Epidemiology of osteoporosis

A Statistical Approach Regarding the Diagnosis of Osteoporosis and Osteopenia From DXA: Are We Underdiagnosing Osteoporosis?

Osteoporosis and osteopenia are diagnosed most commonly by evaluating the lowest T‐score of BMD measurements, typically taken at three sites: the L1‐L4 lumbar spine, femoral neck, and total hip. This study aimed to evaluate the effect of using all three BMD measurements and multivariate statistical theory to evaluate how the diagnoses of osteoporosis and osteopenia change in simulation studies and in real data. First, it was found that the T‐scores from these three BMD measurements rarely give concordant diagnoses using the same World Health Organization (WHO) and International Society for Clinical Densitometry (ISCD) guidelines, so that the diagnosis strongly depends on the BMD sites measured. Next, strong correlations were found between the BMD measurements at different sites within the same person, which resulted in increased congruence/concordance between the diagnoses obtained from the BMD T‐scores. Multivariate statistical theory was used to show that the joint distribution of the BMD T‐scores at different sites follows a multivariate t distribution and found that the marginal distribution of any BMD T‐score follows a univariate t distribution. Confidence ellipsoids were derived that are equivalent to the univariate WHO/ISCD thresholds for osteoporosis (T‐score ≤−2.5) and osteopenia (−2.5 < T‐score <−1). The study found that more patients are diagnosed with osteoporosis using the multivariate version of the WHO/ISCD guidelines rather than the current WHO/ISCD guidelines in both real data and simulation studies. Diagnoses of osteoporosis using the statistics derived method were also associated with higher FRAX (fracture risk assessment tool) probabilities of major osteoporotic (p = 0.001) and hip fractures (p = 2.2 × 10⁻⁶). In conclusion, this study shows that considering all three BMD T‐scores is potentially more informative than using the single lowest BMD T‐score. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Factors Impacting Mortality in Geriatric Patients with Acute Spine Fractures: A 12-Year Study of 613 Patients in Singapore

Study Design

Retrospective database analysis.

Purpose

To identify risk factors that predict mortality following acute spine fractures in geriatric patients of Singapore.

Overview of Literature

Acute geriatric spinal fractures contribute significantly to local healthcare costs and hospital admissions. However, geriatric mortality following acute spine fractures is scarcely assessed in the Asian population.

Methods

Electronic records of 3,010 patients who presented to our hospital’s emergency department and who were subsequently admitted during 2004–2015 with alleged history of traumatic spine fractures were retrospectively reviewed, and 613 patients (mean age, 85.7±4.5 years; range, 80–101 years; men, 108; women, 505) were shortlisted. Mortality rates were reviewed up to 1 year after admission and multivariate analyses were performed to identify independent risk factors correlating with mortality.

Results

Women were more susceptible to spine fractures (82.4%), with falls (77.8%) being the most common mechanism of injury. Mortality rates were 6.0%, 8.2%, and 10.4% at 3, 6, and 12 months, respectively. The most common causes of death at all 3 time points were pneumonia and ischemic heart disease. Based on the multivariate analysis at 1-year follow-up, elderly women had a lower mortality rate compared to men (p<0.001); mortality rates increased by 6.3% (p=0.024) for every 1-year increase in the patient’s age; and patients with an American Spinal Injury Association (ASIA) score of A–C had a much higher mortality rate compared to those with an ASIA score of D–E (p<0.001).

Conclusions

An older age at presentation, male sex, and an ASIA score of A–C were identified as independent factors predicting increased mortality among geriatric patients who sustained acute spine fractures. The study findings highlight at-risk groups for acute spine fractures, thereby providing an opportunity to develop strategies to increase the life expectancy of these patients.

Bone Mineral Density, Anthropometric Indices, and the Prevalence of Osteoporosis in Northern (Beijing) Chinese and Southern (Hong Kong) Chinese Women--The Largest Comparative Study to Date

This study was designed to compare the bone mineral density (BMD) and the prevalence of osteoporosis in community-dwelling women (aged 50-89) living in Northern (Beijing) and Southern (Hong Kong) China. Six thousand ninety-nine ambulatory Chinese women living in Hong Kong and 6302 mainland Chinese women living in Beijing were recruited for the study. The BMD was found to be 2.2% higher at the lumbar spine, 8.4% higher at the total hip, and 7.2% higher at the femoral neck in Beijing women than those in Hong Kong women. However, after adjustment for age, weight, and height, this trend was reversed so that the adjusted BMD at the lumbar spine, total hip, and femoral neck was 4.8%, 2.7%, and 1.4% higher in Hong Kong Chinese women than Beijing Chinese women, respectively. Body weight accounted for 13.3%, 14.6%, and 10.6% of the difference in BMD of lumbar spine, total hip, and femoral neck between the 2 populations. The prevalence of osteoporosis in Hong Kong women (24.9%) was found to be higher than that in Beijing women (20.3%). We conclude that osteoporosis is a major health problem in Chinese women, and in comparing BMD between subjects of the same ethnicity, body weight must be taken into account.

