Low bone mineral density is associated with increased mortality in elderly men: MrOS Sweden

Summary

We studied the nature of the relationship between bone mineral density (BMD) and the risk of death among elderly men. BMD was associated with mortality risk and was independent of adjustments for other co-morbidities. A piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p?=?0.020). Low BMD was associated with a substantial excess risk of death, whilst a higher than average BMD had little impact on mortality.

Introduction

Previous studies have demonstrated an association between low BMD and an increased risk of death among men and women. The aim of the present study was to examine the pattern of the risk in men and its relation to co-morbidities.

Methods

We studied the nature of the relationship between BMD and death among 3,014 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health questionnaires, life style questionnaires and BMD measured using DXA. Men were followed for up to 6.5?years (average 4.5?years). Poisson regression was used to investigate the relationship between BMD, co-morbidities and the hazard function of death.

Results

During follow-up, 382 men died (all-cause mortality). Low BMD at all measured skeletal sites was associated with increased mortality. In multivariate analyses, the relationship between BMD and mortality was non-linear, and a piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p?=?0.020).

Conclusions

Low BMD is associated with a substantial excess risk of death compared to an average BMD, whereas a higher than average BMD has a more modest effect on mortality. These findings, if confirmed elsewhere, have implications for the constructing of probability-based fracture risk assessment tools.     

高龄老年女性股骨颈骨密度独立相关因素的研究

目的 为了筛选高龄老年（≥80岁）女性股骨颈骨密度（FNBMD)的独立相关因素。方法 对332例高龄老年女性进行FNBMD、血液生化、骨代谢和生殖激素等指标的检测,运用多元回归分析方法筛选高龄老年女性股骨颈骨密度的独立相关因素。结果 高龄老年女性FNBMD的独立相关因素有体重指数（β= 0.008,P <0. 001)、睾酮（β= 0. 029,P<0.001)、慢性 阻塞性肺疾病（β= -0.039,P<0.05)、年龄（β= -0.005,P<0.05)和空腹血糖（β= 0. 016,P<0.05)。结论 维持合理的体重指数、睾酮和空腹血糖水平,积极防治慢性阻塞性肺疾病,可能是提高高龄老年女性FNBMD的重要方法。     

Adiponectin is a predictor of bone mineral density in middle-aged premenopausal women

Summary

Adipose-modulated biochemical signal that explains some of the association between fat mass and bone mineral density (BMD) is adiponectin. The results demonstrated an independent association between adiponectin and BMD, while the influence of adiponectin on bone mineral content is mediated by fat free mass in middle-aged women.

Introduction

Positive association between fat mass (FM) and bone mineral density (BMD) is mediated by biochemical factors.

Methods

The relationship between plasma adiponectin concentration and BMD in 98 sedentary premenopausal women aged 38–49 years with a body mass index range of 20.0–42.1 kg/m² was examined. Different body composition and blood biochemical parameters were measured to adjust for possible confounding variables.

Results

The association between adiponectin and BMD values (total BMD: ß?=??0.919; p?=?0.0001, femoral neck BMD: ß?=??0.925; p?=?0.0001 and lumbar spine BMD: ß?=??0.912; p?=?0.0001) was independent of the influences that measured body composition, hormonal and insulin resistance factors may exert on BMD (p??0.21).

Conclusions

Adiponectin is an independent predictor of BMD, while its independent contribution to the interindividual variance in measured values is only modest. The influence of adiponectin on total BMC is mediated or confounded by FFM in middle-aged premenopausal women.

     

Relationship of femoral neck areal bone mineral density to volumetric bone mineral density, bone size, and femoral strength in men and women

Summary

Using combined dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography, we demonstrate that men matched with women for femoral neck (FN) areal bone mineral density (aBMD) have lower volumetric BMD (vBMD), higher bone cross-sectional area, and relatively similar values for finite element (FE)-derived bone strength.

Introduction

aBMD by DXA is widely used to identify patients at risk for osteoporotic fractures. aBMD is influenced by bone size (i.e., matched for vBMD, larger bones have higher aBMD), and increasing evidence indicates that absolute aBMD predicts a similar risk of fracture in men and women. Thus, we sought to define the relationships between FN aBMD (assessed by DXA) and vBMD, bone size, and FE-derived femoral strength obtained from quantitative computed tomography scans in men versus women.

Methods

We studied men and women aged 40 to 90?years and not on osteoporosis medications.

