Body Mass Index,Muscle Strength and Physical Performance in Older Adults from Eight Cohort Studies: The HALCyon Programme

Objective

To investigate the associations of body mass index (BMI) and grip strength with objective measures of physical performance (chair rise time, walking speed and balance) including an assessment of sex differences and non-linearity.

Methods

Cross-sectional data from eight UK cohort studies (total N = 16 444) participating in the Healthy Ageing across the Life Course (HALCyon) research programme, ranging in age from 50 to 90+ years at the time of physical capability assessment, were used. Regression models were fitted within each study and meta-analysis methods used to pool regression coefficients across studies and to assess the extent of heterogeneity between studies.

Results

Higher BMI was associated with poorer performance on chair rise (N = 10 773), walking speed (N = 9 761) and standing balance (N = 13 921) tests. Higher BMI was associated with stronger grip strength in men only. Stronger grip strength was associated with better performance on all tests with a tendency for the associations to be stronger in women than men; for example, walking speed was higher by 0.43 cm/s (0.14, 0.71) more per kg in women than men. Both BMI and grip strength remained independently related with performance after mutual adjustment, but there was no evidence of effect modification. Both BMI and grip strength exhibited non-linear relations with performance; those in the lowest fifth of grip strength and highest fifth of BMI having particularly poor performance. Findings were similar when waist circumference was examined in place of BMI.

Conclusion

Older men and women with weak muscle strength and high BMI have considerably poorer performance than others and associations were observed even in the youngest cohort (age 53). Although causality cannot be inferred from observational cross-sectional studies, our findings suggest the likely benefit of early assessment and interventions to reduce fat mass and improve muscle strength in the prevention of future functional limitations.     

Accelerometer Cut Points for Physical Activity Assessment of Older Adults with Parkinson’s Disease

Objective

To define accelerometer cut points for different walking speeds in older adults with mild to moderate Parkinson’s disease.

Method

A volunteer sample of 30 older adults (mean age 73; SD 5.4 years) with mild to moderate Parkinson’s disease walked at self-defined brisk, normal, and slow speeds for three minutes in a circular indoor hallway, each wearing an accelerometer around the waist. Walking speed was calculated and used as a reference measure. Through ROC analysis, accelerometer cut points for different levels of walking speed in counts per 15 seconds were generated, and a leave-one-out cross-validation was performed followed by a quadratic weighted Cohen’s Kappa, to test the level of agreement between true and cut point–predicted walking speeds.

Results

Optimal cut points for walking speeds ≤ 1.0 m/s were ≤ 328 and ≤ 470 counts/15 sec; for speeds > 1.3 m/s, they were ≥ 730 and ≥ 851 counts/15 sec for the vertical axis and vector magnitude, respectively. Sensitivity and specificity were 61%–100% for the developed cut points. The quadratic weighted Kappa showed substantial agreement: κ = 0.79 (95% CI 0.70–0.89) and κ = 0.69 (95% CI 0.56–0.82) for the vertical axis and the vector magnitude, respectively.

Conclusions

This study provides accelerometer cut points based on walking speed for physical-activity measurement in older adults with Parkinson’s disease for evaluation of interventions and for investigating links between physical activity and health.     

Correlation between Muscle Strength and Muscle Mass,and Their Association with Walking Speed,in Community-Dwelling Elderly Japanese Individuals

Objectives

We aimed to assess the correlation between muscle strength and muscle mass based on sex and age, and their association with walking speed, which is a health predictor for independent living, in elderly Japanese individuals.

Methods

The participants included 318 (111 men, 207 women) community-dwelling elderly Japanese individuals aged ≥65 years. Knee extension strength was assessed as an indicator of muscle strength, and bioelectrical impedance analysis was used to measure muscle mass. The maximum walking speed of participants was recorded. All measurements were categorized based on sex and age groups as follows: young-old (age, 65–74 years) and old-old (age, ≥75 years).

Results

Appendicular muscle mass and knee extension strength decreased with age in both men and women. In men, knee extension strength showed significant positive correlations with leg and appendicular muscle mass in both young-old and old-old age groups. However, in women, only the old-old age group showed significant positive correlations between knee extension strength and leg and appendicular muscle mass. Muscle strength was significantly positively correlated with maximum walking speed in all groups, whereas muscle mass was not significantly correlated with maximum walking speed in men and women.

