Effects of Hormonal Status on Bone Density in Adolescent Girls*

Abstract

Few data are available on bone density in late adolescence. We studied factors affecting peak bone density in females. Forty-three white girls, aged 13-20 yr, were studied. Integrated estrogen exposure over the pubertal years was obtained by a score based on physiological events known to reflect circulation estrogen levels. The subjects were selected to provide great variation in estrogen exposure. Bone mineral density (BMD) was measured by single photon absorptiometry (midradius) and dual photon absorptiometry (spine and first metatarsal of the foot). Weight, estrogen score, and testosterone levels were highly correlated with BMD of the spine, wrist, and foot (P less than 0.05). Age correlated positively only with the BMD of the wrist. Twenty-four girls reaching ages 18-20 yr in the 2 yr of observation were divided into groups reflecting low (less than 24), medium (25-48), and high (greater than or equal to 49) estrogen exposure. The lowest scoring groups had the lowest spine and wrist BMD (P less than 0.05). This group weighed less and had lower weight to height ratio (P less than 0.05), the lowest weight (P less than 0.05) during adolescence, the highest age of menarche, and the highest amount of fiber in the diet (P less than 0.05). These subjects were separated into low and high BMD groups. Those subjects with the lowest values for spine, wrist, and foot were found to have significantly lower estrogen exposure scores and lower weight/height ratios; in addition, low BMD of the foot was associated with higher activity levels. Thus, wrist and spine BMD are affected by estrogen exposure during adolescence and weight; foot BMD, in addition, was negatively affected by activity, suggesting that bone mass in the active adolescent is affected by the absence of estrogen exposure.

Bone mineral density of the lumbar spine of Brazilian children and adolescents aged 6 to 14 years

“…This close relationship between bone mass and anthropometric variables had already been identified in early studies by Mazess and Cameron (22) and was later confirmed in studies performed on bone from the appendicular bone structures (19,(23)(24)(25)(26)(27)(28) and from the lumbar spine (10,11,15,16,29,30).…”

Short-term delay of puberty causes a transient reduction in bone strength in growing female rats

“…The results of the current study reflect results reported in human studies. Delayed menarche has been correlated with low bone mass (BMD) [10][11][12] and an increased incidence of stress fractures [13]. Delayed pubertal onset in humans has been found to delay skeletal maturation, however, this was compensated by a late acceleration of linear growth [22].…”

“…Peak bone mineral accrual rate occurs at puberty [8], with an accrual of 26% of adult total bone mineral within 2 years [9]. However, a delay in the timing of puberty is one factor among many that correlate with low bone mass in young women [10][11][12]. Warren et al (2002) [13] found the age of menarche to be more correlated to stress fracture occurrence than bone mineral density (BMD).…”

A tríade da atleta: posicionamento oficial

“…Como a taxa de perda óssea em mulheres hipoestrogênicas é maior nos cinco a seis anos que se seguem à redução dos níveis de estrogênio endó-geno, pode haver somente uma breve janela de oportunidade para iniciar o tratamento para prevenir uma perda óssea irreversível. Na atleta adolescente, uma má nutrição e uma condição hipoestrogênica pode resultar em uma redução da formação do banco ósseo durante os anos críticos da consolidação do esqueleto 23,[130][131][132][133][134] . Uma questão importante é se a baixa DMO hipoestrogêni-ca pode ser tratada ou revertida até atingir uma DMO normal.…”