Results

In 114 men and 114 women matched for FN aBMD, FN total cross-sectional area was 38% higher (P?P?Conclusions In this cohort of young and old men and women from Rochester, MN, USA who are matched by FN aBMD, because of the offsetting effects of bone size and vBMD, femoral strength and the load-to-strength ratio tended to be relatively similar across the sexes.     

Low bone mineral density is associated with increased risk for myocardial infarction in men and women

Summary  

The association between bone mineral density (BMD) and myocardial infarction (MI) was investigated in 6,872 men and women. For both men and women, lower BMD in the femoral neck and hip was associated with increased risk of MI largely independent of smoking, hypertension, hypertriglyceridemia, and diabetes.     

Diet and lifestyle associated with increased bone mineral density: cross-sectional study of Japanese elderly women at an osteoporosis outpatient clinic

Background Several studies have already demonstrated that lifestyle characteristics, such as physical activity, smoking, and alcohol intake, are associated with bone mineral density (BMD). Coffee intake was shown to be negatively associated with BMD, whereas tea drinking was reported to be associated with increased BMD. A review of the literature, however, revealed that few studies have described the association between BMD and lifestyle, including characteristic Japanese foods such as fish, natto, and Japanese green tea. The aim of this study was to identify lifestyle factors associated with BMD. Methods A total of 632 women age ≥60 years were enrolled in this study. Subjects were interviewed about their lifestyle by means of a questionnaire regarding the consumption pattern of dietary items. BMD was measured at the lumbar spine by dual energy X-ray absorptiometry. Results The BMD was higher in subjects with the habits of alcohol drinking, green tea drinking, and physical activity and lower in those with the habits of smoking and cheese consumption. Multiple regression analysis showed that factors associated with BMD were smoking, alcohol consumption, green tea drinking, and physical activity after adjusting for age and body mass index (BMI). Conclusions In this cross-sectional study at an osteoporosis outpatient clinic, patients with the habits of alcohol drinking, green tea drinking, and physical activity had significantly higher BMD, and those who smoked had significantly lower BMD than patients without each habit after adjusting for age, BMI, and other variables regarding lifestyle.     

Low bone mineral density is not related to failure in femoral neck fracture patients treated with internal fixation

Background and purpose

Internal fixation (IF) in femoral neck fractures has high reoperation rates and some predictors of failure are known, such as age, quality of reduction, and implant positioning. Finding new predictors of failure is an ongoing process, and in this study we evaluated the importance of low bone mineral density (BMD).

Patients and methods

140 consecutive patients (105 females, median age 80) treated with IF had a dual-energy X-ray absorptiometry (DXA) scan of the hip performed median 80 days after treatment. The patients’ radiographs were evaluated for fracture displacement, implant positioning, and quality of reduction. From a questionnaire completed during admission, 2 variables for comorbidity and walking disability were chosen.Primary outcome was low hip BMD (amount of mineral matter per square centimeter of hip bone) compared to hip failure (resection, arthroplasty, or new hip fracture). A stratified Cox regression model on fracture displacement was applied and adjusted for age, sex, quality of reduction, implant positioning, comorbidity, and walking disability.

Results

49 patients had a T-score below –2.5 (standard deviation from the young normal reference mean) and 70 patients had a failure. The failure rate after 2 years was 22% (95% CI: 12–39) for the undisplaced fractures and 66% (CI: 56–76) for the displaced fractures. Cox regression showed no association between low hip BMD and failure. For the covariates, only implant positioning showed an association with failure.

