Exclusive breastfeeding duration and cardiorespiratory fitness in children and adolescents.

Am J Clin Nutr February 2012 vol. 95 no. 2 498-505

1. Idoia Labayen, 
2. Jonatan R Ruiz, 
3. Francisco B Ortega, 
4. Helle M Loit,
5. Jaanus Harro, 
6. Inga Villa, 
7. Toomas Veidebaum, and 
8. Michael Sjostrom

1. Un estudio desarrollado por la UPV/EHU y el Instituto Karolinska de Estocolmo ha concluido que los niños y adolescentes que han recibido lactancia materna tiene un 6% menos de riesgo cardiovascular y presentan mejores valores en capacidad aeróbica, niveles de colesterol, inflamación o presión sistólica.,
   Los estudios han sido publicados por Idoia Labayen, profesora de nutrición en la Facultad de Farmacia en la UPV/EHU en la edición de enero de la revista “American Journal of Clinical Nutrition” y en “Archives of Pediatrics and Adolescent Medicine”.
   Para la realización de las distintas pruebas, la investigación ha contado con la colaboración de personal médico sueco y estonio que ha realizado exámenes de salud a 1.025 niños de 9 y 10 años, y 971 adolescentes de 15 y 16 años en sus respectivos países. De forma previa al estudio, se les preguntaba a las madres si sus hijos habían sido exclusivamente alimentados mediante lactancia materna y, de haberlo hecho, durante cuánto tiempo.
   En las pruebas, además de tomar talla y peso, se realizaron análisis de sangre en los que se detectaron los valores de inflamación o el fibrinógeno, cuya presencia se relaciona con una mayor coagulación de la sangre, lo que aumenta el riesgo de arterosclerosis. Asimismo, se midió la capacidad aeróbica de los participantes mediante pruebas de esfuerzo.
   A falta de estudios posteriores sobre periodos de lactancia más largos que lo confirmen, la investigación en la que ha participado Labayen indica que los beneficios máximos de la lactancia materna se alcanzan a los tres meses ya que no se aprecian diferencias significativas entre el tercer y sexto mes. A partir del sexto mes, además, los niños ya no se alimentan exclusivamente de leche, sino que empiezan a diversificar su alimentación.
   Desde la universidad, han destacado que este estudio en niños y adolescentes suecos y estonios "habría sido difícil de realizar en España porque normalmente en este país las madres no suelen llegar a cumplir esos tres meses de lactancia". Por el contrario, en los países nórdicos "se favorece mucho la existencia de lactancia materna, con bajas maternales de hasta dos años además de ayudas sanitarias de enfermeras que se desplazan a las casas a ayudar y recomendar a las madres sobre la mejor manera de dar el pecho".
   Labayen ha indicado que en España, "aunque muchas madres lo intentan, se da un fracaso elevadísimo en los primeros quince días, cuestión que se podría resolver con un adecuado asesoramiento y apoyo a las madres lactantes". Además, ha resaltado que las madres también abandonan esta práctica en el tercer mes porque "tienen que empezar a trabajar". No obstante, ha apuntado que, "al menos", en el caso de España "hay buenas leches de fórmula", si bien "no mejoran la salud cardiovascular".
   A juicio de la investigadora, la lactancia materna "puede llegar a ser una cuestión de vida o muerte en muchos lugares del tercer mundo en donde se multiplican los problemas que puede haber con la preparación y esterilización de un biberón".
   La colaboración de este equipo europeo investigador ha estado centrada en el estudio de la influencia en la salud de los momentos inmediatamente anterior y posterior al parto, además de en la lactancia materna. En los próximos meses, pretenden dirigir el peso de sus investigaciones hacia los niños que al nacer con menos peso tienen un mayor riesgo de padecer alguna enfermedad cardiovascular. Sus investigaciones intentarán conocer si ese mayor riesgo, de algún modo, puede ser compensado con la lactancia materna. Además, el equipo seguirá observando al grupo de niños suecos y estonios que han participado en el estudio sobre lactancia para conocer las posibles variaciones en su riesgo cardiovascular a medida que vayan creciendo.

Childhood Adiposity, Adult Adiposity, and Cardiovascular Risk Factors

Markus Juonala, M.D., Ph.D., Costan G. Magnussen, Ph.D., Gerald S. Berenson, M.D., Alison Venn, Ph.D., Trudy L. Burns, M.P.H., Ph.D., Matthew A. Sabin, M.D., Ph.D., Sathanur R. Srinivasan, Ph.D., Stephen R. Daniels, M.D., Ph.D., Patricia H. Davis, M.D., Wei Chen, M.D., Ph.D., Cong Sun, M.D., Ph.D., Michael Cheung, M.D., Ph.D., Jorma S.A. Viikari, M.D., Ph.D., Terence Dwyer, M.D., M.P.H., and Olli T. Raitakari, M.D., Ph.D.

