Male osteoporosis: epidemiology and pathophysiology

[Gender-specific differences in comorbidities of rheumatoid arthritis]

BACKGROUND

Comorbidities play an important role in the course and therapy of rheumatoid arthritis (RA). Sex-specific aspects are observed with regard to prevalence and manifestation of RA-related comorbidities.

AIM

A summary of current insights into sex and gender-related aspects of frequent comorbidities in RA is given.

MATERIAL AND METHODS

National data were analyzed and literature findings from meta-analyses, observational studies and reviews with regard to gender and RA-associated comorbidities are presented.

RESULTS

There are gender-specific differences in the prevalence of comorbidities of RA. Depression, fibromyalgia and hypothyroidism are more frequent in women than in men, whereas cardiovascular diseases and diabetes are more common in men. Osteoarthritis and osteoporosis are frequent in both sexes.

CONCLUSION

Sex and gender-specific aspects should be taken into consideration in the diagnostics and treatment of RA-related comorbidities.

Possible Association between Erectile Dysfunction and Osteoporosis in Men

Sexual dysfunction in general and erectile dysfunction (ED) in particular significantly affect men’s quality of life. Some patients who have ED, also develop osteoporosis. So, in this study we investigated the relationship between erectile dysfunction and osteoporosis in men. 95 men with erectile dysfunction and 82 men with normal sexual function were included in the study. The men’s sexual functions were evaluated by International Index of Erectile Function-5 items (IIEF-5). All men received a Dual Energy X-ray Absorptiometry (DEXA; Hologic) scan to measure bone mineral density (BMD) for osteoporosis. Chi-square test was used for statistical analysis. Mean age was 53.5 (38–69) in ED group and 50.1 (31–69) in control group. In ED group the men have lower T score levels than those of the control group. In conclusion, the men who have erectile dysfunction were at more risk for osteoporosis. The results of the present study demonstrate that the men with erectile dysfunction have low bone mineral density and they are at higher risk for osteoporosis. Because of easy and noninvasive evaluation of osteoporosis, patients with ED should be checked for bone mineral density and osteoporotic male subjects should be evaluated for ED.

Myocardial infarction risk among patients with fractures receiving bisphosphonates

OBJECTIVE

To determine if bisphosphonates are associated with reduced risk of acute myocardial infarction (AMI).

PATIENTS AND METHODS

A cohort of 14,256 veterans 65 years or older with femoral or vertebral fractures was selected from national administrative databases operated by the US Department of Veterans Affairs and was derived from encounters at Veterans Affairs facilities between October 1, 1998, and September 30, 2006. The time to first AMI was assessed in relationship to bisphosphonate exposure as determined by records from the Pharmacy Benefits Management Database. Time to event analysis was performed using multivariate Cox proportional hazards regression. An adjusted survival analysis curve and a Kaplan-Meier survival curve were analyzed.

RESULTS

After controlling for atherosclerotic cardiovascular disease risk factors and medications, bisphosphonate use was associated with an increased risk of incident AMI (hazard ratio, 1.38; 95% CI, 1.08-1.77; P=.01). The timing of AMI correlated closely with the timing of bisphosphonate therapy initiation.

CONCLUSION

Our observations in this study conflict with our hypothesis that bisphosphonates have antiatherogenic effects. These findings may alter the risk-benefit ratio of bisphosphonate use for treatment of osteoporosis, especially in elderly men. However, further analysis and confirmation of these findings by prospective clinical trials is required.

Health related quality of life in male patients with osteoporosis: results of a cross sectional study

INTRODUCTION

Osteoporosis is one of the most common diseases affecting elderly persons. Male patients with osteoporosis have rarely been the focus of earlier studies. This study explores health related quality of life (HRQoL) indicators in a sample of German male patients with osteoporosis to determine potential avenues for clinical practice changes.

METHODS

This cross-sectional study describes two HRQoL indicators (EQ5D and QUALEFFO-41) in a sample of male patients being treated for osteoporosis. Questionnaires were sent to all male patients being treated at the Dresden University Hospital outpatient endocrine clinic. Of the 344 patients invited to participate in the study 155 (57.2%) were included.

