Physiological and Cognitive Determinants of Gait Variability of Asian Population: The Yishun Study.

INTRODUCTION: Gait variability is associated with frailty, dementia, and falls. Studies on the association of physiological and cognitive factors with gait variability have seldom included middle-aged adults, even though these adults already experienced loss of muscular strength and postural stability. This study aimed a) to examine and compare the trend of gait variability in men and women, across the adult age spectrum, and b) to identify and compare the contributions of physiological and cognitive factors to gait variability. METHODS: This was a population-based cross-sectional study at a single center. A random sample of 507 community-dwelling, well-functioning adults aged 21-90 years were studied. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status. Physiological factors examined included visual contrast sensitivity (VCS), postural sway, hand reaction time, handgrip strength (HGS), knee extensor strength, and gait variability (coefficient of variation [CoV]). Multivariable regression models were used to examine the association between physiological and cognitive performance with gait CoV. RESULTS: Women walked with greater stride width CoV (p < 0.01) and double support time (DST) CoV (p < 0.01) than men. The stride width (p = 0.01) and DST variability (p = 0.03) were significantly higher in older men as compared to men in younger age-groups. Gait speed accounted for most of the gait CoV variances and attenuated the effects of physiological performance and/or attention cognition on most gait variability, except for CoV of DST and stride width. Adults with better VCS (ß = -0.19), faster hand reaction (ß = 0.12), and greater HGS (ß = -0.15) had lower variability in step length. CONCLUSION: The trends of stride width CoV and DST CoV across adult age spectrum were different between men and women. Greater stride width variability was partly attributed to greater HGS, possibly to better control lateral stability during walking. Physiological factors outweigh cognition in regulating most of the gait CoV in this study. They are modifiable and potential targets for healthy aging program.

Body composition reference values in Singaporean adults using dual-energy X-ray absorptiometry-The Yishun study.

OBJECTIVES: This study establishes age- and sex-specific reference values for fat mass index (FMI), lean mass index (LMI), appendicular LMI (aLMI), and body fat distribution indices including Android/Gynoid % fat ratio and Trunk/Limb % fat ratio in multi-ethnic Singaporean adults. METHODS: A population-based cross-sectional study using dual-energy X-ray absorptiometry (Hologic Discovery Wi) was carried out to measure whole body and regional fat and lean mass in community-dwelling adults. A total of 537 adults (57.5% women), aged from 21 to 90 years, were recruited from the large north-eastern residential town of Yishun. Age- and sex-specific percentile reference values were generated for FMI, LMI, aLMI, Android/Gynoid % fat ratio and Trunk/Limb % fat ratio using the Lambda-Mu-Sigma method. The relationship between the parameters and age were assessed through the Pearson's correlation coefficient. RESULTS: All parameters demonstrated significant correlation with age (p < 0.05) for both men and women, except for LMI in women, with the strength of r ranging from 0.12 (weak correlation) to 0.54 (strong correlation). LMI (r = -0.45) and appendicular LMI (r = -0.54) were negatively associated with age in men while none (r = -0.06) to weak correlation (r = -0.14) were shown in women for the same parameters respectively. The Android/Gynoid % fat ratio and Trunk/Limb % fat ratio were positively related to age for both men (r = 0.37 & 0.43, p < 0.001) and women (r = 0.52 & 0.48, p < 0.001). CONCLUSION: We have established DXA-based body composition reference data for the Singapore adult population. These reference data will be particularly useful in geriatric, obesity and oncology clinics, enabling the prescription of appropriate therapy to individuals at risk of morbidity from unfavorable body composition phenotypes. It also adds on to the limited reference database on Southeast Asian body composition.

Associations of low handgrip strength and hand laterality with cognitive function and functional mobility - the Yishun Study.

