Differential influence of physical activity on lumbar spine and femoral neck bone mineral density in the elderly population

Dynamic Foot Pressure During Walking: A Potential Indicator of Bone Mineral Density

BACKGROUND

Physical skeletal loading can affect the bone mineral density (BMD). This study investigated the association between BMD and dynamic foot pressure during gait.

METHODS

A total of 104 patients (mean age, 62.6 ± 12.4 years; 23 male and 81 female) who underwent dual x-ray absorptiometry and pedobarography were included. BMD values of the lumbar spine, femoral neck, and total femur were assessed. The mean and maximum pressures were measured at the hallux, lesser toes, 1st metatarsal head, 2nd and 3rd metatarsal heads, 4th and 5th metatarsal heads, midfoot, medial heel, and lateral heel. Multivariable regression analysis was performed to identify factors significantly associated with BMD.

RESULTS

The lumbar spine BMD was significantly associated with the mean pressure at the 4th and 5th metatarsal heads (p = 0.041, adjusted R 2 of model = 0.081). The femoral neck BMD was significantly associated with the maximum pressure at the 2nd and 3rd metatarsal heads (p = 0.002, adjusted R 2 = 0.213). The total femoral BMD also showed a significant association with the maximum pressure at the 2nd and 3rd metatarsal heads (p = 0.003, adjusted R 2 = 0.360).

CONCLUSIONS

Foot plantar pressure during gait was significantly associated with BMD, and could potentially be used to predict the presence of osteoporosis.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Is Regular Weight-Bearing Physical Activity Throughout the Lifecourse Associated with Better Bone Health in Late Adulthood?

We considered how weight-bearing physical activity (WBPA) through the lifecourse related to bone health in late adulthood in the Hertfordshire Cohort Study (HCS), a cohort of community dwelling adults born 1931-9, to identify sex-specific differences and periods critical for optimal bone health. Available questionnaire data from 258 participants (128 men and 130 women) included current reported lifestyle factors (including physical activity) and WBPA, coded as participation in WBPA aged < 18 years; aged 18-29 years; aged 30-49 years and aged ≥ 50 years. Responses were recorded as none/once a month/once a week/> once a week. Hip bone mineral density (BMD) was measured using a Lunar Prodigy DXA scanner. The mean age was 75.4 (SD 2.5) years in men and 75.7 (SD 2.6) years in women. Men reported significantly higher levels of past WBPA aged < 18 years (p = 0.006) and aged 18-29 years than women (p < 0.001). We observed greater BMD at total hip in women who reported regular WBPA at ages 18-29 years (p = 0.02) and 30-49 years (p = 0.02) compared with those who reported no WBPA (p = 0.019), after adjustment for confounders including current activity levels. In this cohort of older adults, recalled regular WBPA around the time of peak bone mass acquisition was less common in women than men, but associated with higher hip BMD in women in late adulthood.

Correlational analysis of bone health status and vitamin D-related biomarkers in women working in agriculture

The purpose of this study was to investigate the status of bone health in women working in agriculture and analyze the associations between bone health and various vitamin D-related biomarkers.This observational study enrolled women working in agriculture (n = 210) and control occupations (n = 180). The concentration of serum total 25-hydroxy vitamin D [25(OH)D] was measured using the Elecsys Vitamin D Total Kit, and serum vitamin D-binding protein (VDBP) was measured by enzyme-linked immunosorbent assay. Along with albumin, 25(OH)D and VDBP were used to calculate the concentrations of bioavailable and free 25(OH)D. Bone mineral density (BMD) and T-score were measured at lumbar 1 to 4 and the femur neck using dual-energy X-ray absorptiometry. To identify factors affecting BMD, log-linear model and linear regression analysis were performed for statistical analysis.Agricultural women workers showed higher serum concentrations of bioavailable 25(OH)D (12.8 ± 3.7 vs 8.7 ± 5.1 ng/mL) and lower VDBP concentrations (201.8 ± 45.0 vs 216.0 ± 68.2 μg/mL) than control women. The association between these 2 vitamin D related-biomarkers and femur neck BMD were confirmed through univariable and multivariable linear model analysis. Although lumbar BMD did not differ between groups, the agricultural group displayed a lower femur BMD and a 4.3-fold increase in the risk of osteoporosis compared with the control group.Women working in agriculture showed lower femur BMD than the control group. Of the vitamin D-related biomarkers tested, bioavailable 25(OH)D and VDBP were associated with BMD. As bioavailable 25(OH)D levels are affected mainly by VDBP levels, VDBP may play a role in the lower femur neck BMD values observed in the agricultural group. Thus, the measurement of VDBP concentration might be considered a simple and non-invasive method for measuring bone health status.

