The goal of this randomised controlled trial is to investigate the effects of and compare two modes of physical exercise (strength training and high-intensity aerobic exercise) to unchanged physical activity on vasomotor symptoms (hot flushes) in postmenopausal women. The main question it aims to answer is the effect of 15 weeks of strength training vs high intensity aerobic training vs unchanged physical activity on frequency and severity of hot flushes. Participants will be randomised to: 1. strength training 2. high-intensity aerobic training 3. untreated control group. Researchers will compare strength training, high-intensity aerobic training and untreated control group to see if training can reduce hot flushes.
The overall aim is to investigate the efficacy of and compare two modes of physical exercise (strength training and high-intensity aerobic exercise) to unchanged physical activity on vasomotor symptoms (VMS), as well as secondary outcomes such as health-related quality of life, sleep quality, physical activity levels, clinical outcomes, biomarkers, bone markers (outcome added January 2025), bone mineral density (outcome added January 2025), perceptions of and adherence to the interventions. In a longer perspective, the goal is to find evidence-based treatment options for VMS in postmenopausal women that are safe and effective, and have positive effects on health and quality of life after menopause. Our hypothesis is that strength training and high-intensity aerobic exercise will reduce VMS in postmenopausal women and improve quality of life as well as clinical outcomes more than in a control group with unchanged physical activity. We also hypothesize that strength training and high-intensity aerobic training will have the same effect on the primary outcome (change in VMS) and that most of the changes in secondary outcomes will be superior in the high-intensity aerobic training group compared to the strength training group. This is an open, two-centre, parallel, randomized controlled study performed according to the SPIRIT and CONSORT statements Recruitment will take place by advertising on social media, in local newspapers and in the Women's clinics and primary care centers in Linköping and Kalmar. Women who respond to the advertisements will be contacted by a member of the research group or research nurse to receive information about the study and screen for inclusion and exclusion criteria. Women who are possibly eligible will be invited to a screening visit for further information and informed consent. At the visit, inclusion and exclusion criteria will be checked by a physician, and a clinical examination will be performed. Eligible participants will receive a VMS screening diary and invited to a second visit 2-3 weeks later where inclusion and randomization will be performed if the VMS inclusion criteria are fulfilled. Randomization An allocation sequence using a computerized random number generator will be prepared by a statistician not involved in recruitment. Opaque sealed and sequentially numbered envelopes with group allocation will be prepared and opened in the presence of the participant upon inclusion and randomization. Power analysis: A sample size calculation was made based on the results of our previous study on strength training for VMS (Berin et al 2019) and showed that to detect a 50% difference in moderate and severe hot flushes with 80% power and expected dropout rate of 20% 40 participants in total would be needed. For this three-armed set-up we estimate that 20 participants in each group will be needed, i.e. 60 in total. To also achieve sufficient power for some of the secondary outcomes the intended sample size is increased to 30 per group, 90 in total. Data analysis: The primary analysis will be performed according to the intention-to-treat principle, including all participants who provided more than baseline data for the primary outcome. For quantitative interval data mixed design ANOVAs will be used to analyze the effect over time between and within groups. For the between-group comparisons effect sizes will be calculated. For ordinal data, such as the questionnaires, Kruskal-Wallis and Friedman test will be used for statistical analysis of the effect. Participants who complete two or more training sessions per week will be considered adherent with their assigned intervention and included in a per-protocol analysis. Detailed description of adherence, such as the fidelity with the training interventions, will be presented descriptively.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
90
Both interventions (strength training and high intensity aerobic training) will be introduced with a 3-week adaptation period with lower loads (strength training) or intensity (aerobic training) followed by a 12-week period on the intended load/intensity. All participants in the intervention groups will be recommended to exercise three times per week (one hour per session) and in addition be active with everyday low-intensity physical activity. A structured and detailed training diary will be used in both groups to register frequency of each training session, as well as everyday physical activity. For the strength training, load and dose will also be registered for each training session.
Both interventions (strength training and high intensity aerobic training) will be introduced with a 3-week adaptation period with lower loads (strength training) or intensity (aerobic training) followed by a 12-week period on the intended load/intensity. All participants in the intervention groups will be recommended to exercise three times per week (one hour per session) and in addition be active with everyday low-intensity physical activity. A structured and detailed training diary will be used in both groups to register frequency of each training session, as well as everyday physical activity. For the strength training, load and dose will also be registered for each training session.
Region Kalmar Län
Kalmar, Sweden
RECRUITINGRegion Östergötland
Linköping, Sweden
RECRUITINGFrequency of moderate and severe hot flushes
Frequency of hot flushes per 24 h daily recorded in hot flush diary from baseline throughout 15 weeks of intervention.
Time frame: baseline to 15 weeks
Frequency of moderate and severe hot flushes
Frequency of hot flushes per 24 h daily recorded in hot flush diary 2 weeks at baseline and 2 weeks at each of the time points.
Time frame: baseline to 6 months, 1, 2 and 5 years
Severity of hot flushes
Severity of hot flushes per 24 hours recorded in hot flush diary from baseline throughout 15 weeks of intervention and two weeks during follow-up.
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years
Generic health-related quality of life
Short-form 36, 36 questions in 8 scales. Scores for each domain range from 0-100, and a high score represents a higher health-related quality of life.
