Variables for the prediction of femoral bone mineral status in American women

Risk Factors for Low Bone Mineral Density in Institutionalized Individuals with Developmental Disabilities

BACKGROUND

Persons with intellectual/developmental disabilities (IDD) are exposed to several factors, which have been determined as risks for osteoporosis. Many of these individuals are non-ambulatory, resulting in lack of weight bearing activity, which is well established as a major contributor to bone loss. The purpose of this study was to investigate risk factors for low bone mineral density (BMD) in persons with IDD residing in residential facilities.

METHODS

This cross-sectional study was conducted at an Intermediate Care Facility for individuals with Intellectual and Developmental Disabilities (ICF/IDD). Medical records data were used from 69 individuals, including heal scan T-scores, nutritional, pharmacologic and other risk factors. Chi-Square analysis was used to determine relationships between the variables.

RESULTS

BMD measures were not significantly associated with age, gender, height, weight, or BMI for this population (P > 0.05). The association between BMD diagnoses and DSM-IV classification of mental retardation approached significance (P = 0.063). A significant association was found with anti-seizure medication (P = 0.009).

CONCLUSION

Follow-up studies should focus on how supplementation and medication changes may or may not alter BMD. Persons with IDD are experiencing longer life expectancies, and therefore, studies ascertaining information on diseases associated with this aging population are warranted.

Calcium intake and bone mineral density as an example of non-linearity and threshold analysis

Non-linearity is a likely phenomenon in bone metabolism, but is often ignored in pertinent epidemiological studies. Using NHANES III data on calcium intake and bone mineral density, the most important non-linear methods are introduced and discussed. The results should motivate researchers to consider non-linearity in this field more frequently.

INTRODUCTION

Many relationships in bone metabolism and homeostasis are likely to follow non-linear patterns. Detailed dose-response analyses allowing for non-linear associations nonetheless remain scarce in this field.

METHODS

A detailed analysis of NHANES III data on dietary calcium intake and bone mineral density was used to demonstrate the application and some of the challenges of the most important dose-response methods, including LOESS, categorical analysis, fractional polynomials, restricted cubic splines, and segmented regression.

RESULTS

The spline estimate suggested increasing bone mineral density up to a calcium intake of about 1 g/day and a plateau thereafter. In segmented regression, the break-point marking the beginning of the plateau was placed at an intake of 0.58 (95 % confidence interval, 0.33 to 0.82) g/day. Sensitivity analyses suggested a less curved dose-response in women.

CONCLUSIONS

Knowing about the possibilities and limitations of non-linear dose-response approaches should encourage researchers to consider these methods more frequently in studies on bone health and disease. The example analysis suggested bone mineral density to reach a plateau slightly below current calcium intake recommendations, with fairly pronounced differences of the dose-response shape by sex and menopausal status.

Relationships between physical activity and awareness and treatment status among adults with low femoral bone density in the United States

PURPOSE

To examine relationships between physical activity (PA) and awareness and treatment status of low bone mineral density (BMD) among adults.

DESIGN

Cross-sectional.

SETTING

Stratified sample of adults living independently in the community.

SUBJECTS

A total of 1928 adults aged 50 years and older who participated in the National Health and Nutrition Examination Survey 2005-2006 were included in the analysis. Among those, about 54% were women, 84% were non-Hispanic whites, 65% were married, and 44% were between 50 and 59 years of age.

MEASURES

Objective measures: femoral neck BMD and duration of PA and step counts measured by accelerometers. Self-report: strength exercise, and awareness and treatment of low bone density.

ANALYSIS

Multivariate regression analyses using SUDAAN.

RESULTS

Despite a high prevalence of low BMD, self-reported awareness, treatment, and PA were very low. After controlling socio-demographic and health-related factors, those who were aware of their low bone density status and who received treatment for it were less physically active than those who were unaware of their bone condition or who did not have any treatment.

CONCLUSIONS

PA levels are below the recommended level for bone health benefits. Health care providers should consider screening individuals at risk of low bone density and encourage them to implement prevention and treatment regimen including increasing daily levels of PA.

Factors that contribute to low bone density in postmenopausal women in different amazonian communities

BACKGROUND

The aim of this study was to verify socioeconomic differences, nutrition, body balance and quality of life (QoL) in postmenopausal women with low bone mineral density (BMD) in two Amazonian communities.

METHODS

A total of 42 female volunteers participated in the study. The volunteers were separated into two groups: Villa (n = 20; 53 ± 5.5 years) and City (n = 22; 56 ± 7.9 years). The following evaluation instruments were used: dual energy X-ray absorptiometry (DXA); a socioeconomic questionnaire; a QoL questionnaire; a dietary habits questionnaire; and a balance test. Parametric and nonparametric tests were used.

