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

Green space, genetic susceptibility, and risk of osteoporosis:a cohort study from the UK Biobank

OBJECTIVE

This study aimed to investigate the effect of residential exposure to green space on the incident osteoporosis and further explore the modification effect of genetic susceptibility.

METHODS

Participants from the UK Biobank were followed from 2006 to 2010 (baseline) to December 31st, 2022. Using land use coverage, we evaluated exposure to residential surrounding green space, natural environment, and domestic gardens. We used the Cox regression to examine the association between the residential environment and incident osteoporosis. The interactive effects between polygenic risk score (PRS) of osteoporosis and residential environments on incident osteoporosis were investigated.

RESULTS

This study included 292,662 participants. Over a median follow-up period of 13.65 years, we documented 9177 incidents of osteoporosis. Per interquartile (IQR) increase in greenness and natural environment at a 300 m buffer was associated with a 4% lower risk of incident osteoporosis [HR = 0.96 (95% CI: 0.93, 0.99)] and [HR = 0.96 (95% CI: 0.93, 0.98)], respectively. We did not identify any interactive effects between genetic risk and residential environment on incident osteoporosis.

CONCLUSIONS

This study found that public greenness and natural environments could reduce the risk of incident osteoporosis regardless of genetic predisposition. Developing sustainable and publicly accessible natural environments might benefit populations' bone health.

Molecular and cellular mechanisms linking air pollution and bone damage

Air pollution is the second most important risk factor associated with noncommunicable diseases after smoking. The effects of pollution on health are commonly attributable to particulate matter (PM), a complex mixture of particles suspended in the air. PM can penetrate the lower respiratory tract and has harmful direct and indirect effects on different organs and tissues. Direct effects are caused by the ability of PM components to cross the respiratory membrane and enter the bloodstream; indirect effects are systemic consequences of the local airway response. Recent work suggests that PM is an independent risk factor for low bone mineral density and osteoporosis-related fractures. Osteoporosis is a common age-related disease closely linked to bone fractures, with severe clinical consequences affecting quality of life, morbidity, and mortality. In this review, we discuss potential mechanisms behind the association between outdoor air pollution, especially PM, and bone damage. The discussion features four main mechanisms: 1) several different atmospheric pollutants can induce low-grade systemic inflammation, which affects bone metabolism through a specific effect of cytokines such as TNFα, IL-1β, IL-6, and IL-17 on osteoblast and osteoclast differentiation and function; 2) some pollutants, particularly certain gas and metal compounds, can cause oxidative damage in the airway and bone cells; 3) different groups of pollutants can act as endocrine disruptors when binding to the receptors in bone cells, changing their functioning; and 4) air pollution can directly and indirectly cause vitamin D deficiency. Characterizing these mechanisms will better define the physiopathology of bone damage, and recognizing air pollution as a modifiable risk factor for osteoporosis will inform environmental policies. Such knowledge will also guide the prevention of fractures due to fragility and help reduce health-related costs.

Bone mineral density in an urban and a rural children population-A comparative, population-based study in Enugu State, Nigeria

INTRODUCTION

Osteoporosis is one of the non-communicable diseases linked to urbanisation. The foundation of osteoporotic fractures stems from childhood. Therefore, studies that promote maximising peak bone mass are strongly advocated. Studies have shown that there are differences in the incidence of osteoporotic fractures in rural and urban communities. No study has investigated urban-rural differences in BMD of Nigerian children. This study, therefore, aimed to investigate urban-rural differences in BMD of Nigerian children and the association with physical activity, demographic and anthropometric variables.

METHODS

In a cross-sectional, study in Enugu, Nigeria, estimated bone mineral density (eBMD) was measured at the calcaneum using the QUS densitometer, Hologic Sahara, in 457 urban (Enugu metropolis) and 559 rural (Nsukka community) children aged 6-14 years. Height, weight and physical activity were measured. Independent sample t-test was used for comparative analysis while Pearson correlation coefficients and multiple regression models were used to examine the relationship between the eBMD and the other parameters.

