Screening for fracture risk should be a routine part of HIV care for all over-40s, and all postmenopausal women, all men over 50 and people at high risk for fractures of any age should undergo DEXA screening (a type of X-ray) to assess bone mineral density and their need for treatment, experts on bone disorders recommend in new guidelines published online in the journal Clinical Infectious Diseases.
Low bone mineral density and fragility fractures occur more frequently in people living with HIV than in other people of a similar age. Several studies conducted in US men and women living with HIV have shown that the rate of fractures of the spine, hip and wrist is approximately 60% higher than in the general population.
It is unclear whether HIV causes bone mineral loss, also known as osteoporosis, but bone mineral density usually declines by 2- 6% in the first two years after starting antiretroviral treatment. People living with HIV also tend to have a high frequency of risk factors for osteoporosis including smoking, high alcohol consumption, low body weight and poor nutrition. As the population of people living with HIV ages, bone mineral loss is becoming a more serious problem.
International expert guidelines for management of bone loss were developed by 34 experts from 16 countries. Their recommendations cover screening, diagnosis and monitoring of bone disease and are graded accorded to the strength of evidence available.
Screening and risk assessment
Without screening to identify people at high risk of fractures, it is not possible to provide preventive treatment. The expert panel made several recommendations.
People at high risk of fragility fractures should undergo DEXA screening. Fragility fractures are broken bones which occur without major trauma, for example when falling, and most commonly involve the wrists, arm, shoulder, hip or spine. People at high risk are those with a previous history of fragility fractures, those at high risk of falls and people treated with glucocorticoids for at least three months. All postmenopausal women, all people with major risk factors for fragility fractures and men aged 50 or over, should undergo DEXA screening too.
Men aged 40-49 and premenopausal women aged 40 and over can be assessed for fracture risk if they lack a major risk factor by using the FRAX scoring system (based on the person’s lifestyle and medical history) every three years, without the need for DEXA screening. Anyone in these groups with a ten-year fracture risk above 10% should undergo DEXA screening. Repeat screening should be considered one to two years later in in people who have advanced osteopenia, and after five years in mild-to-moderate cases of osteopenia.
The recommendations emphasise that where DEXA screening is not easily available, FRAX scoring should be used to identify patients at high risk of fracture.
Minor vertebral fractures, described by doctors as subclinical, can occur without major effects on mobility and may go unrecognised despite causing chronic pain. They are a strong risk factor for future fractures. Height should be measured every one to two years in adults aged 50 and over, and DEXA or X-ray screening is recommended in women aged 70 and over and in men aged 80 and over if there is evidence of osteopenia. It is also recommended in over-50s who have lost 4cm in height, suffered a fragility fracture or undergone recent glucocorticoid treatment.
Starting antiretroviral treatment is associated with a 2%-6% loss in bone mineral density during the first two years. There is evidence that tenofovir and boosted protease inhibitors cause greater bone loss compared to other drugs, and alternative regimens should be discussed with patients who have low bone mineral density or osteoporosis. The authors of the guidelines say that well-designed trials are needed to test the impact of integrase inhibitors on bone mineral density during first-line treatment.
Preventing fragility fractures
Dietary and lifestyle changes are the first line of protection against fractures. Men aged 50-70 at risk of fractures should aim to get 1000mg of calcium a day, and men aged 70 and over and women over 50 should aim to get 1300mg a day. (Review the International Osteoporosis Foundation’s checklist of the calcium content of foods here). Calcium supplements may be needed if it isn’t possible to get the recommended intake from the daily diet.
Vitamin D levels are often low in people living with HIV and these should be measured in people with low bone mineral density or a history of fractures. Vitamin D deficiency may lead to hyperparathyroidism (excess production of parathyroid hormone), which damages bone. Vitamin D supplementation should aim to maintain 25 (OH)D levels above 30ng/ml.
People living with HIV who have osteoporosis will benefit from weight-breaking and muscle-strengthening exercises, stopping smoking and reducing alcohol consumption, the guidelines recommend.
Medication to prevent osteoporosis should be administered according to national guidelines. Alendronate (70mg once a week) has been shown to increase bone mineral density in people living with HIV, but if it proves unsuccessful intravenous zoledronic acid once a year may be considered, the guidelines recommend.
Brown T et al. Recommendations for evaluation and management of bone disease in HIV. Clin Infect Dis, advance online publication, 21 January 2015. (Free full-text article available here).