Albuminuria is associated with hip fracture risk in older adults: the cardiovascular health study

Summary

The microcirculation plays an important role in bone health. Here, we examine whether albuminuria, a marker of renal microvascular disease, is associated with the risk of hip fracture in older adults (age, 78 years). We find a small independent association in women but not in men.

Introduction

The microvascular circulation plays an important role in bone physiology. Two studies of middle-aged adults have found that albuminuria (>30 mg albumin/g creatinine), a disorder of the renal microvasculature, is associated with fracture risk. Here, we examine whether albuminuria is related to hip fracture risk and reduced hip bone mineral density (BMD) in older adults with a mean age of 78 years.

Methods

From the Cardiovascular Health Study (41 % male), 3,110 adults with albuminuria testing were followed up for incident hip fracture for up to 9.5 years. BMD was performed in a subset of 1,208 participants.

Results

There were 313 hip fractures during follow-up (7.7 % of men; 11.7 % of women). The incidence rate for men, with and without albuminuria, was 1.43 and 0.93/100 person-years of follow-up (p?=?0.02); for women, 1.84 and 1.33 (p?=?0.04). After adjustment for osteoporosis-related factors, frailty and falling, a doubling of albuminuria was significantly associated with hip fracture risk in women (hazard ratio, 1.12, 95 % CI, 1.001–1.25), but not in men. In the subcohort with BMD measurement, increased urine albumin levels were significantly associated with decreased total hip BMD in men (?0.009 g calcium/cm² (?0.017, ?0.001); p?=?0.04), but not in women.

Conclusions

In older women, albuminuria is associated with a small, but statistically significant, increased risk of hip fracture independent of other explanatory factors. No such risk appears to be present in men, although their total hip BMD is lower in association with albuminuria.     

Race/ethnic differences in associations between bone mineral density and fracture history in older men

Summary

To determine whether there are race/ethnic differences in bone mineral density (BMD) by fracture history in men aged 65 years and older, we performed cross-sectional analysis in five large independent cohorts. Low BMD was associated with a higher prevalence of fracture in all cohorts, and the magnitude of the BMD differences by fracture status was similar across groups.

Introduction

We aimed to determine whether there are race/ethnic and geographic differences in bone mineral density by fracture history in men aged 65 years and older.

Method

The datasets included the Osteoporotic Fractures in Men (MrOS) Study (5,342 White, 243 African-American, 190 Asian, and 126 Hispanic), MrOS Hong Kong (1,968 Hong Kong Chinese), Tobago Bone Health Study (641 Afro-Caribbean), Namwon Study (1,834 Korean), and Dong-gu Study (2,057 Korean). The two Korean cohorts were combined.

Results

The prevalence of self-reported non-traumatic fracture was US white, 17.1 %; Afro-Caribbean, 5.5 %; US African-American, 15.1 %; US Hispanic, 13.7 %; US Asian, 10.5 %; Hong Kong Chinese, 5.6 %, and Korean, 5.1 %. The mean differences in hip and lumbar spine BMD between subjects with fracture and without fracture were statistically significant in all cohorts except US African American and US Asian men. There was a significant race/ethnic interaction for lumbar spine BMD by fracture status (p for interaction?=?0.02), which was driven by the small number of Hispanic men. There was no interaction for femoral neck or total hip BMD. There were no significant race/ethnic differences in the odds ratio of fracture by BMD.

Conclusions

Low BMD was associated with a higher prevalence of fracture in all cohorts and the magnitude of the BMD differences by fracture status was similar across groups suggesting homogeneity in the BMD–fracture relationship among older men.     

Depression and low bone mineral density: a meta-analysis of epidemiologic studies

Summary

The association between depression and loss of bone mineral density (BMD) has been reported inconsistently. This meta-analysis, which pooled results from 14 qualifying individual studies, found that depression was associated with a significantly decreased BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression.

Introduction

The reported association between depression and loss of BMD has been controversial. This meta-analysis was conducted to determine whether depression and BMD are associated and to identify the variation in some subgroups.

Methods

English-language articles published before October 2008 were used as the data source. A total of six case-controlled and eight cross-sectional studies met prestated inclusion criteria (N?=?10,523). Information on study design, participant characteristics, measurements of BMD and depression, and control for potential confounders was abstracted independently by two investigators using a standardized protocol.

