The study of 83 people fitted with pacemakers was conducted by a secondary school student, Jay Thaker, with the help of University of Michigan researchers. “Although the typical pacemaker patient may not be an iPod user, they are often in close contact with grandchildren who are users,” says Thaker.

Credits: RD

The study review found only a small association between birth weight and the future risk of heart disease. “We found a 1kg difference – going from 2.5kg to 3.5kg in birth weight – was associated with just a 10-15 per cent reduction in the risk of heart disease in later life,” says Dr Rachel Huxley, the study’s lead author. “Some reports have suggested a kilogram difference carriers a 25-40 per cent greater risk.”

Huxley says efforts to increase early foetal growth can change birth weight only by as much as 100g, which translates to just a 1-2 per cent lower risk of heart disease. Risk factors operating in later adult life, such as smoking and obesity, are more important, she says.