Conclusions

Muscle strength was significantly correlated with muscle mass in both age groups in men. However, in women, the correlation between muscle strength and muscle mass differed according to age. This finding suggests that the relationship between muscle strength and muscle mass differs according to sex and age. Muscle strength showed significant correlation with walking speed in both men and women in both age groups. These findings suggest that it is necessary to recognize that muscle strength is different from muscle mass, and that an individualized approach to prevent decline of muscle strength and muscle mass is necessary for health promotion in elderly.     

Body Mass Index and Decline of Cognitive Function

Background

The association between body mass index (BMI) and cognitive function is a public health issue. This study investigated the relationship between obesity and cognitive impairment which was assessed by the Korean version of the Mini-mental state examination (K-MMSE) among mid- and old-aged people in South Korea.

Methods

A cohort of 5,125 adults, age 45 or older with normal cognitive function (K-MMSE≥24) at baseline (2006), was derived from the Korean Longitudinal Study of Aging (KLoSA) 2006~2012. The association between baseline BMI and risk of cognitive impairment was assessed using multiple logistic regression models. We also assessed baseline BMI and change of cognitive function over the 6-year follow-up using multiple linear regressions.

Results

During the follow-up, 358 cases of severe cognitive impairment were identified. Those with baseline BMI≥25 kg/m² than normal-weight (18.5≤BMI<23 kg/m²) were marginally less likely to experience the development of severe cognitive impairment (adjusted odds ratio [aOR] = 0.73, 95% CI = 0.52 to 1.03; P_trend = 0.03). This relationship was stronger among female (aOR = 0.63, 95% CI = 0.40 to 1.00; P_trend = 0.01) and participants with low-normal K-MMSE score (MMSE: 24–26) at baseline (aOR = 0.59, 95% CI = 0.35 to 0.98; P_trend<0.01). In addition, a slower decline of cognitive function was observed in obese individuals than those with normal weight, especially among women and those with low-normal K-MMSE score at baseline.

Conclusion

In this nationally representative study, we found that obesity was associated with lower risk of cognitive decline among mid- and old-age population.     

Glycated Hemoglobin and Incident Type 2 Diabetes in Singaporean Chinese Adults: The Singapore Chinese Health Study

Background

The American Diabetes Association recently included glycated hemoglobin in the diagnostic criteria for diabetes, but research on the utility of this biomarker in Southeast Asians is scant. The aim of this study was to evaluate the association between percent HbA1c and incident diabetes in an Asian population of adult men and women without reported diabetes.

Methods

Data analysis of 5,770 men and women enrolled in the Singapore Chinese Health Study who provided a blood sample at the follow-up I visit (1999–2004) and had no cancer and no reported history of diabetes or cardiovascular disease events. Diabetes was defined as self-report of physician diagnosis, identified at the follow-up II visit (2006–2010).

Results

Hazard ratios (and 95% confidence intervals) for incident diabetes by 5 categories of HbA1c were estimated with Cox regression models and continuous HbA1c with cubic spline analysis. Compared to individuals with an HbA1c ≤ 5.7% (≤39 mmol/mol), individuals with HbA1c 5.8–5.9% (40–41 mmol/mol), 6.0–6.1% (42–43 mmol/mol), 6.2–6.4% (44–47 mmol/mol), and ≥ 6.5% (≥48 mmol/mol) had significantly increased risk for incident diabetes during follow-up. In cubic spline analysis, levels below 5.7% HbA1c were not significantly associated with incident diabetes.

Conclusions

Our study found a strong and graded association with HbA1c 5.8% and above with incident diabetes in Chinese men and women.     

Menopausal Status and Physical Performance in Middle Aged Women: A Cross-Sectional Community-Based Study in Northeast Brazil

Objective

To examine associations between menopausal status and physical performance in middle-aged women from the Northeast region of Brazil.

Methods

Cross-sectional study of women between 40 to 65 years old living in Parnamirim. Women were recruited by advertisements in primary care neighborhood centers across the city. Physical performance was assessed by grip strength, gait speed and chair stands. Menopausal status was determined using the Stages of Reproductive Aging Workshop classification and women were classified in: premenopausal, perimenopausal or postmenopausal. Multiple linear regression analyses were performed to model the effect of menopausal status on each physical performance measure, adjusting for covariates (age, family income, education, body mass index, parity and age at first birth).

