That Osteoporosis is not just a women’s disease is poorly appreciated. While osteoporosis does affect more women, it remains a serious male health issue associated with significant morbidity and mortality. It is estimated that one third of all osteoporotic fractures occur in men. The incidence of vertebral deformities (often representing vertebral fractures) is similar in men and women over the age of 50; 21.5% and 23.5% respectively. Although most hip fractures occur in women, men who break a hip are more likely to suffer morbidity and die.
 
Fracture risk and diagnosis:
The WHO has identified certain factors that increase fracture risk in men, independent of bone mineral density (BMD). (Box 1)

Other key risk factors
• Alcohol intake >2 units/day (18 gm)
• Primary or seconday hypogonadism
• Use of LHRH analogues (anti androgen therapy)
• Smoking (current or past history of )
• Family history of osteoporosis or fracture
• Low BMI (< 20 kg/m2)

The role of Bone densitometry in the diagnosis of Osteoporosis:
In men over 50 years of age, a diagnosis of osteoporosis may be considered when the T score is –2.5 or less. The original WHO diagnostic classification for osteoporosis was intended to apply to post menopausal women over 50 years of age and should not be applied to younger people. In men younger than 50 years, Z scores should be used to describe the degree to which the bone density measurement differs from normal: Z scores less than –2 are below the expected range for age. The following classification is recommended when interpreting BMD readings in men.

• Men >/= age 50 
        T score </= -2.5: Osteoporosis
        T score between –1.5 and –2.5: Reduced bone density

• Men < age 50 
        Z score < -2.0: below expected range for age
        Z score >/= -2: Within expected range for age
        Individuals with low bone mass should be further assessed with stratification of 
        fracture risk. A comprehensive calculation by the WHO of 10 year absolute fracture risk
        based on BMD, age, sex and other risk factors is anticipated soon and should help
        physicians determine decisively appropriate candidates for treatment.

How should Osteoporosis be investigated in men?
A complete evaluation includes a detailed history and physical examination with identification of possible contributing factors and baseline and serial height measurements to detect height loss that may be indicative of underlying vertebral compression fractures. Patients with significant height loss, back pain or kyphosis should undergo lateral thoracic and lumbar spine radiographs to identify vertebral fractures. Since there may be an identifiable secondary cause (Box 2) in almost 50% of male osteoporosis, focused laboratory tests (Box 3) should be performed. Osteoclast and Osteoblast activity can be assessed by measuring  biochemical markers of bone turnover, however given the fact that they are subject to considerable biological variances in individuals, they are not recommended in the routine clinical assessment of Osteoporosis in men at the present time.

Box 2
Selected Secondary causes of Bone Loss in Men
• Hyperparathyroidism- Primary or Secondary
• Vitamin D inadequacy
• Hyperthyroidism
• Malignancy ( e.g. Myeloma or Bony Metastasis)
• Hepatic insufficiency
• Rheumatoid arthritis
• Hypercalciurai
• Hypogonadism (Primary or secondary)

Additional tests where indicated by clinical evaluation
• Parathyroid Hormone (PTH)
• Serum 25 –hydroxy Vitamin D
• Serum Immunoelectrophoresis
• 24 hour urine Clacium
• 24 hour Urine Cortisol

Who should be treated?
Pharmacological intervention is recommended for those men at highest risk of a fragility fracture. Physicians should consider therapy for the following groups.

        • Men aged 65 years or older with a T score <-2.5 at any measured site (hip, spine or 
        forearm)
        • Men >/= age 50 with a fragility fracture or vertebral compression fracture and T score
         <-1.5. When the measured BMD is well preserved (particularly at the hip, which is less
         influenced by degenerative osteophyte formation), prevalent vertebral fractures may
         reflect previous trauma rather than osteoporosis
        • All men on glucocorticoid therapy >/= 3months duration with T score <-1.5
        • All men with clinical hypogonadism from any cause with T score <-1.5

Treatment measures:
Preventive interventions in males are similar to that employed in women, including adequate intake of calcium, 1200-1500 mg/day and Vitamin D, 400-600IU/day. Vitamin D should be increased to 600- 800IU/day in men over 70 years old. Adequate exercise also should be strongly recommended. However drug therapy should be initiated in all men at high risk for fracture.

Pharmacological Therapy:
Bisphosphonate therapy remains the mainstay in the treatment of male osteoporosis. Both Alendronate and Risedronate are approved for treatment of osteoporosis in men. Bisphosphonates are also effective for the prevention and treatment of Glucocorticoid-induced bone loss, in the prevention of bone loss in men receiving androgen deprivation therapy for prostate cancer and the osteoporosis associated with organ transplantation. Data on the other bisphosphonate currently approved for use in post -menopausal women with osteoporosis viz Ibandronate is lacking in men.
Testosterone therapy has been shown to improve BMD at the spine and hip in hypogonadal men, but no trials have proven that it reduces fractures. It may be most appropriate for men with symptoms of hypogonadism (e.g. sexual dysfunction), in whom it may provide additional extra skeletal benefits.

Subcutaneous Teriparatide (recombinant human parathyroid hormone 1-34, Forteo ® has recently been approved for the treatment of osteoporosis in both men and women at high risk for fracture –including those with a previous osteoporotic fracture, multiple risk factors for fracture or those who have failed previous treatment. Significant improvements in BMD have been reported with the use of Teriparatide. However, Vertebral and non-vertebral fracture benefits have been reported only in postmenopausal women, as trials in men were not powered for these outcomes. To date no fracture data are available on the use of Calcitonin in men.

Summary: Osteoporosis remains an under-diagnosed condition in men though it is associated with significant morbidity and mortality. A proper  understanding of its evaluation and management can lead to a significant reduction in fracture burden in men.

References:
(1) Jackson SA et al. Osteoporosis Int 200; 11(8): 680-7. Vertebral fracture definition from population based data: preliminary results from the Canadian Multicentre Osteoporosis Study (CaMOS)
(2) Johnell O et al. Calcif Tiss Int 2001; 69 (1);182-4. Mortality, morbidity and assessment of fracture risk in male osteoporosis.
(3) Olszynski WP et al. Clin Ther 2004; 26; 15-28. Osteoporosis in men: epidemiology, diagnosis, prevention and treatment.
(4) Reid D et al. J Bone Miner Res 200; 15:1006-13. Efficacy and safety of daily risedronate in the treatment of corticosteroid induced osteoporosis in men and women.
(5) Saag KG et al. N Engl J Med 1998; 339:292-9. Alendronate for the prevention and treatment of glucocorticoid induced osteoporosis.
(6) Cranney A et al. CMAJ 2006; 175:52-9. Parathyroid hormone for the treatment of Osteoporosis. A Systematic Review