Results

Overall, depression was associated with a significant decrease in mean BMD of spine (?0.053 g/cm² [95% confidence interval {CI} ?0.087 to ?0.018 g/cm²]) and hip (?0.052 g/cm² [95% CI ?0.083 to ?0.022 g/cm²]). A substantially greater BMD decrease was observed in depressed women (?0.076 g/cm² in spine; ?0.059 g/cm² in hip) and in cases of clinical depression (?0.074 g/cm² in spine; ?0.080 g/cm² in hip).

Conclusion

Depression is associated with low BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression. Depression should be considered as an important risk factor for osteoporosis.     

Predictors of the rate of BMD loss in older men: findings from the CHAMP study

Summary

Though bone loss tends to accelerate with age there are modifiable factors that may influence the rate of bone loss even in very old men.

Introduction

The aim of this 2-year longitudinal study was to examine potential predictors of change in total hip bone mineral density (BMD) in older men.

Methods

The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia. For this study, 1,122 men aged 70–97 years had baseline and follow-up measures of total hip BMD measured with dual X-ray absorptiometry. Data about mobility, muscle strength, balance, medication use, cognition, medical history and lifestyle factors were collected using questionnaires and clinical assessments. Serum 25-hydroxyvitamin D [25(OH)D] was also measured. Multivariate linear regression models were used to assess relationships between baseline predictors and change in BMD.

Results

Over a mean of 2.2 years, there was a mean annualised loss of total hip BMD of 0.006 g/cm²/year (0.6 %) and hip BMC of 0.14 g/year (0.3 %). Annual BMD loss accelerated with increasing age, from 0.4 % in men aged between 70 and 75 years, to 1.2 % in men aged 85+ years. In multivariate regression models, predictors of faster BMD loss were anti-androgen, thiazolidinedione and loop-diuretic medications, kidney disease, poor dynamic balance, larger hip bone area, older age and lower serum 25(OH)D. Factors associated with attenuated bone loss were walking for exercise and use of beta-blocker medications. Change in BMD was not associated with baseline BMD, smoking, alcohol consumption, BMI, frailty, or osteoarthritis.

Conclusion

There was considerable variation in the rate of hip bone loss in older men. Walking, better balance and beta blockers may attenuate the acceleration of BMD loss that occurs with age.     

Performance of FRAX in a cohort of community-dwelling, ambulatory older men: the Osteoporotic Fractures in Men (MrOS) study

Summary

We evaluated performance of FRAX in older men who participated in the Osteoporotic Fractures in Men (MrOS) study.

Introduction

FRAX has been extensively studied in women, but there are few studies of its performance in men.

Methods

FRAX estimates for 10-year hip fracture and major osteoporotic fracture (MOF; either hip, clinical spine, forearm, or shoulder) were calculated from data obtained from MrOS participants and compared to observed 10-year fracture cumulative incidence calculated using product limit estimate methods, accounting for competing mortality risk.

Results

Five thousand eight hundred ninety-one men were followed for an average of 8.4 years. Without bone mineral density (BMD) in the FRAX model, the mean 10-year predicted fracture probabilities for hip and MOF were 3.5 % and 8.9 %, respectively; addition of BMD to the calculations reduced these estimates to 2.3 % and 7.6 %. Using FRAX without BMD, predicted quintile probabilities closely estimated cumulative incidence of hip fracture (range of observed to predicted ratios 0.9–1.1). However, with BMD in the FRAX calculation, observed to predicted hip fracture probabilities were not close to unity and varied markedly across quintiles of predicted probability. For MOF, FRAX without BMD overestimated observed cumulative incidence (range of observed to predicted ratios 0.7–0.9) and addition of BMD did not improve this discrepancy (range of observed to predicted ratios 0.7–1.1). Addition of BMD to the calculation had mixed effects on the discriminatory performance of FRAX, depending on the analysis tool applied.

Conclusion

Among this cohort of community-dwelling older men, the FRAX risk calculator without BMD was well calibrated to hip fracture but less well to MOF.     

Osteoporosis in Indian women aged 40–60 years

Summary

The study investigates BMD pattern in Indian women aged 40–60 years through a retrospective assessment using DEXA scan of hip and spine of 1,282 asymptomatic Indian women. The Study group indicated high incidence of decreased bone mass and significantly lower BMD as compared to western and other Asian counterparts.

