Osteoporosis in men: pathophysiology, evaluation, and therapy

Restoration of regenerative osteoblastogenesis in aged mice: modulation of TNF

Skeletal changes accompanying aging are associated with both increased risk of fractures and impaired fracture healing, which, in turn, is due to compromised bone regeneration potential. These changes are associated with increased serum levels of selected proinflammatory cytokines, e.g., tumor necrosis factor alpha (TNF-alpha). We have used a unique model of bone regeneration to demonstrate (1) that aged-related deficits in direct bone formation can be restored to young mice by treatment with TNF blockers and (2) that the cyclin-dependent kinase inhibitor p21 is a candidate for mediation of the osteoinhibitory effects of TNF. It has been hypothesized recently that TNF antagonists may represent novel anabolic agents, and we believe that the data presented here represent a successful test of this hypothesis.

Risk of bone loss in men with multiple sclerosis

CONTEXT

Osteoporosis and the increased fracture risk associated with osteoporosis become apparent in men approximately 10 years later than women. However, in recent studies, approximately 20% of healthy men in the age range 55-64 years were found to be osteopenic. Emerging data suggest a significantly increased prevalence of osteoporosis in men and women with multiple sclerosis (MS) compared to age-matched controls, but no specific clinical testing recommendations are available for men.

OBJECTIVE

To determine the proportion of male MS patients with osteoporosis and to identify the factors associated with the reduction in bone mass.

DESIGN

Consecutive male MS patients seen at our MS clinic were screened with dual-X-ray absorptiometry (DEXA) scan for determining the bone mineral density (BMD). All patients had neurological Expanded Disability Status Scale (EDSS) evaluation. The results were compared to healthy age-matched male reference population using the Z score and to a cohort of women MS patients and women controls. Calcium, total testosterone, sex-hormone binding globulin (SHBG), 25-hydroxy-vitamin-D, and parathyroid hormone (PTH) were evaluated in male patients with decreased BMD. Relevant data on body mass index (BMI), medication, alcohol consumption, smoking, and sexual dysfunction were recorded.

SETTING

Academic MS Centre.

PATIENTS AND OTHER PARTICIPANTS

Forty consecutive male MS patients, age mean 51.2 +/- 8.7 years, and mean EDSS of 5.8 +/- 1.9 were evaluated with DEXA scan. Of these, 17.5% patients were relapsing-remitting (RR) MS, 57.5% were secondary progressive (SP) MS and 25% were primary progressive (PP) MS.

MAIN OUTCOME MEASURE

Proportion of male MS patients with reduced BMD at the lumbar spine and femoral neck.

RESULTS

Thirty-two (80%) of our patients had a reduced bone mass of either lumbar spine or the femoral neck; of these 17 patients (42.5%) had osteopenia and 15 patients (37.5%) had osteoporosis. Twenty-one per cent (eight out of 38 patients) had vertebral, rib or extremities fractures. Multivariate linear regression analysis indicated that the EDSS (P < 0.0001) and BMI (P = 0.0004) were the important factors associated with low BMD at the femoral neck and the EDSS was the important factor (P = 0.0017) associated with low BMD at the lumbar spine. The same factors emerged as significantly associated with the corresponding Z scores, which are corrected for age and sex. No clear association between intravenous steroid therapy and BMD was evident in the multivariate analysis. Low levels of 25-hydroxy-vitamin-D were seen in 37.5% of patients.

CONCLUSIONS

The proportion of male MS patients with reduced bone mass is high and disproportionate to their age and ambulation, consistent with an association between the MS disease process and pathological bone loss. Increased awareness and bone density screening of male and female MS patients over 40 years of age is warranted.

Does bone mineral density and knowledge influence health-related behaviors of elderly men at risk for osteoporosis?

To determine if bone mineral density (BMD) substantially influences health-related behaviors in men at risk for osteoporosis, we surveyed 102 men who were participating in a study of prostate cancer and bone loss. Subjects included 68 men with prostate cancer, 44 of whom were hypogonadal on androgen deprivation therapy, and 34 healthy age-matched controls without prostate cancer. At least 6 mo after an initial evaluation, assessment of BMD, and osteoporosis information session, men were administered a questionnaire regarding their healthrelated behaviors. We found that men with osteopenia were 4 times as likely (13%) and men with osteoporosis were more than 10 times as likely (41%) to start taking bisphosphonates compared to men with a normal bone mass (3%, p < 0.0001). Men with low bone mass were more likely to begin taking calcium (p < 0.05) and vitamin D supplements (p < 0.05). Hypogonadal men were 10 times as likely to begin using bisphosphonates (34%) compared to the control group (3%, p < 0.0001) and twice as likely to begin using calcium supplements (57% vs 24%, p < 0.05). Caffeine consumption, alcohol consumption, dietary calcium intake, exercise, and smoking habits were not different in men with osteoporosis or those who were hypogonadal compared to controls. We conclude that men with low bone mass and hypogonadism were more likely to start using bisphosphonates, calcium supplements, and vitamin D supplements after having a bone density test. However, they were not more likely to make significant health-related lifestyle changes after obtaining the results of their bone mass.