Severe early malnutrition tied to lasting effects on cardiovascular structure

By Anne Harding

NEW YORK (Reuters Health) - Survivors of severe acute malnutrition (SAM) in childhood show changes in cardiovascular structure that put them at increased risk of hypertension, new findings show.

SAM survivors had a smaller left ventricular outflow tract, stroke volume, cardiac output, and pulse wave velocity, with higher diastolic blood pressure and higher systemic vascular resistance, researchers report in Hypertension, online June 30.

"That early period represents a period of developmental plasticity so that insults during that period hold the potential to affect form and function and therefore health going forward," senior author Dr. Terrence Forrester of the University of the West Indies in Kingston, Jamaica, told Reuters Health.

"We are keen to assess the population attributable risk of this early malnutrition and at the same time in the same study use the molecular means at our disposal, primarily epigenetics and cell signaling, to detect novel pathways that might be informative for new interventions," he said.

Several studies have suggested a link between early malnutrition and cardiovascular health in adulthood, Dr. Forrester and his colleagues note in their report. The long-term effects of malnutrition might also vary depending on whether malnutrition is manifested as marasmus or kwashiorkor, they add.

To investigate, the researchers looked at several measures of cardiovascular structure in 116 adult SAM survivors, 54 of whom had marasmus and 62 who had kwashiorkor, and 45 controls matched by age, sex and body mass index.

After adjusting for age, sex, height and weight, the SAM survivors had mean reductions of 0.67 standard deviations (SD) in left ventricular outflow tract diameter; 0.44 SD in stroke volume; 0.5 SD in cardiac output; and 0.32 SD in pulse wave velocity.

Mean diastolic blood pressure was 4.3 mmHg higher in the SAM survivors. Systemic vascular resistance was 30.2 mm Hg x min/L in marasmus survivors and 30.8 mm Hg x min/L in kwashiorkor survivors, versus 25.3 mm Hg x min/L for controls. There were no other differences in cardiovascular parameters between the two SAM groups.

SAM affects hundreds of millions of people worldwide, Dr. Forrester noted, while stunting due to sustained undernutrition in childhood likely affects 40% of the world's children under five.

While kwashiorkor and marasmus are rare in wealthier countries, he added, sustained malnutrition in early childhood does occur, particularly in disadvantaged groups such as inner city children and certain immigrant populations. Developed countries "are not immune, and should pay attention," he said.

Dr. Mark DeBoer, a pediatric endocrinologist at the University of Virginia in Charlottesville who was not involved in the study, said it underscores the importance of efforts to prevent severe malnutrition as well as preventive measures for survivors of malnutrition, such as maintaining a healthy body weight, exercising regularly, and avoiding smoking.

"This study provides further evidence that early life challenges, in this case severe malnutrition, result in long-term changes in an individual, in this case a higher peripheral systemic vascular resistance and higher diastolic blood pressure as well as some cardiovascular structural changes," Dr. DeBoer told Reuters Health.

"There has been a growing support for this type of idea, where there are epigenetic changes in an individual where severe circumstances don't just change the health status of a child at the moment, but result in programming differences where gene expression is altered for the long term, and that has potential consequences later in life," he said.

SOURCE: http://bit.ly/1qunoDh

Hypertension 2014.

(c) Copyright Thomson Reuters 2014. Click For Restrictions - http://about.reuters.com/fulllegal.asp