BACKGROUND: Emerging evidence suggest that in addition to low hand grip strength (HGS), HGS asymmetry is associated with declining cognitive and physical functions. We examined the associations of low HGS and asymmetry with cognitive function and functional mobility in older adults. METHODS: Cross-sectional data of 330 community-dwelling adults (55.2% women) aged ≥ 55 years included HGS, Repeated Battery for the Assessment of Neuropsychological Status (RBANS), and Timed-Up-and-Go (TUG). Low HGS was defined as < 28 kg for men and < 18 kg for women. Participants with HGS above 10% stronger on either hand were considered as having HGS asymmetry. Multiple linear regression models were adjusted for sociodemographic, smoking, education, comorbidity count, physical activity participation, obesity, self-rated health and hand dominance. RESULTS: Low HGS, but not asymmetry, was independently associated with lower functional mobility performance (ß = 1.3, 95%CI = 0.6,1.9), global cognitive function (ß = -10.4, 95%CI = -17.0,-3.8), immediate (ß = -2.6, 95%CI = -4.5,-0.7) and delayed (ß = -2.8, 95%CI = -5.0,-0.7) memory. Compared to normal and symmetric HGS participants, low HGS in combination with HGS asymmetry was associated with poorer language scores. In participants with normal HGS, asymmetric HGS was associated with slower TUG than corresponding groups with symmetric HGS. CONCLUSION: Low HGS, but not asymmetry, was associated with lower cognition and functional mobility. Associations of combined low HGS and asymmetry with cognitive and physical functions were driven by grip strength rather than asymmetry.

Enhanced gait variability index and cognitive performance in Asian adults: Results from the Yishun Study.

BACKGROUND: Although gait variability has been linked to cognitive decline among older adults, the lack of a comprehensive composite gait variability score has dampened the application of gait variability. RESEARCH QUESTION: Does the enhanced gait variability index (EGVI) - a composite score gait variability index - provide differential and useful information on cognitive decline in community-dwelling adults from that using gait speed? METHODS: Healthy community-dwelling adults (n = 311) aged 21-90 were individually administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Habitual gait speed and spatiotemporal parameters were measured using a 6 m instrumented walkway system. The EGVI for each participant was calculated from five spatiotemporal parameters - step length(cm), step time(s), stance time(s), single support time(s) and stride velocity(cm/s). Linear regression models, controlling for age, gender, and education, were built to examine the independent effects of EGVI or gait speed on global cognition and individual domains. RESULTS: Multiple regression revealed that gait speed contributed significantly to the performance of the domain "Attention" (p = 0.04) whereas EGVI contributed significantly for the performance of the domain "Visuospatial" (p = 0.04) and "Delayed Memory" (p = 0.02). SIGNIFICANCE: EGVI provides differential and useful information from using gait speed alone. The EGVI may offer a solution to measure or track GV changes in relation to cognitive changes.

Cross-sectional associations of housework with cognitive, physical and sensorimotor functions in younger and older community-dwelling adults: the Yishun Study.

OBJECTIVES: Regular moderate-to-vigorous intensity recreational physical activity (PA) improves physical and cognitive functions. However, the age-associated relationships between non-recreational PA and functional ability remain less explored. We examined the associations between housework and functional health among younger and older Singaporean community-dwelling adults. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Younger (<65 years, n=249) and older (≥65 years, n=240) community-dwelling adults were randomly recruited from a large residential town in Singapore. OUTCOME MEASURES: Physical function was assessed using Short Physical Performance Battery (SPPB), repeated-chair-sit-to-stand and gait speed. Cognitive and sensorimotor functions were assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Physiological Profile Assessment (PPA), respectively. METHODS: Light housework (LH) and heavy housework (HH), recreational, and occupational and transport-related PAs were assessed using PA questionnaires. Participants were dichotomised into low-volume and high-volume LH and HH groups. Results were adjusted for level of recreational and other non-recreational PAs. RESULTS: Among older but not younger adults, RBANS scores were 8% and 5% higher in high HH and LH groups compared with low HH and LH groups, respectively (p=0.012 and p=0.016). Specifically, HH was associated with 14% higher attention score (p=0.014), and LH was associated with 12% and 8% higher immediate and delayed memory scores, respectively (p<0.001 and p=0.004). In older adults, sit-to-stand time and PPA scores were 8% and 23% lower in the high HH group than the low HH group, respectively (p=0.011 and p=0.040). SPPB and gait speed did not differ with age or HH. LH was not associated with physical or sensorimotor function. CONCLUSIONS: Among older adults, housework is associated with higher cognitive function, specifically in attention and memory. Associations of housework with physical function and sensorimotor performance were intensity dependent. Housework PA is positively associated with functional health among community-dwelling older adults, independent of recreation and other non-recreational PAs. Further longitudinal and intervention studies are needed to establish causality.