Introduction

An understanding of BMD pattern in women aged 40–60 years is crucial for prevention, diagnosis of osteoporosis and management of its complications in later life. Hence, the present study investigates BMD in Indian women aged 40–60 years for which no data exists in literature.

Method

A retrospective assessment of BMD by DEXA scan of hip and spine of 1,282 asymptomatic women in age group 40–60 was performed. Standardized BMD was calculated and compared with other population groups.

Results

Osteoporosis and osteopenia are widely prevalent among females of the 40–60 age group as a meager 35% of subjects had normal bone density. Average BMD of spine was 0.89 (SD 0.14) gm/cm² and average BMD of hip was 0.85(0.15) gm/cm². The correlation between BMD and age was negative. Spine DEXA was found to be more significant than hip DEXA (p value?<?0.0001) for osteoporosis assessment. Similarly, T scores of spine were more significantly correlated in this age group (p value?<?0.0001) for osteoporosis than hip T scores.

Conclusion

The study group indicated high incidence of decreased bone mass, and significantly lower BMD as compared to western and other Asian counterparts. This study emphasizes on early screening and treatment in study group to avoid long-term complications.     

Peak bone mineral density in Vietnamese women

Summary

This cross-sectional study showed that peak bone mineral density in Vietnamese women is comparable to that in Caucasian women; however, the prevalence of osteoporosis in post-menopausal Vietnamese women was slightly higher than in Caucasian women. The age of achieving peak bone mass in Vietnamese women was between 26 and 30 years.

Introduction

While peak bone mass and its determinants have been well-documented in Caucasian populations, little has been studied in Asian populations. The present study was designed to estimate the peak bone mineral density (BMD), age of its attainment, and to examine the prevalence of osteoporosis in Vietnamese women aged 50+.

Methods

The study was designed as a cross-sectional study with 328 women aged between 10 and 65 years (average age: 41) who were randomly selected from two districts around Hanoi city according to a stratified sampling scheme. BMD at the lumbar spine, femoral neck and total hip was measured by a DXA instrument (GE Lunar Prodigy, WI, USA). BMD was modeled as a cubic function of age, from which peak BMD and age at peak BMD were estimated. Bootstrap method was utilized to estimate the 95% confidence interval of peak BMD and age at peak BMD. From the peak BMD, T-score was calculated for each woman, and using the World Health Organization criteria, any woman with femoral neck BMD T-score ≤ -2.5 was classified as having osteoporosis.

Results

Peak BMD was estimated at 1.16 g/cm² (standard deviation [SD]: 0.13 g/cm²) at the lumbar spine, 1.02 g/cm² (SD 0.12) at the total hip, and 0.94 g/cm² (SD 0.11) at the femoral neck. In the cubic polynomial model, the age at peak BMD was estimated to range between 27 and 29 years. The prevalence of osteoporosis among those aged between 50 and 65 years was 23%. This prevalence was higher than in Chinese, Japanese, Korean and Caucasian populations.

Conclusion

These data suggest that although the peak BMD in Vietnamese women is comparable to, the prevalence of osteoporosis is higher than, in some other Asian and Caucasian women. It seems that osteoporosis is an important public health burden in Vietnam.     

Association between hypertension and fragility fracture: a longitudinal study

Summary

Hypertension is an independent risk factor for osteoporosis and osteoporotic fracture in postmenopausal women.

Introduction

Although hypertension has been suggested to be associated with increased fracture risk, it is not clear whether the association is independent of bone mineral density (BMD). The present study sought to examine the interrelationships between hypertension, BMD, and fracture risk.

Methods

The study included 1,032 men and 1,701 women aged 50 years and older who were participants in the Dubbo Osteoporosis Epidemiology Study. BMD at the femoral neck and lumbar spine was measured by dual energy X-ray absorptiometry (GE-LUNAR Corp., Madison, WI, USA). The presence of hypertension was ascertained by direct interview and verification through clinical history. The incidence of fragility fractures was ascertained by X-ray report during the follow-up period (1989–2008). The Cox proportional hazards model was used to assess the association between hypertension and fracture risk.

Results

Women with hypertension had lower BMD at the femoral neck (0.79 versus 0.82 g/cm², P?=?0.02) than those without the disease. After adjusting for BMD and covariates, hypertension was an independent risk factor for fragility fracture [hazard ratio (HR), 1.49; 95 % CI, 1.13–1.96]. In men, hypertension was associated with higher femoral neck BMD (0.94 versus 0.92 g/cm², P?=?0.02), but the association between hypertension and fracture risk did not reach statistical significance.