Results

The premenopausal women were significantly stronger and performed better in chair stands than perimenopausal and postmenopausal women. Gait speed did not vary significantly by menopausal status. In multivariate analyses, menopausal status remained statistically significant only for grip strength. In fully adjusted analyses, premenopausal women had grip strength mean of 2.226 Kgf (95% CI: 0.361 – 4.091) higher than the postmenopausal group.

Conclusions

This study provides further evidence for the associations between menopause and physical performance in middle-aged women, since grip strength is weaker in peri and postmenopausal women compared to premenopausal, even adjusted for age and other covariates.     

Functional Changes during Hospital Stay in Older Patients Admitted to an Acute Care Ward: A Multicenter Observational Study

Objectives

Changes in physical performance during hospital stay have rarely been evaluated. In this study, we examined functional changes during hospital stay by assessing both physical performance and activities of daily living. Additionally, we investigated characteristics of older patients associated with meaningful in-hospital improvement in physical performance.

Methods

The CRiteria to assess appropriate Medication use among Elderly complex patients project recruited 1123 patients aged ≥65 years, consecutively admitted to geriatric or internal medicine acute care wards of seven Italian hospitals. We analyzed data from 639 participating participants with a Mini Mental State Examination score ≥18/30. Physical performance was assessed by walking speed and grip strength, and functional status by activities of daily living at hospital admission and at discharge. Meaningful improvement was defined as a measured change of at least 1 standard deviation. Multivariable logistic regression models predicting meaningful improvement, included age, gender, type of admission (through emergency room or elective), and physical performance at admission.

Results

Mean age of the study participants was 79 years (range 65–98), 52% were female. Overall, mean walking speed and grip strength performance improved during hospital stay (walking speed improvement: 0.04±0.20 m/s, p<0.001; grip strength improvement: 0.43±5.66 kg, p = 0.001), no significant change was observed in activities of daily living. Patients with poor physical performance at admission had higher odds for in-hospital improvement.

Conclusion

Overall, physical performance measurements show an improvement during hospital stay. The margin for meaningful functional improvement is larger in patients with poor physical function at admission. Nevertheless, most of these patients continue to have poor performance at discharge.     

Hepatitis B e Antigen Status and Hepatitis B DNA Levels in Women of Childbearing Age with Chronic Hepatitis B Infection Screening for Clinical Trials

Background

Perinatal or mother-to-child transmission of hepatitis B virus (HBV) results in a high frequency of chronic infection. Risk of mother-to-child transmission is associated with maternal viral factors including hepatitis B e antigen (HBeAg) positivity and viral load.

Aim

To investigate associations between age, HBeAg status, HBV DNA levels and genotype in female patients screened for inclusion into two contemporary, randomized HBV trials.

Methods

Retrospective analyses focused on differences between women of childbearing age (≤44 years) and older women. Female patients (N = 355; 18–69 years) were included in the analysis: 41.7% of patients were Asian. In total, 44.4% were HBeAg-positive.

Results

Significantly more women aged ≤44 years were HBeAg-positive compared to women ≥45 years (57.2% versus 27.5%, respectively, p<0.0001), this proportion declined with increasing age. Younger women were significantly more likely to have high HBV viral load (HBV DNA>10⁸ copies mL: ≤44 years 46.0% vs ≥45 years 25.5%, respectively; p<0.0001), and this declined with increasing age. HBeAg positivity was slightly higher in Asian women, associated with a higher proportion of HBV genotypes B and C in this population. There was no obvious relationship between genotype and viral load.

Conclusions

Women of childbearing age with CHB are more likely to have high HBV viral load and HBeAg positivity than older women; this likelihood decreases with age. Maternal serological and virological status should therefore be established early in pregnancy, taking into account age and genotype, and a risk-reducing strategy implemented in any patient who is HBeAg positive and has a high viral load.     

Effects of Body Mass Index on Risks for Ischemic Stroke,Thromboembolism, and Mortality in Chinese Atrial Fibrillation Patients: A Single-Center Experience

Background

Obesity is considered to be related to recurrence of atrial fibrillation (AF), left atrial thrombus formation, and atrial remodeling. However, whether obesity is an independent risk factor for stroke and other thromboembolic events is still controversial.

