Stéphane Choquette

Accelerometer-based wireless body area network to estimate intensity of therapy in post-acute rehabilitation

BackgroundIt has been suggested that there is a dose-response relationship between the amount of therapy and functional recovery in post-acute rehabilitation care. To this day, only the total time of therapy has been investigated as a potential determinant of this dose-response relationship because of methodological and measurement challenges. The primary objective of this study was to compare time and motion measures during real life physical therapy with estimates of active time (i.e. the time during which a patient is active physically) obtained with a wireless body area network (WBAN) of 3D accelerometer modules positioned at the hip, wrist and ankle. The secondary objective was to assess the differences in estimates of active time when using a single accelerometer module positioned at the hip.MethodsFive patients (77.4 ± 5.2 y) with 4 different admission diagnoses (stroke, lower limb fracture, amputation and immobilization syndrome) were recruited in a post-acute rehabilitation center and observed during their physical therapy sessions throughout their stay. Active time was recorded by a trained observer using a continuous time and motion analysis program running on a Tablet-PC. Two WBAN configurations were used: 1) three accelerometer modules located at the hip, wrist and ankle (M3) and 2) one accelerometer located at the hip (M1). Acceleration signals from the WBANs were synchronized with the observations. Estimates of active time were computed based on the temporal density of the acceleration signals.ResultsA total of 62 physical therapy sessions were observed. Strong associations were found between WBANs estimates of active time and time and motion measures of active time. For the combined sessions, the intraclass correlation coefficient (ICC) was 0.93 (P ≤ 0.001) for M3 and 0.79 (P ≤ 0.001) for M1. The mean percentage of differences between observation measures and estimates from the WBAN of active time was -8.7% ± 2.0% using data from M3 and -16.4% ± 10.4% using data from M1.ConclusionWBANs estimates of active time compare favorably with results from observation-based time and motion measures. While the investigation on the association between active time and outcomes of rehabilitation needs to be studied in a larger scale study, the use of an accelerometer-based WBAN to measure active time is a promising approach that offers a better overall precision than methods relying on work sampling. Depending on the accuracy needed, the use of a single accelerometer module positioned on the hip may still be an interesting alternative to using multiple modules.

Effect of exercise training combined with phytoestrogens on adipokines and C-reactive protein in postmenopausal women: a randomized trial

Phytoestrogens and training could be effective to reduce cardiovascular and type 2 diabetes mellitus risk factors in postmenopausal women. Nevertheless, the impact of their combination on adipokines and systemic inflammation was never investigated. The objective was to verify if 6 months of mixed training combined with phytoestrogens could have an additional effect on adipokine levels and systemic inflammation in obese postmenopausal women. Fifty-two obese women aged between 50 and 70 years were randomly assigned to (1) exercise with placebo (EX + PL; n = 25) or (2) exercise with phytoestrogens (EX + PHY; n = 27). Body weight, waist circumference, fat mass, and lean body mass (dual-energy x-ray absorptiometry) were assessed. Fasting plasma glucose and insulin, adiponectin, leptin, and C-reactive protein (CRP) levels were obtained after a 12-hour overnight fast. Total energy intake was measured with a 3-day dietary record. All measurements were performed before and after the 6-month intervention. Although energy intake remained unchanged, body composition was improved in all women (all Ps < .02). Plasma CRP and leptin levels decreased in both groups similarly (all Ps < .03), whereas plasma adiponectin and insulin did not change with exercise combined with placebo or phytoestrogens. Correlation analyses showed that homeostasis model assessment of insulin resistance (r = -0.58, P = .02) and fasting insulin levels (r = -0.42, P = .02) at baseline were both correlated with changes in leptin levels. Baseline fasting glucose (r = -0.36, P = .03) and adiponectin (r = 0.45, P = .005) levels were associated with changes in CRP concentrations. Although mixed exercise program combined with phytoestrogens does not seem to provide any additional effect, mixed training improves systemic inflammation and leptin concentrations in obese postmenopausal women.

Predicting Energy Expenditure in Elders with the Metabolic Cost of Activities

INTRODUCTION Measuring free-living energy expenditure in aging human is a considerable challenge. The objective of this study was to predict total energy expenditure (TEE) in elders by combining the metabolic cost of activities and accelerometer outputs. METHODS Seventeen elders (7 women, 10 men) aged 60 to 78 yr were recruited. Body composition was measured by dual x-ray absorptiometry. Doubly labeled water was used as the criterion standard to measure TEE on a 7-d time frame. During the same period, participants wore a uniaxial accelerometer (Caltrac) to estimate TEE. Resting metabolic rate and metabolic costs of sitting, standing, and walking (1, 3, and 5 km·h(-1)) were measured by indirect calorimetry. RESULTS There was no correlation between Caltracs outputs and doubly labeled water measurement of TEE. The best predictors of TEE were fat-free mass, the metabolic cost of standing, and the metabolic cost of walking at 3 km·h(-1) (r = 0.78, P < 0.01). CONCLUSIONS Our results suggest that TEE may be estimated with good accuracy using fat-free mass, the cost of standing still, and the cost of walking at 3 km·h(-1). These predictors are easy to measure in older adults. Further work is needed to confirm our findings and develop prediction equation with these parameters.

