In otherwise healthy teens, elevated levels of leptin were associated with artery walls losing elasticity, an early sign of cardiovascular disease. The finding sheds light on the role of leptin in the development of early vascular disease and suggests a physiological link between vascular disease and obesity, says lead researcher Atul Singhal, M.D., deputy director of nutrition at the MRC Childhood Nutrition Research Center in London.
Leptin is produced by fat cells and regulates appetite and metabolism. It can harm blood vessels and obese people have high levels. The stiffness of a person's arteries has a direct effect on the workload of the heart. In healthy individuals, the walls of the arteries expand and contract as blood is pumped through them. As arteries lose their elasticity, (distensibility) they become stiffer and do not dilate to their full diameter. This reduces blood flow and increases heart exertion.
Arterial distensibility is known to correlate closely with atherosclerotic risk, even from an early age. However, few studies have examined distensibility, leptin levels, and fat mass in children.
Singhal and fellow researchers chose to study teen-agers so they could evaluate the role of leptin on vascular changes early in the development of arterial disease, without the presence of contributing factors often present in an older population.
They studied 294 healthy adolescents, ages 13 to 16, with a range of body mass indexes. Researchers performed noninvasive ultrasound tests to examine their arteries, measure blood pressure, blood cholesterol, glucose, leptin and the inflammation marker C-reactive protein (CRP). The average leptin level was 2.8 micromoles per l
Contact: Carole Bullock
American Heart Association