Low-grade inflammation and ambulatory blood pressure response to antihypertensive treatment: the ALPHABET study.

BACKGROUND We examined whether the level of highsensitivity C-reactive protein (hsCRP), a marker of low-grade inflammation, predicted the response of clinic and ambulatory blood pressure (BP) to antihypertensive treatment. METHODS A randomized, open-label, multicenter trial was performed in 88 hypertensive patients (mean age = 63.4 years) allocated to receive losartan 50 mg or amlodipine 5 mg for 4 weeks, and each treatment was changed to losartan 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg in combination or amlodipine 10 mg for a further 4 weeks. Clinic and ambulatory BP were measured before and after 8 weeks of treatment, and hsCRP was measured at baseline. RESULTS The patients were divided into groups with hsCRP levels above and below the median (0.47 mg/L) for the study population. In the total population, 24-hour systolic BP (SBP) (P = 0.03) and daytime SBP (P = 0.01) were significantly higher in the above-median hsCRP group after 8 weeks of treatment. In multivariable regression analysis, baseline hsCRP was a significant determinant of the percentage change in daytime SBP (β = 0.29; P = 0.02) in the total population. In the losartan/HCTZ treatment group, changes in 24-hour SBP, daytime SBP, and diastolic BP were significantly smaller in the above-median hsCRP group than the below-median hsCRP group, whereas the amlodipine group did not show these differences. CONCLUSIONS Baseline low-grade inflammation in patients with hypertension was associated with a poor ambulatory BP response, especially with losartan/HCTZ treatment. Initial measurement of hsCRP could be useful for selection of an appropriate antihypertensive drug.