RESULTS

Overall HRQoL EQ-5D-scores for male patients with osteoporosis were greater than those of comparable groups of the German population. Patients with ≥2 fractures had the highest level of impairment in HRQoL. Of all the dimensions of EQ-5D-scores, pain/discomfort was the most affected. Better HRQoL (median values <10.0/QUALEFFO-41 scores) were detected in the whole sample for jobs around the house, activities of daily living and mobility compared to other dimensions. The highest levels of impairment were observed in the QUALEFFO-41 domains of general health perception, mental function and pain.

CONCLUSION

This analysis confirms the association between number of fractures and worse estimation of HRQoL in male patients. Because men are 3 times less likely to suffer from osteoporosis than women, the specific HRQoL characteristics of male patients with this disease can often be overlooked. Clinicians should consider mental health referral especially for osteoporotic male patients having experienced ≥2 fractures.

The male osteoporosis risk estimation score and the osteoporosis self-assessment screening tool for Indonesian men

PURPOSE

To evaluate the male osteoporosis risk estimation score (MORES) and the osteoporosis self-assessment screening tool (OST) score as a means of screening for osteoporosis in men.

METHODS

Records of 113 Indonesian men aged 50 to 91 (mean, 71) years who underwent evaluation of bone mineral density (T-score) using Dual-energy X-ray absorptiometry were retrospectively reviewed. The MORES was determined by 3 osteoporosis risk factors: age (in years), body weight (in kg), and chronic obstructive pulmonary disorder. A MORES of ≥6 indicated osteoporosis and corresponded to a T-score of ≤-2.5. The OST score was calculated as body weight (in kg) minus age (in years) multiplied by 0.2. An OST score of ≤2 indicated osteoporosis and corresponded to a T-score of ≤-2.5. Sensitivity, specificity, and positive and negative predictive values of the MORES and the OST score were determined.

RESULTS

Respectively for the MORES and the OST score, sensitivity values were 100% and 74%, specificity values were 7% and 41%, positive predictive values were 25% and 28%, and negative predictive values were 100% and 83%. Using receiver operating characteristic curves, the area under curve was 0.535 for the MORES and 0.574 for the OST score.

CONCLUSION

The MORES and the OST score should be used together to screen for osteoporosis in men.

Cannabinoid receptors as target for treatment of osteoporosis: a tale of two therapies

The central nervous system plays an important role in regulating bone metabolism in health and in disease with a number of neurotransmitters been reported to influence bone cell activity through a central relay. In keeping with this, recent studies demonstrated that endocannabinoids and their receptors are involved in the pathogenesis of osteoporosis. The endocannabinoids anandamide and 2-arachidonylglycerol are found in the skeleton and numerous studies also showed that bone cells express the cannabinoid receptors CB1 and CB2 and the orphan receptor GPR55. Pharmacological and genetic inactivation of CB1, CB2 and GPR55 in adult mice suppress bone resorption, increase bone mass and protect against bone loss, suggesting that inverse agonists/antagonists of these receptors may serve as anti-resorptive agents. In the ageing skeleton however CB1 and CB2 receptors have a protective effect against age-dependent bone loss in both male and female mice. CB1 receptor deficiency in aged mice results in accelerated age-dependent osteoporosis due to marked increase in bone resorption and significant reduction in bone formation coupled to enhanced adipocyte accumulation in the bone marrow compartment. Similar acceleration of bone loss was also reported in CB2 deficient mice of similar age but found to be associated with enhanced bone turnover. This review summarises in vitro and in vivo findings relating to the influence of cannabinoid ligands on bone metabolism and argues in favour of the exploitation of cannabinoid receptors as targets for both anabolic and anti-resorptive therapy for treatment of complex multifaceted bone diseases such as osteoporosis.

Male osteoporosis

Osteoporosis develops in males approximately 10 years later than in females. Low vitamin D is a common problem. Decline in testosterone represents a major cause for osteoporosis in men. Bisphosphonates are the treatment of choice for osteoporosis in older males.