Higher-Impact Physical Activity Is Associated With Maintenance of Bone Mineral Density But Not Reduced Incident Falls or Fractures in Older Men: The Concord Health and Aging in Men Project

High-impact physical activities with bone strains of high magnitude and frequency may benefit bone health. This study aimed to investigate the longitudinal associations between changes in loading intensities and application rates, estimated from self-reported physical activity, with bone mineral density (BMD) changes over 5 years and also with incident falls over 2 years and long-term incident fractures in community-dwelling older men. A total of 1599 men (mean age 76.8 ± 5.4 years) from the Concord Health and Aging in Men Project (CHAMP) were assessed at baseline (2005-2007) and at 2- and 5-year follow-up. At each time point, hip and lumbar spine BMD were measured by dual-energy X-ray absorptiometry, and physical activity energy expenditure over the past week was self-reported via the Physical Activity Scale for the Elderly (PASE) questionnaire. Sum effective load ratings (ELRs) and peak force were estimated from the PASE questionnaire, reflecting the total and highest loading intensity and application rate of physical activities, respectively. Participants were contacted every 4 months over 2 years to self-report falls and over 6.0 ± 2.2 years for fractures. Hip fractures were ascertained by data linkage for 8.9 ± 3.6 years. Compared with sum ELR and PASE scores, peak force demonstrated the greatest standardized effect size for BMD maintenance at the spine (β = 9.77 mg/cm² ), total hip (β = 14.14 mg/cm² ), and femoral neck (β = 13.72 mg/cm² ) after adjustment for covariates, including PASE components (all p < .01). Only PASE scores were significantly associated with reduced falls risk (standardized incident rate ratio = 0.90, 95% confidence interval 0.81-1.00, p = .04). All physical activity measures were significantly associated with reduced incident fractures in univariate analyses, but none remained significant after multivariable adjustments. Older men who engaged in physical activity of high and rapid impact maintained higher BMD, while higher energy expenditure was associated with reduced falls risk. Coupling traditional physical activity data with bone loading estimates may improve understanding of the relationships between physical activity and bone health. © 2020 American Society for Bone and Mineral Research (ASBMR).

Determinants of Bone Health in Older Adults

Objective:

The objective of this study was to determine the predictors of bone health in older adults.

Methods:

A total of 313 subjects older than 65 years (mean age 74.2±6.4 years, 70.6% female) were included in the study. Demographic characteristics of participants such as gait speed, handgrip strength, level of physical activity (using Rapid Assessment of Physical Activity-RAPA scale), vitamin D levels, T scores of femur neck (FN) and lumbar spine (LS) were recorded.

Results:

Based on FN, 40.7% of participants had normal T scores whereas 46.2% and 13.1% of them were osteopenic and osteoporotic, respectively. FN was correlated with age (r:-0.184, p<0.001), BMI (r:0.269, p<0.001), and handgrip strength (r:0.149, p:0.009) in addition to the aerobic subscale of RAPA (RAPA-aerobic) (r:-0.133, p:0.02). Similarly, the LS was correlated with female gender (r:-0.207, p<0.001), age (r:0.136, p:0.016), body mass index (BMI) (r:0.246, p<0.001) and handgrip strength (r:0.217, p<0.001). The predictors of bone health were decided upon using multiple logistic regression analysis. The deterministic model consisted of age, gender, BMI, height, weight, handgrip strength, gait speed, RAPA-aerobic and vitamin D. For LS dependent variable, the overall model was significant (F:10.149, p<0.001). However, only two variables were significant predictors in the model ie. weight (β:0.389, p<0.001) and handgrip strength (β=0.186, p<0.001). Similarly for independent variable of FN, the overall model was significant (F:6.525, p<0.001) and only two variables were significant predictors: weight (β:0.371, p<0.001) and RAPA-Aerobic (β:0.148, p:0.009).

