Short people have a 50 percent higher risk of having a heart problem or dying from one than tall people, a new study says, though weight, blood pressure and smoking habits remain more important factors.
Previous studies have suggested a link between height and heart problems like angina, heart attacks and angioplasties. This is the first major review of such studies, including research from around the world, confirming the relationship.
Researchers in Finland looked at 52 previous papers with data on height and heart problems in more than 3 million men and women.
Experts did not consider patients' heights objectively, but within the context of a particular country's population. They found the shortest people in the population were one and a half times more likely to have heart problems or die from them than the tallest people.
On average, short people were under 161 centimeters (5 feet 3 inches) and tall people were at least 174 centimeters (5 feet 9 inches).
The study was paid for by the Finnish Foundation for Cardiovascular Research and others. It was published online Wednesday in the European Heart Journal.
"We don't want to scare short people, but perhaps they should be extra cautious about their lifestyle," said Borge Nordestgaard, a professor of genetic epidemiology at the University of Copenhagen. He was not connected to the study.
Height's impact on heart disease was still less important than things like smoking, which increases the chance of a heart ailment by up to four times, he said.
Scientists aren't sure why short people might be more susceptible to heart problems, but think there could be several explanations. Being short might be a result of being poor, meaning people of small stature could be undernourished and vulnerable to health problems in general.
Experts also suggested there could be a biological explanation, such as a hormone imbalance that hurts the heart. Scientists also suspect that because short people have smaller arteries, those could theoretically get clogged quicker with cholesterol and be more easily damaged by any changes in blood pressure.
But Joep Perk, a professor of health sciences at Linnaeus University in Sweden and a spokesman for the European Society of Cardiology, said it was too early to conclude short people had potentially problematic hearts.
"We should be very cautious to tell short people they're at risk," he said. "This could unfairly stigmatize them."
He said it was premature for cardiologists to consider height as a risk factor. "We need to understand the mechanism behind it before we can do anything with this information," he said. "This is an interesting observation, but I want to know what I can do for my patients."
Tuula Paajanen, the study's lead author from Tempere University Hospital in Finland, said short people shouldn't be alarmed about the findings.
"Height is only one factor (among many) that may contribute to heart disease risk," she said.
Paajanen recommended people focus on other things like not smoking, eating a balanced diet and exercise. "Those are easier to change than your height."