Objective

This study aimed to investigate the effects of body mass index (BMI) on the risks of stroke, thromboembolism, and mortality in AF patients.

Methods

Patients who were diagnosed with nonvalvular AF were included in this observational, retrospective study. The study population was stratified by BMI at baseline. The Cox proportional hazard model was adopted to calculate adjusted hazard ratios of risk factors for adverse clinical events (stroke, thromboembolism, and mortality).

Results

A total of 1286 AF patients (males, 78.30%; mean age, 74.50 years; 94.48% paroxysmal AF) were followed up for a median of 2.1 years (IQR: 1.5–2.9 years). Overall, 159 patients died. A total of 84 strokes and 35 thromboembolic events occurred. Multivariate analysis showed that overweight (25.0≤BMI<30.0 kg/m²) and age ≥75 years were independent risk factors for ischemic stroke (both P<0.01). Obesity (BMI ≥30.0 kg/m²), age ≥75 years, persistent/permanent AF, and prior thromboembolism were independent risk factors for thromboembolism (all P<0.05). Underweight (BMI <18.5 kg/m²), age ≥75 years, prior ischemic stroke/transient ischemic attack, renal dysfunction, and heart failure were independent risk factors for all-cause deaths (all P<0.05).

Conclusions

Overweight or obesity may be a risk factor of ischemic stroke and thromboembolism in AF patients. Excessive low weight is significantly associated with increased all-cause mortality.     

Overweight Is an Independent Risk Factor for Reduced Lung Volumes in Myotonic Dystrophy Type 1

Background

In this large observational study population of 105 myotonic dystrophy type 1 (DM1) patients, we investigate whether bodyweight is a contributor of total lung capacity (TLC) independent of the impaired inspiratory muscle strength.

Methods

Body composition was assessed using the combination of body mass index (BMI) and fat-free mass index. Pulmonary function tests and respiratory muscle strength measurements were performed on the same day. Patients were stratified into normal (BMI < 25 kg/m²) and overweight (BMI ≥ 25 kg/m²) groups. Multiple linear regression was used to find significant contributors for TLC.

Results

Overweight was present in 59% of patients, and body composition was abnormal in almost all patients. In overweight patients, TLC was significantly (p = 2.40×10⁻³) decreased, compared with normal-weight patients, while inspiratory muscle strength was similar in both groups. The decrease in TLC in overweight patients was mainly due to a decrease in expiratory reserve volume (ERV) further illustrated by a highly significant (p = 1.33×10⁻¹⁰) correlation between BMI and ERV. Multiple linear regression showed that TLC can be predicted using only BMI and the forced inspiratory volume in 1 second, as these were the only significant contributors.

Conclusions

This study shows that, in DM1 patients, overweight further reduces lung volumes, as does impaired inspiratory muscle strength. Additionally, body composition is abnormal in almost all DM1 patients.     

Telomere Length and Physical Performance at Older Ages: An Individual Participant Meta-Analysis

Background

Telomeres are involved in cellular ageing and shorten with increasing age. If telomere length is a valuable biomarker of ageing, then telomere shortening should be associated with worse physical performance, an ageing trait, but evidence for such an association is lacking. The purpose of this study was to examine whether change in telomere length is associated with physical performance.

Methods

Using data from four UK adult cohorts (ages 53–80 years at baseline), we undertook cross-sectional and longitudinal analyses. We analysed each study separately and then used meta-analytic methods to pool the results. Physical performance was measured using walking and chair rise speed, standing balance time and grip strength. Telomere length was measured by quantitative real-time polymerase chain reaction (PCR) in whole blood at baseline and follow-up (time 1, time 2).

Results

Total sample sizes in meta-analyses ranged from 1,217 to 3,707. There was little evidence that telomere length was associated with walking speed, balance or grip strength, though weak associations were seen with chair rise speed and grip strength at baseline (p = 0.02 and 0.01 respectively). Faster chair rise speed at follow-up, was associated with a smaller decline in telomere length between time 1 and time 2 (standardised coefficient per SD increase 0.061, 95% CI 0.006, 0.115, p = 0.03) but this was consistent with chance (p = 0.08) after further adjustment.

