Long-term risk of diabetes, hypertension and left ventricular hypertrophy associated with the metabolic syndrome in a general population.

Objectives: Metabolic syndrome is accompanied by an increased risk of developing diabetes mellitus. Limited or no evidence exists on whether and to what extent metabolic syndrome increases the risk of developing office hypertension, daily-life hypertension and left ventricular hypertrophy.

Methods: In 1412 individuals representative of the population of Monza, plasma glucose, office, home and ambulatory blood pressure, and echocardiographic left ventricular mass index were measured between 1990 and 1992 and 10 years later. New onset diabetes mellitus, new onset office, home and ambulatory hypertension as well as new onset left ventricular hypertrophy were assessed in individuals with and without metabolic syndrome (Adult Treatment Panel criteria) at the first examination.

Results: New onset diabetes mellitus, hypertension and left ventricular hypertrophy were all much more frequent in individuals with metabolic syndrome than in those without. In patients with metabolic syndrome, the adjusted risk of new onset diabetes mellitus was five to six times greater (P < 0.001), that of new onset office, home or ambulatory hypertension 3.5, 2.9 and 3.2 times greater (P < 0.001), respectively, and that of new onset left ventricular hypertrophy 2.6 times greater (P < 0.001). The most important predictors of new onset diabetes mellitus, hypertension and left ventricular hypertrophy were the baseline blood glucose, blood pressure and left ventricular mass index, respectively, with an independent contribution, in each condition, from other metabolic syndrome components. The metabolic syndrome as such did not have an additional predictive value.

Conclusion: In the general population, metabolic syndrome is associated with a marked increase in the risk not only of new onset diabetes mellitus but also of new onset office and daily-life hypertension, and left ventricular hypertrophy. This may account for the increased rate of cardiovascular morbidity and mortality exhibited with this condition in long-term studies.