Clinical trials

Falls are a leading cause of injury-related hospitalization among older women. Age-related declines in gait speed and postural stability are known risk-factors for falls. While exercise is well-known to help maintain or improve these losses, only 24.4% of older Canadian women are considered physically active. Dance can act as a fun and social way to engage older women in exercise. Line dancing in particular has been shown to improve gait speed, knee extensor strength and endurance; however high doses are needed to achieve gains. Clifford and colleagues found that program lengths of 24 hours are needed to effect change, while Merome and colleagues recommend 3 hours per week. These high training doses may not be feasible for participants or community centres who offer programming. The time to commute to classes, find parking and caregiver roles at home are all cited as barriers to physical activity. We also propose that BFR could be a novel addition to increase the physiologic strain of online dance classes, which we hypothesize have a lower intensity and thereby lead to less fitness adaptations. Online classes are of interest as they can serve to reduce barriers to physical activity often experienced by older adults in Canada. * We propose online dance classes have reduced efficacy in stimulating adaptations to gait speed, strength and endurance when compared to in-person classes. * We propose blood flow restriction (BFR) as a novel addition to dance classes in order to aid in reaching physiological overload in more efficient time-frame. BFR works by partially reducing blood flowing in and out of working muscles, thereby reducing oxygen availability, promoting anaerobic energy pathways and keeping metabolites in the muscles for a longer time period. Numerous studies have confirmed that when combined with low-intensity exercise BFR is capable of producing similar strength gains as high-intensity exercise. Additionally, BFR is safe and has been widely used among older adults and individuals with various medical conditions, including cardiovascular conditions. While the benefits of BFR for muscle strength and hypertrophy have been greatly studied, there is limited research on its effects on gait and postural stability. Additionally, there is minimal research on potential combinations of BFR with dance-based activity. * This study will examine the differences between online and in-person delivery of 90 minute line dance classes on the postural stability and gait of older females over 10-weeks. * This study will then investigate the effects of combining BFR with 10-weeks of 90 minute line dancing classes for the postural stability and gait of older females. Finally, muscle oxygenation and kinematic analysis will be conducted to help provide insight into any potential changes in gait and postural stability. The intervention will consist of 10-weeks of line dancing classes, during which half the groups will be randomized to wear elasticized BFR bands pulled tight to a 7/10 of perceived pressure. Classes will be once per week for 90 minutes and will include a warm-up, 4 pre-set choreographies and a cool down. Breaks will be provided throughout the class. Assessments will occur at pre, mid and post. Gait will be assessed during a 6-minute walk test. During the test, participants will be filmed from a sagittal view to obtain kinematics. They will also be asked to wear a heart-rate monitor and muscle oxygenation sensors on their lower limbs. Postural stability will be assessed via 30-seconds of quiet standing on force plates in conditions of eyes open, eyes closed and foam. Participants will also be asked to wear an accelerometer on their upper back during the assessment to obtain correlation to force plate data. Functional strength will be assessed using 30-second sit to stand (with a secondary timer to obtain 5 time sit to stand length) and the Calf-Raise Senior test. Dynamic balance and mobility will be evaluated using the Functional Reach Test, and the Timed Up and Go in both single and dual-tasks. Aerobic capacity will be measured using a 3 minute Step Test while the participant wears a heart-rate monitor and muscle oxygenation sensors. Finally scales of fears of falling, social connectedness, and overall mental health will be collected. It is expected that this study will have great practical implications as the accessibility of this program can provide opportunities to older adults from various remote locations to increase their levels of physical activity in a safe manner. The affordability may also aid in adoption by community health and recreation centers as an easy-to-implement program that helps to improve the postural stability and gait of older women, thereby promoting independence and quality of life.

The goal of this study is to understand if there are differences in the fat, muscle and metabolism of individuals who developed obesity during childhood versus those who developed obesity in adulthood. We will do this by having recruited participants undergo subcutaneous adipose tissue biopsies in the abdomen and thigh, a muscle biopsy in the thigh, collect blood and urine samples, a DEXA scan and 3 submaximal exercise tests. participants will also have their resting energy expenditure measured through indirect calorimetry to tailor a targeted weight loss protocol through caloric restriction and cardiovascular exercise (3 times a week). After 10% of weight loss is completed, study participants will repeat all tests during a 2 week weight stabilization period. At 12 weeks into the intervention, indirect calorimetry, DEXA scan and blood tests will be repeated.

Current recommendations for protein intake after bariatric surgery are not based on strong scientific evidence. It remains unclear how much protein should be eaten to minimize muscle loss and preserve the metabolism and function of individuals post-bariatric surgery. The objective of this study is to analyze the relationships between changes in body composition, nutrition and protein intake, and muscle function after bariatric surgery to further our understanding of the nutritional needs of patients after bariatric surgery. We intend to recruit around 75 participants, men and women, aged between 18 and 65 years. Participants will be recruited from the Bariatric Surgery Clinic, McGill University Health Center.

Fat tissue in different parts of the body has different characteristics. Several studies have associated abdominal fat to an increased risk for multiple metabolic diseases, such as type 2 diabetes and cardiovascular disease, compared with fat located under the skin at the hips and thighs. However, the investigators do not know how the abdominal fat causes or contributes to the development of these diseases or how the development of these disease may in turn cause or contribute to changes in the fat tissue. The general objective of this study is to understand these mechanisms. To investigate these questions, the study will recruit 140 participants, both men and women aged 18-65 years. The participants will be divided into three groups: 40 people with obesity, 40 with diabetes, and 60 lean individuals. Participants will be recruited from patients at the CIUSSS du Nord-de-l'Île-de Montréal - Hôpital du Sacré-Coeur de Montréal who are awaiting bariatric or general abdominal surgery, as well as from the general population in the Montreal area.