We noticed you're blocking ads.

Keep supporting great journalism by turning off your ad blocker.

Questions about why you are seeing this? Contact us

Font Size

- Aa +

Sun 25 Jan 2009 04:00 AM

Font Size

- Aa +

Bone loss in men

Osteoporosis also affects men. Discover what the risk factors are and how to protect yourself.

Osteoporosis also affects men. Discover what the risk factors are and how to protect yourself.

Young men may feel invulnerable, but as men get older, they begin to worry about heart disease, high blood pressure, diabetes, stroke, cognitive decline, and prostate disease - all with good reason.

Faced with so many concerns, most are only too happy to cross "women's diseases" off their worry lists. But in the case of osteoporosis, it's a big mistake.

Hard facts

Although osteoporosis is more common in females than males, it's not a woman's disease. In fact, about 2 million American men have osteoporosis and another 12 million are at risk. Because osteoporosis starts later in men than women, most men with "thin bones" are over age 65.

All in all, about one in every five 50-year-old men will suffer an osteoporotic facture during his remaining years. Hip fractures are particularly common and are more serious for men than women, with a one-year mortality rate of up to 37.5%.

So, if you think osteoporosis is a woman's disease, think again. Then think about ways to prevent, recognise, and treat this important disease of men and women.

How osteoporosis develops

Healthy bones are amazingly strong. Ounce for ounce, they can support as much weight as reinforced concrete. But unlike concrete, your bones are metabolically active living tissues and have to repair themselves after injuries.

They do this by constantly remodelling. Cells called osteoblasts, which add bone, are constantly at work forming new tissue and depositing calcium to keep bones strong. At the same time, osteoclasts, which remove bone, are "resorbing" (dissolving) old bone and removing calcium. At any one time, about 7% of your body's bone calcium is on the move.

In youth, bone formation outpaces "resorption" (removal of bone) - that's how we grow. In males, bone calcium density increases rapidly when testosterone levels surge at puberty.

Bone strength peaks at about age 20 and remains stable for the next 10 to 15 years. But boys with delayed puberty, dietary deficiencies of calcium or vitamin D, or insufficient exercise levels have lower peak bone densities and are at increased risk for osteoporosis when they get older.

In both men and women, bone resorption begins to outpace bone formation at about age 35. At first, bone density declines slowly. But when women reach menopause, their oestrogen levels plummet and bone density decreases sharply. In men, testosterone levels decline more gradually, dropping just 1% a year beyond age 40. As a result, bone loss remains relatively slow - but it's steady.

Beyond age 65 or so, men and women lose bone at about the same rate. Over time, the average man will lose about 20% of his cortical bone (the dense outer layer) and 30% of his trabecular bone (the spongy inner layer). And in some men, bone loss is even more substantial, crossing the line that separates men with healthy bones from those with osteoporosis.

With osteoporosis, bones become porous because they lack enough calcium to maintain their structural integrity. In addition to having a low calcium density, osteoporotic bones develop architectural abnormalities.

In healthy bones, normal bone mineral density accounts for about 70% of bone strength, and normal architecture contributes about 30%. The combination of low calcium and poor bone quality produces weak bones that are easily fractured, with or without trauma.

Risk factors

Two of the most important determinants of a man's bone density are beyond his control. Genetic factors explain up to 80% of the variance in peak bone density in young men.

The gene that regulates vitamin D's activity appears to be the most important, which makes sense since vitamin D helps the intestines absorb calcium from the bloodstream. Genetic factors explain why osteoporosis tends to run in families and why the disease is more common in Caucasians and Asians than in African Americans.

The second major determinant of bone density in men is age. Beyond the fourth decade of life, bone density declines progressively in every man. But while men can't control their heredity or slow the tick of the clock, they can modify many of the other osteoporosis risk factors.

Medical factors account for the most severe cases of osteoporosis in men. Low testosterone heads the list, explaining about 15% of cases severe enough to cause fractures. Therapy with prednisone and related drugs is a close second at 13%.

Alcohol abuse is the most common lifestyle contributor, explaining 6% of cases. But in about half the men with osteoporosis, no specific causal abnormality can be identified. Diet and exercise are of major importance for these men diagnosed with primary osteoporosis.

Symptoms

Until it's quite advanced, osteoporosis is a very silent disease. Decreasing bone density doesn't produce any symptoms until it declines below the fracture threshold. Even then, osteoporosis is often painless until soft bones meet up with hard objects - legs can snap from a simple stumble at 70.

In men, as in women, spine fractures are the most common result of osteoporosis. A gradual loss of height may be the only evidence of compressed vertebral bones, but back pain is also common and can be very severe. In advanced cases, a characteristic stooped posture and protuberant waist testify to osteoporotic spinal fractures.