RESULTS

The mean (S.D) eBMD of the urban children [0.52(0.09) g/cm²] were significantly higher (p < 0.05) than their age- and gender-matched counterparts in the rural areas [0.51(0.08) g/cm²]. Age and weight predicted (p < 0.05) the eBMD in the urban subjects while only age was the predictor (p < 0.05) in the rural subjects. The physical activity pattern had no relationship with eBMD in both urban and rural children in Enugu, Nigeria.

CONCLUSIONS

The eBMD of rural children is lower than that of their age- and gender-matched urban counterparts.

Distal Forearm Bone Mineral Density Among Hill Tribes in the Omkoi District, Chiang Mai Province, Thailand

Background:

Osteoporosis is a major public health issue in several countries worldwide because it increases healthcare costs, and is a risk for mortality. There have been several studies that have examined BMD among the various Thai people and the regions that they inhabit.

Objective:

This study examined the distal forearm Bone Mineral Density (BMD) in men and women over 40 years of age among members of various Karen hill-tribes located in the Omkoi District, Chiang Mai Province, Thailand.

Methods:

Two hundred and sixty-two subjects (180 women, 82 men), ranging from 40 to 83 years old were recruited in this study. The non-dominant distal forearm bone mineral density was assessed by using peripheral dual-energy X-ray absorptiometry (pDEXA).

Results:

The results showed that the BMD were 0.530 ± 0.065, 0.508 ± 0.087, 0.461 ± 0.098, and 0.438 ± 0.124 g/cm2 for men age 40-49 years, age 50-59 years, age 60-69 years, and ages 70-83 years, respectively. For women, the BMD were 0.392 ± 0.051, 0.337 ± 0.063, 0.232 ± 0.065, and 0.212 ± 0.069 g/cm2 among women age 40-49 years, age 50-59 years, age 60-69 years, and ages 70-83 years, respectively. BMD had decreased in post-menopause as a function of duration time after menopause.

Conclusion:

We determined the prevalence of osteoporosis of men and women of Karen hill-tribes in the Chiang Mai Province, Thailand. These findings provided important information regarding bone health in Karen hill-tribes for any healthcare planning done in the immediate future.

Bone mineral density at distal forearm in men over 40 years of age in Mae Chaem district, Chiang Mai Province, Thailand: a pilot study

OBJECTIVE

To study the prevalence of bone mineral density (BMD) and osteoporosis in the distal forearm among Thai men over 40 years of age in Mae Chaem District, Chiang Mai Province, Thailand.

METHODS

The subjects in this study were 194 Thai men, aged between 40 and 87 years who resided in Mae Chaem District, Chiang Mai Province, Thailand. Self-administered questionnaires were used for receiving the demographic characteristics information. BMD was measured by peripheral dual energy X-ray absorptiometry at the nondominant distal forearm in all men.

RESULTS

The BMD was highest in the age-group 40-49 years and lowest in the age-group 70-87 years. The average T-score at the distal forearm was also highest in the age-group 40-49 years and lowest in the age-group 70-87 years. The BMD decreased as a function of age-group (p < .05). In contrast, the BMD increased as a function of weight (p < .05). Height had weak impact on the BMD in the distal forearm (p > .05). The percentage of osteopenia and osteoporosis are increased as a function of age-group in, while decreased in that of normal bone density.

CONCLUSIONS

We found the prevalence of osteoporosis in men who resided in Mae Chaem District, Chiang Mai Province, Thailand.

Rural older people had lower mortality after accidental falls than non-rural older people

Objective

This study aimed to investigate the mortality rate after falls of rural and non-rural older people and to explore the risk factors of mortality after falls among older people.

Patients and methods

This population-based case–control study identified two groups from a nationwide claim database (National Health Insurance Research Database in Taiwan): a rural group and a non-rural group, which included 3,897 and 5,541 older people, respectively, who were hospitalized for accidental falls (The International Classification of Diseases, Ninth Revision, Clinical Modification: E880–E888) during 2006–2009. Both groups were followed up for 4 years after falls. Four-year cumulative all-cause mortality rate after falls was calculated, and the demographic factor, comorbidity, and medications were considered as the potential risk factors of mortality after falls.

