Background: Previous studies reported increased white blood cell counts (WBCCs), an inflammatory marker, in hypertension, prehypertension and metabolic syndrome. Evidence suggests that inflammation precedes blood pressure (BP) elevation and may contribute to incident hypertension. Angiotensin receptor blockers (ARBs) may reduce inflammation. We analyzed WBCC trends in TRial Of Preventing HYpertension (TROPHY) to determine if this inflammatory marker predicted incident hypertension in prehypertensive individuals and whether randomized assignment to the ARB candesartan (391 individuals) for 2 years, lowered WBCC compared with placebo-treated controls (381 individuals).
Methods: A new analysis of TROPHY trial data.
Results: In the total population, baseline BMI correlated with WBCC (r = 0.185, P < 0.0001), neutrophils (r = 0.135, P < 0.001) and lymphocytes (r = 0.204, P < 0.0001). Baseline triglycerides also correlated significantly with inflammatory markers. Despite a wide range of home BP (HBP) values, HBP did not correlate with baseline WBCC counts. After 2 years, candesartan decreased placebo corrected HBP by –5.5/–2.5 mmHg, (P < 0.0001), but WBCC, neutrophil and lymphocyte counts were not different in placebo and in candesartan groups. Baseline WBCC, neutrophils and lymphocyte counts did not predict incident hypertension in the placebo group.
Conclusion: In TROPHY, candesartan lowered BP but did not alter WBCC. Baseline WBCC did not predict incident hypertension. Our findings do not support the hypothesis that inflammation contributes to incident hypertension or that ARB treatment suppresses inflammation. The significant independent association of WBCC with baseline BMI and triglycerides is consistent with the evidence that obesity and insulin resistance are associated with inflammation. The findings highlight the importance of effective lifestyle modification in prehypertension to reduce inflammatory cardio-metabolic risk and suppress transition to hypertension.
aDivision of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan
bDepartment of Medicine, Medical University of South Carolina, Charleston, South Carolina
cCenter for Human Growth and Development, University of Michigan, Ann Arbor, Michigan
dDepartmentof Internal Medicine, University of Texas Southwestern, Dallas, Texas
eDivision of Cardiovascular Disease, Scripps Clinic, La Jolla, California, USA
Correspondence to Stevo Julius, MD, ScD, University of Michigan, Division of Cardiovascular Medicine, 2368 Cardiovascular Center SPC 5853, 1500 E. Medical Center Dr Ann Arbor, MI 48109, USA. Tel: +1 734 998 7955; fax: +1 734; 998 8018; e-mail: firstname.lastname@example.org
Abbreviations: ARB, angiotensin receptor blockers; BMI, body mass index; BP, blood pressure; CRP, C reactive protein; CV, cardiovascular; HBP, home blood pressure; hsCRP, high sensitivity CRP; LOCF, last observation carried forward; RAS, renin–angiotensin system; WBCC, white blood cell counts
Received 2 August, 2013
Revised 30 September, 2013
Accepted 30 September, 2013