Particular characteristics of the metabolic syndrome in patients with morbid obesity.

BACKGROUND Criteria for the diagnosis of the metabolic syndrome are currently being reconsidered, as their usefulness is not the same for all phenotypes in relation to the risk of cardiovascular disease. AIM We analyzed the changes in metabolic parameters after a fat overload in different groups of patients. MATERIALS AND METHODS The study included 20 healthy persons, 30 metabolic syndrome patients without morbid obesity, 80 metabolic syndrome patients with morbid obesity and 16 patients with morbid obesity without the metabolic syndrome. All the participants received a fat overload of 60g. Measurements were made before the overload and 3h afterwards of triglycerides, free fatty acids, insulin and uric acid. RESULTS Metabolic syndrome patients with morbid obesity had a lower waist-to-hip ratio, and lower plasma free fatty acid and triglycerides levels at baseline and after the overload than patients without morbid obesity. Plasma uric acid levels rose after the fat overload in the metabolic syndrome patients who had morbid obesity but not in the patients without morbid obesity. A positive relation was found between plasma triglycerides and free fatty acid levels in all the patients but not in the controls after the fat overload. A positive relation was also found between uric acid and insulin levels in the metabolic syndrome patients with morbid obesity. CONCLUSIONS Metabolic syndrome patients with and without morbid obesity presented different metabolic characteristics. This suggests that there are 2 different clinical phenotypes, both grouped under the metabolic syndrome umbrella.