Results

The rural group had a significantly higher frequency of fall-related hospitalizations (7.4% vs 4.3%, P<0.001), but a lower 4-year cumulative all-cause mortality rate after falls than the non-rural group (8.8% vs 23.4%, P<0.001). After adjusting for age, gender, comorbidity, and medication use, the rural group had a significantly lower risk of mortality after falls than the non-rural group (adjusted odds ratio =0.32, 95% confidence interval =0.28–0.37, P<0.001). Age, gender, place of residence, comorbidity, number of medications, and inappropriate medication use were independent risk factors of mortality after falls.

Conclusion

The rural older people had a higher frequency of fall-related hospitalizations but lower mortality after falls than the non-rural older people. Fall prevention programs should be adjusted for difference in place of residence.

Risk of Vertebral Fracture in Patients Diagnosed with a Depressive Disorder: A Nationwide Population-Based Cohort Study

OBJECTIVE:

Previous studies have reported that depression may play a crucial role in the occurrence of vertebral fractures. However, a clear correlation between depressive disorders and osteoporotic fractures has not been established. We explored the association between depressive disorders and subsequent new-onset vertebral fractures. Additionally, we aimed to identify the potential risk factors for vertebral fracture in patients with a depressive disorder.

METHODS:

We studied patients listed in the Taiwan National Health Insurance Research Database who were diagnosed with a depressive disorder by a psychiatrist. The comparison cohort consisted of age- and sex-matched patients without a depressive disorder. The incidence rate and hazard ratios of subsequent vertebral fracture were evaluated. We used Cox regression analysis to evaluate the risk of vertebral fracture among patients with a depressive disorder.

RESULTS:

The total number of patients with and without a depressive disorder was 44,812. The incidence risk ratio (IRR) between these 2 cohorts indicated that depressive disorder patients had a higher risk of developing a subsequent vertebral fracture (IRR=1.41, 95% confidence interval [CI]=1.26-1.57, p<0.001). In the multivariate analysis, the depressive disorder cohort showed a higher risk of vertebral fracture than the comparison cohort (adjusted hazard ratio=1.24, 95% CI=1.11-1.38, p<0.001). Being older than 50 years, having a lower monthly income, and having hypertension, diabetes mellitus, cerebrovascular disease, chronic obstructive pulmonary disease, autoimmune disease, or osteoporosis were considered predictive factors for vertebral fracture in patients with depressive disorders.

CONCLUSIONS:

Depressive disorders may increase the risk of a subsequent new-onset vertebral fracture.

Urban-Rural Differences in Bone Mineral Density: A Cross Sectional Analysis Based on the Hyderabad Indian Migration Study

Background

Fracture risk is rising in countries undergoing rapid rural to urban migration, but whether this reflects an adverse effect of urbanization on intrinsic bone strength, as reflected by bone mineral density (BMD), is currently unknown.

Methods

Lumbar spine (LS) and total hip (TH) BMD, and total body fat and lean mass, were obtained from DXA scans performed in the Hyderabad arm of the Indian Migration Study (54% male, mean age 49 years). Sib-pair comparisons were performed between rural-urban migrants (RUM) and rural non-migrated (RNM) siblings (N = 185 sib-pairs).

Results

In analyses adjusted for height, gender, age and occupation, rural to urban migration was associated with higher lumbar and hip BMD and greater predicted hip strength; ΔLS BMD 0.030 (0.005, 0.055) g/cm², ΔTH BMD 0.044 (0.024; 0.064) g/cm², Δcross-sectional moment of inertia 0.162 (0.036, 0.289) cm⁴. These differences were largely attenuated after adjusting for body composition, insulin levels and current lifestyle factors ie. years of smoking, alcohol consumption and moderate to vigorous physical activity. Further analyses suggested that differences in lean mass, and to a lesser extent fat mass, largely explained the BMD differences which we observed.

Conclusions

Rural to urban migration as an adult is associated with higher BMD and greater predicted hip strength, reflecting associated alterations in body composition. It remains to be seen how differences in BMD between migration groups will translate into fracture risk in becoming years.