Conclusion

Hypertension is associated with increased fracture risk in women, and the association is independent of BMD.     

Impact + resistance training improves bone health and body composition in prematurely menopausal breast cancer survivors: a randomized controlled trial

Summary

Our randomized controlled trial in prematurely menopausal breast cancer survivors showed that impact + resistance training prevented increases in percentage of body fat compared with controls and also improved BMD at the hip and prevented BMD loss at the spine among exercise-trained women who were menopausal for >1 year.

Introduction

Cancer treatment-related menopause worsens bone health and body composition in breast cancer survivors (BCS). We investigated whether impact + resistance training could improve bone mineral density (BMD), reduce bone turnover, build muscle, and decrease fat mass in BCS with premature menopause.

Methods

We conducted a randomized controlled trial in 71 BCS (mean age, 46.5 years) within 5 years of treatment-related menopause. Women were randomly assigned to one of two groups: (1) impact + resistance training (prevent osteoporosis with impact + resistance (POWIR)) or (2) exercise placebo (FLEX) 3×/week for 1 year. Outcomes were hip and spine BMD (in grams per square centimeter) and body composition (percent body fat (%BF) and lean and fat mass (in kilograms)) by DXA and bone turnover markers (serum osteocalcin (in nanograms per milliliter) and urinary deoxypryrodinoline (in nanomoles per milliliter).

Results

There were no significant group × time interactions for bone outcomes when using an intent-to-treat approach on the full sample. In analyses restricted to BCS who were menopausal for ≥1 year, POWIR increased BMD at the hip and slowed BMD loss at the spine compared with FLEX (femoral neck—POWIR, 0.004?±?0.093 g/cm² vs. FLEX, ?0.010?±?0.089 g/cm²; p?<?0.01; spine—POWIR, ?0.003?±?0.114 g/cm² vs. FLEX, ?0.020?±?0.110 g/cm²; p?=?0.03). POWIR prevented increases in %BF (POWIR, 0.01 % vs. FLEX, 1.3 %; p?<?0.04). Women with attendance to POWIR at ≥64 % had better improvements in %BF than women attending less often (p?<?0.03).

Conclusion

Impact + resistance training may effectively combat bone loss and worsening body composition from premature menopause in BCS.     

Forecasting the burden of future postmenopausal hip fractures

Summary

A growing elderly population is expected worldwide, and the rate of hip fractures is decisive for the future fracture burden. Significant declines in hip fracture rates in Norway, the USA, France, Germany, and the UK are required to counteract the impact of the ageing effects.

Introduction

This study aims to evaluate the consequences of the expected growth of the elderly population worldwide on the hip fracture burden using Norway as an example. Furthermore, we wanted to estimate the decline in hip fracture rates required to counteract the anticipated increase in the burden of hip fracture for Norway, the USA, France, Germany, and the UK.

Methods

The burden of future postmenopausal hip fractures in Norway were estimated given (1) constant age-specific rates, (2) continued decline, and (3) different cohort scenarios. Based on population projection estimates and population age-specific hip fracture rates in women 65 years and older, we calculated the required declines in hip fracture rates needed to counteract the growing elderly populations in Norway, the USA, France, Germany, and the UK.

Results

The level of age-specific hip fracture rates had a huge impact on the future hip fracture burden in Norway. Even if the hip fracture rates decline at the same speed, a 22 % increase in the burden of hip fractures can be expected by 2040. An annual decline in hip fracture rates of 1.1–2.2 % until 2040 is required to counteract the effects of the growing elderly population on the future burden of hip fractures in Norway, the USA, France, Germany, and the UK.

Conclusions

Hip fracture rates have a great impact on the burden of hip fractures. The rates will have to decline significantly to counteract the impact of a growing elderly population. A change in preventive strategies and further studies are warranted to identify the complex causes associated to hip fractures.     

Competing mortality and fracture risk assessment

Summary

Failure to account for competing mortality gave higher estimates of 10-year fracture probability than if appropriate adjustment is made for competing mortality, particularly among subgroups with higher mortality. A modified Kaplan–Meier method is easy to implement and provides an alternative approach to existing methods for competing mortality risk adjustment.

