February 16 (HealthDay News) -- Salt intake has more of an effect on blood pressure in people with metabolic syndrome than in others, experts say, suggesting that cutting down on salt could be especially important for these high-risk individuals.

About one in five people are affected by metabolic syndrome, a combination of three or more conditions that increase the risk of developing cardiovascular disease and diabetes. Those conditions include abdominal obesity, elevated blood pressure, high triglyceride concentration, low HDL cholesterol, and high glucose levels.

Researchers studied more than 1,900 Chinese people, 16 years and older, without diabetes. They were given a low-sodium diet for seven days followed by a high-sodium diet for seven days. Their blood pressure was checked a number of times during each diet phase.

The blood pressure of the 283 participants with metabolic syndrome was more sensitive to salt intake, the researchers reported. High salt sensitivity was defined as an increase in mean arterial blood pressure of more than 5 mm Hg during high salt intake and a decrease of more than 5 mm Hg during low salt intake.

Compared to those with no metabolic syndrome risk factors, those with four or five risk factors were 3.5 times more likely to have high salt-sensitivity during the low sodium phase and three times more likely to have high salt-sensitivity during the high sodium phase.

"These results suggest that metabolic syndrome enhances blood pressure response to sodium intake. Reduction in sodium intake could be an especially important component in reducing blood pressure in patients with multiple risk factors for metabolic syndrome," Dr Jing Chen, Tulane University School of Medicine, New Orleans, La. and colleagues concluded.

The study was published online Monday and is expected to be in an upcoming print issue of The Lancet.

SOURCE: The Lancet, news release, Feb. 16, 2009