In men and women with osteoporosis, the hip and the wrist follow close behind the spine on the fracture list. Rib fractures appear to be a bit more likely in men, but osteoporosis victims of either gender can fracture any of their bones.

Height loss and the heartMost men lose height as they age. The spinal column is composed of a set of 24 bones, the vertebral bodies, and the disks that lie between them. Height loss is usually caused by a combination of compressed vertebral bodies due to loss of bone calcium plus compression of the discs due to aging elastic tissue.

But men who lose two inches or more should get a DXA scan for osteoporosis.

And a British study found that height loss is linked to an increased risk of coronary artery disease and a higher death rate.

Diagnosing osteoporosis

Surprisingly, perhaps, ordinary x-rays are not reliable for detecting osteoporosis. But other methods are quite accurate and are now widely available. Dual energy x-ray absorptiometry (DXA) is the standard test. It's quick, safe, and painless, taking only 10 minutes. While you lie on a table, a machine beams photons through your bones, usually at the spine, hip, or wrist.

DXA can compute the bone density in any region of your body, and it exposes you to only one-tenth as much radiation as a chest x-ray. Ultrasound, which uses sound waves to measure bone mineral density at the hip, shin, heel, or finger, is another test. It is not as accurate as DXA, but it can give a rough estimate of bone density painlessly in less than a minute.

For years, the National Osteoporosis Foundation has recommended DXA testing for all women age 65 and older and for all postmenopausal women under age 65 who have one or more risk factors. In 2008, the foundation added similar guidelines for men, setting the age for routine testing at 70. Younger men who have risk factors should also be tested.

Testing is particularly important for men undergoing androgen-deprivation therapy for prostate cancer and for men who have suffered fractures, particularly if only minor trauma was involved ("frailty fractures").

Men who have lost more than two inches of height, who have fewer than 20 teeth, and who are extremely thin (body mass index of 19 or lower) should also be tested. If you have a spinal curvature that prevents you from touching the back of your head to a wall while you stand with your heels and back against the wall, you should have a DXA test.

Osteoporosis is defined in terms of standard deviations from the average peak bone density, also called a T score. Standard deviation expresses the amount of variation away from the average. The lower your T score, the lower your bone density and the higher your risk of a fracture. The World Health Organization (WHO) has established the following classification system:

• If your T score is greater than -1: your bone density is considered normal

• If your T score is -1 to -2.5: you have osteopenia (low bone mass)

• If your T score is less than -2.5: you have osteoporosis.

The T score is a good way to evaluate your bone mineral density, but it's only one component of your fracture risk. To provide a more comprehensive evaluation of your 10-year risk of major fractures, the WHO has developed a tool that incorporates your bone mineral density, age, sex, height, weight, and seven clinical factors. Your doctor can access the tool to calculate your risk at www.shef.ac.uk/FRAX.

Men at risk for osteoporosis may benefit from additional testing to hunt for underlying abnormalities. Useful studies can include blood or urine tests for anaemia and abnormal proteins, liver and kidney disease, calcium, vitamin D, and hormones such as testosterone, thyroid, parathyroid and cortisol. Many specialised tests are also available - but in most men, testing is less important than treatment.

Factors that increase the risk of osteoporosis in menGenetic factors

• Family history of osteoporosis

• Caucasian or Asian heritage

Lifestyle factors

• Smoking

• Excessive alcohol consumption (over two drinks a day)

• Lack of exercise

Dietary factors

• Insufficient calcium

• Insufficient vitamin D

• Excessive vitamin A (over 3,000 IU or 900mcg a day)

• Excessive caffeine (can be offset by sufficient dietary calcium)

• Excessive protein consumption, especially animal products

Hormonal factors

• Hypogonadism (low testosterone level)

• Overactive thyroid, parathyroid, or adrenal gland

• Growth hormone deficiency

Advancing age

Thin body build and weight loss

Medical conditions

• Elevated levels of homocysteine (an amino acid in the blood)

• Chronic kidney, liver, or lung disease

• Chronic intestinal disorders

• Certain malignancies (myeloma, lymphoma)

Medications

• Androgen-deprivation therapy for prostate cancer

• Prednisone

• Certain anti-seizure medications

• Certain chemotherapy drugs

• Proton pump inhibitors (used to block gastric acid production)

• SSRIs (used to treat depression)

• Thiazolidinediones (used to treat diabetes)

• Warfarin (an anticoagulant)

Arabian Business: why we're going behind a paywall

For all the latest health tips & news from the UAE and Gulf countries, follow us on Twitter and Linkedin, like us on Facebook and subscribe to our YouTube page, which is updated daily.
Real news, real analysis and real insight have real value – especially at a time like this. Unlimited access ArabianBusiness.com can be unlocked for as little as $4.75 per month. Click here for more details.