Krachttraining en eiwitsuppletie ter preventie van bijwerkingen van hormonale behandeling bij mannen met prostaatkanker.

Rationale: Due to the increase of our aging population and the advances in prostate cancer (PC) treatment, the prevalence of PC patients rises. One of the cornerstones in PC treatment is the use of androgen deprivation therapy (ADT). Unfortunately, ADT leads to unfavorable changes in body composition, decreased physical performance, fatigue and a lower health related quality of life (HRQoL). Exercise- and nutritional interventions have the potential to diminish the side effects of ADT treatment. A substantial number of studies in patients with PC undergoing ADT show positive effects of exercise training on these side effects. Moreover, studies in elderly have shown that the addition of a protein supplement can enhance the positive effects of exercise training on lean body mass, muscle strength and physical performance compared to exercise alone. However, the usual care of PC patients does not contain a combined exercise and protein supplementation program yet.
Objective: To investigate if a combined intervention of resistance exercise training and protein supplementation is more effective to prevent or decrease the adverse effects of ADT on body weight and body composition in men with PC compared to training alone or usual care.

Study design: Randomized placebo controlled trial with two parallel intervention groups and a separate control group.
Study population: Three groups (usual care (n=64); training with protein enriched supplement (n=72); training with placebo supplement (n=72)) of men ¡Ý 60 years with PC starting with ADT.

Intervention: Patients for the control group will be separately recruited in one hospital. Patients for the intervention groups will be recruited in two other hospitals and randomly assigned to one of the two intervention groups. Both intervention groups receive high-intensity resistance exercise training under direct personal supervision (twice a week, for 60 min, during 20 weeks). After 20 weeks, the patient will be encouraged to continue regular exercise at home or in the neighbourhood. During the 20 weeks training program participants will receive a placebo or protein supplement (35 gram protein) immediately after each exercise session and every evening prior to sleep. Patients in the control group will receive usual care.

Main study parameters/endpoints: The primary study endpoint will be body composition (body mass index, waist circumference, muscle mass, fat mass, body fat distribution), measured by anthropometrics, DEXA and CT scan. Secondary study endpoints will be muscle strength, maximal oxygen uptake, physical performance, level of physical activity, level of independent living, nutritional intake, HRQoL, fatigue, comorbidity and blood results. Measurements of body composition, muscle strength and physical performance will be performed at baseline and after 5 and 12 months. Participants will be asked to wear an accelerometer and to fill in a food diary in the week prior to the three measurements. Questionnaires on level of physical activity and independent living, fatigue, HRQoL, comorbidity and nutritional intake will be taken at baseline, 5, 12 and 24 months. Blood samples will be taken at 0, 5 and 12 months.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: In addition to the appointments for usual medical care, all patients will be asked to spend half a day at 0, 5 and 12 months for measurements of body composition, muscle strength, physical performance, and questionnaires. In addition, participants will be asked to wear an accelerometer and to fill in a food diary for the 3 days in the week prior to the three measurements. At 24 months all patients will be asked to spend 30 minutes on filling in questionnaires.
Risks as the result of participation in this study are minimal. There are no complications associated with the procedure of a DEXA and CT scan. The level of radiation emitted during DEXA and CT scanning is merely a fraction of that emitted during a transcontinental flight. Patients allocated to the intervention groups are supposed to participate in a 20¨Cweek exercise program, twice a week for 60 minutes. We expect that the exercise program will have a beneficial effect on the patients¡¯ health status. As a result of the resistance type exercise training program, participants will likely experience a gain in muscle mass and strength and a healthy improvement in body composition. Depending on the baseline level of fitness, this will result in an increase in functional performance. It is possible that participants may experience muscle soreness induced by unaccustomed exercise. The ingested protein and placebo supplements are regular food substances and therefore part of the normal diet.

1. Training will lead to less gain in fat mass, a better body fat distribution and less loss of muscle mass compared to usual care.

2. Training will lead to an increase in muscle strength, a higher level of physical performance, independent living and HRQoL and less fatigue.

3. Participants in the combined training - protein supplementation group will have an additional positive effect on muscle mass, muscle strength, physical performance, the level of independent living, HRQoL and fatigue compared to participants in the training ¡§C placebo supplementation group.

baseline (before start training), and 5 and 12 months after start ADT.

3 arms:

- control group that receives usual care

- intervention group that receives 20 weeks of resistance exercise plus protein supplements

- intervention group that receives 20 weeks of resistance exercise plus placebo supplements