Association of blood pressure control and metabolic syndrome with cardiovascular risk in elderly Japanese: JATOS study

Abstract

Background: The impact of the metabolic syndrome (MS) on cardiovascular events in elderly subjects has not been clarified. We hypothesized that the impact differs between patients with and without strictly controlled blood pressure (BP) and also between early elderly (<75 years) and late (≥75 years) elderly patients.

Methods: Elderly hypertensive patients (65-85 years old) were randomly assigned to strict (target systolic BP <140 mm Hg) or mild (140-159 mm Hg) BP target, and were treated for 2 years with efonidipine-based regimen. MS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria, except for the use of body mass index (BMI) ≥25 kg/m(2) instead of waist circumference. Primary endpoint was combined incidence of cardiovascular and renal events. Data were obtained from 2,865 patients.

Results: The prevalence of MS was 31.4%. The incidence of primary endpoint in patients with and without MS was 4.0% and 3.1%, respectively. MS was a significant risk factor for cardiovascular events in patients <75 years old (adjusted hazard ratio (HR) 2.17, P = 0.01), but not in patients ≥75 years old (adjusted HR 0.98, P = 0.94). In patients with MS, the event rate was significantly lower with strict treatment than with mild treatment among patients aged <75 years (P = 0.0006) but not in those aged ≥75 years (P = 0.82).

Conclusions: MS was associated with cardiovascular risk in elderly hypertensive patients <75 years old, and strict BP control was beneficial for those with MS. However, MS and intensive control of BP may have little effect on cardiovascular events in elderly patients ≥75 years old.