Associations of fat mass and muscle function but not lean mass with cognitive impairment: The Yishun Study.

BACKGROUND: Sarcopenia and obesity are reportedly associated with risk of cognitive decline, and sarcopenic obesity (SO) heightens the risk, but the evidence is sparse and inconclusive. This study aimed to examine the association between SO and cognitive impairment. METHODS: A total of 542 community-dwelling adults aged between 21 and 90 years were recruited. All participants were assessed for body composition (dual X-ray absorptiometry), handgrip strength (HGS), gait speed (GS), and cognitive function (Repeatable Battery for the Assessment of Neuropsychological Status). Sarcopenia was defined by the presence of low appendicular lean mass index (ALMI) and low HGS or low GS according to the 2019 Asian Working Group for Sarcopenia criteria, and obesity was defined based on the upper two quintiles of fat mass index (FMI). RESULTS: Sarcopenia alone or in combination with obesity were not significantly associated with cognitive impairment after controlling for confounding variables. Obesity on its own was significantly associated with greater odds of impaired attention (OR: 2.05, 95%CI 1.12-3.82). Low ALMI was not associated, but low HGS, slow GS, and high FMI were individually associated with cognitive impairment: low HGS and immediate memory (OR: 1.91, 95% CI 1.04-3.49); low GS and immediate memory (OR: 2.17, 95% CI 1.26-3.72); high FMI and attention (OR: 2.06, 95% CI 1.22-3.51). Co-occurring high FMI with either low HGS or slow GS exacerbated the observed odds of global and domain-specific (attention, visuospatial) cognitive impairment. CONCLUSIONS: Lean mass is not relevant, whereas muscle strength and physical performance or adiposity are relevant in defining sarcopenia or sarcopenic obesity in terms of their cognitive impacts.

Relationship between BMI with percentage body fat and obesity in Singaporean adults - The Yishun Study.

BACKGROUND: The main aim of this study was to the determine relationship between Body Mass Index (BMI) and percentage body fat (BF%) in Singaporean adults, derive a prediction model to estimate BF%, and to report population BF%. The secondary aim was to determine the prevalence of overweight and obesity based on BF% threshold and the new risk categories for obesity in Singaporean population. METHODS: This was a population-based study of 542 community-dwelling Singaporeans (21-90 years old, 43.1% men). Anthropometry and body composition were assessed. Relationship between BMI and BF% were analysed using multiple regression models. Prevalence of overweight and obesity were estimated using WHO and Singapore Ministry of Health (MOH) Clinical Practice Guidelines for BMI classification, and BF% cut-off points of 25 and 35% for men and women respectively. RESULTS: We derived a prediction model to estimate BF% based on BMI, age and sex. The current cohort of Singaporeans when compared to Caucasians in the US and Europe as well as a Singapore cohort from 20 years age have higher BF% when matched for BMI, age, and sex. The overall population-adjusted prevalence of obesity according to WHO International classification (BMI ≥30 kg/m2) was 12.9% (14.9% men; 11.0% women); and 26.6% (30.7% men; 22.8% women) according to the MOH classification (BMI ≥27.5 kg/m2). However, using the BF% cut-off (> 25% for men and > 35% for women) resulted in very high prevalence of obesity of 82.0% (80.2% men; 83.8% women). CONCLUSION: There is a large discrepancy between BF% and BMI measured obesity in Singaporean adults. The results confirmed that Singaporean adults have higher BF% at lower BMI compared to US and Europe white counterparts; and that BF% in our population has increased over two decades.