Comparison of Bone Mineral Density between Urban and Rural Areas: Systematic Review and Meta-Analysis

BACKGROUND

Studies from high income countries (HIC) have generally shown higher osteoporotic fracture rates in urban areas than rural areas. Low bone mineral density (BMD) increases susceptibility to fractures. This review aimed to assess whether urbanicity is consistently associated with lower BMD globally.

METHOD

Ovid MEDLINE, EMBASE, and Global Health (-April 2013) were searched for articles investigating differences in bone mineral content (BMC) or BMD between urban and rural areas. Ratio of means (RoM) of BMD were used to estimate effect sizes in meta-analysis, with an exception for one study that only presented BMC data.

RESULTS

Fifteen articles from eleven distinct populations were included in the review; seven populations from four high income countries and four from three low and middle income countries (LMIC). Meta-analysis showed conflicting evidence for urban-rural difference in BMD; studies from high income countries generally showed higher BMD in rural areas while the results were more mixed in studies from low and middle income countries (HIC RoM = 0.05; 95% CI: 0.03 to 0.06; LMIC RoM = -0.04: 95% CI: -0.1 to 0.01).

CONCLUSIONS

Urban-rural differences of bone mineral density may be context-specific. BMD may be higher in urban areas in some lower income countries. More studies with robust designs and analytical techniques are needed to understand mechanisms underlying the effects of urbanization on bone mass accrual and loss.

Exposure to air pollution increases the risk of osteoporosis: a nationwide longitudinal study

Several studies have indicated that air pollution induces systemic as well as tissue-specific inflammation. Chronic inflammatory diseases such as rheumatoid arthritis and chronic obstructive pulmonary disease reduce bone mineral density (BMD), leading to increased release of immune cells from the bone marrow. However, the association between air pollution and osteoporosis remains poorly defined. Therefore, we conducted this population-based retrospective cohort study to evaluate the risk of osteoporosis in Taiwanese residents exposed to air pollution.We combined 2 nationwide databases in this study. The National Health Insurance Research Database of Taiwan was available from 2000 to 2010. Detailed daily data on air pollution were collected by Taiwan Environmental Protection Agency (EPA) from 1998 to 2010. We calculated the yearly average concentrations of air pollutants from the study start to the date of osteoporosis occurrence, or withdrawal from the NHI program, or December 31, 2010. The yearly average concentrations of air pollutants were categorized into quartiles, and the risks of osteoporosis were evaluated among 4 stages of air pollutants.Among Q1, Q2, Q3, and Q4 of pollutants in all subjects, the adjusted hazard ratios (HRs) of osteoporosis in Q2, Q3, and Q4 were compared with Q1. For carbon monoxide (CO), the adjusted HRs were 1.05 (95% confidence interval [CI], 0.97-1.14), 1.78 (95% CI, 1.65-1.92), and 1.84 (95% CI, 1.71-1.98), respectively. For nitrogen dioxide (NO2), the adjusted HRs were 1.35 (95% CI, 1.25-1.45), 1.24 (95% CI, 1.15-1.35), and 1.60 (95% CI, 1.48-1.73), respectively, in all subjects.The findings of the present study show that CO and NO2 exposure is associated with an increased risk of osteoporosis in the Taiwanese population.

Age-related variation in limb bone diaphyseal structure among Inuit foragers from Point Hope, northern Alaska

Age-related deterioration of limb bone diaphyseal structure is documented among precontact Inuit foragers from northern Alaska. These findings challenge the concept that bone loss and fracture susceptibility among modern Inuit stem from their transition away from a physically demanding traditional lifestyle toward a more sedentary Western lifestyle.

INTRODUCTION

Skeletal fragility is rare among foragers and other traditional-living societies, likely due to their high physical activity levels. Among modern Inuit, however, severe bone loss and fractures are apparently common. This is possibly because of recent Western influences and increasing sedentism. To determine whether compromised bone structure and strength among the Inuit are indeed aberrant for a traditional-living group, data were collected on age-related variation in limb bone diaphyseal structure from a group predating Western influences.

