3 In adults with hypertension, do various antihypertensive drug classes differ in their comparative benefits and harms? 4 In adults with hypertension, does initiating treatment with antihypertensive pharmacological monotherapy versus initiating treatment with 2 drugs (including fixed-dose combination therapy), either of which may be followed by the addition of sequential drugs, differ in comparative benefits and/or harms on specific health outcomes? BP indicates blood pressure. Whelton et al 2017 High Blood Pressure Clinical Practice Guideline e19 2. BP and CVD Risk 2.1. Observational Relationship Observational studies have demonstrated graded associations between higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) and increased CVD risk.S2.1-1,S2.1-2 In a meta-analysis of 61 prospective studies, the risk of CVD increased in a log-linear fashion from SBP levels <115 mm Hg to >180 mm Hg and from DBP levels <75 mm Hg to In that analysis, 20 mm Hg higher SBP and Table 3. 