Coexistence of osteoporosis, sarcopenia and obesity in community-dwelling adults - The Yishun Study.

OBJECTIVES: To 1) report prevalence of 'osteosarcopenia' (OS) and osteosarcopenic obesity (OSO) entities using evidence-based diagnostic techniques and definitions, 2) examine if OSO offers additional predictive value of functional decline over its components, and 3) identify associated factors in a multi-racial Southeast Asian population. METHODS: We performed a cross-sectional study of a representative sample of 542 community-dwelling adults (21-90 years old), and assessed anthropometry, cognition, functional performance, and self-report sociodemographic, health and lifestyle questionnaires. Low muscle mass, and the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, were used to assess sarcopenia. Obesity was defined using percentage body fat and fat mass index. Osteopenia/osteoporosis was determined using lumbar spinal bone mineral density. Associated factors were examined using logistic regression, and OSO's value investigated using linear regressions with functional performance. RESULTS: OS and OSO prevalence were 1.8% and 0% (21-59 years), 12.9% and 2.8% (≥ 60 years), 17.3% and 4.1% (≥ 65 years), and 25.5% and 7.0% (≥75 years), respectively. OSO entity as defined was not a significant predictor (P > 0.05) and did not improve explanations for functional decline over sarcopenia or sarcopenic obesity. Age, sex, race and body mass index (BMI) were associated with OS, while age, sex, race and alcoholism were associated with OSO. CONCLUSIONS: Our results do not support OSO as a distinct entity in relation to functional decline. Aside from biological age, sex, and race, amenable lifestyle factors such as BMI and alcohol intake are important variables that can influence the co-existence of osteopenia/osteoporosis, sarcopenia and obesity.

Timed Up and Go (TUG) Reference Values and Predictive Cutoffs for Fall Risk and Disability in Singaporean Community-Dwelling Adults: Yishun Cross-Sectional Study and Singapore Longitudinal Aging Study.

OBJECTIVES: The "timed up and go" (TUG) test is a simple and widely used test of overall functional mobility. There is a paucity of TUG normative data among Asian individuals who differ in habitual gait speed and fall risk from Western population. The objectives of this study were to determine TUG reference values and optimum cutoffs predicting prevalent and incident disability for community-dwelling adults. DESIGN: One cross-sectional (Study 1-Yishun Study) and one longitudinal (Study 2-Singapore Longitudinal Aging Study) study in Singapore. SETTING AND PARTICIPANTS: Study 1 comprised 538 nondisabled, community-dwelling adults aged between 21 and 90 years. Study 2 comprised 1356 community-dwelling older adults aged ≥55 years followed for 3 years. METHODS: Study 1 collected TUG reference values and assessed physiological fall risk (PFR) using the Physiological Profile Assessment (PPA). Study 2 assessed association of TUG with disability with the Barthel Index and the Lawton scale at baseline and follow-up. RESULTS: From Study 1, mean TUG time for individuals aged 60 to 74 years was 9.80 seconds, shorter than values reported for Westerners of 12.30 seconds. It was significantly associated with high PFR [odds ratio (OR) 1.14, 95% confidence interval (CI) 1.03-1.27], 74.0% agreement, Cohen's kappa = 0.314 (95% CI 0.238-0.390); area under the curve = 0.85 (95% CI 0.80-0.90). A TUG cutoff of 10.2 seconds discriminated high PFR from low PFR with 84.4% sensitivity and 72.6% specificity. In Study 2, the threshold for observing significantly increased risk of disability was ≥9.45 seconds for prevalent disability (OR 2.98, 95% CI 1.41-6.78), functional decline (OR 2.68, 95% CI 1.33-5.80), and incidental disability (OR 2.25, 95% CI 1.08-4.97). CONCLUSIONS AND IMPLICATIONS: TUG reference values and cutoff predicting disability for community-dwelling older adults in Singapore are consistent with Asian data and lower than for Western individuals. TUG could be used to guide development and evaluation of risk screening of adverse health outcomes across the life span in Singapore.