Introduction

A unique feature of FRAX^® is that 10-year fracture probability accounts for mortality as a competing risk. We compared the effect of competing mortality adjustment on nonparametric and parametric methods of fracture probability estimation.

Methods

The Manitoba Bone Mineral Density (BMD) database was used to identify men and women age ≥50 years with FRAX probabilities calculated using femoral neck BMD (N?=?39,063). Fractures were assessed from administrative data (N?=?2,543 with a major osteoporotic fracture, N?=?549 with a hip fracture during mean 5.3 years follow-up).

Results

The following subgroups with higher mortality were identified: men, age >80 years, high fracture probability, and presence of diabetes. Failure to account for competing mortality in these subgroups overestimated fracture probability by 16–56 % with the standard nonparametric (Kaplan–Meier) method and 15–29 % with the standard parametric (Cox) model. When the outcome was hip fractures, failure to account for competing mortality overestimated hip fracture probability by 18–36 % and 17–35 %, respectively. A simple modified Kaplan–Meier method showed very close agreement with methods that adjusted for competing mortality (within 2 %).

Conclusions

Failure to account for competing mortality risk gives considerably higher estimates of 10-year fracture probability than if adjustment is made for this competing risk.     

Is lower income associated with an increased likelihood of qualification for treatment for osteoporosis in Canadian women?

Summary

We examined whether low income was associated with an increased likelihood of treatment qualification for osteoporotic fracture probability determined by Canada FRAX in women aged ≥50 years. A significant negative linear association was observed between income and treatment qualification when FRAX included bone mineral density (BMD), which may have implications for clinical practice.

Introduction

Lower income has been associated with increased fracture risk. We examined whether lower income in women was associated with an increased likelihood of treatment qualification determined by Canada FRAX®.

Methods

We calculated 10-year FRAX probabilities in 51,327 Canadian women aged ≥50 years undergoing baseline BMD measured by dual energy x-ray absorptiometry 1996–2001. FRAX probabilities for hip fracture ≥3 % or major osteoporotic fracture (MOF) ≥20 % were used to define treatment qualification. Mean household income from Canada Census 2006 public use files was used to categorize the population into quintiles. Logistic regression analyses were used to model the association between income and treatment qualification.

Results

Percentages of women who qualified for treatment based upon high hip fracture probability increased linearly with declining income quintile (all p trend <0.001), but this was partially explained by older age among lower income quintiles (p trend <0.001). Compared to the highest income quintile, women in the lowest income quintile had a greater likelihood of treatment qualification based upon high hip fracture probability determined with BMD (age-adjusted odds ratio [OR], 1.34; 95 % confidence intervals (CI), 1.23–1.47) or high MOF fracture probability determined with BMD (age-adjusted OR, 1.31; 95 % CI, 1.18–1.46). Differences were nonsignificant when FRAX was determined without BMD, implying that BMD differences may be the primary explanatory factor.

Conclusions

FRAX determined with BMD identifies a larger proportion of lower income women as qualifying for treatment than higher income women.     

Missense polymorphisms of the WNT16 gene are associated with bone mass, hip geometry and fractures

Summary

Two missense polymorphisms of WNT16 were associated with hip bone mineral density (BMD), the buckling ratio of the femoral neck, calcaneal ultrasound and hip fractures in individuals under 80 years of age. These results confirm the association of the WNT16 gene with bone mass and osteoporotic fractures.

Introduction

Osteoporosis has a strong genetic component. Wnt ligands stimulate the differentiation of osteoblast precursors and play a major role in skeletal homeostasis. Therefore, the aim of this study was to explore the association of allelic variants of the WNT16 gene with BMD, other structural parameters of bone and osteoporotic hip fractures.

Methods

Six single nucleotide polymorphisms were analysed in 1,083 Caucasian individuals over 49 years of age.

Results

Two missense polymorphisms (rs2908004 and rs2707466) were associated with femoral neck BMD, with average differences across genotypes of 35 mg/cm² (p?=?0.00037 and 0.0015, respectively). Likewise, the polymorphisms were associated with calcaneal quantitative ultrasound parameters (p?=?0.00004 and 0.0014, respectively) and the buckling ratio, an index of cortical instability of the femoral neck (p?=?0.0007 and 0.0029, respectively). Although there were no significant differences in the genotype frequency distributions between 294 patients with hip fractures and 670 controls, among the subgroup under 80 years of age, TT genotypes were underrepresented in patients with fractures (odds ratio 0.50; CI 0.27–0.94).