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years after intervention
Women specific health-related quality of life
Women's health questionnaire nine sub-scales with four-point scales (yes definitely, yes sometimes, not not much, no not at all) that are reduced to binary options (0/1). The subscale items are summated and divided by the number of items in each subscale.A higher score represents worse outcome.
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years after intervention
Physical activity levels
International Physical Activity Questionnaire short form, the participant describes the amount of time (minutes and hours) that is spent on different physical activities each week, the more time, the better, except for the question about the amount of time spent in sitting.
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years after intervention
Sleep quality
Pittsburgh sleep quality index, 7 domains. For the total instrument, the lower score, the better, from 0 (best) to 21 (worst).
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years after intervention
Diet
Bespoke questionnaire, primarily to control for changes during the intervention period. Registration of amounts or portions. Results are presented question by question descriptively.
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years
Accomplished physical activity
Bespoke training diary
Time frame: baseline to 15 weeks, 6 months, 1, 2 and 5 years after intervention
Bioimpedance
Fat mass (%) and fat-free (muscle) mass (%)
Time frame: baseline to 15 weeks
Weight
kilogram (kg)
Time frame: baseline to 15 weeks
Lenght
meters (m)
Time frame: baseline to 15 weeks
Body mass index
kilograms/meters2 (kg/m2)
Time frame: baseline to 15 weeks
Waist circumference
millimeters (mm)
Time frame: baseline to 15 weeks
Systolic and diastolic blood pressure
Unit millimetre of mercury (mmHg)
Time frame: baseline to 15 weeks
Hematologic and ironstatus changes
Hemoglobin full body count, Transferrin(gram/Litre), and Ferritin (microgram/Litre)
Time frame: baseline to 15 weeks, and 1 year
Changes in blood-lipids
apolipoprotein A1, apolipoprotein B (gram/Litre) and total cholesterol, low-density lipoprotein, high-density lipoprotein (mmol/L) and leptin (ng/mL)
Time frame: baseline to 15 weeks, and 1 year
Changes in sex hormones and gonadotrophins
Estradiol (pmol/Litre), Sex hormone bindning globulin, Testosterone (nmol/Litre), follicle-stimulating hormone, luteinizing hormone (IE/Litre)
Time frame: baseline to 15 weeks, and 1 year
Changes in glucose profile
HbA1c (mmol/Litre) and fasting blood glucose (mmol/L)
Time frame: baseline to 15 weeks, and 1 year
Changes in inflammatory biomarkers
high-sensitive C-reactive Protein (microgram/Litre), Brain-derived neutrophic factor, Matrix metalloproteinase-2 and -9 (ng/mL), Interleukin -4, -6, -7, -8, 10, -15, tumour necrosis factor, monocyte chemoattractant protein-1 (pg/mL)
Time frame: baseline to 15 weeks, and 1 year
Changes in the lenght of telomeres in white blood cells
Telomeres (kilobase) pair
Time frame: baseline to 15 weeks, and 1 year
Changes in bone markers
25-hydroxyvitamin D (25OHD) (nmol/L), Parathyroid hormone (PTH) (pmol/L), C-terminal telopeptide cross-links of collagen type I (CTX) (ng/L), Tartrate-resistant acid phosphatase isoform 5B (TRACP5B) (U/L), Type I procollagen intact N-terminal propeptide (PINP) (µg/L), Bone-specific alkaline phosphatase (BALP) (µg/L or U/L (assay dependent)), Bioactive sclerostin (pmol/L), Osteoprotegerin (OPG) (pmol/L), Free soluble receptor activator of nuclear factor κB ligand (RANKL) (pmol/L), Intact fibroblast growth factor 23 (FGF23) (pg/mL), Irisin (µg/L). Measurement added in January 2025 and data was only collected for participants entering the study from January 2025.
Time frame: Baseline to 15 weeks, and 1 year
Change in body composition (DXA - dual energy x ray absorptiometry)
Fat mass, lean mass. Measurement added in January 2025 and data was only collected for participants entering the study from January 2025.
Time frame: Baseline to 15 weeks
Change in bone mineral density (DXA - dual energy x ray absorptiometry)
Bone mineral density (g/area) and T-score in spine and hip. Measurement added in January 2025 and data was only collected for participants entering the study from January 2025.
Time frame: Baseline to 15 weeks
Change in exercise capacity
Change in exercise capacity is primarily used as a measure of adherence and obtained through cardiopulmonary exercise testing assessing maximum oxygen uptake milliliter/kilogram/minute (ml/kg/minute) and analysed according to local clinical routines.
Time frame: baseline to 15 weeks
Experiences of the interventions, facilitators and barriers
Bespoke questionnaire, only for intervention groups. Results will be presented descriptively question by question.
Time frame: baseline to 15 weeks
Adherence to the interventions
Assessed through bespoke training diary where each training session is registered and the total number of training sessions as well as training sessions/week will be calculated.
Time frame: baseline to 15 weeks
Muscle strength
For strength training group only, measured using 8 repetition-maximum tests.
Time frame: baseline to 15 weeks
Adverse events
Adverse events of taking part in the study
Time frame: baseline to 15 weeks
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