ABC | Volume 110, Nº6, June 2018

Original Article Soares et al Cardiovascular risk in an indigenous population Arq Bras Cardiol. 2018; 110(6):542-550 49.1% of women and 60.0% of men were indicative of high cardiovascular risk, corroborating the increased levels of TG and decreased levels of HDL-c observed in the population. Plasma apolipoproteins A1 and B and the apo B/apo A1 ratio have been described as the best predictors of cardiovascular risk as compared with lipid and lipoprotein levels or the Castelli index I and II. 21,22 Apolipoproteins are structural and functional components of lipoproteins. Apo A1 constitutes non-atherogenic lipid fractions (HDL-c), whereas apo B constitutes atherogenic ones (chylomicrons, LDL, IDL and VLDL). Thus, apo B/apo A1 ratio represents the balance between atherogenic and antiatherogenic lipoproteins. 21,22 Increased apo B and apoB/A1 and reduced apo A1 levels have been consistently associated with risk for CVDs. 22 In our study group, 12.2% of women and 9.3% of men had an apo B/apo A1 ratio indicative of cardiovascular risk. We have not found any studies evaluating these indicators in other indigenous populations. CRP, an acute-phase protein released into blood in response to inflammatory cytokines and a biomarker of systemic inflammation, was also evaluated in the current study. Increased CRP levels have been associated with coronary disease and stroke, even in patients with normal lipid profile. 14 Approximately half of Xavante people had CRP-hs levels indicative of high cardiovascular risk. However, caution is needed in interpreting these data, as other inflammatory diseases can also increase CRP levels. Infectious and parasite diseases are common in indigenous populations, including the Xavante people, which may have influenced the results. Framingham score is one of the algorithms used in detecting the risk for CVDs. 11 In our study, 15.2% of men and 5.7% of women have increased risk of developing CVDs in the next 10 years according to this score. Although this score has been developed for subjects aged 30 years or older, in the current study, patients aged between 20 and 29 years were also included, corresponding to 28.0% of the study population. In the “age” component of Framingham score calculation, these subjects received the rating assigned for individuals aged between 30 and 34 years (zero). No participant aged between 20 and 39 years showed increased cardiovascular risk. Despite its high predictive value, Framingham score does not consider weight excess or sedentary lifestyle, both considered important cardiovascular risks. 23 Chart 1 – Cardiovascular risk indicators Indicators RISK Total cholesterol (mg/dl) 13 ≥ 200 mg/dl HDL-cholesterol (mg/dl) 13 < 50 mg/dl in women and < 40 mg/dl in men LDL-cholesterol (mg/dl) 13 ≥ 130 mg/dl Triglycerides (mg/dl) 13 ≥ 150 mg/dl Castelli index I 8 > 4.4 for women and > 5.1 for men Castelli index II 8 > 2.9 for women and > 3,3 for men TG/HDL-C ratio 9 ≥ 3.8 ApoB/ApoA1 ratio 10 > 0.8 for women and > 0.9 for men Framingham risk score 11 Low risk – probability < 10% Intermediate risk – probability between 10% and 20% High risk – probability > 20% Hs-CRP (mg/L) 14 Low risk - < 1.0 mg/L Intermediate risk – 1.0 – 3.0 mg/L High risk - >3.0 mg/L BMI (kg/m 2 ) 7,15 ≥ 25.0 kg/m 2 for adults ≥ 27.0 kg/m 2 for elderly subjects Waist circumference (cm) 7 ≥ 94 cm in men and ≥ 80 cm in women Hypertriglyceridemic waist 7,13 Increased WC (≥ 94 cm in men and ≥ 80 cm in women) and TG ≥ 150 mg/dl Glycemia (mg/dL) 16 Casual glucose level ≥ 200 mg/dL and/or Glucose after 2 hours ≥ 140 mg/dL and/or using oral antidiabetic drugs or insulin Blood pressure (mm/Hg) 17 Systolic arterial pressure ≥ 140mmHg and/or Diastolic arterial pressure ≥ 90mmHg and/or Use of anti-hypertensive agents WC: waist circumference; TG: triglycerides; hs-CRP: high sensitivity C-reactive protein; BMI: body mass index 544