Conclusion

Common missense polymorphisms of the WNT16 gene are associated with BMD at the hip, calcaneal ultrasound and the buckling ratio of the femoral neck, as well as with hip fractures in individuals under 80 years of age. Overall, these results confirm the association of the WNT16 locus with BMD identified in genome-wide association studies and support its role in determining the risk of osteoporotic fractures.     

High fracture probability with FRAX® usually indicates densitometric osteoporosis: implications for clinical practice

Summary

Most patients designated as high risk of fracture using fracture risk assessment tool (FRAX^®) with femoral neck bone mineral density (BMD) (i.e., 10-year major osteoporotic fracture probability exceeding 20% or hip fracture exceeding 3%) have one or more T-scores in the osteoporotic range; conversely, almost no high risk patients have normal T-scores at all bone mineral density measurement sites.

Introduction

We determined the agreement between a FRAX^® designation of high risk of fracture [defined as 10-year major osteoporotic fracture probability (≥20%) or hip fracture probability (≥3%)] and the WHO categorizations of bone mineral density according to T-score.

Methods

Ten-year FRAX^® probabilities calculated with femoral neck BMD were derived using both Canadian and US white tools for a large clinical cohort of 36,730 women and 2,873 men age 50 years and older from Manitoba, Canada. Individuals were classified according to FRAX fracture probability and BMD T-scores alone.

Results

Most individuals designated by FRAX as high risk of major osteoporotic fracture had a T-score in the osteoporotic range at one or more BMD measurement sites (85% with Canadian tool and 83% with US white tool). The majority of individuals deemed at high risk of hip fracture had one or more T-scores in the osteoporotic range (66% with Canadian tool and 64% with US white tool). Conversely, there were extremely few individuals (<1%) who were at high risk of major osteoporotic or hip fracture with normal T-scores at all BMD measurement sites.

Conclusions

A FRAX designation of high risk of fracture is usually associated with a densitometric diagnosis of osteoporosis.     

The Auckland calcium study: 5-year post-trial follow-up

Summary

Five years after completion of a randomised placebo-controlled trial of calcium supplements, there was no effect of calcium on total fracture incidence, a significant reduction in vertebral and forearm fractures and, in a subset, no effect on bone density. There was no increased risk of cardiovascular events after discontinuation of calcium.

Introduction

The Auckland calcium study was a 5-year randomised controlled trial of 1 g/day calcium citrate in 1,471 postmenopausal women. Calcium did not reduce total, vertebral or forearm fracture incidence, increased hip fracture incidence and had beneficial effects on bone mineral density (BMD). A secondary analysis raised concerns about the cardiovascular safety of calcium. The purpose of this study was to determine whether the effects of calcium on fracture incidence, BMD and cardiovascular endpoints persisted after supplement discontinuation.

Methods

Approximately 5-years post-trial, we collected information on the 1,408 participants alive at trial completion from the national databases of hospital admissions and deaths. We contacted 1,174 women by phone, and from these we obtained information on medical events and post-trial calcium use. We undertook BMD measurements at 10 years in a selected subset of 194 women who took study medication for 5 years in the original trial, and did not take bone-active medications post-trial.

Results

Over the 10-year period, there was no effect on total fracture (HR 0.90, 95 % CI 0.75–1.07) or hip fracture incidence (1.40, 0.89–2.21), but significant reductions in forearm (0.62, 0.43–0.89) and vertebral fractures (0.52, 0.32–0.85) in those assigned to calcium. There were no between-group differences in BMD at 10 years at any site. The adverse cardiovascular outcomes observed in the 5-year trial did not persist post-trial.

Conclusion

Calcium supplementation for 5 years had no effect on total fracture incidence at 10 years. The positive benefits on BMD and the adverse cardiovascular effects did not persist once supplements were stopped.     

Changes in bone mineral density over time by body mass index in the health ABC study

Summary

Obesity appears protective against osteoporosis in cross-sectional studies. However, results from this longitudinal study found that obesity was associated with bone loss over time. Findings underscore the importance of looking at the longitudinal relationship, particularly given the increasing prevalence and duration of obesity among older adults.

Introduction

Cross-sectional studies have found a positive association between body mass index (BMI) and bone mineral density (BMD), but little is known about the longitudinal relationship in US older adults.