Physiological and Cognitive Determinants of Dual-Task Costs for Gait Parameters: The Yishun Study.

BACKGROUND: Studies indicate that physiological and cognitive aging are causally related and functionally interdependent. However, the relative contribution of physiological factors and cognition to dual-task costs (DTC) of gait parameters has not been well studied. In this cross-sectional study, we examined the trajectory of DTC of gait parameters across the adult age spectrum for both sexes and identified the contributions of physical and cognitive performance to DTC of gait. METHODS: A total of 492 community-dwelling adults, aged 21-90 years, were randomly recruited into the study. Participants were divided into 7 age groups, with 10-year age range for each group. Demographic data, height, body mass, education level, and information on comorbidities were recorded. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status. Physical performance included visual contrast sensitivity, postural sway, hand reaction time, handgrip strength, knee extensor strength, and single-task and dual-task gait assessments. Stepwise multivariable regression was used to examine the association between physical and cognitive performance with DTC of gait parameters. RESULTS: Women were found to have significantly higher DTC of gait speed (p = 0.01), cadence (p < 0.01), and double support time (p < 0.01) than men. However, significant aging effect on DTC of gait speed (p = 0.01), step length (p = 0.01), and double support time (p = 0.01) was observed in men but not in women. Immediate memory was the primary determinant for the DTC of gait speed (ß = -0.25, p < 0.01), step length (ß = -0.22, p < 0.01), and cadence (ß = -0.15, p = 0.03) in men. Besides immediate memory, postural sway (ß = -0.13, p = 0.03) and hand reaction (ß = 0.14, p = 0.02) were also significantly associated with DTC of step length and cadence, respectively, in women. CONCLUSION: There were sex differences in the amplitude and trajectories of DTC of gait parameters. The DTC increased with age in men but not in women. Immediate memory was the primary determinant of DTC of gait parameters in men while immediate memory, postural sway, and reaction time were associated with DTC of gait in women. Future studies should investigate the clinical implications of the sex differences in the DTC with fall risks.

SPPB reference values and performance in assessing sarcopenia in community-dwelling Singaporeans - Yishun study.

BACKGROUND: The Short Physical Performance Battery (SPPB) is an established test of physical performance. We provide reference values for SPPB and determine SPPB performance and cut-offs in assessing sarcopenia for Asian community-dwelling older adults. METHODS: Five hundred thirty-eight (57.8% women) community-dwelling adults aged 21-90 years were recruited. SPPB and its subtest scores and timings (8 ft. gait speed (GS), five-times repeated chair sit-to-stand (STS) and balance) were determined. Appendicular lean mass divided by height-squared, muscle strength (handgrip) and physical performance (6 m GS, STS and SPPB) were assessed to define sarcopenia for various Asian criteria. Area under the ROC curve (AUC) was used to assess performance of SPPB and subtests in discriminating sarcopenia in adults aged ≥60 years. Optimal SPPB and GS subtest cut-offs for each sarcopenia criterion were determined by maximizing sensitivity and specificity. RESULTS: The mean SPPB score was 11.6(SD 1.1) in men and 11.5(SD1.2) in women. Majority of participants(≥50%) aged 21-80 years achieved the maximum SPPB score. SPPB total and subtest scores generally decreased with age (all p < 0.001), but did not differ between sex. Among older adults (≥60 years), SPPB and GS subtest had varied performance in assessing sarcopenia (AUC 0.54-0.64 and 0.51-0.72, respectively), and moderate-to-excellent performance in assessing severe sarcopenia (AUC 0.69-0.98 and 0.75-0.95, respectively), depending on sarcopenia definitions. The optimal cut-offs for discriminating sarcopenia in both sexes were SPPB ≤11points and GS subtest ≤1.0 m/s. The most common optimal cut-offs for discriminating severe sarcopenia according to various definitions were SPPB ≤11points in both sexes, and GS ≤0.9 m/s in men and ≤ 1.0 m/s in women. CONCLUSIONS: Population-specific normative SPPB values are important for use in diagnostic criteria and to interpret results of studies evaluating and establishing appropriate treatment goals. Performance on the SPPB should be reported in terms of the total sum score and registered time to complete the repeated-chair STS and 8-ft walk tests. The performance of GS subtest was comparable to SPPB and could be a useful, simple and accessible screening tool for discriminating severe sarcopenia in community-dwelling older adults.

