Use of β-hydroxy-β-methylbutyrate to Counteract Muscle Loss in Men With Prostate Cancer on Androgen Ablation

It is well established that older patients experience age-related loss of muscle mass and
function (sarcopenia), presumably due to an imbalance of protein synthesis versus protein
breakdown. In addition, studies have shown that men who start on ADT experience increased
muscle protein breakdown and decreased synthesis. β-hydroxy-β-methylbutyrate (HMB), a leucine
metabolite, has been shown to slow protein breakdown. When HMB is given with arginine and
lysine (which support protein synthesis) in randomized trials, researchers have shown that
elderly men and women who receive this nutritional supplementation experience improvement in
fat-free mass, strength, functionality and protein synthesis when compared with controls. In
addition, patients with advanced cancer who experienced weight loss of at least 5% have also
been shown to benefit from HMB, with supplementation resulting in a significant increase of
fat-free mass when compared to controls. Thus, it seems reasonable that older men with
prostate cancer starting on ADT who experience lean muscle loss as a result of aging and ADT,
may achieve some benefit from supplementation with HMB as well. Use of HMB in men with
prostate cancer has not been reported.

Inclusion Criteria:

1. Histologically confirmed adenocarcinoma of the prostate

2. Age 60 years or older

3. Patients with asymptomatic or minimally symptomatic PCa for which they are about to
start androgen deprivation therapy (ADT) per provider recommendation

- Asymptomatic or minimally symptomatic (as judged by treating physician)
metastases allowed

- Men receiving ADT for localized prostate cancer are allowed

4. Patient able to give informed consent.

Exclusion Criteria:

1. Patient already on ADT

2. Patients who are visiting clinic for a second opinion only

3. Patients with a diagnosis of dementia

4. Patients with a diagnosis of a neuromuscular disorder (i.e. multiple sclerosis)