Prevalence of osteoporosis according to nutrient and food group intake levels in Korean postmenopausal women: using the 2010 Korea National Health and Nutrition Examination Survey Data

BACKGROUND/OBJECTIVES

Women's bone health status is closely related with environmental factors and lifestyle factors. The purpose of this study is to evaluate the dietary risks of osteoporosis and osteopenia for Korean postmenopausal women.

SUBJECTS/METHODS

The data from 1,433 subjects from the 2010 KNHANES were used and divided into three groups: normal, osteopenia, and osteoporosis group using bone mineral density (BMD). Nutrient intakes and food intake frequency were evaluated. Logistic regression analysis was applied to determine the odds ratios for osteoporosis and osteopenia.

RESULTS

The RNI percentage of each nutrient and food intake frequency from 12 food groups decreased as bone mineral density status deteriorated. Risk for osteoporosis of low calcium (Ca) intake, under the EAR, showed an odds ratio of 2.13(95% CI; 1.26-3.61, P < 0.05). Higher intake frequency showed preventive effect from osteoporosis compared to lower intake frequency in such food group as dairy products (ORs 0.40, CI 0.21-0.75), beans (ORs 0.49, CI 0.29-0.83), seaweeds (ORs 0.55, CI 0.32-0.94), fish (ORs 0.56, CI 0.32-0.98), and fruits (ORs 0.42, CI 0.23-0.79) after adjusting for age.

CONCLUSION

To prevent osteoporosis in later life, sufficient Ca intake and more frequent intakes of foods containing Ca such as dairy products, beans, fish, seaweeds, and fruits, which help in Ca absorption, should be stressed for Korean postmenopausal women.

Calcium polyphosphate as an additive to zinc-silicate glass ionomer cements

Aluminum-free glass ionomer cements (GICs) are under development for orthopedic applications, but are limited by their insufficient handling properties. Here, the addition of calcium polyphosphate (CPP) was investigated as an additive to an experimental zinc-silicate glass ionomer cement. A 50% maximum increase in working time was observed with CPP addition, though this was not clinically significant due to the short working times of the starting zinc-silicate GIC. Surprisingly, CPP also improved the mechanical properties, especially the tensile strength which increased by ∼33% after 30 days in TRIS buffer solution upon CPP addition up to 37.5 wt%. This strengthening may have been due to the formation of ionic crosslinks between the polyphosphate chains and polyacrylic acid. Thus, CPP is a potential additive to future GIC compositions as it has been shown to improve handling and mechanical properties. In addition, CPP may stimulate new bone growth and provide the ability for drug delivery, which are desirable modifications for an orthopedic cement.

Assessment of calcium intake by adolescents

OBJECTIVE:

To evaluate the daily calcium intake of adolescents in schools from Chapecó, Santa Catarina, Southern Brazil, to check if calcium intake is in accordance with the Dietary Reference Intakes (DRI), and to investigate variables associated with daily calcium intake.

METHODS:

Cross-sectional study approved by the Institutional Review Board and developed in 2010. Students of the 8^th grade completed questionnaires with personal data and questions about the calcium-rich foods intake frequency. In order to compare students with adequate (1300mg) or inadequate intake of calcium/day (<1300mg), parametric and nonparametric tests were used.

RESULTS:

A total of 214 students with a mean age of 14.3±1.0 years were enrolled. The median daily calcium intake was 540mg (interquartile range - IQ: 312-829mg) and only 25 students (11.7%) had calcium intake within the recommendations of the DRI for age. Soft drink consumption ≥3 times/week was associated with a lower intake of calcium.

CONCLUSIONS:

Few students ingested adequate levels of calcium for the age group. It is necessary to develop a program to encourage a greater intake of calcium-rich foods in adolescence.