Methods

We examined average annual rate of change in BMD by baseline BMI in the Health, Aging, and Body Composition Study. Repeated measurement of BMD was performed with dual-energy X-ray absorptiometry (DXA) at baseline and years 3, 5, 6, 8, and 10. Multivariate generalized estimating equations were used to predict mean BMD (femoral neck, total hip, and whole body) by baseline BMI (excluding underweight), adjusting for covariates.

Results

In the sample (n?=?2570), 43 % were overweight and 24 % were obese with a mean baseline femoral neck BMD of 0.743 g/cm², hip BMD of 0.888 g/cm², and whole-body BMD of 1.09 g/cm². Change in total hip or whole-body BMD over time did not vary by BMI groups. However, obese older adults lost 0.003 g/cm² of femoral neck BMD per year more compared with normal weight older adults (p?<?0.001). Femoral neck BMD change over time did not differ between the overweight and normal weight BMI groups (p?=?0.74). In year 10, adjusted femoral neck BMD ranged from 0.696 g/cm² among obese, 0.709 g/cm² among normal weight, and 0.719 g/cm² among overweight older adults.

Conclusions

Findings underscore the importance of looking at the longitudinal relationship between body composition and bone mineral density among older adults, indicating that high body mass may not be protective for bone loss over time.

     

Failure after osteosynthesis of trochanteric fractures. Where is the limit of osteoporosis?

Summary

The aim of this study is to identify osteoporosis values, beyond which there is a high risk of osteosynthesis failure. Bone mineral density (BMD) of 30 cadaveric femora with a pertrochanteric fracture osteotomy was correlated to the risk of cut out after osteosynthesis on a biomechanical testing approach. For a BMD less than 250 mg/cm³, there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. This value can be regarded as a reference value for future experimental and clinical studies.

Introduction

Despite continuous modification of intramedullary load carriers for the surgical stabilization of trochanteric fractures, cut out remains the most frequent complication. The aim of this experimental study was to identify threshold osteoporosis values, beyond which there is a high risk of osteosynthesis failure.

Methods

Bone mineral density (BMD) of 30 cadaveric femora was recorded for the femoral head by QCT measurement. Subsequently, a standardized osteotomy mimicking an unstable trochanteric type fracture was stabilized by intramedullary nailing. The constructs were loaded axially at a force of 2,100 N up to 20,000 cycles. Cut out at the femoral head was documented by radiograph. Statistical evaluation of the cohort group was performed by calculation of relative risk in relation to the BMD values.

Results

In total, there were six cases of cut out after 10,000 cycles. The incidence of cut out for BMD less than 250 mg/cm³ was 0.55 (5 of 9) and for BMD greater than 250 mg/cm³, it was 0.05 (1 of 21). Therefore, the relative risk of cut out for BMD <250 mg/cm³ is 11× greater than for a BMD >250 mg/cm³. After 20,000 cycles, an additional test caused one cut out (relative risk of cut out for a BMD <250 mg/cm³ 5.8).

Conclusions

For a BMD less than 250 mg/cm³, there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. Although this value is based on an experimental in vitro study design with all its associated limitations, it can be regarded as a reference value for future experimental and clinical studies.     

Distribution of bone density and cortical thickness in the proximal femur and their association with hip fracture in postmenopausal women: a quantitative computed tomography study

Summary

The quantitative computed tomography (QCT) scans in an individually matched case–control study of women with hip fracture were analysed. There were widespread deficits in the femoral volumetric bone mineral density (vBMD) and cortical thickness of cases, and cortical vBMD and thickness discriminated hip fracture independently of BMD by dual-energy X-ray absorptiometry (DXA).

Introduction

Acknowledging the limitations of QCT associated with partial volume effects, we used QCT in an individually matched case–control study of women with hip fracture to better understand its structural basis.

Methods

Fifty postmenopausal women (55–89 years) who had sustained hip fractures due to low-energy trauma underwent QCT scans of the contralateral hip within 3 months of the fracture. For each case, postmenopausal women, matched by age (±5 years), weight (±5 kg) and height (±5 cm), were recruited as controls. We quantified cortical, trabecular and integral vBMD and apparent cortical thickness (AppCtTh) in four quadrants of cross-sections along the length of the femoral head (FH), femoral neck (FN), intertrochanter and trochanter and examined their association with hip fracture.

