Premature bone loss found in some nonmenstruating sportswomen

Transcriptomic and cellular decoding of regional brain vulnerability to neurogenetic disorders

Neurodevelopmental disorders have a heritable component and are associated with region specific alterations in brain anatomy. However, it is unclear how genetic risks for neurodevelopmental disorders are translated into spatially patterned brain vulnerabilities. Here, we integrated cortical neuroimaging data from patients with neurodevelopmental disorders caused by genomic copy number variations (CNVs) and gene expression data from healthy subjects. For each of the six investigated disorders, we show that spatial patterns of cortical anatomy changes in youth are correlated with cortical spatial expression of CNV genes in neurotypical adults. By transforming normative bulk-tissue cortical expression data into cell-type expression maps, we link anatomical change maps in each analysed disorder to specific cell classes as well as the CNV-region genes they express. Our findings reveal organizing principles that regulate the mapping of genetic risks onto regional brain changes in neurogenetic disorders. Our findings will enable screening for candidate molecular mechanisms from readily available neuroimaging data.

Hormones and bone health in postmenopausal women

Although it has been known for some time that estrogen deficiency is a major pathogenetic factor for osteoporosis related fractures among postmenopausal women, the capability of estrogen (with or without a progestin) to prevent fractures has often been questioned. The publication of the data from the two hormone clinical trials of the Women's Health Initiative lays that discussion to rest. In both studies what have been considered a standard dose of conjugated estrogen with or without medroxyprogesterone acetate significantly reduced the risk of all fractures, including clinical vertebral fractures and hip fracture, in a population of postmenopausal women, average age 63 yr, not selected for osteoporosis by BMD. These results are particularly impressive given the difficulty of finding a fracture benefit in lower risk populations with other anti-resorptive agents. Surrogate data on lower doses of hormone therapy suggest a fracture benefit would be seen if studies were to be done. The other outcomes in WHI make it important to define appropriate clinical guidelines for use of hormone therapy for prevention of fractures in postmenopausal women.

The effect of sex steroids on the skeleton in premenopausal women

Whereas peak bone mass is genetically determined, the skeletal growth, maturation, and maintenance required to reach this peak may be influenced by physical activity, ovarian function, and nutrition. Estrogen deficiency at menopause leads to increased skeletal remodeling and loss of bone mass, which can result in osteoporotic fractures. Entering menopause with low bone mass is a risk factor itself, because bone mass predicts future risk of fracture. The administration of exogenous steroids can reverse the setting of the "mechanostat" to lower levels after ovarian dysfunction, although it is unclear whether oral contraceptives can modify bone mass in the ovulatory premenopausal woman. Our recent data suggest that the use of steroidal hormones to treat menstrual irregularity (presumably relative to ovarian dysfunction), as opposed to fertility control, is more likely to positively affect bone mass. It is even less clear whether hyperestrogenic states (e.g., pregnancy) affect the skeleton. Recent evidence from bone mass changes that occur in women with ovulatory cycles and inadequate luteal phase function suggests that progestins may also influence skeletal metabolism.

Prevention of osteoporosis: the calcium controversy

The continuing scientific controversy regarding the use of calcium supplements for the prevention of osteoporosis during menopause presents a challenge to the nurse practitioner. There is little doubt that estrogen prevents bone loss following menopause, but there is a growing doubt among many researchers whether calcium supplementation beyond 800 mg/per day produces any benefit at all in preventing postmenopausal osteoporosis. Yet, the medical consensus in this country continues to recommend 1500 mg of calcium per day for menopausal women. The practitioner's clinical questions relate to the effectiveness, cost, and compliance of calcium prescription. An alternate recommendation and protocol are presented here.

Factors Associated With Shin Soreness in Athletes

In brief: Twenty-five exercisers suffering from shin soreness were interviewed, examined, and monitored to identify factors associated with this injury. Twenty-five uninjured persons who matched the injured subjects in age, sex, and activities served as controls. Injured subjects had a greater range of subtalar joint motion and increased ankle dorsiflexion, reported a significantly lower calcium intake, had raised their training intensity before injury, and were using worn or poorly made shoes when injured. Factors not associated with injury included number of months subjects had participated in weight-bearing exercise, exercise surface, amount of stretching, height-weight ratio, and menstrual status. This study is the first to indicate a possible relationship between nutrition and shin soreness.

Osteopenia in hypoestrogenic young women with anorexia nervosa

Replacement estrogen therapy for premenopausal women with secondary hypogonadism (exercise/weight loss amenorrheas) remains controversial. In a group of 14 women with anorexia nervosa, amenorrhea, and no evidence of other endocrinopathy or protein-calorie malnutrition, significant osteopenia was demonstrated as assessed by cortical thickness of carpal bones. The degree of bone thinning was related to the duration and age at onset of amenorrhea as well as abnormalities of pubertal milestone progression. In the young women with "constitutionally delayed" menarche, or with secondary amenorrhea and hypogonadism, significant osteopenia may also be present. For those women with (1) hypoestrogenism and amenorrhea of over 36 months' duration, (2) pubertal delay, and (3) early onset of secondary amenorrhea, evaluation of osteopenia radiographically, and serious consideration for estrogen replacement, is important.