Effectiveness of Community-Delivered Functional Power Training Program for Frail and Pre-frail Community-Dwelling Older Adults: a Randomized Controlled Study.

Translation of community-based functional training for older adults to reduce frailty is still lacking. We evaluated the effectiveness and implementation of a community-delivered group-based functional power training (FPT) program for frail older adults within their neighborhoods. A two-arm, multicenter assessor-blind stratified randomized controlled trial was conducted at four local senior activity centers in Singapore. Sixty-one community-dwelling older adults with low handgrip strength were randomized to intervention (IG) or control (CG) group. The IG underwent the FPT program (power and balance exercises using simple equipment) delivered by a community service provider. The 12-week program comprised 2 × 60 min sessions/week. CG continued usual activities at the centers. Functional performance, muscle strength, and frailty status were assessed at baseline and 3 months. Program implementation was evaluated using RE-AIM framework. The program was halted due to Coronavirus Disease 2019-related suspension of senior center activities. Results are reported from four centers, which completed the program. IG showed significantly greater improvement in the Short Physical Performance Battery test as compared to CG (p = 0.047). No effects were found for timed up and go test performance, muscle strength, and frailty status. The community program exhibited good reach, effectiveness, adoption, and implementation. Our study demonstrated that FPT was associated with greater improvement in physical function in pre-frail/frail participants as compared to exercise activities offered at local senior activity centers. It is a feasible intervention that can be successfully implemented for frail older adults in their neighborhoods. Trial registration ClinicalTrials.gov, NCT04438876. Registered 19 June 2020-retrospectively registered.

Fast gait spatiotemporal parameters in adults and association with muscle strength - The Yishun study.

BACKGROUND: There is limited data on fast gait speed and spatial-temporal parameters across age groups among Asian adults, and the associations between upper and lower extremity muscle strength with gait. RESEARCH QUESTION: What values characterise fast gait spatiotemporal parameters across the age groups of an Asian population? Are hand grip strength (HGS) and knee extension strength (KES) associated with fast gait speed and spatiotemporal parameters? METHODS: Healthy community-living adults between 21-90 years (n = 487) were recruited. Fast gait was assessed using a 6 m instrumented walkway, and spatiotemporal parameters including variability for fast gait speed, stride length, stride width, stride time, stance time, swing time, single support time and double support time were analysed. Maximum HGS and KES were also assessed. Linear regression modelling was used to explore the association of HGS and KES with fast gait speed, spatiotemporal parameters and their variability. RESULTS: Age reduced fast gait speed and stride length, but increased stride width, stance time, stride time and double support time. Age increased all investigated gait variabilities except stride width variability. Gender differences were observed for all gait features except for fast gait speed and double support time. Both HGS and KES were positively associated with fast gait speed in both young and old adults. KES was positively associated with spatiotemporal variations in stride length, stride time, stance time and double support time. HGS was also significantly associated with two additional temporal parameters - positively with swing time and negatively with double support time variability. SIGNIFICANCE: The data from this study contributes to reference values database for the use of fast gait assessments in adults.