Conclusion:

Lower levels of body weight, participation in aerobic activity and handgrip strength might be risk factors for deterioration of bone health in older adults.

The relationship between BPAQ-derived physical activity and bone density of middle-aged and older men

The bone-specific physical activity questionnaire (BPAQ) accounts for activities that affect bone but has not been used in studies with older adults. Relationships exist between the BPAQ-derived physical activity and bone density in healthy middle-aged and older men but not men with prostate cancer. Disease-related treatments detrimental to bone should be considered when administering the BPAQ.

INTRODUCTION

The bone-specific physical activity questionnaire (BPAQ) was developed to account for bone-specific loading. In this retrospective study, we examined the relationship between BPAQ-derived physical activity and bone mineral density (BMD) in middle-aged and older men with and without prostate cancer.

METHODS

Two groups, 36 healthy men and 69 men with prostate cancer receiving androgen suppression therapy (AST), completed the BPAQ and had whole body, total hip, femoral (FN) and lumbar spine BMD assessed by dual-energy X-ray absorptiometry.

RESULTS

Past (pBPAQ), current (cBPAQ) and total BPAQ (tBPAQ) scores for the healthy men were related to FN BMD (pBPAQ r = 0.36, p = 0.030; cBPAQ r s = 0.35, p = 0.034; tBPAQ r = 0.41, p = 0.014), and pBPAQ and tBPAQ were related to total hip (r s = 0.35, p = 0.035 and r s = 0.36, p = 0.029, respectively) and whole body BMD (r s = 0.44, p = 0.007 and r s = 0.45, p = 0.006, respectively). In men with prostate cancer, the BPAQ was not significantly associated with BMD. In stepwise regression analyses, body mass and tBPAQ predicted 30 % of the variance in total hip BMD (p = 0.003), cBPAQ predicted 14 % of the variance in FN BMD (p = 0.002), and body mass, age and tBPAQ predicted 47% of the variance in whole body BMD (p < 0.001) in healthy men. In men with prostate cancer, the BPAQ was not an independent predictor of BMD.

CONCLUSIONS

Although BPAQ-derived estimates of physical activity are related to bone status in healthy middle-aged and older men, the adverse effect of AST on bone appears to obscure this relationship in men with prostate cancer.

Multivariate analysis of lifestyle, constitutive and body composition factors influencing bone health in community-dwelling older adults from Madeira, Portugal

This study describes the association between habitual physical activity (PA), other lifestyle/constitutive factors, body composition, and bone health/strength in a large sample of older adults from Madeira, Portugal. This cross-sectional study included 401 males and 401 females aged 60-79 years old. Femoral strength index (FSI) and bone mineral density (BMD) of the whole body, lumbar spine (LS), femoral neck (FN), and total lean tissue mass (TLTM) and total fat mass (TFM) were determined by dual-energy X-ray absorptiometry-DXA. PA was assessed during face-to-face interviews using the Baecke questionnaire and for a sub-sample by Tritrac accelerometer. Demographic and health history information were obtained by telephone interview through questionnaire. The relationship between habitual PA variables and bone health/strength indicators (whole body BMD, FNBMD, LSBMD, and FSI) investigated using Pearson product-moment correlation coefficient was similar for females (0.098≤r≤0.189) and males (0.104≤r≤0.105). Results from standard multiple regression analysis indicated that the primary and most significant predictors for FNBMD in both sexes were age, TLTM, and TFM. For LSBMD, the most significant predictor was TFM in men and TFM, age, and TLTM in females. Our regression model explained 8.3-14.2% and 14.8-29.6% of the total variance in LSBMD and FNBMD for males and females, respectively. This study suggests that habitual PA is minimally but positively associated with BMD and FSI among older adult males and females and that body composition factors like TLTM and TFM are the strongest determinants of BMD and FSI in this population.

