Optimal cutoff point of waist circumference and use of home blood pressure as a definition of metabolic syndrome: The Ohasama study

Background: Self-measured blood pressure (BP) at home (HBP) has a stronger predictive power for cardiovascular mortality and morbidity than casual-screening BP (CBP). No studies have evaluated the clinical significance of self-measured HBP for diagnosing metabolic syndrome (MS). Eight scientific associations recently defined MS for the Japanese population. However, this definition remains controversial, especially with respect to the cutoff value of waist circumference (WC) being higher in women than in men. Methods: The participants of this population-based survey were the 395 residents (≥35 years of age) of Ohasama, a rural Japanese community. They measured HBP and underwent the oral glucose tolerance test between the years 2000 and 2006. We calculated the optimal cutoff values of WC required to diagnose MS, and examined the association of HBP with metabolic risk-factor clustering using multivariate analyses. Results: Receiver operation characteristic analysis indicated that the optimal WC cutoff values for identifying clusters of metabolic risk factors were 87 and 80 cm in men and women, respectively. Elevated HBP was significantly associated with the clustering of metabolic risk factors but CBP was not. Conclusion: The appropriate WC cutoff value in the current MS criteria for Japanese women would be 80 cm. We suggest that HBP would be useful when considering a diagnosis of MS. The association between MS determined using HBP and the prognosis of cardiovascular diseases (CVDs) requires further investigation.