Sensorimotor Performance and Reference Values for Fall Risk Assessment in Community-Dwelling Adults: The Yishun Study.

OBJECTIVE: This study sought to answer the following questions: What are the reference values of sensorimotor performance for fall risk in community-dwelling adults? How do population norms compare with that of other populations? Are younger adults at risk of falls? METHODS: In a cross-sectional study design, sensorimotor functions and fall risk scores of community-dwelling adults were assessed and calculated to derive corresponding fall risk categories. Reference values were determined using the average scores by age group. A total of 542 community-dwelling adults were recruited (21-90 years old) across 10-year (21-60 years) and 5-year age groups (>60 years) to obtain a representative sample of community-dwelling adults in Singapore. Five physiological domains were assessed: vision, proprioception, muscle strength, reaction time, and postural balance according to the Physiological Profile Assessment (PPA). Fall risk scores and the corresponding fall risk profiles were generated from an online calculator. RESULTS: Sensorimotor performance and PPA fall risk scores were significantly worse for increasing age categories. Females had significantly slower reaction time, lower muscle strength, and higher fall risk. The representative sample of older adults (≥65 years) performed poorer in postural sway (z = -0.50) and reaction time (z = -0.55), but better in proprioception (z = 0.29) and vision (z = 0.23) compared with Caucasian norms. Among younger adults (21-59 years), 36.8% appeared to exhibit higher fall risk. CONCLUSION: This study presents important reference data and compared sensorimotor functions and physiological fall risk across age groups of community-dwelling adults in a Southeast Asian population. Poor sensorimotor performance and fall risk appear already pertinent in younger adults. Further studies are warranted to improve understanding of fall risk among younger adults. IMPACT: In physical therapist practice, PPA reference values can aid clinicians in the development of targeted interventions tailored towards an individual's physiological risk profile, addressing specific physiological systems that require particular attention.

Prevalence and Associated Factors of Sarcopenia in Singaporean Adults-The Yishun Study.

OBJECTIVES: To describe the normative values of sarcopenia among community-dwelling adults (≥21 years of age); compare the prevalence of sarcopenia using Asian Working Group for Sarcopenia criteria, 2014 (AWGS2014), Asian Working Group for Sarcopenia criteria, 2019 (AWGS2019), and European Working Group on Sarcopenia in Older People criteria, 2018 (EWGSOP2) guidelines; and identify factors associated with sarcopenia. DESIGN: Participants were recruited through random sampling. Sarcopenia assessments were performed using a dual-energy x-ray absorptiometry scan (muscle mass), handgrip test (muscle strength), and usual walking test (physical performance). Questionnaires were administered to evaluate lifestyle and cognition. SETTING AND PARTICIPANTS: In total, 542 community-dwelling Singaporeans were recruited (21‒90 years old, 57.9% women). METHODS: We assessed anthropometry, body composition, and questionnaire-based physical and cognitive factors, and estimated sarcopenia prevalence according to the AWGS2014, AWGS2019, and EWGSOP2 recommendations, and examined associations using logistic regression. RESULTS: According to AWGS2019, the Singapore population-adjusted sarcopenia prevalence was 13.6% (men 13.0%; women 14.2%) overall, and 32.2% (men 33.7%, women 30.9%) in those aged 60 years and above. The cut-offs derived from young adult reference group for low appendicular lean mass index were 5.28 kg/m2 for men and 3.69 kg/m2 for women (lower than AWGS recommended cut-off); for gait speed it was 0.82 m/s, (AWGS2019 recommended cut-off 1.0 m/s, AWGS2014 cut-off was 0.8 m/s); and for handgrip strength it was 27.9 kg/m2 for men and 16.7 kg/m2 for women (close to AWGS2019 recommendation). Age, sex, marital status, alcoholism, physical activity, body mass index, waist circumference, and global cognition were associated with sarcopenia (P < .05). CONCLUSIONS AND IMPLICATIONS: This is the first study to provide reference values of muscle mass, strength, and gait speed across the adult lifespan of Singaporeans. Using AWGS2019 criteria, sarcopenia is prominent in older age (32.2% in ≥60 years old), but it is already nontrivial (6.9%) among young and middle-age persons. Multidomain lifestyle modifications addressing muscle strength, cognition, and nutrition over the adult lifespan are important to delay the development of sarcopenia.

