Cholesterol levels and prevalence of hypercholesterolemia in Mexican children and teenagers

Proposition of decision limits for serum lipids in Brazilian children aged one to 13 years

OBJECTIVE

To determine decision limits for total cholesterol, LDL-cholesterol, non-HDL cholesterol, HDL-cholesterol, and triglycerides in healthy children and adolescents from Cuiabá, Brazil.

METHODS

This was a cross-sectional study of 1866 healthy children and adolescents randomly selected from daycare centers and public schools in Cuiabá. The desirable levels of serum lipids were defined using the classic criteria, i.e., total cholesterol, LDL-cholesterol, non-HDL cholesterol, and triglycerides levels below the P75 percentile, and HDL-c above the P10 percentile.

RESULTS

For CT, P75 was: 160mg/dL for the age range of 1 to <3 years, 170mg/dL for ≥3 to <9 years, and 176mg/dL for ≥9 to <13 years. For non-HDL cholesterol, it was 122mg/dL for the age range of 1 to <13 years. For LDL-c, it was 104mg/dL at the age range of 1 to <9 years and 106mg/dL from ≥9 to <13 years. For TG, it was 127mg/dL from 1 to <2 years; 98mg/dL from ≥2 to <6 years; and 92mg/dL from ≥6 to <13 years. As for HDL-cholesterol, P10 was 24mg/dL, 28mg/dL, 32mg/dL, and 36mg/dL, for the age ranges of 1 to <2 years, ≥2 to <3 years, ≥3 to <4 years, and ≥4 to <13 years, respectively.

CONCLUSION

The decision limits for the serum lipid levels defined in this study differed from those observed in the current Brazilian and North-American guidelines, especially because it differentiates between the age ranges. Using these decision limits in clinical practice will certainly contribute to improve the diagnostic accuracy for dyslipidemia in this population group.

Lipid and lipoprotein profiles and prevalence of dyslipidemia in Mexican adolescents

The objective of the study was to determine the prevalence of different forms of dyslipidemia in an urban population of Mexican adolescents. A cross-sectional study was conducted in 1846 students from 8 randomly selected public junior high schools in Mexico City. Anthropometry, blood pressure, and 12-hour fasting lipids and lipoproteins were measured. We studied 770 male and 1076 female adolescents (13.2 +/- 1 years). The most prevalent dyslipidemia was low high-density lipoprotein cholesterol (HDL-C) (<35 mg/dL) either combined with other abnormalities (17.5% for male and 12.9% for female subjects, P < .001) or isolated (13.5% and 9.6% for male and female subjects, respectively, P < .001). Obese subjects showed the highest prevalence of low HDL-C (47.2% for male and 34.4% for female subjects) and of high total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) (19.4%, 27.8%, and 36.1%, respectively, for male subjects; 9.8%, 13.1%, and 24.6%, respectively, for female subjects). Multiple regression analysis showed that waist circumference was negatively associated with HDL-C and positively associated with LDL-C and TG levels, whereas Tanner stages were negatively associated but sex was positively associated with total cholesterol, LDL-C, and TG concentrations. As in Mexican adults, low HDL-C and high TG levels were the most prevalent dyslipidemias. Increased blood lipids over long periods suggest that, as adults, these adolescents will be facing a higher risk for atherosclerosis.

Prevalence and interrelations of cardiovascular risk factors in urban and rural Mexican adolescents

PURPOSE

To examine the prevalence of coronary risk factors in Mexican adolescents, and their relations to school type, gender, and residence in urban and rural areas.

METHODS

A cross-sectional survey was conducted in 3121 junior high school students, aged 12 to 16 years, attending urban schools (eight public, n = 1850, two private, n = 480) and three rural public (n = 791) schools. Weight, height, waist circumference, blood pressure, and fasting glucose and lipid-lipoprotein levels were measured. Tobacco smoking and physical activity were also ascertained. The prevalence rates of cardiovascular risk factors were determined by gender and school type.

RESULTS

Obesity, overweight, high blood pressure, cigarette smoking, and physical inactivity were higher for urban than rural adolescents. The prevalence of the low HDL-C level was exceedingly high in adolescents of three school types (> 30%) but particularly in male rural students (48.9%). Compared with rural students, high LDL-cholesterol was twice as high in private schoolchildren. The prevalence of impaired fasting glucose was .35% in the whole population and much higher in obese males (1.6%) and obese females (2.4%).

CONCLUSIONS

Our findings highlight an epidemic of coronary risk factors mainly in adolescents living in the urban area, suggesting the importance of environmental factors.

[Lipid profile among school children in Campinas, Brazil]

OBJECTIVE

To describe the lipid profile and the prevalence of hypercholesterolemia among schoolchildren aged 7 to 14 years in Campinas, São Paulo State, Brazil.

METHODS

Plasma cholesterol levels, fractions, ratios and triglycerides were determined according to age and gender in a total of 1,600 schoolchildren. Hypercholesterolemia was considered borderline for 170 mg/dl</= cholesterol <185 mg/dl, moderate for 185 mg/dl pound cholesterol <200 mg/dl and severe for cholesterol >/=200 mg/dl.

RESULTS

Schoolchildren presented a cholesterol mean of 160 mg/dl, HDL-cholesterol mean of 49 mg/dl, LDL-cholesterol mean of 96 mg/dl, VLDL-cholesterol mean of 16 mg/dl, triglycerides mean of 79 mg/dl, cholesterol/HDL-cholesterol mean of 3.5 and LDL-cholesterol/HDL-cholesterol mean of 2.1. In general, females had higher cholesterol and triglycerides values than males. The prevalence of hypercholesterolemia was 35.0%: 15.6% was borderline high, 9.8% moderate and 9.5% severe. Females presented higher prevalence of hypercholesterolemia than males.

CONCLUSIONS

The results pointed to the emergence of hypercholesterolemia as a public health problem in Brazil.

Worldwide distribution of blood lipids and lipoproteins in childhood and adolescence: a review study

Review and pooled analysis of the relevant worldwide literature was investigated from 1975 to 1996. Eighteen surveys out of 54 were suitable for analysis according to the selection criteria. This represents a total of 60494 observations from 26 countries all over the world. Data suggests differences as great as 76 mg/dl when comparing northern European countries to black African children. The overall curve of cholesterol with age observed in the pooled population indicates a pre-adolescent peak and then a slightly inverse change is observed for both boys and girls, from 3 to 12 years old being almost coincident absolute values. Beyond age 12, values for boys continue to slightly decrease to age 16, while for girls values tend to increase through this age-range. The curve in the late teens (16-18 years) tends to reach pre-teen levels for both sexes, although girls have consistently higher absolute values than boys. There is a great variation in the specific age-sex and race levels of cholesterol among different populations or even in the same populations over a period of time. However, an apparently universal pattern of an early rise, a fall, and a subsequent rise in mean values of total cholesterol by age from the preadolescence to late teens is observed. More data are needed on total cholesterol and lipid fractions between late school age and mid-adulthood.