Results

Women with hip or intracapsular (IC) fracture had significantly (p?<?0.05) lower vBMD and AppCtTh than the controls in the majority of cross-sections and quadrants of the proximal femur, and both cortical and trabecular compartments are involved. Cortical vBMD and AppCtTh in the FH and FN were associated with hip and IC fractures independent of hip areal BMD (aBMD). The combination of AppCtTh and trabecular or integral vBMD discriminated hip fracture, whereas the combination of FH and FN AppCtTh discriminated IC fracture significantly (p?<?0.05) better than the hip aBMD.

Conclusion

Deficits in vBMD and AppCtTh in cases were widespread in the proximal femur, and cortical vBMD and AppCtTh discriminated hip fracture independently of aBMD by DXA.     

Skeletal health in adult patients with classic galactosemia

Summary

This study evaluated bone health in adults with galactosemia. Associations between bone mineral density (BMD) and nutritional and biochemical variables were explored. Calcium level predicted hip and spine BMD, and gonadotropin levels were inversely associated with spinal BMD in women. These results afford insights into management strategies for these patients.

Introduction

Bone loss is a complication of galactosemia. Dietary restriction, primary ovarian insufficiency in women, and disease-related alterations of bone metabolism may contribute. This study examined relationships between clinical factors and BMD in patients with galactosemia.

Methods

This cross-sectional sample included 33 adults (16 women) with classic galactosemia, mean age 32.0?±?11.8 years. BMD was measured by dual-energy X-ray absorptiometry, and was correlated with age, height, weight, fractures, nutritional factors, hormonal status, and bone biomarkers.

Results

There was a significant difference in hip BMD between women and men (0.799 vs. 0.896 g/cm², p?=?0.014). The percentage of subjects with BMD-Z <?2.0 was also greater for women than men [33 vs. 18 % (spine), 27 vs. 6 % (hip)], and more women reported sustaining fractures. Bivariate analyses yielded correlations between BMI and BMD-Z [at the hip in women (r?=?0.58, p?<?0.05) and spine in men (r?=?0.53, p?<?0.05)]. In women, weight was also correlated with BMD-Z (r?=?0.57, p?<?0.05 at hip), and C-telopeptides (r?=??0.59 at spine and ?0.63 hip, p?<?0.05) and osteocalcin (r?=??0.71 at spine and ?0.72 hip, p?<?0.05) were inversely correlated with BMD-Z. In final regression models, higher gonadotropin levels were associated with lower spinal BMD in women (p?=?0.017); serum calcium was a significant predictor of hip (p?=?0.014) and spine (p?=?0.013) BMD in both sexes.

Conclusions

Bone density in adults with galactosemia is low, indicating the potential for increased fracture risk, the etiology of which appears to be multifactorial.     

Effect of alendronate in elderly patients after low trauma hip fracture repair

Summary

One year of once weekly alendronate, when given shortly after the surgical repair of a hip fracture, produces reductions in bone markers and increases proximal femoral bone density. The therapy was well tolerated.

Introduction

Hip fracture is the most devastating type of osteoporotic fracture and increases notably the risk of subsequent fractures. The aim of this paper was to evaluate the effects of 1 year therapy with a weekly dose of alendronate in the bone mineral density and bone markers in elderly patients after low trauma hip fracture repair.

Methods

Two hundred thirty-nine patients (81?±?7 years; 79.8% women) were randomized to be treated either with calcium (500 mg/daily) and vitamin D₃ (400 IU/daily; Ca–Vit D group) or with alendronate (ALN, 70 mg/week) plus calcium and vitamin D₃ (500 mg/daily and 400 IU/daily, respectively; ALN + Ca–Vit D group).

Results

One hundred forty-seven (61.5%) patients completed the trial. Alendronate increased proximal femoral bone mineral density (BMD) in the intention-to-treat analysis (mean difference (95% confidence interval); total hip 2.57% (0.67; 4.47); trochanteric 2.96% (0.71; 5.20), intertrochanteric 2.32% (0.36; 4.29)), but the differences were not significant in the BMD of the femoral neck (0.47%; (?2.03; 2.96) and the lumbar spine (0.69%; (?0.86; 2.23)). Bone turnover markers decreased during alendronate treatment.

Conclusion

The present study demonstrates for the first time the anti-resorptive efficacy of alendronate given immediately after surgical repair in an elderly population with recent hip fracture. This effect should positively affect the rate of subsequent fractures.