Reference Values of Gait Speed and Gait Spatiotemporal Parameters for a South East Asian Population: The Yishun Study.

BACKGROUND: Age-related slowing of gait has been reported to start as early as the fifth decade and accelerate beyond the seventh decade of life. A single cut-off for slow gait may not be appropriate for men and women of different ages. We aimed to report reference values for gait speed and spatiotemporal gait parameters of adult age groups in a South East Asian population. METHODS: A total of 507 community-dwelling adults, aged 21-90 years were recruited into the study through random sampling, filling quotas of 20-40 participants in each sex and age group (10-year age groups between 21 and 60 years; 5-year age groups beyond age 60 years). Demographic data, height, weight and information on comorbidities were recorded. Habitual gait speed and spatiotemporal parameters were measured, and the average of three trials was recorded using the GAITRite system. RESULTS: Gait speed peaked in their 40s for both men and women, but the trajectories differed slightly across age groups. Although similar for men in their 50s and 60s, gait speed was significantly slower among those aged 71 years and older. For women beyond 50 years old, gait slowed with age. After adjusting for height, women were found to walk significantly faster and with a longer step length than men. Women also walked with a significantly narrower stride width and less external rotation of the feet. The lowest quintile for gait speed in our study cohort was 0.9m/s, below the recommended cut-off of 1.0m/s. CONCLUSION: We established the reference values as well as the quintiles for gait speed and spatiotemporal gait parameters across adult age groups in a multi-ethnic Asian population. This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.

Bone mineral density reference values in Singaporean adults and comparisons for osteoporosis establishment - The Yishun Study.

BACKGROUND: While there have been studies in Singapore on the prevalence and economic burden of osteoporotic hip fracture, there is a severe lack of reference data on bone mineral density and prevalence of osteoporosis. The purpose of this study is to establish the reference values for BMD and compare prevalence of osteoporotic conditions using other available reference values so as to better understand the status of bone health in Singaporean adults. METHODS: We carried out a population-based cross-sectional study using dual-energy x-ray absorptiometry (Hologic Discovery Wi) to measure the bone mineral density of Singaporean adults aged ≥21 years. A total of 542 participants were recruited from the large north-eastern residential town of Yishun. We computed T- scores (denoted by TSG) for each individual in the study. Similar diagnoses were also done based on T-scores provided by the densitometer (TDXA), NHANES database (TNHANES), and China (TCHN), and the differences in prevalence compared. We then compared the concordance between TSG and TDXA in the classification of osteoporosis. Osteoporosis was defined according to criteria by the World Health Organization (WHO). RESULTS: Peak lumbar spine BMD was 1.093 ± 0.168 g/cm2 in women, and 1.041 ± 0.098 g/cm2 for men. Peak whole-body BMD was 1.193 ± 0.93 g/cm2 in women at, and 1.224 ± 0.112 g/cm2 for men. Prevalence of osteoporosis based on lumbar spine was 9.3% in postmenopausal women, and 0.7% in men after 50 years of age. The percentage difference in prevalence range from 60.5-163.6%, when using reference values from TDXA, TNHANES, and TCHN. Comparing diagnosis using TDXA and TSG cut-off values, 28 versus 15 women were diagnosed as osteoporotic respectively.  The kappa statistics was 0.81 for women and 0.85 for men. CONCLUSION: Our study shows that T-scores provided by DXA manufacturer over-diagnosed osteoporosis in Singaporeans, and the prevalence of osteoporotic conditions is not accurately represented. This over-diagnosis may result in unnecessary treatment in some individuals.