Conclusions

Whereas shortening of leukocyte telomeres might be an important measure of cellular ageing, there is little evidence that it is a strong biomarker for physical performance.     

Earlier Menarche Is Associated with Lower Insulin Sensitivity and Increased Adiposity in Young Adult Women

Objective

We aimed to assess whether age at menarche was associated with insulin sensitivity in young adult women.

Methods

We studied 54 healthy young women aged 20–30 years. Participants were grouped according to age at menarche: Early (≤11.0 years; n=13), Average (>12.0 and ≤13.0 years; n=28), and Late (≥14.0 years, n=13). Primary outcome was insulin sensitivity measured using intravenous glucose tolerance tests and Bergman’s minimal model. Body composition was assessed using whole-body dual-energy X-ray absorptiometry.

Results

Earlier menarche was associated with lower insulin sensitivity (p=0.015). There was also a continuous increase in adiposity with younger age at menarche, which was associated with increased weight (p=0.001), BMI (p=0.002), total body fat (p=0.049), and truncal fat (p=0.020). Stratified analyses showed that insulin sensitivity in Early women (5.5 x10^-4·min^-1(mU/l)) was lower than in Average (8.0 x10^-4·min^-1(mU/l), p=0.021) and Late (8.6 x10^-4·min^-1(mU/l), p=0.033) groups. Early women (weight=66.1 kg; BMI=24.1 kg/m²) were considerably heavier and fatter than Average (59.0 kg, p=0.004; 21.4 kg/m², p=0.002) and Late (57.0 kg, p=0.001; 20.8 kg/m², p=0.0009) women.

Conclusions

Early menarche is associated with lower insulin sensitivity and increased adiposity in young adulthood, potentially increasing the risk of type 2 diabetes and the metabolic syndrome later in life.     

Associations of Fibroblast Growth Factor-23 with Markers of Inflammation,Insulin Resistance and Obesity in Adults

Introduction

Elevated fibroblast growth factor-23 (FGF23) is an established marker of cardiovascular disease. The underlying reason(s) for the rise accompanying cardiovascular health decline are unclear. Prior studies have shown that FGF23 concentrations are associated with markers of inflammation and insulin resistance but they have been limited by a focus on persons with chronic kidney disease (CKD) and lack of race and sex diversity. The objective of this study was to examine the associations of FGF23 and markers of inflammation, insulin resistance, and anthropometrics in a large cohort of community-dwelling adults.

Methods

Associations of FGF23 with markers of inflammation [interleukin-6 (IL-6), IL-10, high sensitivity-CRP (hsCRP)], insulin utilization [resistin, adiponectin, homeostatic model assessment of insulin resistance (HOMA-IR)] and anthropometrics [BMI and waist circumference (WC)] were examined cross-sectionally in a 1,040 participants randomly selected from the Reason for Geographic and Racial Differences in Stroke (REGARDS) Study, a national study of black and white adults ≥45 years. Effect modification by race and CKD status was tested, and stratified models were analyzed accordingly.

Results

Median FGF23 concentration was 69.6 RU/ml (IQR: 53.2, 102.7). Higher quartiles of FGF23 were associated with higher mean concentrations of IL-6, IL-10, hsCRP and resistin (P _trend<0.001 for all). There were no significant differences in HOMA-IR, adiponectin concentrations, BMI, or WC across FGF23 quartiles in the crude analyses. CKD significantly modified the relationships between FGF23 and inflammatory markers, HOMA-IR, BMI and WC (P ≤ 0.01 for all). In linear regression models adjusted for sociodemographic and clinical variables, FGF23 was positively associated with IL-6, hsCRP, IL-10, HOMA-IR, BMI and WC in individuals without CKD, but not among individuals with CKD. Additionally, FGF23 was positively associated with resistin irrespective of CKD status.

Conclusions

Elevated FGF23 concentrations may be considered a biomarker for decline in metabolic function among individuals with normal kidney function.     

Effect of Serum Cholesterol on Insulin Secretory Capacity: Shimane CoHRE Study

Objectives

Previous studies indicate that, in addition to the blood glucose level, the lipid level in the blood may affect functions of pancreatic beta cells. In this study, we aimed to examine whether there was a relationship between the serum level of total cholesterol (TC) and the insulin secretory capacity in healthy subjects.