Interpretation

We found no statistically significant association between low hip BMD and fixation failure in femoral neck fracture patients treated with IF.Internal fixation (IF) for femoral neck fracture has many advantages such as minimal blood loss, short operating time, and low infection rate (Rogmark and Johnell 2006). The trend is, however, to treat displaced fractures with hemiarthroplasty due to a high reoperation rate of IF in comparison to arthroplasty (40% vs. 11%), and also due to better functional outcome (Parker and Gurusamy 2006). The high reoperation rate is mainly due to early failure of fixation.There are several factors that can lead to an increased risk of failure. The most important is fracture displacement, which leads to 11% failure in undisplaced fractures and 40% failure in displaced fractures (Parker and Gurusamy 2006, Gjertsen et al. 2011). There is an increased risk of non-union with older age (Parker et al. 2007), poor quality of reduction (Schep et al. 2004, Heetveld et al. 2007), and poor implant positioning (Schep et al. 2004). Low BMD may be another predictor of failure. Low BMD is a well-defined risk factor for hip fracture (Kanis et al. 2008) and experimentally, several studies have shown that low BMD affects the strength of osteosynthesis (Sjostedt et al. 1994, Bonnaire et al. 2005). In addition, low BMD appears to delay fracture healing but the association between low BMD and failure in clinical studies is more uncertain (Giannoudis et al. 2007). Karlsson et al. (1996) and Heetveld et al. (2005) found no association between low BMD and failure, but the known predictors of failure were not adjusted for in these studies. The only study that used all the known potential confounders in the analysis was Spangler et al. (2001). However, this study was retrospective and used the osteoporosis diagnosis from a register. We evaluated the effects of low BMD on failure of femoral neck fractures treated with IF while adjusting for known predictors of failure.     

Muscle strength as a predictor of bone mineral density in young women

It is widely accepted that physical activity is beneficial to bone. However, the specific relationships of muscle strength to bone mineral density (BMD) are poorly understood. We examined strength and BMD in 59 women aged 18-31 years who ranged in exercise patterns from sedentary to active. Mineral density of the right proximal femur (hip) and spine (L2-4) was evaluated by dual-energy x-ray absorptiometry. BMD at the midradius was measured by single-photon absorptiometry. Dynamic strength (one repetition maximum) was measured for the following muscle groups: back, elbow flexors (biceps), leg extensors (quadriceps), and the hip flexors, extensors, adductors, and abductors. Isometric grip strength was assessed by dynamometry. Mineral density at the hip correlated independently with muscle strength and body weight, but not with age. Specifically, femoral neck BMD was significantly correlated with back strength and weight, whereas trochanter and overall hip mineral density were significantly related to biceps, back, and hip adductor strength. Hip mineral density was not related to strength of the quadriceps groups or to that of the hip flexors, extensors, or abductors. In addition, muscle strength was an independent predictor of lumbar spine and midradius mineral density. In stepwise multiple regression analysis, biceps strength proved the most robust predictor of hip BMD and grip strength best predicted bone density at the lumbar spine and radius. We conclude that muscle strength is an independent predictor of bone mineral density, accounting for 15-20% of the total variance in bone density of young women.(ABSTRACT TRUNCATED AT 250 WORDS)     

股骨颈骨折合并抑郁老年男性骨密度和骨代谢变化

目的分析老年男性股骨颈骨折合并抑郁患者骨密度和骨代谢生化指标变化,探讨抑郁对骨质疏松骨代谢的影响。 方法选取于北京医院骨科2017年1月至2019年1月住院的老年男性股骨颈骨折患者102例。排除病理性骨折、认知功能障碍等患者。依据老年抑郁量表(GDS)将老年男性股骨颈骨折患者分为抑郁组和对照组。通过测定并比较两组患者的骨密度(BMD)、血清碱性磷酸酶(ALP)、血钙、血磷、25-羟基-维生素D[25(OH)D]、骨钙素(OC)、Ⅰ型原胶原氨基端前肽(P1NP)、血清Ⅰ型胶原羧基末端肽交联β特殊序列(β-CTX)水平,分析抑郁严重程度(GDS评分)与骨密度及骨代谢生化指标的相关性。分类变量的比较采用卡方检验,连续变量的比较采用t检验,两组连续性变量的相关性应用Pearson相关分析。 结果抑郁组患者BMD明显低于对照组(腰椎t ＝5.964、髋部t ＝2.845,P <0.05)。与对照组相比,抑郁组血清25(OH)D水平下降(t ＝3.077,P <0.05),抑郁组血清OC水平低于对照组(t ＝2.013,P <0.05),而血清β-CTX水平高于对照组(t ＝2.938,P <0.05),P1NP水平与对照组差异无统计学意义(t ＝0.684,P >0.05)。抑郁严重程度(GDS评分)与BMD(r＝-0.456,P <0.05)、25(OH)D(r＝-0.546,P <0.05)、OC(r＝-0.215,P <0.05)呈负相关,与P1NP(r＝-0.115,P>0.05)相关性不显著,与β-CTX(r＝0.372,P<0.05)呈正相关。 结论抑郁症患者的骨形成标志物水平降低和骨吸收标志物水平升高,抑郁症是低骨密度和骨折的危险因素。应重视老年抑郁症患者骨代谢指标和25(OH)D的检测,及时进行维生素D的补充和有效的抗骨吸收药物治疗。     

