Multi-Omics to Predict the Blood Pressure Response to Antihypertensives

The goal of this clinical trial is to develop biomarkers composed of multiple OMICs (MOMICs) for prediction of blood pressure response to antihypertensive drugs in the treatment of primary hypertension. The main objectives are: * Primary objective: \- To identify MOMICs biomarkers that predict the response in 24-hour blood pressure to antihypertensive treatment for each treatment group (olmesartan, amlodipine, hydrochlorothiazide, olmesartan/amlodipine) * Secondary objectives: * To identify a MOMICs biomarker that predict the response in night-time blood pressure to anti-hypertensive treatment for each treatment group (olmesartan, amlodipine, hydrochlorothiazide, olmesartan/amlodipine) * To identify MOMICs biomarkers that predict side effects, including changes in QoLof olmesartan, amlodipine and hydrochlorothiazide. * Exploratory objective: * To assess changes in MOMICs biomarkers induced by each drug Participants will undergo three 4-week treatment periods: * Each subject receives 3 out of 4 possible treatments (olmesartan, amlodipine, hydrochlorothiazide, olmesartan/amlodipine). * Before and after each treatment period OMICS measurements and an ABPM are performed. * At the end of each treatment period blood is sampled for drug level testing to assess adherence. * Electrolytes and kidney function are checked 5-7 days after start of each treatment period.