Subjects and Methods

In participants of health examinations conducted from 2006 to 2010, we analyzed data from a total of 2,499 subjects (1,057 men and 1,442 women) after exclusion of individuals with dyslipidemia, thyroid dysfunction, diabetes, HbA1c≥6.5%, or fasting blood glucose≥126 mg/dL. Homeostasis model assessment for beta cell function (HOMA-beta) was utilized as a model representing the pancreatic beta cell function.

Results

Although the serum TC level had a positive correlation with HOMA-beta in a univariate correlation analysis, after adjustment by confounding factors in a multiple regression analysis, HOMA-beta had a negative correlation with TC. This was further confirmed in a multiple logistic regression analysis, showing that higher TC was an independent risk factor for decreased insulin secretory capacity (defined as HOMA-beta≤30%) together with higher age, lower BMI, lower TG, male sex and regular alcohol intake. After the participants were stratified by BMI into three groups, the effect of TC on HOMA-beta increased along with the increase in BMI, and it was highly significant in the highest tertile.

Conclusion

This cross-sectional study indicated that increased serum TC level might be related to the decrease of insulin secretory capacity in aged healthy population and that reduction of TC is more necessary in obese subjects to prevent diabetes.     

Multi-Morbidity in Hospitalised Older Patients: Who Are the Complex Elderly?

Background

No formal definition for the “complex elderly” exists; moreover, these older patients with high levels of multi-morbidity are not readily identified as such at point of hospitalisation, thus missing a valuable opportunity to manage the older patient appropriately within the hospital setting.

Objectives

To empirically identify the complex elderly patient based on degree of multi-morbidity.

Design

Retrospective observational study using administrative data.

Setting

English hospitals during the financial year 2012–13.

Subjects

All admitted patients aged 65 years and over.

Methods

By using exploratory analysis (correspondence analysis) we identify multi-morbidity groups based on 20 target conditions whose hospital prevalence was ≥ 1%.

Results

We examined a total of 2788900 hospital admissions. Multi-morbidity was highly prevalent, 62.8% had 2 or more of the targeted conditions while 4.7% had six or more. Multi-morbidity increased with age from 56% (65-69yr age-groups) up to 67% (80-84yr age-group). The average multi-morbidity was 3.2±1.2 (SD). Correspondence analysis revealed 3 distinct groups of older patients. Group 1 (multi-morbidity ≤2), associated with cancer and/or metastasis; Group 2 (multi-morbidity of 3, 4 or 5), associated with chronic pulmonary disease, lung disease, rheumatism and osteoporosis; finally Group 3 with the highest level of multi-morbidity (≥6) and associated with heart failure, cerebrovascular accident, diabetes, hypertension and myocardial infarction.

Conclusions

By using widely available hospital administrative data, we propose patients in Groups 2 and 3 to be identified as the complex elderly. Identification of multi-morbidity patterns can help to predict the needs of the older patient and improve resource provision.     

Validity of Self-Reports of Height and Weight among the General Adult Population in Japan: Findings from National Household Surveys, 1986

Background/Objectives

Growing evidence indicates that self-reported height and weight are biased, but little is known about systematic errors in the general adult population in Japan. This study takes advantage of the unique opportunity to examine this issue provided by the 1986 National Nutrition Survey.

Subjects/Methods

Individual-level data on a nationally representative sample aged 20–89 years from the National Nutrition Survey (November 1986) were merged with Comprehensive Survey of Living Conditions (September 1986) data to obtain a dataset containing both self-reported and measured data on height and weight for each person (n = 10,469). Discrepancies between self-reported and measured means of height, weight, and body mass index (BMI) were tested across measured BMI categories (<18.5, 18.5–24.9, 25.0–27.4, 27.5–29.9, and ≥30.0 kg/m²), age groups (20–44, 45–64, and 65–89 years), and sexes. Reporting bias in mean BMI was decomposed into the contributions of misreporting height and weight. The sensitivity and specificity of self-reported BMI categories were estimated.