The type 2 deiodinase Thr92Ala polymorphism is associated with increased bone turnover and decreased femoral neck bone mineral density

The role of type 2 deiodinase (D2) in the human skeleton remains unclear. The D2 polymorphism Thr92Ala has been associated with lower enzymatic activity, which could result in lower local triiodothyronine (T₃) availability in bone. We therefore hypothesized that the D2 Thr92Ala polymorphism may influence bone mineral density (BMD) and bone turnover. We studied 154 patients (29 men, 125 women: 79 estrogen‐replete, 46 estrogen‐deficient) with cured differentiated thyroid carcinoma. BMD and bone turnover markers [bone‐specific alkaline phosphatase (BAP), cross‐linking terminal C‐telopeptide of type I collagen (CTX), procollagen type 1 amino‐terminal propeptide (P1NP), and cross‐linked N‐telopeptide of type I collagen (NTX)] were measured. Effects of the D2 Thr92Ala polymorphism on BMD and bone turnover markers were assessed by a linear regression model, with age, gender, estrogen state, body mass index (BMI), serum calcium, 25‐hydroxyvitamin D, parathyroid hormone (PTH), thyroid‐stimulating hormone (TSH), and free triiodothyroxine (T₄) as covariables. Sixty patients were wild type (Thr/Thr), 66 were heterozygous (Thr/Ala), and 28 were homozygous (Ala/Ala) for the D2 polymorphism. There were no significant differences in any covariables between the three genotypes. Subjects carrying the D2 Thr92Ala polymorphism had consistently lower femoral neck and total hip densities than wild‐type subjects (p = .028), and this was accompanied by significantly higher serum P1NP and CTX and urinary NTX/creatinine levels. We conclude that in patients with cured differentiated thyroid carcinoma, the D2 Thr92Ala polymorphism is associated with a decreased femoral neck BMD and higher bone turnover independent of serum thyroid hormone levels, which points to a potential functional role for D2 in bone. © 2010 American Society for Bone and Mineral Research     

中药对绝经妇女股骨颈骨密度及股骨颈抗骨折能力的影响

目的 观察中药强骨胶囊（QGJN）对绝经妇女股骨颈骨密度（BMD）及股骨颈抗骨折能力（FS）的影响。方法 择自愿参加研究的绝经1年以上，年龄60岁以下的骨量减少或骨质疏松的绝经妇女150例，随机分为3组：中药＋激素组（50例）：采用中药QGJN联合雌激素戊酸雌二醇治疗；中药组（50例）：单纯用中药QGJN治疗；激素组（50例）：单纯用雌激素戊酸雌二醇周期序贯治疗；另50例符合上述条件，目前不愿接受研究用药的绝经妇女作为对照组。各组均于治疗前及治疗后24W采用DEXA骨密度仪测定股骨颈（BMD）。采用肌肉功能分析仪测定股骨颈抗骨折能力（FS）。结果 因各种原因失访18例，182例（包括对照组）完成了总疗程。中药＋激素组（46例）、中药组（48例）、激素组（42例）、股骨颈BMD及FS较治疗前均有明显升高，增幅分别为7．33％、9．04％（P〈0．01）；3．38％，5．87％（P〈0.01）；3．57％，5．91％（P〈0．01），其中中药＋激素组BMD及FS升高幅值均明显高于中药组（P〈0．01）和激素组（P〈0.01）；而激素组上述指标较中药组略高，但差异无显著性（P〉0．05）；对照组（46例）的BMD及FS明显下降。下降幅值分别为3、30％、5．31％。P〈0．01）。结论 中药强骨胶囊能提高绝经妇女股骨颈骨密度及股骨颈抗骨折能力。从而对绝经妇女骨质疏松具有较好的防治作用。其效果与雌激素戊酸雌二醇相仿。两药联用效果更好。     

Cold-activated brown adipose tissue is an independent predictor of higher bone mineral density in women

Summary

In animals, defective brown adipogenesis leads to bone loss. Whether brown adipose tissue (BAT) mass relates to bone mineral density (BMD) in humans is unclear. We determined the relationship between BAT mass and BMD by cold-stimulated positron-emission tomography (PET) and dual-energy X-ray absorptiometry (DXA) in healthy volunteers. Higher BAT mass was associated with higher BMD in healthy women, but not in men, independent of age and body composition.

