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J. Pediatr. (Rio J.) vol.80 no.4 Porto Alegre July/Aug. 2004
LETTERS TO THE EDITOR
Low birth weight and early weaning: new risk factors for atherosclerosis
The study by Romaldini et al.1 on the risk factors for atherosclerosis in children and adolescents, regarded as the main cause of death in the world and in Brazil, was very appropriate. The authors detected one or more risk factors for atherosclerosis in 41% of 109 children and adolescents with family history of early heart disease. The higher the number of risk factors, the higher the probability of disease, since the effects are multiplied. Therefore, the recent publications of scientific evidence regarding two new risk factors for cardiovascular diseases, namely low birth weight and absence of breastfeeding, are of utmost importance, especially to those who provide child care.
Singhal et al.2 suggest that nutrition during childhood permanently affects the lipoproteic profile throughout life and that breastmilk has a protective effect on this profile. In a recent randomized clinical trial, they found a lower cholesterol concentration and a lower LDL/HDL ratio in adolescents with a preterm birth who had been breastfed. The ALSPAC (Avon Longitudinal Study of Parents and Children) also revealed long-term protective effects of breastmilk against cardiovascular diseases, suggesting that the promotion of exclusive breastfeeding is essential for the management of hypertension.3 These pieces of evidence, for both rich and poor countries, are supported by the recent WHO publication about the role of diet and nutrition in the prevention of chronic diseases.4
Lower birth weight, which results from fetal malnutrition, leads to cellular adaptation in critical periods of growth, which permanently alters the cell metabolism. In an attempt to protect vital tissues, such as the brain, the fetus produces hormonal changes in order for the body to adapt to a lower protein and energy supply, which compromises the development of several organs (liver, kidneys, pancreas) and systems (vascular, muscular and bone). After the first months of life, when malnutrition has been resolved, this mechanism predisposes to cardiovascular disorders, cerebrovascular disease, type 2 diabetes mellitus, obesity, hypertension, osteopenia, some kinds of cancer, and mental diseases.5,6
These pieces of evidence represent new preoccupations with public health for rich countries, which still have high rates of early weaning, and for poor countries, which show a shorter duration of breastfeeding and a high rate of low birth weight newborns. To what extent can these new risk factors explain the increase in the prevalence of obesity and type 2 diabetes mellitus (more than 40% in the last decades) in Brazil or predict a rise in morbidity and mortality due to cardiovascular diseases in poor areas? The answer to this and other questions is necessary so as to allow the prevention of adult diseases that can be traced back to intrauterine life or childhood.
João Guilherme B. Alves
M.Sc. Associate professor, Universidade Estadual de Pernambuco (UPE), Recife, PE, Brazil.
1. Romaldini CC, Issler H, Cardoso AL, Diament J, Forti N. Fatores de risco para aterosclerose em crianças e adolescentes com história de doença arterial coronariana prematura. J. Pediatr (Rio J). 2004;80:135-40.
2. Singhal A, Cole TJ, Fewtrell, Lucas A. Breastmilk feeding and lipoprotein profile in adolescents born preterm: follow-up of a prospective randomised study. Lancet. 2004;363:1571-8.
3. Martin RM, Ness AR, Gunnell D, Emmett P, Davey Smith G, ALSPAC Study Team. Does breast-feeding in infancy lower blood pressure in childhood? The Avon Longitudinal Study of Parents and Children (ALSPAC). Circulation. 2004;16:1259-66.
4. WHO Technical Report Series 916. Diet, nutrition and the prevention of chronic diseases. Geneva; 2003.
5. Krishnaswamy K, Naidu NA, Prasad MP, Reddy GA. Fetal malnutrition and adult chronic disease. Nutr Rev. 2002;60:S35-9.
6. Barker DJ. The development origins of adult disease. Eur J Epidemiol. 2003;18:733-6.