Sex steroids and bone health in older Chinese men

This study examines the association between sex steroids, bone mineral density (BMD), and incident fractures in 1,489 community-living Chinese men aged 65 and over. Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

INTRODUCTION

This study examines the association between serum total testosterone (TT), free testosterone (free T), estradiol (E(2)), bioavailable estradiol (bioE(2)), sex hormone binding globulin (SHBG), BMD, and incident fractures.

METHODS

This is a cohort study with 4-year follow-up in the community in Hong Kong SAR, China. One thousand four hundred eighty-nine community-living Chinese men aged 65 and over participated. Sex steroid levels and BMD were measured at baseline; BMD was repeated after 4 years of follow-up, and fracture incidence from ascertainment from hospital databases was determined over 4 years of follow-up.

RESULTS

The strongest age-adjusted positive association with total hip and femoral neck BMD was with bioE(2), followed by E(2). Greater bone loss occurred in the lowest quartile of E(2) and bioE(2). The lowest quartile of free T and bioE(2) and the two highest quartile of SHBG were associated with the highest percentage of participants with incident fractures. Those in the lowest quartile of E(2) and bioE(2) had approximately a 50% increased risk of incident fractures compared with the other three quartiles. This relationship remains significant for nonvertebral incident fractures (hip, radius, pelvis, and humerus) for E(2) only, but not bioE(2). Compared with the group with the three highest quartiles of TT and E(2), the group with the lowest quartile of both had approximately twice the risk of nonvertebral osteoporosis-related incident fractures.

CONCLUSION

Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

Adherence to osteoporosis medications amongst Singaporean patients

Compliance and persistence to bisphosphonates amongst Singaporean patients with osteoporosis were estimated. Mean medication possession ratio (MPR) ± standard deviation (SD) was 78.9 ± 27.5%, and 69.0% was persistent at 1 year. In contrast to US and Europe where poor adherence is noted, our study suggests higher adherence rates to bisphosphonate therapy amongst patients.

INTRODUCTION

Adherence to bisphosphonate therapy during treatment of osteoporosis has been reported to be poor. We aimed to estimate the compliance and persistence to prescribed bisphosphonate therapy amongst patients at the largest public restructured hospital in Singapore.

METHODS

This is a retrospective analysis of records of patients who were prescribed the two most commonly used oral bisphosphonates-alendronate and risedronate. The study was conducted between January 2007 and December 2008. Prescription and pharmacy refill records of all patients were extracted and matched. Compliance was calculated using the MPR, while persistence, a dichotomous variable, was defined as continuous refill of bisphosphonates for at least 12 months with a permissible gap of 30 days.

RESULTS

Seven hundred ninety-eight patients were included in the study. Mean MPR ± SD was 78.9 ± 27.5%, and 69.0% of the patients were persistent with bisphosphonate therapy at 1 year. The proportion of patients with MPR ≥ 80% at 6, 12 and 18 months was 90%, 72% and 62%, respectively. Age <69 years was associated with better compliance (OR, 1.34; 95% CI, 0.99-1.82; P = 0.043), and history of fractures was associated with better compliance (OR, 1.38; 95% CI, 1.02-1.87; P = 0.038) and persistence (OR, 1.33; 95% CI, 0.97-1.82; P = 0.046).

CONCLUSION

In contrast to studies conducted in the US and Europe that show poor adherence, our study suggests higher adherence rates to bisphosphonate therapy amongst Singaporean patients.

Bone mineral density enhances use of clinical risk factors in predicting ten-year risk of osteoporotic fractures in Chinese men: the Hong Kong Osteoporosis Study

This prospective study aimed to determine the risk factors and the 10-year probability of osteoporotic fracture in Southern Chinese men. The findings show substantial population differences in fracture incidence and risk prediction compared to the FRAX(TM) model, and the addition of BMD information to clinical risk factor assessment improved fracture risk prediction in Chinese men.

INTRODUCTION

Clinical risk factors with or without bone mineral density (BMD) measurements are increasingly recognized as reliable predictors of fracture risk. Prospective data on fracture incidence in Asian men remain sparse. This prospective study aimed to determine the risk factors and the 10-year absolute fracture risk in Southern Chinese men.

METHODS

This is a part of the Hong Kong Osteoporosis Study. One thousand eight hundred ten (1,810) community-dwelling, treatment-naive men aged 50 years or above were evaluated. Baseline demographic characteristics, clinical risk factors and BMD were recorded. Ten-year risk of osteoporotic fracture was calculated using Cox proportional hazards models.

