Bone mineral changes

osteo = bone, necrosis = death, porosis= thin.

Are bone mineral changes a side effect?
Osteopenia and osteoporosis
Osteonecrosis and avascular necrosis (AVN)
Protecting bones

Are bone mineral changes a side effect?

HIV is one of several conditions that are linked to bone changes.

Even though this may not be a side effect, we have included information as this is a new area of research that is important for your long-term health.

The two main changes linked to bone are:

changes in content and structure of bone where your bone becomes thinner. This is called osteopenia at mild levels and osteoporosis at more severe levels that require treatment.
interruption of proper blood supply to the bone, which causes death of bone tissue - osteonecrosis and avascular necrosis (AVN).

Osteopenia and osteoporosis

Rates of both osteopenia and osteoporosis are significantly higher in HIV-positive people compared to age and sex-matched people who are HIV-negative.

It is still unclear if this is just related to HIV or whether side effects from HIV drugs also contribute.

In some studies, protease-based combinations have been linked to reduced bone mass but other studies have shown contradictory results.

Tenofovir can cause a small drop in bone mineral density in the first six months, but this does not appear to progress with longer use of treatment.

The focus on bone density is important because it reduces with age, yet the HIV population is also getting older.

Osteopenia and osteoporosis are related to low weight and low Body Mass Index (BMI).

These changes in bone structure often overlap with issues of lipodystrophy and may be related to these metabolic changes and the way your body processes sugar and fat.

Corticosteroids (like prednisone) and heavy alcohol use are associated with higher risk of bone problems.

Other risk factors for osteoporosis include Caucasian/Asian race, low body weight, smoking, lack of physical activity, family history of osteoporosis, low testosterone levels in men and early menopause in women.

Leading an active life, and including exercise, maintains healthy bone. This includes weight-bearing exercise (walking, jogging, running, steps and dancing) and muscle strengthening exercise. Improvements include better posture, balance and strength and a direct improvement in bone density.

Your bones are a living structure, 10% of which naturally die each year to be replaced by new cells. If the bone isn’t replaced quickly enough or in sufficient quantities, your bones become thinner and more brittle.

Osteopenia is very common in older people and several studies showed high levels in people with lipodystrophy.

Osteoporosis is a more serious progression of osteopenia and can be diagnosed with a DEXA scan. Unlike osteopenia this can lead to fractures and pain (commonly to the spine in men and the hip in women.

Osteonecrosis and avascular necrosis

With osteonecrosis and AVN, inadequate blood supply reaches the bone, and these tissues then die as a result. It is much less common, and usually affects hip, shoulder or knee joints, and requires replacement surgery.

It is very common for corticosteroid use to be a contributing factor in cases of AVN.

Early diagnosis of AVN makes a big difference to the success of treatment as well as your quality of life. If you experience pain in these joints, ask your doctor to refer you to a specialist, and to provide an MRI scan that can make an appropriate diagnosis.

Protecting bones

Treatment and prevention measures are similar, regardless of whether you are HIV-positive or not - although closer monitoring of HIV-positive people is clearly important.

Reducing smoking and alcohol, taking exercise and eating a diet adequate in calcium, protein and vitamin D (and spending some time in the sunshine) protect you against bone mineral loss.

Bone-building nutrients include calcium and vitamin D3 (colecalciferol) and any deficiency should be corrected by increasing dietary intake or use of supplements.

The (US) National Osteoporosis Foundation 2008 guidelines (www.nof.org) recommend adult targets of 1200mg daily for calcium and 800 -1000 IU/day for vitamin D3 (for people at higher risk).

These nutrients can be prescribed by your doctor and sometimes require special monitoring and dosing.

The target level of vitamin D monitoring is to get blood levels of 25(OH)D over 75 nmol/L.

A link has also been suggested between bone damage and mitochondria damage, and a link to high levels of lactic acid has also been reported. The HIV medications related to these changes may therefore be nucleosides. This may be a reason to use mitochondria protecting nutrients such as vitamins C and E, L-carnitine and co-enzyme Q.

Other potential treatments to improve bone mineral density for people with diagnosed bone problems include bisphosphonates such as alendronate (Fosamax) and statins.