Correlates of Gait Speed Among Older Adults From 6 Countries: Findings From the COSMIC Collaboration.

BACKGROUND: Few studies have compared gait speed and its correlates among different ethnogeographic regions. The goals of this study were to describe usual and rapid gait speed, and identify their correlates across Australian, Asian, and African countries. METHODS: We used data from 6 population-based cohorts of adults aged 65+ from 6 countries and 3 continents (N = 6 472), with samples ranging from 231 to 1 913. All cohorts are members of the Cohort Studies of Memory in an International Consortium collaboration. We investigated whether clinical (body mass index [BMI], hypertension, stroke, apolipoprotein status), psychological (cognition, mood, general health), and behavioral factors (smoking, drinking, physical activity) correlated with usual (N = 4 cohorts) and rapid gait speed (N = 3 cohorts) similarly across cohorts. Regression models were controlled for age, sex, and education, and were sex-stratified. RESULTS: Age- and sex-standardized usual gait speed means ranged from 0.61 to 1.06 m/s and rapid gait speed means ranged from 1.16 to 1.64 m/s. Lower BMI and better cognitive function consistently correlated with faster gait speed in all cohorts. Less consistently, not having hypertension and greater physical activity engagement were associated with faster gait speed. Associations with mood, smoking, and drinking were largely nonsignificant. These patterns were not attenuated by demographics. There was limited evidence that the associations differed by sex, except physical activity, where the greater intensity was associated with usual gait among men but not women. CONCLUSIONS: This study is among the first to describe the usual and rapid gait speeds across older adults in Africa, Asia, and Australia.

Determinants of cognitive performance and decline in 20 diverse ethno-regional groups: A COSMIC collaboration cohort study.

BACKGROUND: With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups. METHODS AND FINDINGS: We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife. CONCLUSIONS: These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.

Sedentary bout durations and metabolic syndrome among working adults: a prospective cohort study.

BACKGROUND: This study aimed to examine the associations between time spent in prolonged and non-prolonged sedentary bouts and the development of metabolic syndrome. METHODS: We used data from a prospective study of Japanese workers. Baseline examination was conducted between 2010 and 2011. A total of 430 office workers (58 women) aged 40-64 years without metabolic syndrome were followed up by annual health checkups until 2014. Metabolic syndrome was defined as having ≥ 3 out of 5 diagnostic criteria from the Joint Interim Statement 2009 definition. Sedentary time was assessed using a tri-axial accelerometer. Time spent in total, prolonged (accumulated ≥ 30 min) and non-prolonged sedentary bouts (accumulated < 30 min) was calculated. Cox proportional hazards models were used to estimate the risk of developing metabolic syndrome. RESULTS: During a median follow-up of 3 years, 83 participants developed metabolic syndrome. After adjustment for age, sex, education, smoking, and family income, positive associations were observed between time spent in prolonged sedentary bouts and the development of metabolic syndrome. After additional adjustment for moderate-to-vigorous physical activity, those in the three highest quartiles of time spent in prolonged sedentary bouts showed higher risk of metabolic syndrome compared to the lowest quartile group, with adjusted hazard ratios (95 % confidence intervals) of 2.72 (1.30 - 5.73), 2.42 (1.11 - 5.50), and 2.85 (1.31 - 6.18), respectively. No associations were seen for time spent in total and non-prolonged sedentary bouts. CONCLUSIONS: Sedentary behavior accumulated in a prolonged manner was associated with an increased risk of metabolic syndrome. In devising public health recommendations for the prevention of metabolic disease, the avoidance of prolonged uninterrupted periods of sedentary behavior should be considered.

Association between participation in social activity and physical fitness in community-dwelling older Japanese adults.

Purpose This study aimed to examine the relationship between participation in social activity and both, composite and individual measures of physical fitness in community-dwelling older adults.Methods This study was conducted using baseline data from the Sasaguri Genkimon Study (SGS), a longitudinal cohort study conducted in 2011. Participants were 1,365 community-dwelling men and women aged 65 years or above, who did not require certified nursing care and who resided in Sasaguri, a town located east of the Fukuoka metropolitan area. Participation in social activity was assessed by asking participants whether they engaged in any of eight social activities. Physical fitness tests assessed participants' handgrip strength and knee extension strength as measures of muscle strength, and their one-leg standing time, 5-m maximum gait speed, and 5-repetition sit-to-stand rate as measures of their physical performance. Multiple linear regression and logistic regression analyses were conducted to assess the relationship between participation in social activity and each measure of physical fitness, adjusting for sex; age; body mass index; socioeconomic status; solitary living; exercise, habitual drinking and smoking; accelerometer-measured, moderate-to-vigorous physical activity; cognitive function; instrumental activities of daily living; distress; social network; and comorbidities.Results A total of 83.6% of the participants were engaged in at least one social activity. After adjusting for potential confounders, engagement in social activity was positively associated with a higher composite physical fitness score, faster gait speed and 5-repetition sit-to-stand rate, and longer one-leg standing time (P=0.008, P=0.030, P=0.034, and P=0.009, respectively).Conclusion Participation in social activity was significantly associated with physical fitness, specifically those related to locomotive function. These associations were independent of various confounders including socioeconomic status, and comorbidities.

Objective assessment of proficiency with bimanual inanimate tasks in robotic laparoscopy.

PURPOSE: Development of objective criteria and optimum training protocols are priorities for robotic laparoscopy. However, studies that have attempted to objectify learning have been limited due to lack of task complexity and absence of comparisons between experts and novices. Our aim was to address these limitations and assess proficiency in robotic laparoscopy using bimanual inanimate tasks. MATERIALS AND METHODS: Six experts and 18 novice users of the da Vinci surgical system (Innovative Surgical, Sunnyvale, CA) performed three bimanual surgical manipulations, two of them in opposite directions, for a total of five different test tasks. During each task, elapsed time and kinematics with respect to the instrument tips were measured and a bimanual coordination analysis was conducted to assess the relationship between the simultaneous movements of both arms. Specifically, task completion time, total traveling distance of the instrument tips, and mean absolute relative phase-a variable for the assessment of bimanual coordination-were calculated for each task and compared between groups. RESULTS: The experts showed significantly shorter task completion times for all tasks (P < 0.05). Significantly higher mean absolute relative phase values were observed for the experts in two tasks (P < 0.05). There were no significant differences regarding total travel distance. CONCLUSION: Expert users of the da Vinci surgical system performed the designed surgical tasks faster and with higher bimanual dexterity than novices. Bimanual coordination analysis and the tasks used in this study show promise for becoming important components of the objective criteria needed to quantify proficiency in robotic laparoscopy.