Lumbar trabecular bone mineral density distribution in patients with and without vertebral fractures: a case-control study

PURPOSE

The proportion of load transmitted through the lumbar neural arch increases with aging, spinal degeneration, and lordosis, effectively shielding the lumbar vertebral bodies from load. This stress shielding may contribute to bone loss in the vertebral body, leading to increased fracture risk. To test his hypothesis, we performed a study to determine if vertebral body fractures were associated with a higher neural arch/vertebral body volumetric bone mineral density (vBMD) ratio.

METHODS

Trabecular vBMD was calculated by quantitative CT in the L3 vertebral body and neural arch (pars interarticularis) of 36 women with vertebral compression fractures and 39 controls. Neural arch/vertebral body vBMD ratio was calculated, and its relationship to fracture status was determined using linear regression models adjusted for age and body mass index.

RESULTS

Vertebral body trabecular vBMD was lower in fracture cases as compared to controls (mean ± SD, 49.0 ± 36.0 vs. 87.5 ± 36.8 mg/cm(3), respectively; P < 0.001), whereas trabecular vBMD of the neural arch was similar (96.1 ± 57.6 in cases vs. 118.2 ± 57.4 mg/cm(3) in controls; P = 0.182). The neural arch/vertebral body vBMD ratio was significantly greater in the fracture group than in controls (2.31 ± 1.07 vs. 1.44 ± 0.57, respectively; P < 0.001).

CONCLUSION

These results support the hypothesis that stress shielding is a contributor to vertebral body bone loss and may increase fracture risk. Although further studies are needed, there may be a role for interventions that can shift vertebral loading in the spine to help prevent fracture.

Low sit-to-stand performance is associated with low femoral neck bone mineral density in healthy women

Bone mass may be adjusted to control the strains produced by muscular activity. We assessed the relationship between maximum rising strength (MRS), a new measurement of sit-to-stand performance, and femoral neck (FN) bone mineral density (BMD), taking into account possible confounding variables. The study population consisted of 249 healthy women aged 18-76. We measured MRS with a dynamometer fixed on the ground and connected by an adjustable nonelastic cord to a padded belt. FN BMD was measured by dual X-ray absorptiometry. Women in the first quartile of FN BMD (<0.702 g/cm(2)) had significantly lower values of MRS, body weight, height, lean mass, past 5-year physical activity expenditures, blood 17 beta estradiol (E2), 25-hydroxyvitamin D (25(OH)D), dehydroepiandrosterone sulfate (DHEAS), and insulin like growth factor 1, and higher values of age and parathyroid hormone than other women. In the logistic regression model, FN BMD values in the lowest quartile were associated with age (adjusted odds ratio [OR(a)] per 10-year increase = 1.84, 95% confidence interval [95% CI] = 1.33-2.54, P < 0.001), body weight (OR(a) per 10-kg decrease = 3.67, 95% CI = 2.08-6.47, P < 0.001), MRS (OR(a) per 20-kg decrease = 1.17, 95% CI = 1.02-1.34, P = 0.03), serum DHEAS (OR(a) < 0.5 mg/ml vs > or =0.5 mg/ml = 2.83, 95% CI = 1.3-6.12, P = 0. 01), and serum E2 (OR(a) per 10-pmol/l decrease = 1.02, 95% CI = 1.01-1.03, P = 0.03). The present study suggests a significant association between low FN BMD and low sit-to-stand performance in healthy women, independent of possible confounding variables.

