RESUMEN
OBJECTIVE: To investigate whether body mass index (BMI) and body composition can affect peak bone mass in a population of obese (OB) (BMI SDS>2.0) and normal weight (NORM) (BMI-SD score <2.0) pubertal subjects (Tanner stage T3 to T5). PATIENTS AND METHODS: 151 subjects (81 OB, age 14.5±2.4 yr) were analyzed using dual-X-ray absorbiometry technique to study Lumbar and whole body bone mineral density (BMD) (areal, normalized for height) and Z-score, lean mass (LM) and lean/fat ratio. RESULTS: As a whole group, OB males did not show any significant difference in bone parameters vs NORM, while OB females showed higher bone density parameters (p<0.05). When grouped according to T, while OB males showed higher bone density at T3-4 stage (p<0.01), and lower at T5 (p<0.01) compared to NORM, OB females showed a tendency through increased BMD at T3-4 and T5 although statistically different only at T5. BMD was independently correlated to LM, lean/fat ratio, and testosterone in NORM males and, at lower level, in OB males, while to LM in NORM females and only to age in OB females. CONCLUSION: Our data seem to confirm the possible negative influence of obesity on bone density in boys, a possible explanation could be an unfavorable body composition during sexual maturation that seems not to affect bone development in adolescents girls.
Asunto(s)
Composición Corporal , Índice de Masa Corporal , Densidad Ósea , Obesidad , Pubertad/fisiología , Caracteres Sexuales , Absorciometría de Fotón , Adolescente , Desarrollo Óseo/fisiología , Estradiol/sangre , Femenino , Humanos , Masculino , Testosterona/sangreRESUMEN
Estrogen deficiency in females and androgen deficiency in males may harm periosteal and endosteal apposition, reduce bone size and both cortical and trabecular thickness, modifying in this way the bone structure later in life. To date, few systematic studies on bone mineral density (BMD) and hypogonadism in adolescents are available. Therefore we aimed to determine if sexual hormone deficiency during pubertal age might have an impact on peak bone mass and body composition. We compared areal BMD (L-aBMD), volumetric lumbar spine BMD (L-vBMD), lumbar spine Z-score (L-Z-score), lumbar spine bone mineral content (L-BMC), whole body (wbBMD), normalized whole body (n-wbBMD) BMD, and whole body BMC (wb-BMC) of 25 male children with hypogonadism (HYPO) with 37 sex-, age-, and body mass index-matched healthy subjects (CNT) using dual-energy X-ray absorptiometry. Furthermore we analyzed whether a difference in lean (lean%) and fat (fat%) mass as percentage of body weight and as a lean/fat ratio is present in the two groups of children. HYPO demonstrated a statistically lower L-aBMD, LvBMD, L-BMC, Z score, wbBMD, n-wbBMD, and wb-BMC compared to CNT. CNT showed a higher lean% and lower fat% and a higher lean/fat ratio when compared with HYPO group. Lean mass correlated positively with L-aBMD, L-BMC, and wb-BMC. Our study seems to confirm previous observations that sex hormone deficiency during puberty reduces bone mass accrual. Body composition alterations may play a role in bone parameters during development in healthy as such as in hypogonadal children during developmental age.
Asunto(s)
Composición Corporal , Densidad Ósea , Hipogonadismo , Pubertad/fisiología , Absorciometría de Fotón , Adolescente , Índice de Masa Corporal , Niño , Femenino , Humanos , Hipogonadismo/diagnóstico por imagen , Hipogonadismo/patología , Vértebras Lumbares/diagnóstico por imagen , MasculinoRESUMEN
Extraterrestrial exploration has gone on for decades before reversible testicular failure was shown to be a consequence of space flight in humans and animals at the end of the XXth century. This phenomenon was initially thought to depend on the psycho-physical stress expected to derive from a decidedly unusual environment, but the lack of consistent data concerning cortisol increase and/or gonadotrophin suppression pointed to the possibility of a primary defect. This was indirectly confirmed by the observation that a continuum of testicular androgen secretion potential exists from microgravity to centrifuge-derived hypergravity. Further experiments using tissue slices and suspended cells confirmed a direct inhibitory effect of microgravity upon testicular androgen production. A parallel deterioration of major physiological parameters, such as bone density, muscle mass/force, red blood cell mass, hydration and cardiopulmonary performance, has been repeatedly described during space missions, which, luckily enough, fully recover within days to weeks after landing, the time lag depending on single organ/system adaptation rates. According to the Authors of the present review, when taking together all reported changes occurring in space, a picture emerges closely resembling the so-called aging male syndrome, which is currently the object of daily screening and clinical care in their endocrine unit, so that microgravity may become a tool for better understanding subtle mechanisms of testicular senescence.