N Engl J Med 2011; 365:1876-1885

Background: Obesity in childhood is associated with increased cardiovascular risk. It is uncertain whether this risk is attenuated in persons who are overweight or obese as children but not obese as adults.

Methods: We analyzed data from four prospective cohort studies that measured childhood and adult body-mass index (BMI, the weight in kilograms divided by the square of the height in meters). The mean length of follow-up was 23 years. To define high adiposity status, international age-specific and sex-specific BMI cutoff points for overweight and obesity were used for children, and a BMI cutoff point of 30 was used for adults.

Results: Data were available for 6328 subjects. Subjects with consistently high adiposity status from childhood to adulthood, as compared with persons who had a normal BMI as children and were nonobese as adults, had an increased risk of type 2 diabetes (relative risk, 5.4; 95% confidence interval [CI], 3.4 to 8.5), hypertension (relative risk, 2.7; 95% CI, 2.2 to 3.3), elevated low-density lipoprotein cholesterol levels (relative risk, 1.8; 95% CI, 1.4 to 2.3), reduced high-density lipoprotein cholesterol levels (relative risk, 2.1; 95% CI, 1.8 to 2.5), elevated triglyceride levels (relative risk, 3.0; 95% CI, 2.4 to 3.8), and carotid-artery atherosclerosis (increased intima–media thickness of the carotid artery) (relative risk, 1.7; 95% CI, 1.4 to 2.2) (P≤0.002 for all comparisons). Persons who were overweight or obese during childhood but were nonobese as adults had risks of the outcomes that were similar to those of persons who had a normal BMI consistently from childhood to adulthood (P>0.20 for all comparisons).

Conclusions: Overweight or obese children who were obese as adults had increased risks of type 2 diabetes, hypertension, dyslipidemia, and carotid-artery atherosclerosis. The risks of these outcomes among overweight or obese children who became nonobese by adulthood were similar to those among persons who were never obese. (Funded by the Academy of Finland and others.)

Reduced or modified dietary fat for preventing cardiovascular disease

Editorial Group: Cochrane Heart Group.Published Online: 6 JUL 2011

Assessed as up-to-date: 1 DEC 2010 DOI: 10.1002/14651858.CD002137.pub2
Abstract

Background

Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear.


Objectives

To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration.


Search strategy

For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, were searched through to June 2010. References of Included studies and reviews were also checked.


Selection criteria

Trials fulfilled the following criteria: 1) randomised with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available.


Data collection and analysis

Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed.


Main results

This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis.

Few studies compared reduced with modified fat diets, so direct comparison was not possible.


Authors' conclusions

The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.



Plain language summary

Cutting down or changing the fat we eat may reduce our risk of heart disease

Modifying fat in our food (replacing some saturated (animal) fats with plant oils and unsaturated spreads) may reduce risk of heart and vascular disease, but it is not clear whether monounsaturated or polyunsaturated fats are more beneficial. There are no clear health benefits of replacing saturated fats with starchy foods (reducing the total amount of fat we eat). Heart and vascular disease includes heart attacks, angina, strokes, sudden cardiovascular death and the need for heart surgery. Modifying the fat we eat seems to protect us better if we adhere in doing so for at least two years. It is not clear whether people who are currently healthy benefit as much as those at increased risk of cardiovascular disease (people with hypertension, raised serum lipids or diabetes for example) and people who already have heart disease, but the suggestion is that they would all benefit to some extent.

Childhood obesity and adult cardiovascular disease risk: a systematic review

Lloyd LJ, Langley-Evans SC, McMullen S. Childhood obesity and adult cardiovascular disease risk: a systematic review. Int J Obes (Lond). 2010 Jan;34(1):18-28. Epub 2009 May 12. (Review) PMID: 19434067
ABSTRACT
BACKGROUND: Although the relationship between adult obesity and cardiovascular disease (CVD) has been shown, the relationship with childhood obesity remains unclear. Given the evidence of tracking of body mass index (BMI) from childhood to adulthood, this systematic review investigated the independent relationship between childhood BMI and adult CVD risk.
OBJECTIVE: To investigate the association between childhood BMI and adult CVD risk, and whether the associations observed are independent of adult BMI. DESIGN: Electronic databases were searched from inception until July 2008 for studies investigating the association between childhood BMI and adult CVD risk. Two investigators independently reviewed studies for eligibility according to inclusion/exclusion criteria, extracted the data and assessed study quality using the Newcastle-Ottawa Scale.
RESULTS: Positive associations between childhood BMI and adult blood pressure or carotid intima-media thickness were generally attenuated once adjusted for adult BMI. Associations between childhood BMI and CVD morbidity/mortality had not been adjusted and do not provide evidence of an independent relationship. Negative associations between childhood BMI and blood pressure were observed in several adjusted data sets.
CONCLUSIONS: Little evidence was found to suggest that childhood obesity is an independent risk factor for CVD risk. Instead, the data suggest that relationships observed are dependent on the tracking of BMI from childhood to adulthood. Importantly, evidence suggests that risk of raised blood pressure is highest in those who are at the lower end of the BMI scale in childhood and overweight in adulthood. The findings challenge the widely accepted view that the presence of childhood obesity is an independent risk factor for CVD and that this period should be a priority for public health intervention. Although interventions during childhood may be important in prevention of adult obesity, it is important to avoid the potential for negative consequences when the timing coincides with critical stages of neurological, behavioural and physical development.

