Bone-loss patients 'taking wrong drugs'

Bone-loss patients 'taking wrong drugs'

SINGAPORE - Osteoporosis, the "porous bone" disease, is on the rise in Singapore but as many as one in two patients could be taking potent medicines that may do little for their condition.

The long-term medication given to most patients to help stem bone loss may not work well for those with what is described as secondary osteoporosis, doctors have found, following a study.

They are recommending tests to identify the real reasons why different people are afflicted, so that patients can be treated appropriately.

"I see many patients labelled as having just garden-variety osteoporosis due to menopause and ageing," said Dr Manju Chandran, director of the Osteoporosis and Bone Metabolism Unit at the Singapore General Hospital (SGH), who led a recent study into the subject.

For years, many patients with osteoporosis have been prescribed medicines to slow down bone loss or stimulate bone formation. For many, she said, "this is as useful as pouring water into a leaky bucket".

She suggests separating patients into two groups:

Those with primary osteoporosis associated with ageing and post-menopausal bone loss in women with depleted oestrogen levels; and

Those with secondary osteoporosis precipitated by factors ranging from Vitamin D deficiency to the excretion of too much calcium in the urine and thyroid problems.

It is the patients in the second group who need more appropriate medication, and most likely will not improve if given standard treatment that works for those with primary osteoporosis.

Osteoporosis causes bones to become weak and brittle, so that a fall or even mild stresses like bending over or coughing can cause a fracture. It has no symptoms in the early stages, and is diagnosed through a bone density scan.

Fractures resulting from osteoporosis are on the rise here, given the ageing population and sedentary lifestyles. In fact, osteoporotic hip fracture rates here are among Asia's highest.

In 2010, about 2,200 people aged 50 and above were hospitalised for hip fractures. More than one in five with such injuries die within a year.

Yet, local and regional information on the condition has been sparse, said Dr Chandran, who is also a consultant at the SGH endocrinology department and president of the Endocrine and Metabolic Society of Singapore.

The study she led, the first of its kind in South-east Asia on secondary osteoporosis, looked at 400 patients.

It found that secondary osteoporosis occurred in six out of 10 older men with the disease, and in almost 45 per cent of post-menopausal women.

Stressing the lack of awareness of the condition, she said: "Even specialists tend to put patients on standard medications and send them on their way without looking further at the underlying causes."

The research was published in the journal Archives of Osteoporosis this year.

Noting that it would be expensive and unnecessary to screen patients for the entire spectrum of causes, Dr Chandran suggests limiting it to the most common ones.

Hypercalciuria, for example, where increased calcium is excreted in the urine, was found in 22 per cent of patients in the study with secondary osteoporosis - a figure much higher than reported in the West.

This, Dr Chandran believes, is likely due to the high salt content in the Singapore diet which can cause leaching of calcium from the bones into the urine.

In men, levels of the male hormone testosterone should also be checked since low testosterone levels were found in close to 10 per cent of the male patients.

She and her team recommend a handful of basic blood and urine tests that even family doctors can administer to an osteoporosis patient, together with a thorough look at the patient's history and whether they are on steroids, as extended use of them can also cause bone loss.

Dr Joyce Koh, a senior consultant at SGH's Department of Orthopaedic Surgery, agreed that there is a general lack of awareness when it comes to treating secondary osteoporosis here.

"Hip fractures, if left untreated, have dire consequences due to the acute pain and sudden loss of mobility," she said. "I would like to see at-risk individuals properly assessed and treated to prevent an osteoporotic fracture."

ailien@sph.com.sg


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