Lipodystrophy and metabolic changes
Lipid = fat; dystrophy = disorder.
Lipodystrophy is a medical term referring to changes in body fat.
When this is part of a set of symptoms related to HIV treatment, it is usually linked to other metabolic changes.
The word ‘metabolic’ refers to how your body processes food into energy. This includes the production, regulation and storage of fats and sugars.
Although doctors are now aware of lipodystrophy as a side effect, you might still have to take an active role in getting the best monitoring and care.
The mechanism that causes fat loss is now understood. Hopefully, over the next few years, research will discover the cause(s) of metabolic fat gain.
What are the symptoms?
There are three broad sets of lipodystrophy symptoms (see also the Table below).
|Fat loss||From legs and arms leaving veins more prominent, also from buttocks and the face.||Now rare.|
|Fat gain||In the stomach, breasts in both women and men, shoulders, neck and sometimes small lumps of fat under the skin (called lipoma).||Much less common with modern ART.|
|Metabolic changes.||How your body produces and processes fats and sugars.||Changes are common: routine monitoring is important.|
Any information about lipodystrophy needs to specify which of these symptoms are being discussed.
Each symptom is thought to have a different mechanism. You can have one symptom without the others.
Even when symptoms are generally linked to one class of drug, the effect of each drug can be very different.
Lipodystrophy is likely to be the result of several different factors rather than any single cause.
These include your HIV treatment history, individual drugs, lowest CD4 count, age, diet, exercise and family health.
These changes have been reported in men, women and children from a wide range of racial backgrounds.
How many people are affected?
Many people are unlikely to notice any changes in body shape. Lipodystrophy occurs more rarely with current drugs compared to the earliest HIV meds.
The benefits from treatment still outweigh the risks. For most people any changes are likely to be mild. However, for a minority, problems are more serious.
Preventing lipodystophy is more important and more successful than trying to treat lipodystophy after it has developed.
As no one can predict who will be affected before starting treatment, careful monitoring is important. You use try switching to other HIV meds if you get symptoms with your first combination.
Monitoring changes in fat distribution
There are several ways that changes in body fat distribution can be measured and monitored.
- Most people are sensitive to physical changes in their body. This means that ‘self-reporting’, perhaps with careful measuring by a dietician, or photography can record any changes.
- Some HIV clinics have access to scanning equipment, but unfortunately lipodystrophy is rarely monitored in this way. MRI and DEXA scans look at the breakdown within your body of fat and muscle. A test called BIA (Bio Impedance Analysis) are sometimes used. (See side box on Monitoring Tests).
- Getting a DEXA scan, or well-lit photo, even if you only have slight changes, will give you a reference to know how quickly symptoms are progressing or improving. Some specialist clinics, including the lipodystrophy clinic at St Thomas’ Hospital in London, provide baseline DEXA scans to all patients. You can self refer to this clinic.
- As with your CD4 and viral load results, a single test result might only provide limited information. You are likely to need several tests over time to monitor changes.
If you are worried that you have lipodystrophy, make sure this is taken seriously. You should be offered monitoring and have any treatment choices explained.
Changing treatment can sometimes reverse fat loss.
Studies to reduce fat accumulation, have been less helpful.
Just because studies haven’t shown a benefit, it doesn’t mean that other treatments might not be better for you.
Whether you decide to change your treatment will depend on several things, including:
- Your treatment history, and
- How badly the lipodystrophy is affecting you.
If you change your combination, you have to change it to one that is just as effective against HIV.
Using combinations without nucleosides is one new strategy that is being studied. Another might be to use an entry inhibitor or integrase inhibitor instead of a PI or NNRTI.
Switching to drugs that have less impact on blood lipids can help with cholesterol and triglycerides.
It will be much easier to know if the switch has worked if you have been monitored before you make any change.
Even if this does not reverse the symptoms, changing to a different HIV drug might stop the symptoms getting worse.
The following tests can monitor changes.
Having a measurement before starting treatment will make it easier to interpret any change.
Careful measurement by a dietician using callipers can be useful if nothing else is available. This might be useful for fat increases but will be less sensitive for fat loss. Results might vary depending on the dietician. Measurement by callipers is not sensitive for small changes. Waist circumference (over 102 cm for men and 88 cm in women) and waist:hip ratio (higher than 0.95 in men and 0.90 in women) are also used.
DEXA (or DXA) scan (Dual X-ray Absorptiometry)
These scans are available at most main hospitals as they are routinely used for checking bone changes as people get older. You lay on a flatbed scanner for 5–20 minutes (depending on the scanner) for a full body scan. Your head is not scanned. The results provide a breakdown of your body composition into fat, bone and muscle. Some doctors would like a DEXA scan before any HIV treatment is started, and repeated annually to monitor for changes.
DEXA scans can show the percentage of body fat in each main section of your body – in each arm, leg, your head and your trunk. An important limitation is that DEXA scans cannot show whether trunk fat is visceral (around the organs inside your abdomen) or subcutaneous (love handles – under the skin but outside the abdomen). Visceral fat is most associated with HIV-related fat accumulation, and with increased health complications.
MRI scan (Magnetic Resonance Imaging)
These scans are much less readily available and the equipment required is more sophisticated and expensive. An MRI scan provides a computer image of the tissues, muscle and bone in a cross-section of any part of your body. An MRI scan can show how fat is distributed – whether it is subcutaneous (under the skin) or visceral (around your central organs) – and is very accurate at measuring any changes.
Bio-electrical Impedance Analysis (BIA)
BIA is a simple painless procedure that calculates the percentages of fat, muscle and water in the body according to height, weight, sex and age. It has mainly been used for HIV-related wasting but might also be useful in monitoring lipodystrophy.
Weight in people with lipodystrophy is generally stable. Fat redistribution (rather than weight gain or loss) is usually the issue. However, weighing yourself is important in case you have lost or gained weight without realising it.
Last updated: 1 August 2016.