ABC | Volume 114, Nº1, January 2019

Original Article Gomes et al. Characterization of dyslipidemias in the youth Arq Bras Cardiol. 2020; 114(1):47-56 Other works performed in North and South American countries showed lower frequencies. In the United States 22 between 2011 and 2014, in individuals aged 6 to 19 years, the reported frequency of dyslipidemia was 21% (increased TC and/or NHDL-C and/or reduced HDL-C). In Santiago, Chile 23 (2009-2011) in 2,900 individuals aged 10 to 14 years, the frequency of dyslipidemia was 32% (elevated TC and/or TG and/or LDL-C and/or reduced HDL-C). The higher prevalence in the present study may have been caused in part by the lower cut-off values ​used by the national guideline 3 when compared to the international guidelines. 19,20 In the analyses performed to evaluate the effect of sex, dyslipidemias were more frequent for all lipid parameters in females, and these results are consistent with national 24 and international studies. 25 In fact, variations in serum lipoprotein levels are inherent to these individuals in the developmental stages and, consequently, to variations in sex hormones. 26 Some studies indicate that estrogens increase HDL-C in part due to their action in reducing hepatic lipase (HL) activity and increasing ATP-binding cassette transporter A1 receptors (ABCA1). 27 In addition, they decrease LDL-C 27 levels by positively regulating LDL receptors, thus exerting a beneficial effect on the lipoprotein profile. 28 On the other hand, androgens increase HL activity, leading to an inverse effect: 27 HDL-C is reduced while LDL-C is increased. In contrast, Zhang et al. 29 indicated that testosterone may be associated with changes in SR-B1 receptor and HL activity, facilitating the selective uptake of HDL and playing an antiatherogenic role. 29 Comparisons by age groups revealed that infants presented higher levels of TG, NHDL-C and combination of LDL-C and TG as well as a high frequency of individual dyslipidemias; few studies report this data up to two years of age due to the difficulty of blood collection and metabolic instability in this phase of rapid growth before 24 months of life. 30 In addition, the high frequency of hypertriglyceridemia would occur through lactation and lack of food fasting. The current DBD defines the cut-off value of TGwithout fasting for the 0-9 years of age range as ≥ 85 mg/dL. Evaluating this interference, we applied that cut-off value, and the results showed a lower frequency, 56% instead of 67% (≥ 75 mg/dL, with fasting). In this context, it is also worth noting that according to the national guidelines, 10 it is recommended to determine the lipid profile in children and adolescents when: i) grandparents, parents, siblings and first cousins ​present dyslipidemia, mainly severe or with manifestation of premature atherosclerosis; ii) in the presence of clinical signs of dyslipidemia; in the presence of other cardiovascular risk factors; iii) with involvement of other pathologies, and iv) in the use of contraceptives, immunosuppressants and other drugs that may lead to dyslipidemia. 31 Therefore, it is expected that other factors, not collected here, would potentially justify these variations. As for children, elevated TC and LDL-C were 40% and 35%, respectively. This increase in TC is close to that of a 2009 study with 217 individuals (84 obese), aged 2-9 years in Campina Grande/PB, ranging from 37% to 46%. 32 Moreover, this result of TC in children is consistent with data from the National Health and Nutrition Examination Survey (NHANES) of individuals aged 4-19 years, where elevations of TC levels were observed in the 9-11 years age group, decreasing later along the pubertal development. 33 Ramos et al. (2011) 32 reported that the increase in LDL-C ranged from 14% to 14.8% in children (non-obese and obese), a finding that is lower than that of our study (35%). However, the cut-off value we used is lower than that of the referred population. In addition, similar results were observed in a study in Mexico with children from 2 to 10 years of age: 30% of subjects presented LDL-C ≥ 110 mg/dL. 34 As for adolescents, there was a high frequency of low HDL-C (41%), a value close to the one reported in the ERICA study, which was 47% among 38,069 schoolchildren, 8 results aligned with those of this study, even considering the different methodological approaches of the two studies. Other national studies have shown important data. A study conducted in the Northeast, with individuals aged 6 to 18 years, showed a lowHDL-C frequency of 41%, 19 and another one carried out in Natal, RN, with students aged between 10 and 19 showed that 50% of the sample had this type of dyslipidemia. 35 Another study conducted in the metropolitan region of Guadalajara, Mexico with 132 individuals aged 5 to 15 years showed a lower prevalence (38.7%), but not very different from our findings. 36 The high frequency of reduced HDL-C in adolescents may be associated with young people's lifestyle, which involves inappropriate eating habits, overweight and physical inactivity. 37 It is worth mentioning that in this study, 349 individuals presented serum phenotype with LDL-C ≥ 190 mg/dL, that is in 0.56% (1:200) the results were suggestive for FH. 10 In relation to the regions of Campinas, the frequency of dyslipidemias was higher in the south and southwest than in the other regions. According to unpublished reports from the City Hall of Campinas, these regions have the highest number of records (25.7% and 27.6%, respectively) 38 in the Cadastro Único , a platform of the Federal Government that characterizes low-income families. In fact, according to Johansen et al., 12 they make up the so-called “poverty mountain range”, where there is a socioeconomic homogeneity not observed in the other regions. 39 Additionally, they are the ones that have a greater number of SUS users, accounting for 50% of the test results in this study. Socioeconomic asymmetry can compromise the lifestyle of populations with direct repercussions on morbidity and mortality indicators. According to the WHO, currently three‑quarters of deaths from cardiovascular disease are occurring in low and middle-income regions. 1 The ERICA study showed significant increases in dyslipidemias in the north and northeast regions of the country (regions reportedly with the highest poverty indices in Brazil); 40 also, ERICA suggests that regional differences in dyslipidemias occur through the process of epidemiological transition, that is, regions may be at different stages. 8 This study evaluated the secondmost populous city in the state of São Paulo, located in the southeastern region of Brazil, where urban sprawl occurredwithout adequate planning and culminated in the expansion of occupation areas with the consequence for the population of inappropriate access to urban services. 12 53