METHODS

Skeletons of 184 adults were analyzed from the Point Hope archaeological site. Mid-diaphyseal structure was measured in the humerus, radius, ulna, femur, and tibia using CT. Structural differences were assessed between young, middle-aged, and old individuals.

RESULTS

In all bones examined, both females and males exhibited significant age-related reductions in bone quantity. With few exceptions, total bone (periosteal) area did not significantly increase between young and old age in either sex, nor did geometric components of bending rigidity (second moments of area).

CONCLUSIONS

While the physically demanding lifestyles of certain traditional-living groups may protect against bone loss and fracture susceptibility, this is not the case among the Inuit. It remains possible, however, that Western characteristics of the modern Inuit lifestyle exacerbate age-related skeletal deterioration.

Life-course determinants of bone mass in young adults from a transitional rural community in India: the Andhra Pradesh Children and Parents Study (APCAPS)

BACKGROUND

Undernutrition and physical inactivity are both associated with lower bone mass.

OBJECTIVE

This study aimed to investigate the combined effects of early-life undernutrition and urbanized lifestyles in later life on bone mass accrual in young adults from a rural community in India that is undergoing rapid socioeconomic development.

DESIGN

This was a prospective cohort study of participants of the Hyderabad Nutrition Trial (1987-1990), which offered balanced protein-calorie supplementation to pregnant women and preschool children younger than 6 y in the intervention villages. The 2009-2010 follow-up study collected data on current anthropometric measures, bone mineral density (BMD) measured by dual-energy X-ray absorptiometry, blood samples, diet, physical activity, and living standards of the trial participants (n = 1446, aged 18-23 y).

RESULTS

Participants were generally lean and had low BMD [mean hip BMD: 0.83 (women), 0.95 (men) g/cm²; lumbar spine: 0.86 (women), 0.93 (men) g/cm²]. In models adjusted for current risk factors, no strong evidence of a positive association was found between BMD and early-life supplementation. On the other hand, current lean mass and weight-bearing physical activity were positively associated with BMD. No strong evidence of an association was found between BMD and current serum 25-hydroxyvitamin D or dietary intake of calcium, protein, or calories.

CONCLUSIONS

Current lean mass and weight-bearing physical activity were more important determinants of bone mass than was early-life undernutrition in this population. In transitional rural communities from low-income countries, promotion of physical activity may help to mitigate any potential adverse effects of early nutritional disadvantage.

Prevalence of sarcopenia and associated factors among Thai population

The purpose of this study was to determine the prevalence of sarcopenia using the skeletal muscle index (SMI) criteria in the Thai population. The secondary objective was to demonstrate factors influencing low SMI in this population. Femoral neck bone mass density (BMD) was measured by dual-energy X-ray absorptiometry (GE Lunar, Madison, WI, USA) in 435 urban and 397 rural subjects (334 men and 498 women) between 20 and 84 years of age. Body mass index (BMI) was calculated from weight and height. The respective prevalence of sarcopenia among men and women was 35.33 % (95 % CI, 29.91, 40.41) and 34.74 % (95 % CI, 30.56, 39.10). Factors associated with sarcopenia using multiple logistic regression analyses in both sexes were (a) living in the city, (b) higher BMI, and (c) older age. Living in an urban area was the strongest factor, with an odds ratio (OR) of 17.26 ± 7.12 (95 % CI, 7.68, 38.76) in men and 8.62 ± 2.74 (95 % CI, 4.62, 16.05) in women (p < 0.05). The prevalence rate ratio for persons living in urban compared to rural areas was 2.01 (95 % CI, 1.14, 3.53) in men and 1.69 (95 % CI, 1.31, 2.17) in women (p < 0.05). Sarcopenia, as based on SMI, occurs frequently in the Thai population and increases with age. The prevalence of sarcopenia is particularly high among pre-retirement women (50-59 years of age) whereas the number of men with sarcopenia gradually rises with age. An urban environment is the most predictive factor for sarcopenia, followed by high BMI and age. Given the aging population, early recognition of this condition can be beneficial for prevention of an epidemic of sarcopenia-related disability.