Introduction

Contrary to the traditional belief that BAT is present only in infants, recent studies revealed significant depots of BAT present in adult humans. In animals, defective brown adipogenesis leads to bone loss. While white adipose tissue mass is a known determinant of BMD in humans, the relationship between BAT and BMD in humans is unclear. We thus examined the relationship between BAT and BMD in healthy adults.

Methods

BAT volume (ml) and activity (standard uptake value) were determined by ¹⁸F-fluorodeoxyglucose PET after overnight mild cold exposure at 19 °C, and BMD was determined by DXA.

Results

Among 24 healthy adults (age 28?±?1 years, F?=?10), BAT volumes were 82.4?±?99.5 ml in women and 49.7?±?54.5 ml in men. Women manifested significantly higher BAT activity, by 9.4?±?8.1 % (p?=?0.03), than men. BAT volume correlated positively with total and spine BMD (r ²?=?0.40 and 0.49, respectively, p?<?0.02) in women and remained a significant predictor after adjustment for age, fat, and lean body mass (p?<?0.05). Total and spine BMD were higher in women who harbored visually detectable BAT on PET images than those without by 11?±?2 % (p?=?0.02) and 22?±?2 % (p?<?0.01), respectively. No associations were observed between BAT parameters and BMD in men.

Conclusions

This study demonstrated higher BMD among healthy women with more abundant BAT, independent of age and other body compositional parameters. This was not observed in men. The data suggest that brown adipogenesis may be physiologically related to modulation of bone density.     

Association between femoral neck bone mineral density and lower limb fat-free mass in postmenopausal women.

Aging is associated with several physiological changes that lead to increased disability and mortality. Examples of these changes are deteriorations in bone and muscle tissues, referred, respectively, as osteopenia and sarcopenia. Both have been linked to multiple morbid outcomes in older adults. The main purpose of this study was to determine the association between femoral neck and trochanter bone mineral density (BMD) and lower limb non-bone fat-free mass (MM) in postmenopausal women. One hundred eighty nine postmenopausal women volunteered to participate in the study (mean age 66.92+/-5.23 yr). Subjects were divided into different groups according to lower limb MM, femoral neck, and trochanter BMD measurements using the 2-step cluster analysis. Pearson chi-square was used to analyze the correlation between the BMD and MM distributions. The 2-step cluster analysis leads to the formation of 3 groups according to the levels of lower limb MM (LMM--low values of MM, IMM--intermediate values of MM, and HMM--high values of MM), 2 groups according to the values of femoral neck BMD (LFN--low values and HFN--high values), and 3 groups for trochanter BMD (LTR--low values, ITR--intermediate values, and HTR--high values). The results of Pearson chi-square revealed a significant association between femoral neck BMD and lower limb MM, and trochanter BMD and lower limb MM, suggesting that individuals with reduced lower limb MM are prone to have decreased femoral neck and trochanter BMD. The present study supports the hypothesis of a relation between the incidence of low BMD and MM. It is recommended that dual-energy X-ray absorptiometry screening should be used to identify both BMD and MM in postmenopausal women to assess more accurately the risk of fractures and disability.     

Low bone mineral density is associated with intracranial posterior circulation atherosclerosis in women

Low bone mineral density (BMD) is associated with carotid atherosclerosis and the incidence of stroke. However, there are no data on the association of BMD with intracranial atherosclerosis. The study population consisted of 357 participants who underwent dual energy x-ray absorptiometric scanning of the lumbar spine and brain 3D time of flight magnetic resonance angiography as part of their voluntary health checks. The basilar, middle cerebral, intracranial internal carotid and intracranial vertebral arteries were evaluated. Low BMD was defined as a T-score of less than − 1. All analyses were stratified by sex and intracranial atherosclerosis location. One hundred seventy-six women (53 years; 66.9% postmenopausal; 33.5% low BMD; 60.2% intracranial atherosclerosis in the anterior circulation (AC); 60.2% intracranial atherosclerosis in the posterior circulation (PC)) and 181 men (51 years; 28.7% low BMD; 61.9% intracranial atherosclerosis in the AC; 55.8% intracranial atherosclerosis in the PC) were included. In women, low BMD was significantly associated with intracranial atherosclerosis in the PC with the odds ratio of 2.57 (95% confidence interval 1.11–5.99). However, intracranial atherosclerosis in the AC was not associated with BMD in women. In men, there were no significant associations between BMD and intracranial atherosclerosis. In conclusion, this study shows that low BMD is associated with subclinical intracranial PC atherosclerosis in women but not in men.     