Efeitos da natação e do treinamento resistido na densidade mineral óssea de mulheres idosas

Exercícios com impacto como caminhada, saltos, corridas e exercícios resistidos são muito utilizados para prevenção da perda óssea em idosas. No entanto, poucos são os estudos que relatam os efeitos da natação na manutenção da massa óssea em mulheres idosas. Portanto, o objetivo deste estudo foi comparar os efeitos da natação com o treinamento resistido na densidade mineral óssea (DMO) de mulheres idosas. Vinte e três mulheres com idade média de 63,9 ± 6,49 anos foram divididas em dois grupos: 1) grupo natação (NAT, n = 13, que) treinou em intensidade entre 60 e 90% da freqüência cardíaca de reserva; 2) grupo treinamento resistido (TR, n = 10), que treinou os principais grupamentos musculares com três séries a 80% de 1RM. Os dois grupos praticaram três vezes por semana com uma hora de duração para cada sessão, durante seis meses. A DMO do colo do fêmur e da coluna lombar (L2-L3-L4) foi mensurada através de DXA antes (T0) e após seis meses de treino (T6). Os resultados mostraram que as médias para a DMO lombar em T0 (0,9250 ± 0,1506g/cm²) e T6 (0,9303 ± 0,1269g/cm²) para o NAT e em T0 (0,9739 ± 0,1249g/cm²) e T6 (0,9737 ± 0,1317g/cm²) para o TR não foram diferentes quando comparadas intra ou intergrupos. De modo similar, não houve diferenças entre a DMO do colo do fêmur em T0 (0,7784 ± 0,1523g/cm²) e T6 (0,7905 ± 0,1610g/cm²) para o NAT e T0 (0,7546 ± 0,1360g/cm²) e T6 (0,7522 ± 0,1421g/cm²) para o TR. Os resultados deste estudo não demonstraram diferenças na DMO entre NAT e TR após seis meses de treino; e que tanto TR quanto NAT não produzem aumentos significativos na DMO de mulheres idosas nesse período.

Habitual and low-impact activities are associated with better bone outcomes and lower body fat in older women

The influence of habitual and low-impact physical activity (PA) on bone health and soft tissue including bone-free lean (BFL) and fat mass is less elucidated than the influence of high-impact activities. This study examines the interactive effects of PA and soft tissue on bone mineral density (BMD) and content (BMC) in healthy Caucasian women, aged 68.6 +/- 7.1 years, with body mass index (BMI) of 26.0 +/- 3.8 kg/m(2) evaluated at baseline and every 6 months for 3 years. Measurements/assessments included BMD/BMC and soft tissue (by dual-energy X-ray absorptiometry), anthropometrics, dietary intake, and PA. Activities assessed were past activity, present heavy housework, gardening, do-it-yourself activities, stair-climbing, walking, walking pace, sports/recreation, and total activity. Baseline analyses revealed significant positive associations between past activity, heavy housework, faster-paced walking, BFL, and BMD/BMC of various skeletal sites. Prospective analyses showed subjects with more walking hours/week had significantly higher BMD/BMC of several skeletal sites (P < 0.05). Stratification by cumulative (over 3 years) median for heavy housework, walking, sports/recreational, and total activities revealed higher BMD and BMC in the femur and spine (P = 0.01) in subjects with those activities above median. Multivariate analysis of covariance results revealed that weight had the strongest influence on BMD and BMC, followed by BFL. Various modes of PA were negatively associated with BMI and fat but not with BFL. In conclusion, heavy housework, walking (faster pace), sports/recreational activities, and overall total participation in low-impact PA were beneficial for bone and for achieving more favorable body weight and fat but were not associated with BFL. The results indicate that even habitual activities engaged in by older women could benefit their bone and diminish body fat.

