Regular exercise has several positive health effects including increased physical fitness and muscle mass. It is well known that increased muscle mass is associated with increased resting energy expenditure which may facilitate weight loss and maintenance. Previous studies have, however, failed to show any consistent association between the intensity of physical exercise and energy expenditure, or relate the variance in these adaptations to genetic variability. Whether high-intensity exercise (HIE) is associated with improved health related quality of life in severely obese patients remains unknown. This PhD-project is based on a planned randomised controlled study including 50 or more treatment seeking morbidly obese patients who will be randomised to either a 24 week moderate-intensity exercise (MIE) programme or a 24 week high-intensity exercise (HIE) programme. The investigators main hypothesis is that patients randomised to the HIE-program will achieve higher energy expenditure during rest and physical activity after treatment than those allocated to the MIE-programme. In addition, the investigators hypothesise that the HIE-group will achieve a better health related quality of life than the MIE-group after treatment. The investigators also hypothesize that inter-individual variability in adaptation to the two training regimens may be due to genetic factors. If the investigators hypotheses are confirmed, this project might have beneficial clinical implications for future obesity treatment strategies.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
50
High intensity training group describes the group performing high intensity exercise intervention. Moderate intensity training group describes the the group performing moderate exercise intervention
Duke University School of Medicine
Durham, North Carolina, United States
Vestfold University College
Horten, Raveien, Norway
Telemark University College
Bø, Norway
University in Agder
Kristiansand, Norway
Norges Teknisk-naturvitenskapelig Universitet
Trondheim, Norway
Vestfold Hospital Trust
Tønsberg, Norway
Energy expenditure during physical activity
Energy expenditure (EE) during volitional activity will be measured with ergo-spirometry tests one week before the exercise intervention period starts, and repeated after each exercise period. Increasing the aerobic work capacity is supposed to give the same proportional increase in energy expenditure at any given maximal intensity.
Time frame: 0, 8, 12 and 24 weeks
Resting metabolic rate
Resting metabolic rate will be measured with ergo-spirometry test one week before the exercise intervention period starts, and repeated after each exercise period. Increasing the aerobic work capacity is supposed to give increased resting metabolic rate.
Time frame: 0, 8, 12 and 24 weeks
Cardiorespiratory fitness
Exercise may have a positive effect on cardiorespiratory fitness and will be measured with ergo-spirometry test
Time frame: 0, 8, 12 and 24 weeks
Body mass index
Exercise may have a positive effect on weight change and will be calculated as weight in kilograms divided by height in meters squared
Time frame: 0, 8, 12 and 24 weeks
Waist circumference
Exercise may have a positive effect on waist circumference and will be measured midway between the bottom edge of the lower rib and upper iliac crest in the horizontal plane.
Time frame: 0, 8, 12 and 24 weeks
Fat mass and fat free mass
Exercise may have a positive effect on body composition and will be measured with the bioelectrical impedance analyser Tanita BC-418
Time frame: 0, 8, 12 and 24 weeks
Appetite control
Patient self-appraisal of hunger and fullness will be assessed during fasting and after a standardised breakfast every 30 minutes (for a period of 3hours) using visual analogue scales.
Time frame: 0,12 and 24 weeks
Genetic susceptibility
We hypothesize that inter-individual variability in adaptation/response to the two training regimens may also be due to genetic factors. We have designed a gene panel consisting of recognized and previously reported risk genes/variants with flanking sequences relevant for exercise (VO2max), participation in physical activity, obesity, diabetes, asthma and obesity related sub-phenotypes. The panel covers 1.2 Mb and includes 299 genes (exons with exon-intron junctions) and 1468 intronic and intergenic SNPs. Next-generation sequencing will be performed using a gene panel of selected genes/genetic regions by Illumina Nextera technology. The method involves enzymatic fragmentation of DNA and probe-based enrichment. The samples will be sequenced (paired-end, 2x100 bp) on a HiScanSQ. All wet lab methods (with other gene panels) are ISO15189 certified and in routine use at Unit for Medical Genetics at Telemark Hospital.
Time frame: 0, 8, 12 and 24 weeks
Short form health survey (RAND-36)
RAND-36 is a 36-item measure of generic HRQOL consisting of eight additive subscales (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health) and two summary scores each based on four subscales (Physical Component Summary and Mental Component Summary). Scores on all subscales range from 0 to 100. Summary-scores will be norm-based, with mean (SD) 50 (10). Higher scores on all scales represent better HRQOL.
Time frame: 0,12 and 24 weeks
Impact on Weight Questionnaire (IWQOL-Lite)
IWQOL-Lite is a 36-item measure of generic HRQOL consisting of eight additive subscales (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health) and two summary scores each based on four subscales (Physical Component Summary and Mental Component Summary). Scores on all subscales range from 0 to 100. Summary-scores will be norm-based, with mean (SD) 50 (10). Higher scores on all scales represent better HRQOL.
Time frame: 0,12 and 24 weeks
Weight-Related Symptom Measure (WRSM)
WRSM is a 20-item measure for the presence and distress of 20 weight-related symptoms. The distress scores of the symptoms are reported on a six-point likert scale. Two summary scores are calculated; an additive score of presence of symptoms ranging from 1 to 20 and a symptom distress score for all symptoms. Symptom distress scores range from 0 to 100, with higher scores indicating a higher or worse total symptom distress.
Time frame: 0,12 and 24 weeks
Power of Food scale (PFS)
PFS assess both the psychological impact and respondent's responsiveness to a food-abundant environment. This is a 15-item scale whose items pertain to three situations: food being readily available in the environment but not physically present, food is physically present, but not tasted, and food is first tasted but not already consumed. The three subscales is scored 0-100 with higher scores indicating greater eating problems.
Time frame: 0,12 and 24 weeks
Binge Eating Scale (BES)
BES comprise 16 items assessing binge eating problems. Additive scores range between 0-46, with higher scores indicating greater problems. Cut-off scores have been established to determine binge severity, with "severe" represented by scores \> 27, "moderate" by scores 18-26, and "mild-none" by scores \< 17.
Time frame: 0,12 and 24 weeks
Three Factor Eating Questionnaire (TFEQ -R21)
TFEQ -R21 is a 21-item questionnaire covering eating behavior domains: the cognitive restraint scale (6 items) assesses control over food intake and influence over body weight and body shape; the emotional eating scale (6 items) measures the propensity to overeat in relation to negative mood states, e.g., when feeling lonely, anxious, or depressed; and, the uncontrolled eating scale (9 items) assesses the tendency to lose control over eating when feeling hungry or when exposed to external stimuli
Time frame: 0,12 and 24 weeks
Body weight change
Exercise may have a positive effect on weight change
Time frame: 0, 8, 12 and 24 weeks
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