High impact exercise increased femoral neck bone mineral density in older men: A randomised unilateral intervention

IntroductionThere is little evidence as to whether exercise can increase BMD in older men with no investigation of high impact exercise. Lifestyle changes and individual variability may confound exercise trials but can be minimised using a within-subject unilateral design (exercise leg [EL] vs. control leg [CL]) that has high statistical power.PurposeThis study investigated the influence of a 12 month high impact unilateral exercise intervention on femoral neck BMD in older men.MethodsFifty, healthy, community-dwelling older men commenced a 12 month high impact unilateral exercise intervention which increased to 50 multidirectional hops, 7 days a week on one randomly allocated leg. BMD of both femurs was measured using dual energy X-ray absorptiometry (DXA) before and after 12 months of exercise, by an observer blind to the leg allocation. Repeated measures ANOVA with post hoc tests was used to detect significant effects of time, leg and interaction.ResultsThirty-five men (mean ± SD, age 69.9 ± 4.0 years) exercised for 12 months and intervention adherence was 90.5 ± 9.1% (304 ± 31 sessions completed out of 336 prescribed sessions). Fourteen men did not complete the 12 month exercise intervention due to: health problems or injuries unrelated to the intervention (n = 9), time commitments (n = 2), or discomfort during exercise (n = 3), whilst BMD data were missing for one man. Femoral neck BMD, BMC and cross-sectional area all increased in the EL (+ 0.7, + 0.9 and + 1.2 % respectively) compared to the CL (− 0.9, − 0.4 and − 1.2%); interaction effect P < 0.05. Although the interaction term was not significant (P > 0.05), there were significant main effects of time for section modulus (P = 0.044) and minimum neck width (P = 0.006). Section modulus increased significantly in the EL (P = 0.016) but not in the CL (P = 0.465); mean change + 2.3% and + 0.7% respectively, whereas minimum neck width increased significantly in the CL (P = 0.004) but not in the EL (P = 0.166); mean changes being + 0.7% and + 0.3% respectively.ConclusionA 12 month high impact unilateral exercise intervention was feasible and effective for improving femoral neck BMD, BMC and geometry in older men. Carefully targeted high impact exercises may be suitable for incorporation into exercise interventions aimed at preventing fractures in healthy community-dwelling older men.     

Low bone mineral density is associated with bone microdamage accumulation in postmenopausal women with osteoporosis

Marked suppression of bone turnover by bisphosphonates is associated with increased bone microdamage accumulation in animal models. The purpose of this study was to test the hypothesis that long-term treatment with alendronate (ALN) results in accumulation of microdamage in bone in women after menopause. Sixty-six postmenopausal women with osteoporosis (mean age of 68.0 years and mean BMD T-score of -1.7 at total hip and -2.8 at lumbar spine; 62% with prevalent fractures) were evaluated in this cross-sectional analysis. Thirty-eight had been treated previously with ALN (10 mg/day or 70 mg/week for a mean duration of 63.6 months) while twenty-eight were treatment naive (TN). Without adjustments, crack surface density (Cr.S.Dn) and crack density (Cr.Dn) were not different between ALN and TN patients. After adjustment for potential confounders (age, prevalent fractures, femoral neck BMD, activation frequency and center), Cr.Dn was elevated in ALN patients (P=0.028 and P=0.069 for Cr.S.Dn). In ALN patients only, lower femoral neck BMD (Cr.S.Dn, r=-0.58, P=0.003; Cr.Dn, r=-0.54, P=0.005) and increased age (Cr.S.Dn, r=0.43, P=0.03; Cr.Dn, r=0.43, P=0.03) were associated with microdamage accumulation. Among potential confounders, femoral neck BMD was the only independent predictor for these correlations (P=0.04 for Cr.Dn and P=0.03 for Cr.S.Dn). We conclude that increased microdamage accumulation may occur in low BMD patients treated with alendronate.     

Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis

Background  

Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis.     

