In this large sample of HIV infected patients, the overall prevalence of metabolic syndrome, under either classification, was noticeable. The AHA/NHLBI definition accounted for higher prevalence of MetS than those observed in the NCEP-ATPIII and IDF, which is in accordance with lower cutoff and lacking of the obligatory abnormal waist circumference. The overall prevalence of most MetS components differed considerably among men and women, but the overall prevalence did not vary by sex. Even though the three definitions of MetS were based on the same components, the cutoffs for waist circumference differ markedly on NCEP-ATPIII and IDF, as well as the hierarchy of the central obesity.
This study also estimated the PAR in order to assess separately the contribution of each component on MetS prevalence. This approach assumes that the abnormal MetS components are randomly distributed among the HIV-infected population, but they might be clustered as a consequence of HAART, and, therefore, the PAR could be overestimated. HAART can cause abnormality on lipids and glucose metabolisms [15, 16], but these changes could also be caused by the HIV infection [28, 29]. In order to minimize the confounding factors, PAR were adjusted for age, skin color, and HAART use.
This study detected lower prevalence rate of MetS, by NCEP-ATPIII definition, than previously described [30–32], which could be attributed to the similar number of men and women, and to the 66% of subjects on HAART, versus the dominance of men and HAART use in those studies. The estimate of MetS based on the IDF definition verified in this study was similar  or higher  than other studies, which can be partially explained by the high lipodystrophy rate detected among Italian volunteers , and the waist circumference cutoffs, which for Brazilians should be the same as those recommended for the South Asians [4, 7].
This study detected high prevalence of MetS for men and women with abnormal waist circumference by the IDF and AHA/NHLBI definition. The cutoffs for waist circumference used for South Asians might be excessively low for Brazilians, but they have been previously used in different contexts among non HIV-infected populations [34, 35]. The trend for higher prevalence of metabolic syndrome among women might be related to their increased prevalence of central obesity, abnormal HDL-cholesterol, and use of protease inhibitors in comparison with men. Since waist circumference is a mandatory component of the IDF, its impact on MetS prevalence was conceivably 100%.
This study detected lower MetS prevalence by IDF than observed in the general population of Greece [36, 37]. Probably, those differences could be attributed to the cutoffs for waist circumference that used ethnic recommendations for abdominal obesity and to lower mean age of HIV-infected patients, which is directly related to abdominal obesity [38, 39].
The highest impact of triglycerides and waist circumference suggest that there are consequences associated with the MetS definition adopted to implement any preventive strategy. However, the other components also contributed to the metabolic syndrome burden, and changing their status could result on a substantial reduction on MetS due to triglycerides in males, or waist circumference, in women. The PAR of MetS components might be used to assess the impact of comorbidities, the need for comorbidities treatment, and the HAART toxicity of specific drugs . Interventions to face the burden of metabolic syndrome as well as to determine the health care priority among those who needs medical attention and are at risk for cardiovascular disease are also potential uses for PAR in this area of knowledge.