HIGH-NORMAL BLOOD PRESSURE IS PARTICULARLY ASSOCIATED WITH INCREASED RISK FOR ACUTE CORONARY SYNDROMES IN WOMEN: THE HORDALAND HEALTH STUDY

Abstract

Abstract Objective: Hypertension is a major risk factor for acute coronary syndromes (ACS). Less is known about whether high-normal blood pressure (BP) carries a different risk for ACS in women and men. We tested associations of high-normal BP with incident ACS in women and men participating in the community-based Hordaland Health Study (HUSK). Design and method: We followed 8262 participants aged 42 years (52% women) in HUSK from 1992/93 through 2009 by coupling them to the Cardiovascular Disease in Norway (CVDNOR) project and Cause of Death Registry. BP was measured at baseline in triples at after at least 2 minutes rest in seated position with calibrated sphygmomanometers in 1992/93. The average of the two last measurements was taken as the clinic BP measure. The cohort was divided according to BP class: normal BP (BP < 130/85 mmHg), high-normal BP (BP130–139/85–89) and hypertension (BP > 140/90 or use of antihypertensive drugs). ACS was defined as hospitalization or death with an acute myocardial infarction or unstable angina pectoris diagnosis (ICD-9 codes 410, 411 and ICD-10 codes I20.0, I21 and I22) in the period 1994–2009. The association between BP category and ACS was tested in sex-specific Cox regression analyses adjusted for diabetes, smoking and total cholesterol. Normal BP was used as the reference group. Results: At baseline, 17% women and 27% men had high-normal BP and 16% women and 32% men had hypertension (both p < 0.001 between sexes). During follow-up, 1.4% of women and 6.1% of men experienced an ACS (p < 0.001). In multivariable analyses in women, both hypertension and high-normal BP were associated with incident ACS (hazard ratio (HR) 2.79, 95% confidence interval (CI) 1.36–5.72 and HR 2.22, 95 % CI 1.05–4.71, respectively). In men, hypertension but not high-normal BP was associated with incident ACS (HR 1.63, 95 % CI 1.16–2.30 and HR 1.20, 95 % CI 0.81–1.77 respectively). Conclusions: In the Hordaland Health Study, high-normal BP was a stronger risk factor for ACS in middle-aged women than men. Our findings suggest that sex-specific diagnosis of high-normal BP and hypertension may be warranted.