Results

Mean self-reported BMI was substantially underestimated in older women (P<0.001; Cohen’s d, -0.4), and the major contributor to the bias was their over-reported height. Mean self-reported BMI was also considerably underestimated in both men and women who were overweight and obese (P<0.001; Cohen’s d, -1.0 to -0.6), due mainly to their underreported weight. In contrast, mean self-reported BMI was considerably overestimated in underweight men (P<0.001; Cohen’s d, 0.5), due largely to their over-reported weight. The sensitivity of self-reported BMI categories was particularly low for individuals who had a measured BMI of 27.5–29.9 kg/m² (40.9% for men and 26.8% for women).

Conclusions

Self-reported anthropometric data were not sufficiently accurate to assert the validity of their use in epidemiological studies on the general adult population in Japan in the late 1980s.     

Reliability and Validity of Dual-Task Mobility Assessments in People with Chronic Stroke

Background

The ability to perform a cognitive task while walking simultaneously (dual-tasking) is important in real life. However, the psychometric properties of dual-task walking tests have not been well established in stroke.

Objective

To assess the test-retest reliability, concurrent and known-groups validity of various dual-task walking tests in people with chronic stroke.

Design

Observational measurement study with a test-retest design.

Methods

Eighty-eight individuals with chronic stroke participated. The testing protocol involved four walking tasks (walking forward at self-selected and maximal speed, walking backward at self-selected speed, and crossing over obstacles) performed simultaneously with each of the three attention-demanding tasks (verbal fluency, serial 3 subtractions or carrying a cup of water). For each dual-task condition, the time taken to complete the walking task, the correct response rate (CRR) of the cognitive task, and the dual-task effect (DTE) for the walking time and CRR were calculated. Forty-six of the participants were tested twice within 3–4 days to establish test-retest reliability.

Results

The walking time in various dual-task assessments demonstrated good to excellent reliability [Intraclass correlation coefficient (ICC_2,1) = 0.70–0.93; relative minimal detectable change at 95% confidence level (MDC₉₅%) = 29%-45%]. The reliability of the CRR (ICC_2,1 = 0.58–0.81) and the DTE in walking time (ICC_2,1 = 0.11–0.80) was more varied. The reliability of the DTE in CRR (ICC_2,1 = -0.31–0.40) was poor to fair. The walking time and CRR obtained in various dual-task walking tests were moderately to strongly correlated with those of the dual-task Timed-up-and-Go test, thus demonstrating good concurrent validity. None of the tests could discriminate fallers (those who had sustained at least one fall in the past year) from non-fallers.

Limitation

The results are generalizable to community-dwelling individuals with chronic stroke only.

Conclusions

The walking time derived from the various dual-task assessments generally demonstrated good to excellent reliability, making them potentially useful in clinical practice and future research endeavors. However, the usefulness of these measurements in predicting falls needs to be further explored. Relatively low reliability was shown in the cognitive outcomes and DTE, which may not be preferred measurements for assessing dual-task performance.     

The Prognostic Value of Peak Cardiac Power Output in Chinese Patients with Chronic Heart Failure

Background

Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO₂) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO₂. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO₂ in Chinese patients with CHF.

Methods

Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m² and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths.

Results

Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO₂,VE/VCO₂ slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO₂≤13.4 ml.kg^-1.min^-1, and VE/VCO₂ slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg^-1.min^-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05).

Conclusions

Peak CPO was not a predictor of cardiac death in Chinese CHF patients.     

Reference Values of Grip Strength Measured with a Jamar Dynamometer in 1526 Adults with Intellectual Disabilities and Compared to Adults without Intellectual Disability

Aim

The aim of this study was to investigate grip strength in a large sample of people with intellectual disabilities, to establish reference values for adults with intellectual disabilities (ID) and compare it to adults without intellectual disability.

Methods

This study analysed pooled baseline data from two independent studies for all 1526 adults with ID: Special Olympics Funfitness Spain (n = 801) and the Dutch cross-sectional study ‘Healthy aging and intellectual disabilities’ (n = 725).

Results

The grip strength result of people with ID across gender and age subgroups is presented with CI95% values from higher 25.5–31.0 kg in male younger to lower 4.3–21.6 kg in female older.

Conclusion

This study is the first to present grip strength results of a large sample of people with ID from 20–90 years of age. This study provides reference values for people with ID for use in clinical practice.