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Novel Risk Factors for Coronary Disease: Plasma Serum Homocysteine and its relationship with classical risk factors for Coronary Disease in scholarships. La Pintana Municipality. Metropolitan Region. Chile. 1999.

Szot-Meza Jorge, Berríos Ximena

Department of Public Health
School of Medicine
Catholic University
Santiago de Chile.

Materials and Methods

Introduction: Serum homocysteine levels (SHL) would be an independent Risk Factor (RF) for Coronary Heart Disease (CHD) in adults. Little information exists on homocysteine levels in children.
Objectives: To describe the distribution of SHL and its relationship with classic RF for CHD.
Materials and Methods: 112 schoolchildren both sexes, mean age: 10.1 years-old (DS+-1.03). Data collection was done at schools by trained field personnel measuring Height and Weight, Systolic Blood Pressure and Diastolic Blood Pressure according international recommendations.
Fasting Total cholesterol, HDL-cholesterol ,tryglicerides, and SHL were assessed as well. Conventional laboratory methods were used. Criteria to state Prevalence (P) of RF is according to international recomendations. For High SHL (HSHL) value: ³ 8.96m mol/lt. SMK was assessed by a self-administered questionnaire and defined as current conssumption. In the entire population were assessed SES through Graffar method, and sexual maturity (SM).
Results: 47.3% boys, and 52.7% girls. 79.7% in low-middle social class. 47.5% boys are at first Tanner degree. 57.1% girls are at 2nd and 3rd Tanner degree. The mean of SHL is 5.74 m mol/lt.(DS+-1.67 CI 95%5.42-6.05)for all children. In boys 6.02 m mol/lt (DS+-1.93, CI 95%5.49-6.56) and girls: 5.48 m mol/lt.(DS+-1.36 CI 95%5.12-5.83)respectively. (p-value=.005). There are not differences in SHL levels according to sexual maturity.
The SHL means in children do not exhibit any association with other RF. Global prevalence for HSHL is 6.3%: 9.3% in boys and 3.4% in girls.
Conclusions: The SHL mean values are coincident with reports published in the international litarature. The mean of SHL is lower in children than in adults, and in girls than in boys. No significant association with other RF assessed here was founded. The importance of this study is to have a baseline of a novel RF which allows follow up to detect changes during childhood and adolescence.


Introduction:  Risk Factors (RF) for Coronary Heart Disease (CHD), as High Blood Pressure (HBP), Obesity (OB), abnormal Lipid Profile (LP) and Smoking (SMK) could be present at early stages during life. These have been considered "classic" RF. Since the late 80´s "new risk factors" (NRF) for CHD have been added. These have been assessed mainly in adulthood. Among these NRF its important to mention: the Plasmatic Fibrinogen, C-reactive Protein (CRP), Lipoproteins A, B and LpA and the Serum Homocysteine high level (SHHL). The first signal that SHHL could become a coronary risk appeared in the 60´s: Carson found that homocysteinuric children were keen to atherosclerosis. In fact, prospective studies have demonstrated that elevations in the concentration of the Plasmatic Homocysteine (PH) could precede the developing of the CHD. The SHHL is related to adults ´s Systolic Hypertension (SH) and the effect increases when people smoke. The PH is produced by the metionine´s demetilation, and can be removed by two enzymes, which must have B-12 vitamin and folic acid as a cofactor. The explanation of damage produced by SHHL is well known: This substance can inhibit the anticoagulant mechanism and to favor the LDL´s oxidation. On despite of this great amount of information about homocysteine (H), most of it has been produced through research in adult population. There isn't enough information about H in children.

The purpose of this communication is to provide information about the presence of H in school population.



To describe the distribution of PH and its association with classical RF for CHD: OB, HBP, LP and SMK in a schoolchildren population.

Materials and Methods: The study population is a non-random sample of 112 schoolchildren both sexes, mean age: 10.1 years old (DS+-1.03) of 4th and 5th grade at schools of La Pintana Municipality. (Located in the southeast area of Santiago, the capital city).

The data collection was done according to international recommendations, during September and October of 1998. A self-administered questionnaire to collect information about current SMK and either biological measurements such as weight, height, blood pressure, classical lipid profile, and PH were performed by trained field personnel. Informed written consent was asked to the children's parents. All blood samples to assess lipid profile and PH were studied at the Central Laboratory of the Faculty of Medicine at Catholic University.

The risk criteria were: for OB: Body Mass Index (BMI)³ 85th percentile distributed by sex and age; for HBP: Systolic or diastolic blood pressure ³ 95th percentile distributed by sex and age; for LP: total cholesterol (TC)³ 180 mg/dl, HDL-cholesterol (HDL)£ 35 mg/dl, LDL-cholesterol (LDL)³ 130 mg/dl, triglicerides (TG)³ 200 mg/dl, and index TC/HDL ³ 4. For PH two cut points were considered: 1). 8.99 m mol/lt of PH corresponding to +2SD(standard deviations) of the distribution in a large North American schoolchildren population (n=3524), and 2). 8.5m mol/lt corresponding to the value of 95th percentile of the distribution of the same population. Socioeconomic Situation (SES) was assessed through Graffar method, and Sexual Maturity (SM) through Tanner Index.

The statistics analysis was done using the SPSS for Windows 95 Program and processed at the Public Health Department of the Catholic University of Chile.



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