Fatores envolvidos no pico de massa óssea

Abstract

A massa óssea de um indivíduo adulto, que está estreitamente relacionada ao risco de fraturas osteoporóticas, depende da diferença entre o pico de massa óssea alcançado no final do período de maturação sexual e esquelética, e as perdas acumuladas durante a vida. A enorme variabilidade observada no pico de massa óssea da adolescência está relacionada, principalmente, a fatores genéticos, mas também a parâmetros antropométricos, como peso e altura, hábitos dietéticas, influências hormonais diversas, atividade física, uso de medicamentos e doenças intercorrentes. A identificação dos fatores envolvidos na aquisição do pico de massa óssea na infância e adolescência e a compreensão deste longo período de maturação esquelética, permitirão a criação de estratégias para prevenção da osteoporose. (Arq Bras Endocrinol Metab 1999;43/6: 401-408) Unitermos: Pico de massa óssea; Densidade mineral óssea em crianças e adolescentes ABSTRACT Bone mass in the adult life, which is closely related to osteoporotic fracture risk, depends on the differences between the peak bone mass attained at the end of the sexual and skeletal maturation and the rate of involutional bone mass. The great variability in peak bone mass observed at adolescence is related not only to genetic factors, but also to diet, hormonal status, anthropometric variables, as weight and height, physical activity, drugs and intercurrent diseases. The identification of the factors involved with the acquisition of the peak bone mass and the comprehension of this long period of skeletal maturation will indicate strategies for prevention of osteoporosis. (Arq Bras Endocrinol Metab 1999;43/6: 401-408) Keywords: Peak bone mass; BMD in children and adolescents A INCIDÊNCIA DE FRATURAS OSTEOPORÓTICAS está estreitamente relacionada à massa óssea do indivíduo, que depende tanto da velocidade de perda durante a vida quanto da quantidade de tecido ósseo presente no final da puberdade e início da vida adulta. A enorme variância no pico de massa óssea é explicada não só por fatores hereditários, como também por sexo, raça, hábitos dietéticos, atividade física, influências hormonais diversas, composição corporal de massa magra e gordurosa, doenças intercorrentes, uso crônico de medicamentos. A compreensão do longo processo de maturação óssea que ocorre na infância e adolescência vai permitir identificar os fatores passíveis de alguma intervenção e a criação de estratégias para prevenção precoce da osteoporose. Se o ganho mineral ósseo puder ser otimizado durante a puberdade, é provável que o indivíduo adulto esteja menos susceptível a sofrer as devastadoras complicações da osteoporose.

Características epidemiológicas e causas da fratura do terço proximal do fêmur em idosos

“…In this study we verified a mean body mass index (BMI) of 22.6 (without significant difference between men and women), i.e., the fractures occurred in people with BMI within the normal range (19)(20)(21)(22)(23)(24)(25) and not in overweight or obese people. This fact was also observed by other authors (17)(18)(19) .…”

“…A low rate of fractures was observed in black patients (6.4% against 93.6% in the white population), similar to the value found in literature of 6.2% (2) . An explanation for this occurrence is that blacks present greater bone mass accumulation, which must be related to the greater renal calcium reabsorption and resistance to the action of parathormone (PTH) on bone (22) ; in addition, according to some studies, black individuals exhibit lower levels of osteocalcin, of the bone fraction of alkaline phosphatase and of urinary hydroxyproline (23,24) . A significant difference was observed between the sexes as regards the place where the patient suffered the facture: while 81% of the women were at home, only 58% of the men were also inside the home.…”

Bone development in children and adolescents with PKU

“…It is assumed that bone mass peak is an individual characteristic influenced by genetic, hormonal, and dietary factors. During adolescence, nutrients consumption is the determinant and necessary key to achieve the bone mass peak (Brandão et al 1999).…”

Physical Exercise for Prevention of Falls and Fractures

“…The incidence of osteoporotic fractures (Figure 1) is strictly related to the individual bone mass that depends on the speed of loss throughout life as well as the amount of bone tissue in the end of puberty and beginning of adulthood. The great variation in bone mass peak is explained not only by hereditary factors but also by gender, race, eating habits, several hormone influence, body composition of lean mass and body fat, intercurrent diseases, chronic use of medications and physical activity (Brandão & Vieira, 1999). Like any other chronic disease, the ethiology of osteoporosis is multifactorial.…”