Metabolic syndrome as a predictor of non-dipping hypertension

Metabolic syndrome (MS) and non-dipping hypertension both increase cardiovascular mortality. Although both clinical modalities share common pathophysiologic factors in their etiologies, previous studies did not find any association between them. We aimed to investigate the association between MS and non-dipping blood pressure by comparing different definitions of MS. One-hundred-thirty-two consecutive patients (58 men) who underwent 24-hour ambulatory blood pressure monitoring were analyzed. MS was evaluated according to the currently used Adult Treatment Panel (ATP) III definition criteria, named MS-ATP III. In order to reveal the weights of risk contributing to MS, a new diagnostic scoring method (MS-Score) was used in comparison with MS-ATP III. Nocturnal non-dipping refers to a reduction in average systolic and/or diastolic blood pressure at night (< or = 10%) compared with daytime average values. Non-dipping pattern was found in 61.4% of patients. The frequency of MS according to MS-Score, but not MS ATP III, was significantly higher in patients with non-dipping pattern than those without it (p = 0.009). Although more prominent in the nighttime, MS-Score showed positive correlation with all systolic blood pressure results (r = 0.27, p = 0.002). Adjusted for baseline characteristics, high (> or = 27.5) MS-Score remained as an independent predictor of non-dipping pattern (OR 2.64, p = 0.038). Finally, high MS-Score, but not MS-ATP III, is a predictor of non-dipping pattern. Nighttime systolic blood pressure is higher in patients with high MS-Score. Therefore, patients with high MS-Score may be more prone to cardiovascular events than those with low MS-Score.