Obesity, Metabolic Syndrome
Conditions
Keywords
Obesity, Metabolic Syndrome, Dyspnea, Pulmonary Function, Exercise Capacity
Brief summary
Dyspnea is a common complaint in obese patients. The mechanisms behind this dyspnea and the effects of weight loss on dyspnea are not completely understood. The objectives of this study were to examine the relationships between exercise parameters and dyspnea in obesity and assess the effects of weight loss. The investigators compared pulmonary function, exercise performance and dyspnea in 34 patients with abdominal obesity and metabolic syndrome (MS) against 34 age and sex-matched controls. The study also assessed within-group changes in physiology and symptoms in a subset of patients following participation in a weight management program. Because obesity is a heterogeneous condition, with variable genetic associations, co-morbidities and distributions of adipose tissue, the study focused on patients with abdominal obesity who met diagnostic criteria for metabolic syndrome.
Detailed description
The study has two parts: first, the investigators compared dyspnea, pulmonary function and exercise measurements between obese patients and control subjects with normal weight; then, the investigators assessed the effects of medical weight loss in the obese group on these parameters. Baseline dyspnea was assessed using the baseline dyspnea index.The effect of weight loss on dyspnea was assessed using the transitional dyspnea index. The main physiologic measurement of interest was the inspiratory capacity (L, measured at rest and during exercise).
Interventions
Obese subjects partake in a medically supervised weight management program. This lifestyle modification program involves weekly three hour sessions for six months and monthly sessions for six months. The first twelve weeks comprise an initial weight loss phase when patients are placed on a 900 Kcal/day meal replacement. This is followed by a four week transition to a 1200-1800 Kcal diet followed by a ten week maintenance phase of 10 weekly sessions.The majority of weight loss occurs during the first 26 weeks followed by a 26 week period of stabilization of weight loss. Hence subjects are evaluated after the first 26 weeks.
Sponsors
Ontario Lung Association
The Ottawa Hospital
University of Ottawa
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Individuals accepted into the behavioural weight management program at the Ottawa Hospital Bariatric Centre * Age between 20 and 60 years * BMI greater than 30 * Abdominal girth (for females) greater than 88 cm * Abdominal girth (for males) greater than 102 cm * Plus any two of the other criteria for Metabolic Syndrome: i.e. Blood Pressure greater or equal to 130/85; Fasting Glucose greater or equal to 6.1 mmol/L * Controls-normal weight (NW) and sedentary
Exclusion criteria
* Smoker * Any medical conditions which would affect exercise performance * Use of medications that could affect exercise performance (i.e. Beta-blockers) * Inability to pedal on a cycle ergometer and provide reproducible inspiratory capacity (IC) measurements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dyspnea (measured by Transitional Dyspnea Index) | Within 6 months following completion of 6 months (weight loss period) in the weight management program | Dyspnea was assessed using a questionnaire based on the Transitional Dyspnea Index |
| Resting Inspiratory Capacity (L) | Within 6 months following completion of 6 months (weight loss period) in the weight management program | Inspiratory capacity (difference between total lung capacity and functional residual capacity), measured at rest |
| Inspiratory Capacity during Exercise (L) | Within 6 months following completion of 6 month (weight loss period) in the weight management program | Inspiratory capacity measured at identical time points during incremental exercise tests, performed before and after weight loss |
Countries
Canada
Outcome results
None listed