Lower peak bone mass and its decline

Key components and potential benefits of a comprehensive approach to women's musculoskeletal health

Over the last 40 years there has been a significant increase in the number of female athletes, as well as a rise in musculoskeletal injuries observed in women. There is sufficient evidence from past medical research identifying various musculoskeletal injuries and conditions that more commonly affect women, such as osteoarthritis, osteoporosis, stress fractures, and anterior cruciate ligament tears. Several women's sports medicine and musculoskeletal health programs have been developed throughout the United States in an attempt to provide more tailored care to the female athlete. The goal of a comprehensive approach to women's musculoskeletal health is to create an interdisciplinary team to facilitate treatment for a variety of injuries and related conditions. This manuscript outlines the musculoskeletal conditions that commonly affect women and highlights the various etiologies of these sex disparities. We discuss the role of interdisciplinary women's musculoskeletal health and sports medicine programs, and define the potential benefits of such an approach. Future studies should focus on assessing the outcomes of multidisciplinary women's sports medicine programs as current literature in this area is lacking.

Radiomorphometric indices of mandibular bones in an 18th century population

OBJECTIVE

To estimate four radiomorphometric indices of mandibular bones in an 18th century population sample, and possibly associate the findings with bone mass loss related to sex, age, nutritional habits and pathologies reflecting on the bone.

DESIGN

Thirty-six sculls (31 males, 5 females), recovered from the crypt of Požega Cathedral in Croatia were analyzed. Age estimation was based on tooth wear, and Eichner class was determined according to the number of occlusal supporting zones. The parameters in recording analogue orthopantomographs were set to constant current of 16 mA, exposure time of 14.1s, and voltage between 62-78 kV. Films were processed in an automatic dark chamber processor for 12 min, and digitized at 8-bit, 300 dpi. The thickness of the mandibular cortex was assessed below the mental foramen (MI), at antegonion (AI), at gonion (GI). Qualitative mandibular cortical index (MCI) was assessed.

RESULTS

Average values of MI, AI and GI were 3.97 ± 0.94 mm, 2.98 ± 0.56 mm, and 1.99 ± 0.55 mm, respectively. Statistically significant differences between males and females were found for AI right (p=0.014), GI left (p=0.010) and GI average (p=0.006), and were in all cases higher in males. There were no statistically significant differences between age groups for either index (p>0.05). Considering Eichner classification the differences were not significant for MI (p=0.422), AI (p=0.516), and GI (p=0.443), but in Eichner classes II, MCI was significantly higher (p=0.02).

CONCLUSION

The obtained data does not suggest generalized malnutrition or calcium, phosphorus and vitamin D deprivation in the historic population studied.

Health in older women athletes

Physical activity has been identified as a protective factor against a wide spectrum of diseases, but little is known about the link between older women's health and their professional involvement in sport in the past. The aim of this narrative review is to characterize and summarize the available data concerning the influence of physical activity on morbidity and mortality in former female athletes. Concerning bone health, it seems that physical activity in the past can be protective against osteoporosis in postmenopausal women, but these data come from observational studies only. Also the cardiovascular system appears to benefit in older women from regular sport in the past. This refers mainly to better heart efficiency, and improved endothelial function and metabolic profile. The incidence of different types of neoplasms, especially breast cancer, is also decreased in former athletes. Professional sport, on the other hand, acts negatively on the pelvic floor and is a risk factor for urinary incontinence. The overall effect on mortality is difficult to assess, because of many parameters, such as the sport's intensity, variety of the sport and exposure to extreme danger in some disciplines. Also, caution should be kept in interpretation of the data because of the shortage of well-designed studies.

Hypoestrogenism in young women and its influence on bone mass density

One of the most important hormonal factors responsible for bone health is estradiol. Genetic factors, adequacy of hormonal functioning, nutrition and physical activity may be the markers of bone status and development in young women. During adolescence, women reach peak bone acquisition and develop a skeletal mass. This process is largely regulated by endocrine factors mainly such as adequate levels of gonadal, adrenal and pituitary hormones. The crucial role played by estradiol and its impact on bones are very multiple. Estradiol induces growth factors' activation, receptor activator of nuclear factor kappa B ligand (RANKL) production inhibition and is mainly referred to antiresorptive activity. Clinical situations leading to hypoestrogenism has been linked to decreased bone mineral density leading to osteopenia and osteoporosis. This status both in fertile and perimenopausal women can increase the risk of pathological fractures. Such conditions as hypothalamic-pituitary insufficiency (functional hypothalamic amenorrhea, anorexia nervosa, Kallmann syndrome, hyperprolactinemia), ovarian failure (gonadal dysgenesis, premature ovarian failure) and iatrogenic treatment (surgery, chemotherapy, radiotherapy) can cause hypoestrogenism. The treatment of osteopenia and osteoporosis caused by hypoestrogenism is very essential and multidirectional. The crucial role of the therapy is the achievement of proper serum estradiol concentration and eliminate the causes of hypoestrogenism.

