Measures to prevent bone loss have not been a part of stroke management thus far

Dr Kenneth Poole, Review author

The breakdown occurs more quickly in patients with diffuse osteoporosis, and results in weak and brittle bones.

The "bone-eating" cells may over-react after a stroke, and the "bone-making" cells cannot keep up.

Over half of all strokes occur in people aged over 70, who are already at risk of osteoporosis because of their age.

A team led by Dr Kenneth Poole, specialist registrar in stroke medicine at Addenbrooke's Hospital, Cambridge and a Medical Research Council clinical research fellow, suggest specific bone-loss prevention drugs could be used for stroke patients.

They add that doctors should also consider mechanical hip protectors and Vitamin D and calcium supplements.

Fall risk

The researchers reviewed several studies which looked at osteoporosis and hip fracture after strokes.

Two Swedish studies showed hip fractures were up to four times more likely in stroke patients than in a general population of the same age.

Stroke patients who break their hips also suffer more illness and deaths.

One study found almost three-quarters of 108 patients had suffered a fall in the six months after having a stroke.

Most fractures occurred on the side paralysed by stroke, and were usually caused by accidental falls.

The risk of stroke patients falling is also increased by problems with their lower limbs and their vision.

Drug hope

Dr Poole said drugs called bisphosphonates might prevent the bone loss associated with strokes.

The drugs work by preventing cells in the bone called osteoclasts from breaking down bone tissue.

He said the drugs may be most helpful if administered early after a stroke occurs.

They have already been used to treat osteoporosis in postmenopausal women, but would have to be given to stroke patients intravenously, as the pill form needs patients to sit up or stand for 30 minutes - something many stroke patients cannot do.

Dr Poole, who is carrying out a study looking at the effectiveness of bisphosphonates in stroke patients, funded by the National Osteoporosis Society (NOS), said: "Osteoporosis is a significant complication of stroke.

"Acting early is the important thing to do as bone loss seems to occur early after strokes.

"Measures to prevent bone loss have not been a part of stroke management thus far.

"Our review makes a good case for a trial of intravenous bisphosphonates after stroke."

'Significant complication'

Eoin Redahan, a director of the Stroke Association, said: "Osteoporosis is a complication of limb immobility of any cause.

"As stroke can cause limb immobility it therefore makes sense that osteoporosis is a significant complication of stroke.

"However, this is just one factor in stroke rehabilitation."

An NOS spokesman said: "We welcome this review which has highlighted this important group of mainly older people who have osteoporosis due to secondary causes."

The research is published in Stroke: a Journal from the American Heart Association.