Forearm bone mineral density and incidence of hip fractures in Swedish urban and rural men 1987-2002

BACKGROUND

It is not known whether the recently described break in the trend in hip fracture incidence in many settings applies in both women and men, depends on changes in bone mineral density (BMD) or changes in other risk factors, or whether it is apparent in both urban and rural settings.

METHODS

We evaluated changes in annual hip fracture incidence from 1987 to 2002 in Swedish men aged ≥60 years in one urban (n = 25,491) and one rural population (n = 16,432) and also secular differences in BMD, measured by single-photon absorptiometry at the distal radius and multiple other risk factors for hip fracture in a population-based sub-sample of the urban and the rural men aged 60-80 years in 1988/89 (n = 202 vs. 121) and in 1998/99 (n = 79 vs. 69).

RESULTS

No statistically significant changes in the annual age-adjusted hip fracture incidence per 10,000 were apparent from 1987 to 2002 in urban (0.38 per year, 95% CI -0.12 to 0.88) or rural men (-0.05 per year, 95% CI -0.63 to 0.53). BMD was similar in 1988/89 and 1998/99 when examining both urban (-19.6 mg/cm(2), 95% CI -42.6 to 3.5) and rural (-23.0 mg/cm(2), 95% CI -52.1 to 6.1) men.

CONCLUSIONS

Since no secular change in age-adjusted hip fracture incidence was found during the study period, a levelling off in hip fracture incidence is present also in Swedish men. Because BMD on a group level was similar in 1988/89 and 1998/99, changes in other risk factors ought to be either of minor importance or counteracted by changes in different risk factors.

Bone mineral density and incidence of hip fracture in Swedish urban and rural women 1987-2002

BACKGROUND AND PURPOSE

Although the incidence of hip fracture during the past 50 years has increased, a break in this trend has been reported in the last decade. Whether this change is attributable to changes in bone mineral density (BMD) or whether it varies between urban and rural regions is unknown.

METHODS

We evaluated changes in annual hip fracture incidence in women aged > or = 50 years in one urban population (n = 51,757) and one rural population (n = 26,446) from 1987 to 2002. We also examined secular differences in BMD (mg/cm(2)), evaluated by single-photon absorptiometry at the distal radius, prevalence of osteoporosis, and several other risk factors for hip fracture in one population-based sample of urban women and one sample of rural women aged 50-80 years at two time points: 1988/89 (n = 257 and n = 180, respectively) and 1998/99 (n = 171 and n = 118, respectively).

RESULTS

No statistically significant changes were evident in annual age-adjusted hip fracture incidence per 10(4) when analyzing all women (-0.01 per year (95% CI: -0.37, 0.35)), rural women (-0.38 per year (-1.05, 0.28)), or urban women (0.19 per year (-0.28, 0.67)). BMD (expressed as T-score) was similar in 1988/99 and 1998/99 when analyzing all women (-0.09 (-0.26, 0.09)), urban women (-0.04 (-0.27, 0.19)), or rural women (-0.15 (-0.42, 0.13)) women.

INTERPRETATION

Since no changes in age-adjusted hip fracture incidence and no differences in BMD were found during the study period, changes evident in the other risk factors for hip fracture that we investigated (such as gait velocity and balance) are either of minor importance or are counteracted by changes in other risk factors.

Osteoporosis in developing countries

Osteoporosis poses a huge challenge in developing countries due to demographic transition and aging of the population coupled with limited availability of resources. The exact disease burden is difficult to quantify because of the paucity of data. Ethnicity affects bone density as well as fracture risk. Population-specific normative data for bone density are lacking in large parts of the world. Vitamin D deficiency is common even in sunny countries. The WHO has developed an algorithm for estimation of 10-year fracture risk which may be used even in the absence of bone mineral density.

