Effect of urbanization on bone mineral density: A Thai epidemiological study

BACKGROUND: The incidence of fractures in rural populations is lower than in urban populations, although the reason for this difference is unclear. This cross-sectional study was designed to examine the difference in bone mineral density (BMD), a primary predictor of fracture risk, between urban and rural Thai populations. METHODS: Femoral neck and lumbar spine BMD was measured by dual-energy X-ray absorptiometry (GE Lunar, Madison, WI) in 411 urban and 436 rural subjects (340 men and 507 women), aged between 20 and 84 years. Body mass index (BMI) was calculated from weight and height. RESULTS: After adjusting for age and body weight in an analysis of covariance model, femoral neck BMD in rural men and women was significantly higher than those in urban men and women (P < 0.001), but the difference was not observed at the lumbar spine. After stratifying by sex, age group, and BMI category, the urban-rural difference in femoral neck BMD became more pronounced in men and women aged <50 years and with BMI ≥ 25 kg/m(2). CONCLUSIONS: These data suggest that femoral neck BMD in rural men and women was higher than their counterparts in urban areas. This difference could potentially explain part of the urban-rural difference in fracture incidence

Hyponatremia-Induced Osteoporosis

There is a high prevalence of chronic hyponatremia in the elderly, frequently owing to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Recent reports have shown that even mild hyponatremia is associated with impaired gait stability and increased falls. An increased risk of falls among elderly hyponatremic patients represents a risk factor for fractures, which would be further amplified if hyponatremia also contributed metabolically to bone loss. To evaluate this possibility, we studied a rat model of SIADH and analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III). In rats, dual-energy X-ray absorptiometry (DXA) analysis of excised femurs established that hyponatremia for 3 months significantly reduced bone mineral density by approximately 30% compared with normonatremic control rats. Moreover, micro-computed tomography (µCT) and histomorphometric analyses indicated that hyponatremia markedly reduced both trabecular and cortical bone via increased bone resorption and decreased bone formation. Analysis of data from adults in NHANES III by linear regression models showed that mild hyponatremia is associated with increased odds of osteoporosis (T-score –2.5 or less) at the hip [odds ratio (OR) = 2.85; 95% confidence interval (CI) 1.03–7.86; p < .01]; all models were adjusted for age, sex, race, body mass index (BMI), physical activity, history of diuretic use, history of smoking, and serum 25-hydroxyvitamin D [25(OH)D] levels. Our results represent the first demonstration that chronic hyponatremia causes a substantial reduction of bone mass. Cross-sectional human data showing that hyponatremia is associated with significantly increased odds of osteoporosis are consistent with the experimental data in rodents. Our combined results suggest that bone quality should be assessed in all patients with chronic hyponatremia. © 2010 American Society for Bone and Mineral Research

The Oslo Health Study: Is bone mineral density higher in affluent areas?

<p>Abstract</p> <p>Background</p> <p>Based on previously reported differences in fracture incidence in the socioeconomic less affluent Oslo East compared to the more privileged West, our aim was to study bone mineral density (BMD) in the same socioeconomic areas in Oslo. We also wanted to study whether possible associations were explained by socio-demographic factors, level of education or lifestyle factors.</p> <p>Methods</p> <p>Distal forearm BMD was measured in random samples of the participants in The Oslo Health Study by single energy x-ray absorptiometry (SXA). 578 men and 702 women born in Norway in the age-groups 40/45, 60 and 75 years were included in the analyses. Socioeconomic regions, based on a social index dividing Oslo in two regions – East and West, were used.</p> <p>Results</p> <p>Age-adjusted mean BMD in women living in the less affluent Eastern region was 0.405 g/cm²and significantly lower than in West where BMD was 0.419 g/cm². Similarly, the odds ratio of low BMD (Z-score ≤ -1) was 1.87 (95% CI: 1.22–2.87) in women in Oslo East compared to West. The same tendency, although not statistically significant, was also present in men. Multivariate analysis adjusted for education, marital status, body mass index, physical inactivity, use of alcohol and smoking, and in women also use of post-menopausal hormone therapy and early onset of menopause, did hardly change the association. Additional adjustments for employment status, disability pension and physical activity at work for those below the age of retirement, gave similar results.</p> <p>Conclusion</p> <p>We found differences in BMD in women between different socioeconomic regions in Oslo that correspond to previously found differences in fracture rates. The association in men was not statistically significant. The differences were not explained by socio-demographic factors, level of education or lifestyle factors.</p

Hip fractures and area level socioeconomic conditions: a population-based study

Icks A, Haastert B, Wildner M, et al. Hip fractures and area level socioeconomic conditions: a population-based study. BMC Public Health. 2009;9(1):114.Background: Only a limited number of studies have analyzed the association between hip fracture incidence and socioeconomic conditions. Most, but not all found an association, and results are in part conflicting. The aim of our study was to evaluate the association between hip fractures and socioeconomic conditions in Germany, from 1995 to 2004, on a census tract area level. Methods: We used data from the national hospital discharge diagnosis register and data on socioeconomic and demographic characteristics of 131 census tracts from official statistics. Associations between the hip fracture incidence and socioeconomic conditions were analyzed by multiple Poisson regression models, taking overdispersion into account. Results: The risk of hip fracture decreased by 4% with a 7% increase (about one interquartile range) of non-German nationals. It decreased by 10% with a 6% increased rate of unemployment, increased by 7% with a 2% increase of the proportion of welfare recipients, and also increased by 3% with an increase of the proportion of single parent families of 1.9%. Conclusion: Our results showed weak associations between indicators of socioeconomic conditions at area level and hip fracture risk; the varied by type of indicator. We conclude that hip fracture incidence might be influenced by the socioeconomic context of a region, but further analysis using more specific markers for deprivation on a smaller scale and individual-level data are needed

Potential use of mealworm (Tenebrio molitor) frass in fruit tree pest management

Masteroppgave i biologiBIO399MAMN-BIOMAMN-HAVS

Effects of hormonal conditions and drugs on both muscle and bone strength can be assessed in a single rat test.

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