Risk of new-onset metabolic syndrome associated with white-coat and masked hypertension: data from a general population.

Aim: In the Pressioni Arteriose Monitorate e Loro Associazioni (PAMELA) study, clinical and metabolic variables as well as office, home and ambulatory blood pressure (BP) values were simultaneously measured at baseline and after a 10-year follow-up. The study design allowed us to assess the value of selective and combined elevation of different BP phenotypes in predicting new-onset metabolic syndrome (MetS).
Methods: The present analysis included 1182 participants without MetS at baseline, as defined by the APT III criteria. On the basis of office, 24-h ambulatory BP and home values, participants were divided into four groups: normal, white-coat hypertension (WCH), masked hypertension and sustained hypertension.
Results: Compared with participants with in-office and out-of-office normal BP, a greater incidence of new-onset age-adjusted and sex-adjusted MetS was observed in WCH (OR = 1.75, CI 1.01-3.04, P = 0.0046), masked hypertension (OR = 2.58, CI 1.26-5.30; P = 0.009) and sustained hypertension (OR = 2.14, CI 1.20-3.79, P = 0.009)) when out-of-office BP was defined by ambulatory criteria. This was not the case when out-of-office BP was defined by home criteria, as only the WCH group showed a greater risk (OR 2.16, CI 1.28-3.63, P = 0.003). Similar findings were obtained for single components of the MetS such as abdominal obesity and hyperglycemia.
Conclusion: Our study provides evidence that either isolated or combined BP elevations identified by office/ambulatory measurements, carry an increased risk of new-onset MetS, whereas, only WCH is associated with a greater risk of incident MetS whenever BP phenotypes are identified by office/home measurements. In a clinical perspective, a comprehensive evaluation of BP status based on office/ambulatory measurements may improve diagnosis of new-onset MetS and activate measures for its prevention.