Starvation linked to greater risk of cardiac complications

Russians born during the Leningrad Siege in World War II, which was responsible for some of the greatest losses of civilian life in history, are giving scientists new strategies to identify people who experienced intrauterine growth restriction (IUGR) and starvation during childhood at greatest risk of developing long term heart complications. The abstract study¹, presented at the Frontiers in CardioVascular Biology (FCVB) meeting, in London, UK, 30 March to 1 April 2012, makes use of a unique population of people exposed to extreme starvation both as foetuses and during childhood.

The cellular changes identified, investigators suggested, might be used to target treatments to children at greatest risk of developing heart complications. In a second study ², also presented at FCVB 2012, Spanish investigators elucidated structural changes occurring in the heart as a direct consequence of IUGR. Monitoring reversal of these changes, suggested the authors, might offer a "fast track" approach for testing effectiveness of new therapies.

"Together, these innovative studies demonstrate the impact that basic research can have on the development of new approaches to heart treatments," said Sian Harding, FCVB 2012 chairperson of the Core Scientific Committee. "New treatments preventing heart changes associated with poor nutrition would benefit those exposed to IUGR and also children who've experienced reduced calorie intakes, either due to food shortages or extreme dieting."

Intrauterine growth restriction (IUGR), defined as a birth weight below the 10th percentile for gestational age, currently has an incidence estimated to be 8.1% of births in developed countries, and 6 to 30% of births in developing countries. Common causes include chronically malnourished mothers, maternal health problems during pregnancy (such as diabetes) and placentas that fail to transfer adequate nutrients from mother to foetus.

The connection between IUGR and development of subsequent heart disease was first recognised in 1989 when David Barker, from the MRC Unit at the University of Southampton, UK, showed that the lower the weight of a baby at birth and during infancy, the higher the risk of developing cardiovascular disease (CVD) and other chronic conditions in later life ³. IUGR newborns show signs of CV remodelling and dysfunction, including reduced myocardial velocities, dilated hearts and increased thickness of artery walls.

Studies have shown that children with IUGR have a distinct cardiac morphology, with "less elongated and more globular" cardiac ventricles. "As a consequence IUGR hearts are not as efficient in generating the normal stroke volumes, which results in the need for an increased heart rate to maintain cardiac outputs. The overall result is less efficient hearts," explained Iratxe Torre, one of the investigators, from The Hospital Clinic of Barcelona, Spain.

No treatments are currently available to reverse the structural heart changes resulting from IUGR.