Self-reported number of remaining teeth is associated with bone mineral density of the femoral neck,but not of the spine,in Japanese men and women

Recent studies suggest that a small number of remaining teeth may be associated with low skeletal bone mineral density (BMD) in postmenopausal women. Estrogen deficiency after menopause is considered potential cause relating to tooth loss accompanied by low skeletal BMD in women. Since estrogen plays a dominant role in regulating the male skeleton, it is likely that a small number of remaining teeth also may be associated with low skeletal BMD in men. However, it remains uncertain whether tooth loss is associated with low skeletal BMD in both men and women. We investigated the association between self-reported number of remaining teeth and BMD of the spine and the femoral neck in a cohort of 1914 Japanese subjects aged 48–95 years who were recruited from the Adult Health Study conducted by the Radiation Effects Research Foundation (RERF). BMD of the spine and the femoral neck was measured by dual energy X-ray absorptiometry (DXA). Tooth count was self-reported in response to a simple question to subjects about the number of remaining teeth they had at the time of the survey. Multiple regression analysis adjusted for age, weight, height, smoking, estrogen use, and years since menopause revealed a significant association between number of remaining teeth and BMD of the femoral neck in both men and women; however, no association was found between number of remaining teeth and BMD of the spine in both sexes. Retention of four teeth was significantly associated with a 0.004 g/cm² increase in femoral neck BMD in men (P<0.05), which was similar to that observed in women (P<0.01). Our results suggest the presence of common causes, except age and body weight, relating to tooth loss accompanied by low BMD of the femoral neck in both men and women.     

Low bone mass in Pompe disease: Muscular strength as a predictor of bone mineral density

Pompe disease is an inherited metabolic myopathy caused by deficiency of acid alpha-glucosidase. The introduction of enzyme replacement therapy as treatment for the disease may change prospects for patients and may require that more attention be paid to co-morbidities such as osteoporosis.MethodsBone mineral status was assessed in children and adults with Pompe disease and compared with reference values by means of dual energy X-ray absorptiometry (DXA) technology (GE Lunar DPX, GE Health Care). Bone mineral density (BMD) of the total body and the lumbar spine (L2–L4) was measured in adults and children; BMD of the femoral neck was measured in adults only. Exclusion criteria were: age < 4 years, severe contractures, and inability to transfer the patient.Results46 patients were enrolled in the study; 36 adults and 10 children. The BMD was significantly lower in Pompe patients than in healthy individuals. Sixty-seven percent of patients had a BMD Z-score below ?1, 26% were classified as osteoporosis/low bone mass for chronological age (T-score < ?2.5 in adults or Z-score < ?2 in children), 66% had a BMD Z-score below ?1 of the femoral neck, and 34% had a BMD Z-score below ?1 for the lumbar spine. Osteoporosis/low bone mass for chronological age was more frequent in patients who were wheelchair-bound, but was also observed in ambulant patients. We found a significant correlation between proximal muscle strength and total body BMD. Of the 10 children, 8 (all four patients with the classic infantile form) had a low BMD.ConclusionLow BMD is a frequent finding in patients with Pompe disease and may be causally related to decreased proximal muscle strength. BMD should be monitored at regular intervals. Children deserve specific attention.     

IGFBP-2 is a negative predictor of cold-induced brown fat and bone mineral density in young non-obese women

Recent studies have shown a positive correlation between brown adipose tissue (BAT) and bone mineral density (BMD). However, mechanisms underlying this relationship are unknown. Insulin-like growth factor 1 (IGF-1) is an important regulator of stem cell differentiation promoting bone formation. IGF binding protein 2 (IGFBP-2) binds IGF-1 in the circulation and has been reported to inhibit bone formation in humans. IGF-1 is also a crucial regulator of brown adipocyte differentiation. We hypothesized that IGFBP-2 is a negative and IGF-1 a positive regulator of BAT-mediated osteoblastogenesis. We therefore investigated a cohort of 15 women (mean age 27.7 ± 5.7 years): 5 with anorexia nervosa (AN) in whom IGF-1 levels were low due to starvation, 5 recovered AN (AN-R), and 5 women of normal weight. All subjects underwent assessment of cold-activated BAT by PET/CT, BMD of the spine, hip, femoral neck, and total body by DXA, thigh muscle area by MRI, IGF-1 and IGFBP-2. There was a positive correlation between BAT and BMD and an inverse association between IGFBP-2 and both BAT and BMD. There was no association between IGF-1 and BAT. We show for the first time that IGFBP-2 is a negative predictor of cold-induced BAT and BMD in young non-obese women, suggesting that IGFBP-2 may serve as a regulator of BAT-mediated osteoblastogenesis.