A lipodystrophy case definition developed by a working party convened by the European Medicines Evaluation Agency has been published in the March 1 edition of The Lancet.
The group, led by Dr Andrew Carr of Sydney’s St Vincent’s Hospital, conducted an international case control study in which 1081 consecutive HIV-positive individuals without active opportunistic infections were assessed by clinicians to identify 417 cases in which lipodystrophic changes were clearly evident to both doctor and patient, and 317 controls without lipodystrophic changes.
Objective measures of HIV disease-related parameters, fat distribution, lipids, glucose and blood chemistry were recorded, together with physical symptoms such as dry skin, reduced libido, blood pressure, and behaviours such as alcohol consumption and physical activity. The variables were then submitted to multivariate logistic regression analysis to identify significant associations.
The final model, with a specificity of 79% (95 CI 70-85) and a sensitivity of 80% (CI 71-87), contained ten variables (see table below). Models with fewer variables, omitting body composition measurements using DEXA or CAT only, or body composition and laboratory measurements, proved less sensitive and specific. Nevertheless, the study website offers details of the minimal definition that may prove useful to the clinician without the resources to carry out body composition measures.
A major controversy concerning the definition is its lack of agreement with the FRAM study, which found that lipoatrophy was the only body composition feature that differed between HIV-positive men and age-matched HIV-negative controls. The authors say that even when they excluded patients who only exhibited fat accumulation without lipoatrophy, the final model still contained the same variables. A separate case definition for lipoatrophy was impossible to develop because too few patients had lipoatrophy alone.
| Full case
definition |
Clinical and
laboratory data (but no body imaging data) |
Clinical data
(but no body imaging or laboratory data) |
| Female gender Age over 40 years HIV duration > 4 years CDC category C Increased waist:hip ratio Decreased HDL cholesterol Increased anion gap Increased ratio of visceral adipose tissue to subcutaneous adipose tissue (>1.59) Increased trunk to limb fat ratio Decreased leg fat percentage (
| Gender Age HIV Duration CDC category Waist:Hip ratio Estimated LDL cholesterol Triglycerides Lactate Anion gap
|
Age HIV duration CDC Category CD4 change from nadir waist circumference |
Further information
HIV Lipodystrophy Case Definition Group. An objective case definition of Lipodystrophy in HIV-infected adults: a case-control study. The Lancet 361: 726-35, 2003.