Association of white blood cell count with systolic blood pressure within the normotensive range

Abstract

Hypertension and inflammation promote cardiovascular disease (CVD). Even high normal systolic blood pressure (SBP) is associated with increased CVD risk. We assessed the relationship of elevated SBP within the normotensive range and white blood cell (WBC) count. This is a cross-sectional study of 3484 white asymptomatic individuals (mean age: 4378 years, 79% males) without hypertension with SBPo140 mm Hg. White blood cell count X75th percentile (8.35 Â 10 9 cells/l) was considered cutoff for elevated WBC. Subjects were classified into three levels of SBP (first: o120 mm Hg, n ¼ 1176, 34%; second: 120-129 mm Hg, n ¼ 1654, 47%; third: 130-139 mm Hg, n ¼ 654, 19%). Mean WBC count increased linearly across SBP categories (first: 6.1471.54, second: 6.2071.52, third: 6.4171.62, P ¼ 0.02 for trend). There was a linear increase in prevalence of elevated WBC across higher SBP categories (22, 24 and 28%, P ¼ 0.02). As compared to those with SBPo120 mm Hg, in multivariate linear regression analyses (adjusting for age, gender, smoking status, diabetes, body mass index, physical activity, cholesterol/ high-density lipoprotein cholesterol ratio) WBC count was significantly higher among participants with SBP 130-139 mm Hg (regression coefficient: 2.64, 95% confidence interval: 1.04-4.24, P ¼ 0.001). Odds ratio for prevalence of elevated WBC with SBPo120 mm Hg as reference group was 1.14 (0.92-1.41) for SBP 120-129 mm Hg and 1.50 (1.15-1.92) for SBP 130-139 mm Hg. In conclusion, Higher SBP within the normotensive range is also associated with elevated WBC count. Further studies are needed to clarify the role of inflammation in high normal SBP and associated CVD risk.

White blood cell count and hypertension

“…The Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure (JNC 7) report 16 has redefined a SBP of 120-139 mmHg or a diastolic blood pressure of 80-89 mmHg as 'prehypertensive' with suggestions to health promoting lifestyle modifications to prevent cardiovascular disease. This study by Orakzai et al 15 furthers our current, albeit limited, understanding of a possible relationship between WBC count and high blood pressure. Of note, even in the high normal SBP categories (currently classified as the 'pre-hypertensive range'), the WBC count was still high.…”

“…In this issue of the Journal of Human Hypertension, Orakzai et al 15 add further weight to data on the relationship between WBC count and rising systolic blood pressure (SBP) within the normotensive range. In this cross-sectional study, blood pressures and WBC counts were measured in 3484 white asymptomatic low-risk subjects (mean age 43 years, predominantly males) attending a primary prevention clinic, after assessments for cardiovascular risk factors.…”

Nicotine Exposure, Blood Pressure, and Inflammation in Tobacco Smokers and Chewers in a Rural Community in Nepal

“…Several studies have associated an increased incidence of hypertension with a raised white blood cells (WBCs) count (Friedman, Selby, & Quesenberry, 1990;Gillum, & Mussolino, 1994;Shankar, Klein, & Klein, 2004;Orakzai et al, 2006). Cigarette smokers have been shown to have leukocyte counts that average 30%-40% higher than those for men who have never smoked (Yarnell et al, 1987).…”

Use of white blood cell counts to predict metabolic syndrome in the elderly: a 4 year longitudinal study

“…Subsequently, Abramson et al [36] showed that increased blood pressure was also associated with increased inflammation. Orakzai et al further demonstrated that higher SBP within the normotensive range was also associated with elevated WBC counts [37]. Moreover, high normal SBP was also associated with increased CVD risk [37].…”