Lean body mass, not estrogen or progesterone, predicts peak bone mineral density in premenopausal women

Estrogen and body fat content are important predictors of bone mineral density (BMD) in postmenopausal women, but their association with BMD in premenopausal women is less clear. Mounting evidence suggests that dietary fats can have detrimental effects on bone health. In a cross-sectional sample of healthy 30- to 40-y-old women (n = 242), we investigated the predictors of BMD at the hip and spine by multilevel multiple regression analyses. Predictor variables in the models included dietary intake of various fats, serum concentrations of sex steroids, blood chemistries and markers of metabolic syndrome, anthropometric variables, and ethnicity. Among these premenopausal women, lean body mass was the strongest independent predictor (P < 0.0001) and African-American ethnicity (P < 0.05) was another positive independent predictor of BMD at the hip and spine. Dietary fats were not independent predictors of BMD of hip and spine. Lean body mass and being African-American explained 33% of the variance in hip BMD. Lean body mass, African-American ethnicity, and serum concentrations of triglycerides (a negative predictor, P = 0.0001) explained 28% of the variance in spine BMD. In contrast, luteal phase serum concentrations of estradiol, progesterone, and testosterone were not predictors of BMD. It remains to be determined whether efforts to increase lean body mass in premenopausal women with normal levels of endogenous estrogen may be an effective preventive strategy to preserve bone health.

Higher prevalence of osteoporosis among female Holocaust survivors

The prevalence of osteoporosis was statistically significantly higher among female Holocaust survivors than among those who were not exposed to the Holocaust. These findings support the importance of nutrition and environmental conditions during childhood and adolescence on BMD in older adults.

INTRODUCTION

Holocaust survivors during childhood and adolescence experienced undernutrition and lack of exercise and sunlight. The study aimed to establish if Holocaust survivors have higher prevalence of osteoporosis than subjects who were not Holocaust survivors.

METHODS

Seventy-three female Jewish Holocaust survivors > or = 60 years old and 60 female European-born Jews > or =60 years old who were not in the Holocaust were examined. BMD was measured using DXA of the lumbar spine and hips. The Cochran-Armitage trend test was used to test for an increasing trend in decreased BMD in the Holocaust survivors versus controls.

RESULTS

Among Holocaust survivors 54.8% had osteoporosis, 39.7% osteopenia, and 5.5% normal BMD, whereas among controls 25.0% had osteoporosis, 55.0% osteopenia, and 20.0% normal BMD (p = 0.0001). In those who were <17 years old in 1945, among Holocaust survivors 58.0% had osteoporosis, 34.0% osteopenia, and 8.0% normal BMD, whereas among controls 20.0% had osteoporosis, 57.8% osteopenia, and 22.2% normal BMD (p = 0.0003). In those > or =17 years old in 1945, among Holocaust survivors 47.8% had osteoporosis, 52.2% osteopenia and none had normal BMD, whereas among controls 40.0% had osteoporosis, 46.7% osteopenia, and 13.3% normal BMD (p = 0.28).

CONCLUSION

The prevalence of osteoporosis was significantly higher among Holocaust survivors.

Maternal vitamin D status during pregnancy and childhood bone mass at age 9 years: a longitudinal study

BACKGROUND

Vitamin D insufficiency is common in women of childbearing age and increasing evidence suggests that the risk of osteoporotic fracture in adulthood could be determined partly by environmental factors during intrauterine and early postnatal life. We investigated the effect of maternal vitamin D status during pregnancy on childhood skeletal growth.

METHODS

In a longitudinal study, we studied 198 children born in 1991-92 in a hospital in Southampton, UK; the body build, nutrition, and vitamin D status of their mothers had been characterised during pregnancy. The children were followed up at age 9 years to relate these maternal characteristics to their body size and bone mass.

