Short people are 50 percent likelier than tall people to die prematurely of heart disease, researchers reported Wednesday in a major review of three million people.
The study showed that women under 1.53 metres (5 feet) and men under 1.65m (5 ft 5 in) are significantly more prone to cardiovascular or coronary heart problems than women and men taller than 1.66 (5 ft 6 in) and 1.73 metres (5 ft 8 in), respectively.
The findings, published in the European Heart Journal, suggest that short stature should be added to the list of known heart disease risk factors alongside obesity, advanced age and high cholesterol levels, the researchers said.
The link between height and heart conditions has been examined in nearly 2,000 studies from around the world over the last 60 years, but evidence remained contradictory.
Scientists in Finland led by Puula Paajanen of the University of Tampere sifted through all this research to see if they could tease out a definitive answer.
The best approach, they decided, was to compare the shortest group to the tallest group to highlight any differences that might emerge.
They focussed on 52 earlier studies, examining more than three million people in all, that met their criteria for both comparability and high standards.
"The results are unequivocal: short stature is associated with increased risk of coronary heart disease," said Jaakko Tuomilehto, a professor at the University of Helsinki in commenting on the new study.
"But the possible patho-physiological, environmental, and genetic background of this peculiar association is not known," he added in a commentary, also in the European Heart Journal.
One theory is that shorter people have smaller coronary arteries that may become clogged earlier in life, especially when combined with poor nutrition or infections resulting in poor foetal or childhood growth.
But recent findings also suggest genes may be a culprit, Paajanen said.
"The genetic background of body height suggest that inherited factors ... may explain the association between small stature and an increased risk of heart disease in later life," she said in a statement.
Short people should not be worried about the new findings, she added.
"Height is only one factor that may contribute to heart disease. Whereas people have no control over their height, they can control their weight, lifestyle habits such as smoking, drinking and exercise."
She also pointed out that being tall eliminated a risk factor for coronary heart disease but was not in itself a protection against it.