RESULTS

The mean age of subjects was 68.0 ± 10.3 years. After a mean follow-up period of 3.5±2.9 years (range 1 to 14 years), 37 incident low-trauma fractures were recorded. The incidence for all osteoporotic fractures and hip fractures was 635/100,000 and 123/100,000 person-years, respectively. The most significant predictors of osteoporotic fracture were history of fall (RR 14.5), femoral neck BMD T-score < -2.5 (RR 13.8) and history of fracture (RR 4.4). Each SD reduction in BMD was associated with a 1.8 to 2.6-fold increase in fracture risk. Subjects with seven clinical risk factors and BMD T-score of -1 had an absolute 10-year risk of osteoporotic fracture of 8.9%, but this increased to 22.7% if they also had a femoral neck BMD T-score of -2.5.

CONCLUSIONS

These findings show substantial population differences in fracture incidence and risk prediction. The addition of BMD information to clinical risk factor assessment improved fracture risk prediction in Chinese men.

Mortality and cancer in patients with new musculoskeletal episodes: a cohort study

BACKGROUND

The risk of serious outcome in persons presenting to primary care with common regional musculoskeletal problems is unknown.

AIM

To determine the risk of mortality and cancer in older patients presenting with new musculoskeletal problems.

DESIGN OF STUDY

Cohort study.

SETTING

One hundred and seventy-nine general practices contributing to the General Practice Research Database.

METHOD

Cases were 48,206 people aged > or =50 years, with a recorded musculoskeletal problem in 1996 but none during the previous 2 years. Cases were allocated to groups based on problem location (for example, the back). A total of 40,254 controls had no musculoskeletal consultation during 1996 or during the previous 2 years. Outcome measures were mortality and recorded malignant and pre-malignant neoplasms 1 and 10 years after baseline consultation.

RESULTS

Mortality rates in the first year of follow-up were higher for cases (373 per 10,000 person-years) than controls (244). The hip (standardised mortality ratio 2.36; 95% confidence interval [CI] = 1.99 to 2.77 compared to controls) and back (2.07; 95% CI = 1.87 to 2.28) groups had the highest 1-year rates. Ten-year mortality rates were closer between groups. Higher cancer rates were found for the back, hip, and neck groups. The first-year excess mortality in cases was only partly explained by cancer and other comorbidity (hip hazard ratio 1.72; 95% CI = 1.43 to 2.07; back 1.68; 95% CI = 1.49 to 1.90).

CONCLUSION

New consulting episodes of musculoskeletal problems in the back or hip are associated with higher subsequent cancer rates and increased mortality risk in older people. Unexpected cancer and death in these patients remains rare but the ability of clinical signs and symptoms to identify persons at risk needs to be confirmed.

Association analyses of vitamin D-binding protein gene with compression strength index variation in Caucasian nuclear families

This study was conducted to test whether there exists an association between vitamin D-binding protein (DBP) gene and compression strength index (CSI) phenotype. Candidate gene association analyses were conducted in total sample, male subgroup, and female subgroup, respectively. Two single-nucleotide polymorphisms (SNPs) with significant association results were found in males, suggesting the importance of DBP gene polymorphisms on the variation in CSI especially in Caucasian males.

INTRODUCTION

CSI of the femoral neck (FN) is a newly developed phenotype integrating information about bone size, body size, and bone mineral density. It is considered to have the potential to improve the performance of risk assessment for hip fractures because it is based on a combination of phenotypic traits influencing hip fractures rather than a single trait. CSI is under moderate genetic determination (with a heritability of approximately 44% found in this study), but the relevant genetic study is still rather scarce.

METHODS

Based on the known physiological role of DBP in bone biology and the relatively high heritability of CSI, we tested 12 SNPs of the DBP gene for association with CSI variation in 405 Caucasian nuclear families comprising 1,873 subjects from the Midwestern US. Association analyses were performed in the total sample, male and female subgroups, respectively.

RESULTS

Significant associations with CSI were found with two SNPs (rs222029, P = 0.0019; rs222020, P = 0.0042) for the male subgroup. Haplotype-based association tests corroborated the single-SNP results.

CONCLUSIONS

Our findings suggest that the DBP gene might be one of the genetic factors influencing CSI phenotype in Caucasians, especially in males.

Can abdominal multi-detector CT diagnose spinal osteoporosis?