FINDINGS

49 (31%) mothers had insufficient and 28 (18%) had deficient circulating concentrations of 25(OH)-vitamin D during late pregnancy. Reduced concentration of 25(OH)-vitamin D in mothers during late pregnancy was associated with reduced whole-body (r=0.21, p=0.0088) and lumbar-spine (r=0.17, p=0.03) bone-mineral content in children at age 9 years. Both the estimated exposure to ultraviolet B radiation during late pregnancy and the maternal use of vitamin D supplements predicted maternal 25(OH)-vitamin D concentration (p<0.0001 and p=0.0110, respectively) and childhood bone mass (p=0.0267). Reduced concentration of umbilical-venous calcium also predicted reduced childhood bone mass (p=0.0286).

INTERPRETATION

Maternal vitamin D insufficiency is common during pregnancy and is associated with reduced bone-mineral accrual in the offspring during childhood; this association is mediated partly through the concentration of umbilical venous calcium. Vitamin D supplementation of pregnant women, especially during winter months, could lead to longlasting reductions in the risk of osteoporotic fracture in their offspring.

Prior oral contraception and postmenopausal fracture: a Women's Health Initiative observational cohort study

OBJECTIVE

To test for the possible association of past oral contraceptive (OC) use and incident fracture after menopause.

DESIGN

A prospective cohort of 93,725 postmenopausal women.

SETTING

Forty Women's Health Initiative (WHI) clinical centers across the United States.

PATIENT(S)

Ethnically diverse 93,725 volunteer postmenopausal women, 50 to 79 years old.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The main outcome was self-reported incident first fracture assessed prospectively by annual questionnaire.

RESULT(S)

The adjusted relative hazard (HR) for fracture among past OC users was 1.07 (95% CI, 1.01-1.15). Among women without any postmenopausal hormone treatment, past OC use for < or =5 years led to an HR of 1.15 (95% CI, 1.04-1.27) and for past OC use >5 years led to an HR of 1.09 (95% CI, 0.97-1.23) compared with never users.

CONCLUSION(S)

This study does not support the idea that past OC use protects against later fracture.

Effects of an Oral Contraceptive Containing Drospirenone on Bone Turnover and Bone Mineral Density

OBJECTIVE

To compare the effects of a new 21-day combined oral contraceptive containing 30 microg ethinyl/estradiol plus 3 mg drospirenone with a 21-day preparation containing 30 microg ethinyl/estradiol plus 75 microg gestodene on bone turnover and bone mineral density in young fertile women.

METHODS

A randomized, controlled trial was conducted with healthy fertile women treated with 30 microg ethinyl/estradiol plus 3 mg drospirenone (group A; n = 24), 30 microg ethinyl/estradiol plus 75 microg gestodene (group B; n = 24) and healthy controls (group C, n = 23). At 3, 6, 9, and 12 months of the study, serum and urinary calcium, osteocalcin, urinary pyridinoline, and deoxypyridinoline were measured. At baseline and after 12 months, lumbar bone mineral density was determined by dual-energy X-ray absorptiometry.

RESULTS

In groups A and B, urinary pyridinoline and deoxypyridinoline at 6, 9, and 12 months were significantly reduced in comparison with basal values and group C (P < .05). Pyridinoline and deoxypyridinoline levels were lower in group A than in group B throughout the study, but not significantly. In group A serum calcium levels were significantly increased after 6 months. At 12 months, no significant difference was detected in lumbar bone mineral density values among the 3 groups and in comparison with basal values.

CONCLUSION

Both combined oral contraceptives exert a similar positive influence on bone turnover and bone-sparing effect in young postadolescent women.

Risk factors for low bone mineral density and the 6-year rate of bone loss among premenopausal and perimenopausal women

