

METHODS

One hundred and twenty individuals were divided into three groups according their PA levels: vigorous group (VG); moderate group (MG); low group (LG). The ability to maintain static trunk posture in sitting position as assessed based on the cervical angle (CA) and thoracic angle (TA) was measured.

RESULTS

There were no significant differences between measurements in CA for the VG. However, LG and MG participants exhibited a significant decrease in CA from minute 1 to 10 and from minute 2 to 10, respectively. In the thoracic region, only the MG exhibited significant differences in TA from minute 2 to 10 compared to minute 1 (p < 0.05). No significant differences were found in TA between measurements for either VG or LG.

CONCLUSIONS

PA has a high impact on the ability to maintain static trunk posture in the older adults.

Explaining declining hip fracture rates in Norway: a population-based modelling study

Background

Although age-standardised hip fracture incidence has declined in many countries during recent decades, the number of fractures is forecast to increase as the population ages. Understanding the drivers behind this decline is essential to inform policy for targeted preventive measures. We aimed to quantify how much of this decline could be explained by temporal trends in major risk factors and osteoporosis treatment.

Methods

We developed a new modelling approach, Hip-IMPACT, based on the validated IMPACT coronary heart disease models. The model applied sex- and age stratified hip fracture numbers and prevalence of pharmacologic treatments and risk/preventive factors in 1999 and 2019, and best available evidence for independent relative risks of hip fracture associated with each treatment and risk/preventive factor.

Findings

Hip-IMPACT explained 91% (2500/2756) of the declining hip fracture rates during 1999-2019. Two-thirds of the total decline was attributed to changes in risk/preventive factors and one-fifth to osteoporosis medication. Increased prevalence of total hip replacements explained 474/2756 (17%), increased body mass index 698/2756 (25%), and increased physical activity 434/2756 (16%). Reduced smoking explained 293/2756 (11%), and reduced benzodiazepine use explained (366/2756) 13%. Increased uptake of alendronate, zoledronic acid, and denosumab explained 307/2756 (11%), 104/2756 (4%) and 161/2756 (6%), respectively. The explained decline was partially offset by increased prevalence of type 2 diabetes and users of glucocorticoids, z-drugs, and opioids.

Interpretation

Two-thirds of the decline in hip fractures from 1999 to 2019 was attributed to reductions in major risk factors and approximately one-fifth to osteoporosis medication.

Funding

The Research Council of Norway.