The aim of this study was to (1) generate quantitative CT (QCT) densitometric data based on routine abdominal multi-detector (MDCT) examinations and (2) investigate whether these data can be used to differentiate osteoporotic from healthy females. Twenty-five female patients (group A) with a history of radiotherapy were examined both with routine abdominal MDCT and standard QCT to generate a MDCT-to-QCT conversion equation. Twenty-one osteoporotic (group B) and 23 healthy female patients (group C) were also recruited in the study. Patients of groups B and C underwent routine abdominal MDCT examination for various clinical indications. Mean bone mineral density (BMD) in patients of group A was 103.4 mg/ml +/- 32.8 with routine abdominal MDCT and 91.0 mg/ml +/- 28.5 with QCT. Quantitative CT BMD(QCT) values for patients in groups B and C were calculated utilizing the BMD(MDCT) values derived from routine abdominal MDCT data sets and the MDCT to QCT conversion equation: BMD(QCT)=0:78 x BMD(MDCT) + 10:13. The calculated QCT densitometric data adequately differentiated osteoporotic from healthy females (area under ROC curve 0.828, p = 0.05). In conclusion, this study showed that in a group of female patients, QCT data derived from routine abdominal MDCT examinations discriminated osteoporotic from healthy subjects.

Genome-wide scan identified QTLs underlying femoral neck cross-sectional geometry that are novel studied risk factors of osteoporosis

A genome-wide screen was conducted using a large white sample to identify QTLs for FNCS geometry. We found significant linkage of FNCS parameters to 20q12 and Xq25, plus significant epistatic interactions and sex-specific QTLs influencing FNCS geometry variation.

INTRODUCTION

Bone geometry, a highly heritable trait, is a critical component of bone strength that significantly determines osteoporotic fracture risk. Specifically, femoral neck cross-sectional (FNCS) geometry is significantly associated with hip fracture risk as well as genetic factors. However, genetic research in this respect is still in its infancy.

MATERIALS AND METHODS

To identify the underlying genomic regions influencing FNCS variables, we performed a remarkably large-scale whole genome linkage scan involving 3998 individuals from 434 pedigrees for four FNCS geometry parameters, namely buckling ratio (BR), cross-sectional area (CSA), cortical thickness (CT), and section modulus (Z). The major statistical approach adopted is the variance component method implemented in SOLAR.

RESULTS

Significant linkage evidence (threshold LOD = 3.72 after correction for tests of multiple phenotypes) was found in the regions of 20q12 and Xq25 for CT (LOD = 4.28 and 3.90, respectively). We also identified eight suggestive linkage signals (threshold LOD = 2.31 after correction for multiple tests) for the respective geometry traits. The above findings were supported by principal component linkage analysis. Of them, 20q12 was of particular interest because it was linked to multiple FNCS geometry traits and significantly interacted with five other genomic loci to influence CSA variation. The effects of 20q12 on FNCS geometry were present in both male and female subgroups. Subgroup analysis also revealed the presence of sex-specific quantitative trait loci (QTLs) for FNCS traits in the regions such as 2p14, 3q26, 7q21 and 15q21.

CONCLUSIONS

Our findings laid a foundation for further replication and fine-mapping studies as well as for positional and functional candidate gene studies, aiming at eventually finding the causal genetic variants and hidden mechanisms concerning FNCS geometry variation and the associated hip fractures.

Mapping quantitative trait loci for cross-sectional geometry at the femoral neck

A genome-wide linkage scan was performed in a sample of 79 multiplex pedigrees to identify genomic regions linked to femoral neck cross-sectional geometry. Potential quantitative trait loci were detected at several genomic regions, such as 10q26, 20p12-q12, and chromosome X.

INTRODUCTION

Bone geometry is an important determinant of bone strength and osteoporotic fractures. Previous studies have shown that femoral neck cross-sectional geometric variables are under genetic controls. To identify genetic loci underlying variation in femoral neck cross-sectional geometry, we conducted a whole genome linkage scan for four femoral neck cross-sectional geometric variables in 79 multiplex white pedigrees.

MATERIALS AND METHODS

A total of 1816 subjects from 79 pedigrees were genotyped with 451 microsatellite markers across the human genome. We performed linkage analyses on the entire data, as well as on men and women separately.

RESULTS

Significant linkage evidence was identified at 10q26 for buckling ratio (LOD = 3.27) and Xp11 (LOD = 3.45) for cortical thickness. Chromosome region 20p12-q12 showed suggestive linkage with cross-sectional area (LOD = 2.33), cortical thickness (LOD = 2.09), and buckling ratio (LOD = 1.94). Sex-specific linkage analyses further supported the importance of 20p12-q12 for cortical thickness (LOD = 2.74 in females and LOD = 1.88 in males) and buckling ratio (LOD = 5.00 in females and LOD = 3.18 in males).