Effect of exercise combined with phytoestrogens on quality of life in postmenopausal women

ABSTRACT Background Postmenopausal women seem to favor alternative therapies such as exercise and phytoestrogens as a substitute for potentially harmful hormone replacement therapy. Based on previous research, we hypothesized that phytoestrogens combined with exercise could have a synergic effect on womens health. Objective To verify whether phytoestrogens enhance the response to mixed training regarding menopausal symptoms and quality of life in postmenopausal women. Methods From a pool of women participating in a 6-month randomized, controlled exercise study, 21 received a placebo (mean age 58.3 ± 5.4 years, body mass index 29.8 ± 5.1 kg/m2) and 19 received phytoestrogen supplements (mean age 60.1 ± 3.4 years; body mass index 30.3 ± 4.6 kg/m2). Body weight, fat mass and lean body mass (dual-energy X-ray absorptiometry) were assessed. Quality of life was estimated by the Short Form-36 (SF-36) and Perceived Stress Scale-10 (PSS-10) questionnaires, and menopausal symptoms by the Kupperman index. All measurements were performed before and after the intervention. Results Although the Kupperman index and PSS-10 remained unchanged in both groups, the SF-36 Physical Component Summary and almost all the SF-36 subscales (except for role-emotional and mental health) increased only in the exercise group taking phytoestrogens (0.001 < p < 0.04). Conclusion While phytoestrogens combined with mixed exercise were not sufficient to improve menopausal symptoms, it seemed to be a better strategy than exercise alone to improve the general quality of life in postmenopausal women.

Is fat mass distribution related to impaired mobility in older men and women? Nutrition as a determinant of successful aging: the Quebec longitudinal study.

It is established that a high level of fat mass (FM) is related to mobility impairment in older adults. However, FM distribution has received very little attention. In this study, 904 well-functioning older adults aged between 68 and 82 years old were recruited to examine the association between waist circumference, trunk FM, leg FM, and mobility. The results show that waist circumference was the only measure of body fat distribution independently associated with mobility (p ≤ .001). Therefore, the use of objective measures of FM distribution may not be necessary to examine the impact of FM distribution on mobility.

Effect of 1-h moderate-intensity aerobic exercise on intramyocellular lipids in obese men before and after a lifestyle intervention

Intramyocellular lipids (IMCL) are depleted in response to an acute bout of exercise in lean endurance-trained individuals; however, it is unclear whether changes in IMCL content are also seen in response to acute and chronic exercise in obese individuals. We used magnetic resonance spectroscopy in 18 obese men and 5 normal-weight controls to assess IMCL content before and after an hour of cycling at the intensity corresponding with each participants maximal whole-body rate of fat oxidation (Fatmax). Fatmax was determined via indirect calorimetry during a graded exercise test on a cycle ergometer. The same outcome measures were reassessed in the obese group after a 16-week lifestyle intervention comprising dietary calorie restriction and exercise training. At baseline, IMCL content decreased in response to 1 h of cycling at Fatmax in controls (2.8 ± 0.4 to 2.0 ± 0.3 A.U., -39%, p = 0.02), but not in obese (5.4 ± 2.1 vs. 5.2 ± 2.2 A.U., p = 0.42). The lifestyle intervention lead to weight loss (-10.0 ± 5.4 kg, p < 0.001), improvements in maximal aerobic power (+5.2 ± 3.4 mL/(kg·min)), maximal fat oxidation rate (+0.19 ± 0.22 g/min), and a 29% decrease in homeostasis model assessment score (all p < 0.05). However, when the 1 h of cycling at Fatmax was repeated after the lifestyle intervention, there remained no observable change in IMCL (4.6 ± 1.8 vs. 4.6 ± 1.9 A.U., p = 0.92). In summary, there was no IMCL depletion in response to 1 h of cycling at moderate intensity either before or after the lifestyle intervention in obese men. An effective lifestyle intervention including moderate-intensity exercise training did not impact rate of utilisation of IMCL during acute exercise in obese men.

Soy isoflavones and exercise to improve physical capacity in postmenopausal women

ABSTRACT Aim In postmenopause, ovarian decline along with sedentary lifestyle could contribute to the loss of lean body mass (LBM) and muscle strength. This study aimed to verify whether exercise and isoflavones could have additive effects on muscle quality, muscle mass index, relative strength and physical capacity in overweight sedentary postmenopausal women. Method We recruited 70 overweight-to-obese (body mass index 32.2±4.8 kg/m2) postmenopausal women (59±5 years old) to participate in a 6-month clinical study combining isoflavones (70 mg/day) and exercise (resistance and aerobic training) treatments. Subjects were divided into four groups: (1) placebo (n =15), (2) isoflavones (n =15), (3) exercise and placebo (n =20), and (4) exercise and isoflavone (n =20). Principal outcome variables included maximal muscle strength (1RM) at the leg press and the bench press, muscle mass index, muscle quality in the legs and relative strength. Results After 6 months of training, exercise produced 49% and 23% increases, respectively, in leg press and bench press 1RM (p ≤0.01). Leg relative strength and muscle quality increased by more than 50% (both p <0.01), while muscle mass index increased by 7% (p <0.05) in both exercise groups only. Conclusion Exercise training can improve muscle tissue strength, function and quality in sedentary postmenopausal women. Isoflavones, irrespective of exercise, did not produce changes in these variables. From a clinical perspective, these results suggest that overweight women could reduce the risks of mobility impairments, even in the absence of weight loss, by following a sound exercise intervention that includes both resistance and aerobic training at a high intensity.