Metabolic syndrome in the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study: daily life blood pressure, cardiac damage, and prognosis

The prevalence of the metabolic syndrome (National Cholesterol Education Program Adult Treatment Panel III criteria) and its relationships with daily life blood pressures, cardiac damage, and prognosis were determined in 2013 subjects from a Northern Italian population aged 25 to 74 years. Home blood pressure, 24-hour blood pressure, and left ventricular mass index (echocardiography) were also measured. Cardiovascular and noncardiovascular deaths were registered over 148 months. Metabolic syndrome was found in 16.2% of the sample, an office blood pressure elevation being the most frequent (95.4%) and the blood glucose abnormality the least frequent (31.5%) component. There was in metabolic syndrome a frequent elevation in home and/or 24-hour average blood pressure, as well as a greater left ventricular mass index and prevalence of left ventricular hypertrophy, which was manifest even when data were adjusted for between-group differences, including blood pressure. The adjusted risk of cardiovascular and all-cause mortality was greater in metabolic syndrome subjects (+71.0% and +37.0%; P<0.05), a further marked increase being observed with left ventricular hypertrophy or "in-office" and "out-of-office" blood pressure elevations. The increased risk was related to the blood pressure and the blood glucose component of metabolic syndrome, with no contribution of the remaining components. Thus, metabolic syndrome is common in a Mediterranean population in which it significantly increases the long-term risk of death. Cardiac abnormalities and increases in home and 24-hour blood pressure are common in metabolic syndrome, and their occurrence further enhances the risk. The contribution of metabolic syndrome components to the risk, however, is unbalanced and mainly related to blood pressure and glucose abnormalities.