Low energy availability reduces bone mass and gonadal function in male mice

Area of Science:

• Sports Medicine
• Endocrinology
• Orthopedics

Background:

• The female athlete triad links low energy availability to stress fractures in women.
• Risks and mechanisms of stress injuries in men are less understood.

Purpose of the Study:

• To investigate the effects of low energy availability and exercise on bone health and reproductive function in male mice.
• To evaluate the therapeutic potential of active vitamin D analogues in mitigating these effects.

Main Methods:

• Male mice were subjected to food restriction (FR) or ad libitum feeding, with voluntary exercise (ex).
• Some mice received active vitamin D analogues.
• Measurements included testicle weight, serum testosterone, bone mass, and bone turnover markers.

Main Results:

• Food restriction significantly reduced testicle weight, testosterone, and bone mass in male mice.
• Exercise exacerbated bone loss in food-restricted mice, indicating low bone turnover.
• Active vitamin D analogues rescued bone mass and osteoblastic activity, lowering IGF-I.

Conclusions:

• Low energy availability poses a risk for stress injuries in men, linked to gonadal dysfunction and osteoporosis.
• Active vitamin D analogues show promise for preventing and treating stress injuries in males.