CONCLUSIONS

This study is the first genome-wide linkage scan searching for quantitative trait loci underlying femoral neck cross-sectional geometry in humans. The identification of the genes responsible for bone geometric variation will improve our knowledge of bone strength and aid in development of diagnostic approaches and interventions for osteoporotic fractures.

Epidemiology of hip fractures in 2002 in Rabat, Morocco

Hip fracture has never been studied before, either in Morocco or in the adjacent countries of the south bank of the Mediterranean Sea. The aim of this study was to investigate the incidence rate of hip fracture in 2002 in Rabat Province, a large area in the northwest of The Kingdom of Morocco, by the use of register information and medical records collected from the five public hospitals of the region. The hip fracture data were restricted to cervical or trochanteric types. There was a total of 150 hip fractures (83 in women and 67 in men) in the over-50-year-old population in the Province of Rabat during 2002. The age-adjusted 1-year cumulative incidence of hip fracture was 52.1/100,000 [95% confidence interval (CI) 40.9-63.3/100,000] in women and 43.7/100,000 (95% CI 33.3-52.2/100,000) in men. The standardized incidence rate against the 1985 US population was 80.7/100,000 (95% CI 78.5-93.0/100,000) for women and 58.5/100,000 (95% CI 47.9-68.1/100,000) for men. The mean (standard deviation) age of patients with a hip fracture was 70.7 (9.4) years for women and 70.4 (10.0) years for men. The overall female-to-male ratio of hip fracture was 1.19 for age-adjusted hip fracture incidence and 1.30 for standardized incidence. A marked increase in incidence rate was found for both men and women with increasing age, becoming exponential after the age of 50 years. The mean age for hip fracture was 70.7 (9.4) years in women and 70.4 (10.0) years in men (P > 0.05). Women had a cervical-to-trochanteric ratio of 0.97 compared to men, at 1.03. The characteristics of hip fractures described in this study suggest that fragility fractures occur in North Africa, although substantially less frequently than in most European, North American and Asian countries but more frequently than sub-Saharan African countries, in agreement with the north-south gradient observed in the epidemiology of osteoporosis. The low incidence of hip fragility fracture rate is most likely the result of reduced longevity in Morocco.

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/m².

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.

The effect of low-dose prednisone on bone mineral density in Peruvian rheumatoid arthritis patients

OBJECTIVE

The aim of this study was to determine the difference between bone mineral density (BMD) of rheumatoid arthritis (RA) patients on low-dose prednisone and matched RA patients without prior systemic corticosteroid therapy.

METHODS

Ninety patients attending our clinics and receiving 10 mg/day of prednisone or less for at least the previous 3 consecutive months were studied. The control group comprised 90 selected RA patients without corticosteroid therapy matched for age, race, gender, disease duration, use of methotrexate, postmenopause, and Health Assessment Questionnaire score. The BMD was measured using dual X-ray absorptiometry.

RESULTS

Patients on prednisone had lower BMD than controls (0.94 +/- 0.17 vs 0.96 +/- 0.17 for L2-4 and 0.73 +/- 0.14 vs 0.76 +/- 0.16 for femoral neck), but these differences were not statistically significant (P > 0.05). In post hoc analysis, postmenopausal women on prednisone had more bone loss in femoral neck than controls (0.68 +/- 0.13 vs 0.74 +/- 0.15).

CONCLUSION

Bone mineral density was not significantly reduced by low-dose prednisone in this diverse group of RA patients. A reduction in hip BMD was seen in postmenopausal women on prednisone.

Osteoporosis: a rapid review of risk factors and screening methods

Osteoporosis is a significant problem in women and it is beginning to become a recognized etiology of morbidity and mortality in men. However, before reviewing any potential therapies, it is imperative that clinicians first gain adequate knowledge on the risk factors for osteoporosis and fractures, and the various screening methods that are utilized in clinical practice. For example, advancing age, hormonal status, lifestyle, and overall diet are just a few of the potential risk factors. The majority of the risk factors in men seem to parallel those that have already been well known in women. Heel ultrasound (HUS), dual-energy X-ray absorptiometry (DEXA), and quantitative computerized tomography (QCT) are the most popular and effective methods utilized for osteoporosis screening. All of these imaging tests contain an inherent number of advantages and limitations. This brief review serves as a simplistic but important primer to a condition that is increasing in prevalence in a diverse area of medical fields.