title: Resistant hypertension and chronotherapy.
abstract: Resistant hypertension is defined as blood pressure that remains above 140/90 mmHg in spite of the continuous use of three antihypertensive agents in optimal dose, including diuretic, and lifestyle changes. According to data from United States of America and Europe, the prevalence ranges from 10 up to 30% in patients with hypertension. Numerous biological and lifestyle factors can contribute to the development of resistant hypertension: medications, volume overload, obesity, diabetes mellitus, older age, renal parenchymal and renovascular disease, primary aldosteronism, obstructive sleep apnea, pheochormocytoma, Cushing's syndrome, thyroid diseases, aortic coarctation. For diagnosing patient's history is important, assessing compliance, regular blood pressure measurement, physical examination, biochemical evaluation and noninvasive imaging. The evaluation including 24h ambulatory monitoring of blood pressure (ABPM) in the identification of "non-dipper" hypertension. Non-dipper has particular importance and the prevalence of abnormally high sleep blood pressure is very often in chronic kidney patients. Therapeutic restoration of normal physiologic blood pressure reduction during night-time sleep (circadial variation) is the most significant independent predictor of decreased risk and the basis for the chronotherapy. The resistant hypertension treatment is achieved with nonpharmacological and pharmacological approach, treating secondary hypertension causes and invasive procedures.
authors.affiliation: Merkur University Hospital, Department of Internal Medicine, University of Zagreb, School of Medicine, Zagreb, Croatia.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Prkacin
authors.affiliation: General Hospital Sisak, Department of Internal Medicine, Sisak, Croatia.
authors.forename: Diana
authors.initials: D
authors.lastname: Balenovic
authors.affiliation: Merkur University Hospital, Department of Internal Medicine, University of Zagreb, School of Medicine, Zagreb, Croatia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Djermanovic-Dobrota
authors.affiliation: Merkur University Hospital, Department of Internal Medicine, University of Zagreb, School of Medicine, Zagreb, Croatia.
authors.forename: Iva
authors.initials: I
authors.lastname: Lukac
authors.affiliation: Merkur University Hospital, Department of Internal Medicine, University of Zagreb, School of Medicine, Zagreb, Croatia.
authors.forename: Petra
authors.initials: P
authors.lastname: Drazic
authors.affiliation: General Hospital Zadar, Department of Emergency Medicine, Zadar, Croatia.
authors.forename: Iva-Klara
authors.initials: IK
authors.lastname: Pranjic
keywords: chronotherapy; circadian variation; resistant hypertension