RESULTS

The data showed significant differences in socioeconomic level (Δ%=+15.9%, p = 0.000), lumbar spine L(2)-L(4) (Δ% = +0.10%, p = 0.007), balance (Δ% = +4.3%, p = 0.03) and some important aspects of nutrition, such as the consumption of milk (Δ%=+34%, p = 0.01) and alcohol (+14.8%, p = 0.0001). These significant differences also contributed to the total QoL score (Δ%=+76.2%, p = 0.000) and the majority of the QoL-related functions.

CONCLUSION

This study verified that socioeconomic level, nutritional status, physical activity levels and QoL can influence the BMD of postmenopausal women. The study suggests new strategies for official health organizations to use in order to prevent and treat osteoporosis. In addition, this study can provide an orientation to physical activity, nutrition and medical professionals.

The effect of weight training on bone mineral density and bone turnover in postmenopausal breast cancer survivors with bone loss: a 24-month randomized controlled trial

SUMMARY

This study examined whether 24 months of weight training exercises enhanced the effectiveness of risedronate, calcium, and vitamin D in maintaining or improving bone mineral density (BMD) in 223 postmenopausal breast cancer survivors. Subjects who were > or =50% adherent to exercise had no improvement in BMD but were less likely to lose BMD.

INTRODUCTION

This study examined whether (1) postmenopausal breast cancer survivors (BCS) with bone loss taking 24 months of risedronate, calcium, and vitamin D had increased bone mineral density (BMD) at the total hip, femoral neck, L1-L4 spine, total radius and 33% radius, and decreased bone turnover; (2) subjects who also participated in strength/weight training (ST) exercises had greater increases in BMD and greater decreases in bone turnover; and (3) subjects who also exercised were more likely to preserve (at least maintain) BMD.

METHODS

Postmenopausal BCS (223) were randomly assigned to exercise plus medication or medication only groups. Both groups received 24 months of 1,200 mg of calcium and 400 IU of vitamin D daily and 35 mg of risedronate weekly, and the exercise group additionally had ST exercises twice weekly.

RESULTS

After 24 months, women who took medications without exercising had significant improvements in BMD at the total hip (+1.81%) and spine (+2.85%) and significant decreases in Alkphase B (-8.7%) and serum NTx (-16.7%). Women who also exercised had additional increases in BMD at the femoral neck (+0.29%), total hip (+0.34%), spine (+0.23%), total radius (+0.30%), and additional decreases in Alkphase B (-2.4%) and Serum NTx (-6.5%). Additional changes in BMD and bone turnover with exercise were not significant. Subjects who were > or =50% adherent to exercise were less likely to lose BMD at the total hip (chi-square [1] = 4.66, p = 0.03) and femoral neck (chi-square [1] = 4.63, p = 0.03).

CONCLUSION

Strength/weight training exercises may prevent loss of BMD in postmenopausal BCS at risk for bone loss.

[Factors associated with low bone mineral density among white women]

OBJECTIVE

To analyze whether the factors causing low bone mineral density among elderly women are the same as those observed in other age groups.

METHODS

A cross-sectional study was carried out on the medical records of a random sample of 413 white women seen at an imaging diagnostics service in a city of Southern Brazil, in 2003. Femoral bone mineral densities with adjustment using T-scores were used. The following variables were investigated: age, body mass index, tobacco smoking, alcohol consumption, milk consumption, physical activity and hormone replacement therapy. Univariate and multivariate unconditional logistic regression were used.

RESULTS

In the sample, 52.5% were up to 59 years old and 47.5% were 60 or over. The mean bone mineral density was 0.867 g/cm2 (SD=0.151) for the femoral neck. Significant age-adjusted values were obtained for physical activity (adjusted OR=0.47; 95% CI: 0.23;0.97), body mass index greater than or equal to 30.0 kg/m2 (adjusted OR=0.10; 95% CI: 0.05;0.21), alcohol consumption (adjusted OR=7.90; 95% CI: 2.17;28.75), low milk consumption (adjusted OR=3.29; 95% CI: 1.91;5.68) and hormone replacement (adjusted OR = 0.44; 95% CI: 0.21;0.90). Among the elderly women, body mass, milk consumption and physical activity were independent protection factors.

CONCLUSIONS

Advanced age, body mass, physical activity, milk and alcohol consumption were important factors in bone mass regulation. The influence of behavioral factors was maintained among the women of advanced aged, thus reinforcing the role of preventive measures in medical practice and public health promotion policies aimed at healthy aging.