Vitamin D and its implications for musculoskeletal health in women: an update

Vitamin D is a hormone that controls phosphorus, calcium, and bone metabolism and neuromuscular function. Vitamin D synthesis is a process in which the skin, liver, and kidney are sequentially involved. The vitamin D pool is completed by the amount taken with food and supplements. Vitamin D deficiency causes osteopenia, precipitates and exacerbates osteoporosis, causes a painful disease, osteomalacia, and increases muscle weakness, which worsens the risk of falls and fractures. A high prevalence of vitamin D insufficiency exists in the apparently healthy population, osteoporotic patients, and patients with prior fractures. Factors contributing to low vitamin D levels include low sunlight exposure, decreased skin synthesis and intestinal absorption, and inadequate diet. The simplest way to correct hypovitaminosis is adequate nutrition and supplements. However, few patients with osteoporosis and/or fractures, receive adequate supplements. Vitamin D insufficiency may alter the regulatory mechanisms of parathyroid hormone and may induce a secondary hyperparathyroidism that increases the risk of osteoporosis and fractures, although the necessary degree of this is not established. Monitoring of serum 25-hydroxyvitamin D levels is the only way to assess vitamin D status. The ideal healthy blood levels of 25-hydroxyvitamin D are controversial, although a range from 30 to 60ng/mL is widely accepted. The role of vitamin D supplementation is to provide humans with the nutrient in an amount closer to the biological norm for our species. This amount of vitamin D results in optimal function of many aspects of health, including balance and muscle strength, thus reducing the risk of fracture beyond what is possible via the quality and quantity of bone itself.

Lifetime sport and leisure activity participation is associated with greater bone size, quality and strength in older men

INTRODUCTION

It remains uncertain whether long-term participation in regular weight-bearing exercise confers an advantage to bone structure and strength in old age. The aim of this study was to investigate the relationship between lifetime sport and leisure activity participation on bone material and structural properties at the axial and appendicular skeleton in older men (>50 years).

METHODS

We used dual-energy X-ray absorptiometry (DXA) to assess hip, spine and ultradistal (UD) radius areal bone mineral density (aBMD) (n=161), quantitative ultrasound (QUS) to measure heel bone quality (n=161), and quantitative computed tomography (QCT) to assess volumetric BMD, bone geometry and strength at the spine (L(1)-L(3)) and mid-femur (n=111). Current (>50+ years) and past hours of sport and leisure activity participation during adolescence (13-18 years) and adulthood (19-50 years) were assessed by questionnaire. This information was used to calculate the total time (min) spent participating in sport and leisure activities and an osteogenic index (OI) score for each participant, which provides a measure of participation in weight-bearing activities.

RESULTS

Regression analysis revealed that a greater lifetime (13-50+ years) and mid-adulthood (19-50 years) OI, but not total time (min), was associated with a greater mid-femur total and cortical area, cortical bone mineral content (BMC), and the polar moment of inertia (I (p)) and heel VOS (p ranging from <0.05 to <0.01). These results were independent of age, height (or femoral length) and weight (or muscle cross-sectional area). Adolescent OI scores were not found to be significant predictors of bone structure or strength. Furthermore, no significant relationships were detected with areal or volumetric BMD at any site. Subjects were then categorized into either a high (H) or low/non-impact (L) group during adolescence (13-18 years) and adulthood (19-50+ years) according to their OI scores during each of these periods. Three groups were subsequently formed to reflect weight-bearing impact categories during adolescence and then adulthood: LL, HL and HH. Compared to the LL group, mid-femur total and cortical area, cortical BMC and I (p) were 6.5-14.2% higher in the HH group. No differences were detected between the LL and HL groups.

CONCLUSIONS

In conclusion, these findings indicate that long-term regular participation in sport and leisure activities categorized according to an osteogenic index [but not the total time (min) spent participating in all sport and leisure activities] was an important determinant of bone size, quality and strength, but not BMD, at loaded sites in older men. Furthermore, continued participation in weight-bearing exercise in early to mid-adulthood appears to be important for reducing the risk of low bone strength in old age.

L'ostéoporose masculine: épidémiologie, physiopathologie, diagnostic, prévention et traitement

PURPOSE

This article reviews the most current information about epidemiology, risk factors, diagnosis, prevention and management of male osteoporosis.

MAIN POINTS

Although osteoporosis is often regarded as a disease of women, 30% of osteoporotic fractures occur in men. Risk factors for osteoporosis or fractures in men include previous fragility fractures, maternal history of fragility fracture, hypogonadism, low body mass index, smoking, high alcohol consumption, low calcium intake, corticoid therapy, physical inactivity, and the presence of conditions such as hyperthyroidism, hyperparathyroidism, hypercalciuria or chronic inflammatory diseases. Treatment of osteoporosis is recommended in men aged > 65 years with low bone mass (T-score < -2.5), in men aged 50 to 65 years with low bone mass and at least one risk factor for osteoporosis or fracture, in men aged < 50 years with Z-score < -2 with at least one risk factor for osteoporosis or fracture and in men with at least two fragility fractures.