Body mass index in adolescence in relation to cause-specific mortality: a follow-up of 230,000 Norwegian adolescents

Bjorge T, et al. Body mass index in adolescence in relation to cause-specific mortality: a follow-up of 230,000 Norwegian adolescents. Am J Epidemiol. 2008 Jul 1;168(1):30-7

Abstract

The prevalence of obesity in childhood and adolescence has increased worldwide. Long-term effects of adolescent obesity on cause-specific mortality are not well specified. The authors studied 227,000 adolescents (aged 14-19 years) measured (height and weight) in Norwegian health surveys in 1963-1975. During follow-up (8 million person-years), 9,650 deaths were observed. Cox proportional hazards regression was used to compare cause-specific mortality among individuals whose baseline body mass index (BMI) was below the 25th percentile, between the 75th and 84th percentiles, and above the 85th percentile in a US reference population with that of individuals whose BMI was between the 25th and 75th percentiles. Risk of death from endocrine, nutritional, and metabolic diseases and from circulatory system diseases was increased in the two highest BMI categories for both sexes. Relative risks of ischemic heart disease death were 2.9 (95% confidence interval (CI): 2.3, 3.6) for males and 3.7 (95% CI: 2.3, 5.7) for females in the highest BMI category compared with the reference. There was also an increased risk of death from colon cancer (males: 2.1, 95% CI: 1.1, 4.1; females: 2.0, 95% CI: 1.2, 3.5), respiratory system diseases (males: 2.7, 95% CI: 1.4, 5.2; females: 2.5, 95% CI: 1.4, 4.8), and sudden death (males: 2.2, 95% CI: 1.2, 4.3; females: 2.7, 95% CI: 1.1, 6.6). Adolescent obesity was related to increased mortality in middle age from several important causes.
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Pues eso, que los gorditos adolescentes mueren más en los años medios de la vida adulta... si son noruegos ;-)

Factores de riesgo cardiovascular en la edad infantil. Resultados globales del estudio Cuatro Provincias

Carmen Garcésa y Manuel de Oya (en nombre de los investigadores del estudio Cuatro Provincias) Unidad de Lípidos. Fundación Jiménez Díaz. Universidad Autónoma de Madrid. Madrid. España.
Rev Esp Cardiol 2007; 60: 517 - 524
La aterosclerosis es un proceso que se inicia en las primeras décadas de la vida y evoluciona de forma asintomática, en general, sin expresión clínica hasta la edad adulta. En el estudio Cuatro Provincias hemos analizado, en 1.275 niños de edad prepuberal, factores de riesgo (dieta, variables antropométricas, concentraciones de lípidos, vitaminas y algunos determinantes genéticos) que pueden estar relacionados con la aparición de la enfermedad coronaria en la edad adulta. En esta revisión resumimos de forma global, las principales aportaciones del estudio. El estudio 4P ha reflejado que los aspectos relacionados con el síndrome metabólico (obesidad, concentraciones elevadas de glucosa y triglicéridos) que conducen a la enfermedad coronaria en el adulto están ya expresados en la edad escolar. En este sentido, los niños de las provincias con una alta mortalidad coronaria pesan más y tienen unas concentraciones más altas de triglicéridos y glucosa. El porcentaje de niños que supera las concentraciones recomendables de colesterol total y colesterol unido a lipoproteínas de baja densidad es elevado en todas las provincias. A pesar de que hay aspectos positivos, como que las concentraciones de colesterol unido a lipoproteínas de alta densidad son también elevadas y que la prevalencia del alelo ε4 del gen de la apo-E, claramente relacionada con el riesgo cardiovascular, es baja en el conjunto de la población, si las alteraciones metabólicas descritas persisten, la situación de España respecto al riesgo cardiovascular puede empeorar en el futuro. Estos aspectos metabólicos se asocian con una alimentación rica en grasas y con un bajo consumo de hidratos de carbono, alejada de las recomendaciones actuales para la infancia. Su corrección en edades tempranas tendría enormes beneficios en la prevención de la enfermedad coronaria.