Signs and symptoms

The following signs have been described as part of the lipodystrophy syndrome in reports since 1997:

• Increased waist size.
• Increased breast size.
• Fat accumulation around the neck and upper back (cervical lipomatosis or 'buffalo hump').
• Fat accumulation around the neck and jaw ('moon face').
• Fat deposits in other locations.
• Loss of subcutaneous fat in all parts of the body, most visibly in the limbs.
• Loss of subcutaneous fat in the face (facial wasting), especially the cheeks.
• Fat wasting of the buttocks.
• Prominent leg veins due to loss of subcutaneous fat.
• Metabolic abnormalities in blood fats (lipids), sugar (glucose) and insulin.

The many disparate aspects of the lipodystrophy syndrome, and the subjective nature of many evaluations, have made it challenging to produce a standardised, objective case definition. An objective HIV-associated lipodystrophy case definition (HDCD) was published in The Lancet in 2003 by a working group of the European Medicinal Evaluation Agency, led by Dr Andrew Carr of St Vincent’s Hospital in Sydney.¹

This case definition was derived from an international case-control study including over 1000 HIV-positive adults. Lipodystrophy-associated changes were clearly evident in over 400 patients who were then compared to control cases that did not have signs of lipodystrophy. The resulting model identified ten objective, measurable quantities that can be used to distinguish lipodystrophy in around 80% of cases (specificity and sensitivity).¹ A scoring system assesses whether and to what extent a patient meets each criterion and then uses a weighed system to produce a final score. The 2003 case definition for lipodystrophy (LDCD) is based on the following criteria:

• Female gender.
• Age over 40 years.
• Duration of HIV infection longer than four years.
• CDC disease category C.
• Increased waist to hip ratio.
• Decreased HDL cholesterol levels.
• Increased anion gap (blood acidity).
• Increased ratio of visceral adipose tissue to subcutaneous adipose tissue (greater than 1.59).
• Increased trunk to limb fat ratio.
• Decreased leg fat percentage (below 8.8%).

This case definition has been called into question with results from the later Study of Fat Redistribution and Metabolic Change in HIV in 2006 (discussed below), that concludes that the increased ratio of visceral adipose tissue to subcutaneous adipose tissue is also found in the general population.

It is also difficult to carry out this assessment in clinical settings without DEXA (dual energy X-ray absorptiometry) and computerised tomography (CT) equipment available for use. An alternate case definition was later devised that did not require a CT scan and this performed well. It was equally sensitive to the earlier method and more sensitive than DEXA alone or spontaneous clinical assessment.²