Risk factors that are associated with lower bone mineral density (BMD) may not necessarily be associated with increased bone loss among premenopausal and perimenopausal women. We determined risk factors for lower premenopausal and perimenopausal BMD while simultaneously determining risk factors for increased 6-year rate of bone loss among women aged 24-50 years within a population-based prospective cohort study. BMD of the lumbar spine and femoral neck, reported as t scores, were measured five times within the 6-year study among 614 women who were between the ages of 24 and 44 in 1992/1993. Rates of bone loss were calculated from the repeated BMD measurements. Risk factors for lower BMD over time at the lumbar spine included history of any fracture ( P=0.005). The major risk factor for lower BMD over time at the femoral neck was family history of osteoporosis ( P<0.002). The major protective factor for greater BMD over time at both skeletal sites was additional body weight ( P<0.0001). Other protective factors for greater BMD over time at the femoral neck were modest alcohol consumption ( P=0.0002) and high-school sports participation ( P=0.002). Risk factors for greater bone loss at either skeletal site included postmenopausal status ( P<0.0001 at the lumbar spine; P=0.01 at the femoral neck), and the reporting of a reproductive cancer ( P<0.0001 at the lumbar spine; P=0.0008 at the femoral neck). Body weight was protective against bone loss at both skeletal sites ( P<0.0001). Baseline age, calcium intake, smoking, and current physical activity were not associated with BMD or bone loss. The understanding of the relative importance of risk factors for both low BMD and bone loss may assist in the identification of women at greater risk for subsequent low postmenopausal BMD.

Noninvasive estimation of bone mass in ancient vertebrae

Histomorphometry is useful in the assessment of trabecular bone mass (TBM), and thus, in the estimation of the prevalence and intensity of osteopenia in ancient population groups. However, it is a destructive method. It is therefore necessary to explore the accuracy of nondestructive approaches, such as radiography, bone mineral density (BMD) assessed by double-energy X-ray absorptiometry (DEXA), bone density (BD), or optical density (OD) in the diagnosis of osteopenia. We selected 51 vertebrae out of a total sample composed of 333 T12, L1, and L2 vertebrae belonging to adult pre-Hispanic inhabitants from El Hierro. These vertebrae underwent histomorphometrical analysis, a fine-grained film radiography with assessment of trabecular pattern following standard methods, OD, DEXA-assessed BMD, and BD. The presence of biconcave vertebrae and wedge-shaped vertebrae was also assessed by measuring anterior height (a), posterior height (p), and height at the middle point of the vertebral body (m), and further calculating the indices 2m/(a + p) ("spine score") and a/p. Significant correlations were observed between TBM and BMD (r=0.43), TBM and BD (r=0.49), TBM and OD (r=0.52), BMD and OD (r=0.51), and BMD and BD (r=0.36), but not between TBM and the indices 2m/(a + p) and a/p. In the stepwise multiple correlation analysis between TBM and BMD, BD, and OD, OD entered into first place and BD into second place, whereas BMD became displaced; the multiple correlation coefficient was 0.63, with a standard error of 3.78. A BMD greater than 0.60 g/cm2, or a bone density greater than 0.60 g/cm3, excluded osteopenia (TBM <15%) with a specificity greater than 90%, whereas a BMD value less than 0.35 g/cm2, a BD less than 0.35 g/cm3, or optical density >1.6 excluded a normal bone mass (TBM >20%) with a specificity greater than 90%. Based on radiographic criteria on the total sample, we also conclude that the overall prevalence of vertebral fractures in the adult pre-Hispanic population of El Hierro of any age is 7.5%.

Sport and home physical activity are independently associated with bone density

PURPOSE

To study the relations between four domains of physical activity-sport, home, work, and active living-and bone mineral density (BMD).

METHODS

Baseline data from African-American (N = 544), Caucasian (N= 1044), Chinese (N= 230), and Japanese (N= 239) participants, aged 42-52 yr, from the study of Women's Health Across the Nation were analyzed. BMD was measured with Hologic 2000 or 4500A densitometers. Physical activity was assessed with the Kaiser Physical Activity Scale, which rates each domain of activity between 1 (low) and 5 (high). Multiply adjusted linear regression models were used to estimate the relations between each activity domain and BMD.

RESULTS

The mean and median values of sport, home, work, and active living each approximated the midpoint of the scale and did not differ substantially among ethnic groups. Scores for each domain of activity were not highly correlated, with r values ranging between -0.03 and 0.33. Independent of age, body mass index, ethnic group, alcohol use, dietary calcium, smoking, menopause status, SWAN site, and other domains of physical activity, higher sport activity was statistically significantly associated with greater BMD at the lumbar spine (P= 0.008), femoral neck (P= 0.0002), and total hip (P< 0.0001). More home physical activity was associated with higher BMD at the spine (P= 0.049) and femoral neck (P= 0.008). Neither work physical activity nor active living was related to BMD at any bone site.

CONCLUSIONS

These results highlight the need to consider domain-specific physical activity in relation to health outcomes in women.