Computer-based screening of chest X-rays for vertebral compression fractures as an osteoporosis index in men

We evaluated the recognition of osteoporosis in the veteran male population through a computer-based review of chest X-ray (CXR) reports in the Veterans Affairs Northern California Health Care System database, looking for unrecognized vertebral fractures. All CXR reports between January 1, 2000 and December 31, 2001, were scanned for the terms "compression" or "wedg (where the "" indicates a wild card search encompassing such terms as "wedge" or "wedging")". During this time, 26,994 CXR examinations were performed on 18,069 patients. 22,494 (83.3% of the total) CXR examinations were done in 14,561 men >or=50 years of age. 780 CXR reports (3.5%) encompassing 664 men (4.5%) contained at least one key phrase suggesting osteoporosis. Three years later, 495 of these 664 men were still living. 99 of these (20%) had been diagnosed with osteoporosis, 72 (15%) had a dual-energy X-ray absorptiometry (DXA) scan, and 89 (18%) had ever been prescribed a bisphosphonate. Overall, only 126 (25%) men had chart documentation indicating some recognition by the provider of the abnormality reported on CXR. We conclude that a significant fraction of men >50 years old may have unrecognized osteoporosis severe enough to result in vertebral fracture. We conclude that computerized screening of CXR reports may represent an effective strategy to aid clinicians in identifying men at risk for further debilitating fractures.

Testosterone correlated to symptoms of partial androgen deficiency in aging men (PADAM) in an elderly Swedish population

OBJECTIVE

To investigate the prevalence of different symptoms of partial androgen deficiency in aging men (PADAM) and to correlate them with blood concentrations of testosterone and bioavailable testosterone.

DESIGN

A total of 370 men, aged 55 to 75 years, were invited to one of three primary healthcare centers in Sweden. They were asked to complete a questionnaire regarding demographic data, medical history, mood status, medication, castration therapy and smoking, exercise and alcohol habits, as well as different symptoms of PADAM. The 10 questions from a previously used questionnaire (the ADAM questionnaire) were included. The men were offered blood tests for analyses of testosterone, follicle stimulating hormone, luteinizing hormone, steroid hormone-binding globulin, and albumin. From these test results, we calculated the bioavailable testosterone.

RESULTS

Of the questionnaires sent out, 81.6% were returned and eligible for evaluation. Blood samples were obtained from 85.8% of men answering the questionnaire. Many of the symptoms, including five from the ADAM questionnaire, were more common in older age groups (P < 0.05). Three symptoms, deterioration in work performance, decreased strength and/or endurance, and bothersome hot flushes, were associated with low bioavailable testosterone and/or testosterone (P < 0.05). Testosterone and bioavailable testosterone did not differ between age groups, but bioavailable testosterone was higher in men with three or fewer symptoms on the ADAM questionnaire.

CONCLUSIONS

Symptoms associated with PADAM often occur in an elderly population, but we could only find an association between three symptoms and blood testosterone concentrations, one being bothersome hot flushes. It is likely that these symptoms have a more complex background than only PADAM.

The relationship between body composition and bone mineral content: threshold effects in a racially and ethnically diverse group of men

We examined BMC and body composition in 1,209 black, Hispanic, and white men. Weight, BMI, waist circumference, and fat mass were associated with BMC only up to certain thresholds, whereas lean mass exhibited more consistent associations. The protective influence of increased weight appears to be driven by lean mass.

INTRODUCTION

Reduced body size is associated with decreased bone mass and increased fracture risk, but associations in men and racially/ethnically diverse populations remain understudied. We examined bone mineral content (BMC) at the hip, spine, and forearm as a function of body weight, body mass index (BMI), waist circumference, fat mass (FM), and nonbone lean mass (LM).

METHODS

The design was cross-sectional; 363 non-Hispanic black, 397 Hispanic, and 449 non-Hispanic white residents of greater Boston participated (N = 1,209, ages 30-79 y). BMC, LM, and FM were measured by DXA. Multiple linear regression was used to describe associations.

RESULTS

Weight, BMI, waist circumference, and FM were associated with BMC only up to certain thresholds. LM, by contrast, displayed strong and consistent associations; in multivariate models, femoral neck BMC exhibited a 13% increase per 10 kg cross-sectional increase in LM. In models controlling for LM, positive associations between BMC and other body composition measures were eliminated. Results did not vary by race/ethnicity.

CONCLUSIONS

The protective effect of increased body size in maintaining bone mass is likely due to the influence of lean tissue. These results suggest that maintenance of lean mass is the most promising strategy in maintaining bone health with advancing age.

Older Elite Football Players Have Reduced Cardiac and Osteoporosis Risk Factors

INTRODUCTION/PURPOSE

Aging with a sedentary lifestyle is associated with increased risk for developing cardiovascular disease (CVD), osteoporosis, and sarcopenia. The purpose of this study was to determine whether former professional football athleticism would be associated with reduced risk factors for CVD and osteoporosis, and higher muscle mass in later life.