FUTURE ASPECTS

Further studies are needed to better estimate the benefit of of bisphophonates in the prevention of glucocorticoid-induced osteoporosis and the prevention of androgen-deprivation therapy (treatment of prostate cancer) in men at high-risk for osteoporosis, of parathyroid hormone (1-34) in male primary osteoporosis, and of androgen therapy in men with symptoms (including low bone mineral density) and biological signs (with low blood free testosterone levels) of hypogonadism.

Fitness, fatness and activity as predictors of bone mineral density in older persons

OBJECTIVES

To determine relationships of bone mineral density (BMD) with fitness, physical activity, and body composition and fat distribution.

DESIGN

Cross-sectional.

SETTING

General Clinical Research Center, Johns Hopkins Bayview Medical Center, Baltimore, Maryland.

SUBJECTS

Men (n = 38) and women (n = 46), aged 55-75 years with high normal blood pressure or mild hypertension but otherwise healthy.

METHODS

Aerobic fitness (oxygen uptake) on a treadmill, muscle strength by one-repetition maximum, activity by questionnaire, abdominal obesity by magnetic resonance imaging; anthropometrics, and body composition by dual energy X-ray absorptiometry (DXA) which measured total fat and lean mass, and BMD for the total skeleton, lumbar spine (L1-L4) and total hip.

RESULTS

Aerobic fitness did not correlate with BMD. Using multivariate analysis to ascertain independent contributions to the variance in BMD, in women, with adjustment for hormone replacement therapy (HRT), total skeleton BMD was independently related to muscle strength and abdominal total fat; total hip BMD to body weight; lumbar spine BMD to abdominal total fat. HRT also influenced BMD in the lumbar spine. In men, lumbar spine BMD was independently related to abdominal total fat physical activity and total hip BMD related to lower body strength. P < 0.05 for all of these correlations.

CONCLUSIONS

Abdominal obesity and muscle strength emerge as predominant correlates of BMD in older persons with stronger relationships seen in women. Body weight and HRT also explained portions of the variance in BMD in women. Whether abdominal obesity is simply a marker for general obesity or has independent protective effects on bone is yet to be determined.

Effect of vitamin D on bone mineral density of elderly patients with osteoporosis responding poorly to bisphosphonates

BACKGROUND

Bisphosphonates are indicated in the prevention and treatment of osteoporosis. However, bone mineral density (BMD) continues to decline in up to 15% of bisphosphonate users. While randomized trials have evaluated the efficacy of concurrent bisphosphonates and vitamin D, the incremental benefit of vitamin D remains uncertain.

METHODS

Using data from the Canadian Database of Osteoporosis and Osteopenia (CANDOO), we performed a 2-year observational cohort study. At baseline, all patients were prescribed a bisphosphonate and counseled on vitamin D supplementation. After one year, patients were divided into two groups based on their response to bisphosphonate treatment. Non-responders were prescribed vitamin D 1000 IU daily. Responders continued to receive counseling on vitamin D.

RESULTS

Of 449 patients identified, 159 were non-responders to bisphosphonates. 94% of patients were women. The mean age of the entire cohort was 74.6 years (standard deviation = 5.6 years). In the cohort of non-responders, BMD at the lumbar spine increased 2.19% (p < 0.001) the year after vitamin D was prescribed compared to a decrease of 0.55% (p = 0.36) the year before. In the cohort of responders, lumbar spine BMD improved 1.45% (p = 0.014) the first year and 1.11% (p = 0.60) the second year. The difference between the two groups was statistically significant the first year (p < 0.001) but not the second (p = 0.60). Similar results were observed at the femoral neck but were not statistically significant.

CONCLUSION

In elderly patients with osteoporosis not responding to bisphosphonates, vitamin D 1000 IU daily may improve BMD at the lumbar spine.