Prevalence of dyslipidemia in adolescents: comparison between definitions.

INTRODUCTION: The indiscriminate use of different diagnostic criteria for the definition of dyslipidemia may result in inaccurate interpretations, which could compromise diagnosis and therefore the therapeutic and prophylactic actions to be taken. OBJECTIVE: To analyze possible differences in prevalence rates of dyslipidemia in adolescents based on three diagnostic definitions. METHODS: A cross-sectional study was conducted of a representative sample of Brazilian adolescents between 11 and 16 years of age. Blood samples were collected from 1000 students (423 boys and 577 girls) to determine fasting total cholesterol (TC), HDL and LDL cholesterol, and triglycerides (TG). The prevalence of dyslipidemia was established according to three definitions: those of the National Cholesterol Education Program (NCEP), the Brazilian Society of Cardiology (BSC), and the National Health and Nutrition Examination Survey (NHANES). RESULTS: Significant differences (p<0.01) were found between the diagnostic criteria for TC (BSC 38.3%; NCEP 11.2%; NHANES 4.8%), HDL cholesterol (BSC 30.0%; NCEP 15.8% NHANES 18.4%), LDL cholesterol (BSC and NCEP 10.8% and NHANES 5.9%), and TG (BSC and NCEP 4.7% and NHANES 1.3%). The overall prevalence of dyslipidemia was 61% (BSC), 28.6% (NCEP) and 24.2% (NHANES). Agreement rates varied significantly (kappa 0.15-0.90). CONCLUSIONS: Although a high prevalence of dyslipidemia was observed in this study regardless of the diagnostic criteria used, the wide variation in rates highlights the need to establish a single definition with appropriate discriminatory power for adolescents.

The acute-phase proteins serum amyloid A and C reactive protein in transudates and exudates.

The distinction between exudates and transudates is very important in the patient management. Here we evaluate whether the acute-phase protein serum amyloid A (SAA), in comparison with C reactive protein (CRP) and total protein (TP), can be useful in this discrimination. CRP, SAA, and TP were determined in 36 exudate samples (27 pleural and 9 ascitic) and in 12 transudates (9 pleural and 3 ascitic). CRP, SAA, and TP were measured. SAA present in the exudate corresponded to 10% of the amount found in serum, that is, the exudate/serum ratio (E/S) was 0.10 +/- 0.13. For comparison, the exudate/serum ratio for CRP and TP was 0.39 +/- 0.37 and 0.68 +/- 0.15, respectively. There was a strong positive correlation between serum and exudate SAA concentration (r = 0.764; p < 0.0001). The concentration of SAA in transudates was low and did not overlap with that found in exudates (0.02-0.21 versus 0.8-360.5 g/mL). SAA in pleural and ascitic exudates results mainly from leakage of the serum protein via the inflamed membrane. A comparison of the E/S ratio of SAA and CRP points SAA as a very good marker in discriminating between exudates and transudates.