Osteoporosis in urban post-menopausal women of the Philippines: prevalence and risk factors

Summary

The prevalence of osteoporosis was assessed among post-menopausal women dwelling in an urban community of Davao, Philippines using quantitative ultrasonic bone densitometry and its predictors were investigated. The prevalence of osteoporosis was 19.8%. Advancing age, lower body weight, and higher educational attainment were identified as the independent predictors of osteoporosis.

Introduction

This cross-sectional study assessed the prevalence of osteoporosis among post-menopausal women dwelling in an urban community of the Philippines and investigated the risk factors for osteoporosis using a quantitative ultrasonic bone densitometer.

Methods

The study site was an area with high population density in Davao, the Philippines. Data collection was based on a structured questionnaire interview, and measurements of body size and speed of sound (SOS) at the calcaneus. The SOS T-score was calculated using the young adult mean (YAM) SOS based on data from 905 women aged 20 years and over residing in the community. The data for 339 post-menopausal women were analyzed to identify the prevalence of osteoporosis and its predictors in this study. The predictors of osteoporosis were determined by logistic regression analysis.

Results

The majority of the women lived on low-incomes. The prevalence of osteoporosis was 19.8% in post-menopausal women. Age in 1 year increments (odds ratio [OR] 1.168), body weight (OR 0.954), and duration of education in years (OR 1.132) were predictors of osteoporosis.

Conclusions

This study identified body weight as a modifiable risk factor of osteoporosis for post-menopausal women. Longitudinal observation of the same participants will be necessary to confirm these findings.

Smoking status as a predictor of hip fracture risk in postmenopausal women of northwest Texas

INTRODUCTION

The purpose of this study was to determine the effect of cigarette smoking on the risk of hip fracture for postmenopausal women living in rural and urban areas of Northwest Texas.

METHODS

Using an unmatched case-control design, we compared postmenopausal women who had recently experienced osteoporotic hip fracture with women who had not. Both study groups completed a questionnaire on demographic, clinical, and behavioral risk factors for osteoporotic hip fracture. We categorized smoking status as never smoked, former smoker, and current smoker. Covariates included age, weight, age at menopause, physical activity, estrogen replacement, calcium supplementation, and rurality. We used univariate and multivariate logistic regressions to test the associations between hip fracture and the independent variables of interest.

RESULTS

We found an increased risk of hip fracture for former smokers (adjusted odds ratio [OR], 2.27; 95% confidence interval [CI], 1.22-4.21) and current smokers (adjusted OR, 3.72; 95% CI, 1.59-8.70). Residence in a rural county (population <100,000) also was associated with increased risk (adjusted OR, 2.71; 95% CI, 1.48-4.95).

CONCLUSION

Former and current smoking increased the risk of hip fracture in this population of postmenopausal women.

Urban-rural differences in distal forearm fractures: Cohort Norway

The prevalence of forearm fractures increased with increasing degree of urbanization for both genders in the population-based study "Cohort Norway" with more than 180,000 participants. The differences were not explained by available risk factors. Prospective studies with information on bone mineral density and falls are warranted.

INTRODUCTION

The purpose was to investigate urban-rural gradients in self-reported forearm fractures and assess the contribution of possible explanatory factors.

METHODS

"Cohort Norway" comprises ten population-based surveys inviting 309,742 individuals age 20 years and older. All 181,891 participants underwent a standardized examination and answered 50 common questions, including one concerning former forearm fractures. Based on the home-addresses, participants were divided into three population density groups: cities, densely populated areas and sparsely populated areas. Analyses were limited to 149,725 participants 30 years or over with valid information on exposure and outcome. Of these, 21,627 reported having suffered a forearm fracture.

RESULTS

The prevalence of forearm fractures increased with increasing degree of urbanization for both genders. After adjustment for age and explanatory factors, the odds ratio of having sustained a forearm fracture in men living in densely populated areas and in cities were 1.12 (95% CI, 1.04-1.21) and 1.38 (95% CI, 1.30-1.46), respectively, compared to rural areas. Similar odds ratios were observed among women.

CONCLUSIONS

Prospective studies are needed to verify whether lower bone mineral density, different lifestyle and/or more falls may explain the higher proportion of self-reported forearm fractures found in urban compared to rural areas.