METHODS

Maximal aerobic capacity (VO2max), body composition, and lipid and glucose risk factors for CVD were compared between 16 older former professional football players and never-athletic men matched for age, body mass index, current physical activity, and race. Regional bone mineral density of the football players was compared with age-matched reference norms.

RESULTS

Despite greater physical activity into middle age, the former football players had similar VO2max as the controls. Former football players had 26% lower total-body fat mass, 26% lower visceral adipose tissue area, and 13% higher muscle mass compared with the controls (P < 0.05). High-density lipoprotein cholesterol (HDL-C) levels were 37% higher (P < 0.001), HDL2-C levels were fourfold higher (P < 0.001), and triglycerides were 31% lower (P < 0.05) in the former football players than the controls. The former football players also had 20% and 6% higher total-body bone mineral content and density than the controls (P < 0.05) and higher lumbar spine, femoral neck, and greater trochanter bone mineral density than similar age-referenced norms (P < 0.05).

CONCLUSION

Elite athlete physical activity status in young adulthood, and remaining physically active in middle age, may confer body composition changes that are sustained in older adulthood. In this small sample of older men, former successful professional athletes who remained physically active in middle age have a favorable body composition and reduced risk factors for CVD and osteoporosis compared with healthy age- and BMI-matched older men.

Soy protein and bone mineral density in older men and women: A randomized trial

OBJECTIVE

Test the hypothesis that soy isoflavone supplementation preserves bone mineral density (BMD) in men and women.

METHODS

We conducted a controlled, parallel-arm, double-blinded trial with 145 participants, 50-80 years, with random assignment to soy beverage daily for 12 months. Active treatment (+ISO) received soy protein containing 83 mg isoflavones (45.6 mg genistein, 31.7 mg daidzein), aglycone units; the comparison group (-ISO) received soy protein containing 3mg isoflavones. We measured BMD using dual-energy X-ray absorptiometry at the total hip and posterior-anterior spine (L1-L4) at baseline in 22 women and 123 men, and at 12 months in 13 women and 98 men. We used linear mixed models to test for an isoflavone effect on percentage BMD change from baseline in spine and hip.

RESULTS

Among all participants, mean percent change in spine BMD (+/-S.E.) was 0.16+/-0.44 in -ISO (P=0.10) at 12 months. Treatment effects on spine BMD were significantly greater in women than men (P=0.01). At 12 months, in women, mean percent change was 0.58+/-0.70 in +ISO and -1.84+/-0.86 in -ISO (P=0.05); among men it was 1.32+/-0.53 in +ISO and 0.31+/-0.48 in -ISO (P=0.16). By comparison, percent change in hip BMD was similar in the treatment groups, and was not different between men and women. Mean percent change in hip BMD from baseline to 12 months was 0.54+/-0.38 in +ISO and -0.13+/-0.36 in -ISO (P=0.20) among all participants.

CONCLUSIONS

Soy protein containing isoflavones showed a modest benefit in preserving spine, but not hip BMD in older women.

An update on biomarkers of bone turnover and their utility in biomedical research and clinical practice

BACKGROUND

Maintenance of the structural and functional integrity of the skeleton is a critical function of a continuous remodeling driven by highly associated processes of bone resorption and synthetic activities driven by osteoclasts and osteoblasts, respectively. Acceleration of bone turnover, accompanied with a disruption of the coupling between these cellular activities, plays an established role in the pathogenesis of metabolic bone diseases, such as osteoporosis. During the past decades, major efforts have been dedicated to the development and clinical assessment of biochemical markers that can reflect the rate of bone turnover. Numerous studies have provided evidence that serum levels or urinary excretion of these biomarkers correlate with the rate of bone loss and fracture risk, proving them as useful tools for improving identification of high-risk patients.

OBJECTIVE

The aim of the present review is to give an update on biomarkers of bone turnover and give an overview of their applications in epidemiological and clinical research.

DISCUSSION

Special attention is given to their utility in clinical trials testing the efficacy of drugs for the treatment of osteoporosis and how they supplement bone mass measurements. Recent evidence suggests that biochemical markers may provide information on bone age that may have indirectly relates to bone quality; the latter is receiving increasing attention. A more targeted use of biomarkers could further optimize identification of high-risk patients, the process of drug discovery, and monitoring of the efficacy of osteoporosis treatment in clinical settings.