Bone density in the adolescent athlete

Abstract

Adolescence is a critical time for bone mass accrual, and increases in bone mass through puberty are dependent on rising levels of gonadal steroids, growth hormone and insulin like growth factor-1. Many high school girls are involved in athletic activities, and as many as 23.5% of adolescent athletes have been reported to develop amenorrhea. This review focuses on (1) factors that determine which athletes are likely to develop amenorrhea, such as a negative energy balance state, low levels of leptin and high levels of ghrelin, and (2) the impact of hypogonadism in athletes on bone metabolism. Beneficial effects of increased mechanical loading from athletic activity do not appear to protect against the deleterious effects of hypogonadism in adolescent athletes.

Menstrual function in sports

“…60 In cell cultures, ghrelin exerted proliferative effects on osteoblasts, whereas studies on animal models indicated that leptin decreases bone mass. 61 Christo et al reported higher ghrelin and lower leptin levels in amenorrheic adolescent athletes compared to eumenorrheic athletes and sedentary controls. 62 This study showed bone age, lean mass, IGF-1 and estradiol, but not ghrelin and leptin, as important positive predictors of bone mass parameters.…”

Phytase supplementation increases bone mineral density, lean body mass and voluntary physical activity in rats fed a low-zinc diet☆

“…In humans, bone mineral accrual is maximal in adolescence and 90% of peak bone mass is achieved by 18 years of age [1]. Low bone mass increases the risk of fracture [2], and for every standard deviation of decrease in bone mineral density (BMD), fracture risk increases two to three times.…”

Bone Metabolism Markers in Sportswomen with Menstrual Cycle Dysfunctions

“…Previous researches docu men ted the influence of hypoes tro genism on the increase of the level of bone resorption markers, reduction of BMD and the consequential occurrence of osteo po rosis in postmenopausal women (22)(23)(24). However, very few researches have targeted the dynamics of bone metabolism markers in sports women with menstrual dysfunctions or secon dary osteoporosis (25)(26)(27)(28). Since estrogen supp resses remodeling of the bone and acts antire sor p tively, reduction of its level may turn the bone meta bolism in the resorption direction, with a prevalence of its markers (4,28).…”

“…However, very few researches have targeted the dynamics of bone metabolism markers in sports women with menstrual dysfunctions or secon dary osteoporosis (25)(26)(27)(28). Since estrogen supp resses remodeling of the bone and acts antire sor p tively, reduction of its level may turn the bone meta bolism in the resorption direction, with a prevalence of its markers (4,28). Values of bone metabolism markers in our study showed a statistically significant difference in the level of bone resorption marker, b-CrossLaps, between the groups of amenorrheic and oligomenorrheic sports women in comparison to eumenorrheic women, both sportswomen and those in the control group.…”

“…There are data pointing out the influence of surface, that is, that activities with great impact on the bone and increased BMI can reduce potentially dangerous hormone changes in amenorrheic sports women (30,31). However, Misra (28) main tains that this influence is not sufficient to offset the bone loss due to HPA. What limited our study was the inability to measure BMD and conse quently confirm the morp hological status of the bone.…”