A study of 1900 Chinese people has revealed that the blood pressure of people with metabolic syndrome is more sensitive to salt intake. Thus reduction of salt intake could be an especially important component in reducing blood pressure in patients with multiple risk factors for metabolic syndrome. These are the conclusions of authors of an article published Online First in a forthcoming edition of The Lancet, written by Dr Jing Chen, Tulane University School of Medicine, New Orleans, LA, USA.
Metabolic syndrome is a combination of medical disorders that increase the risk of developing diabetes and cardiovascular disease. It affects 1 in 5 people and prevalence increases with age. Symptoms and features are:
- Fasting hyperglycemia — diabetes mellitus type 2 or impaired fasting glucose, impaired glucose tolerance, or insulin resistance;
- High blood pressure;
- Central obesity (also known as visceral, male-pattern or apple-shaped adiposity), overweight with fat deposits mainly around the waist;
- Decreased HDL cholesterol;
- Elevated triglycerides
The study analysed 1906 Chinese participants without diabetes, aged 16 or more, who were selected to receive a low-sodium diet for 7 days followed by a high-sodium diet (six-fold higher than the low-sodium phase) for an additional 7 days. Participants were excluded from the analysis if metabolic risk factor information was missing or if they did not complete their dietary interventions. Blood pressure was measured at baseline and on days 2,5,6 and 7 of each intervention. Metabolic syndrome was defined as the presence of three of more of: abdominal obesity, raised blood pressure, high triglyceride concentration, low HDL cholesterol, or high glucose. High salt sensitivity was defined as a decrease in mean arterial blood pressure of more than 5 mm Hg during low-sodium or an increase of more than 5 mm Hg during high-sodium intervention.
The researchers found that 283 of 1881 patients with complete data had metabolic syndrome. In both the high-sodium and low-sodium phase, the blood pressure of patients with metabolic syndrome was more sensitive to changes in salt intake. Compared with those with no risk factors, participants with four or five risk factors had a three-and-a-half times higher risk of salt sensitivity during the low-sodium phase and a three-fold higher risk of high salt sensitivity during the high-sodium phase.
The authors conclude that “the results suggest that the 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.”
Epidemiological evidence suggests a lower prevalence of the metabolic syndrome is associated with dietary patterns rich in whole grains, fruit, vegetables and unsaturated fats. For information and practical tuition in preparing such food, why not come along to a Cooking for Health course, which are held throughout the year in Somerset, UK.