Hypertension Subtypes among Hypertensive Patients in Ibadan

Background. Certain hypertension subtypes have been shown to increase the risk for cardiovascular morbidity and mortality and may be related to specific underlying genetic determinants. Inappropriate characterization of subtypes of hypertension makes efforts at elucidating the genetic contributions to the etiology of hypertension largely vapid. We report the hypertension subtypes among patients with hypertension from South-Western Nigeria. Methods. A total of 1858 subjects comprising 76% female, hypertensive, aged 18 and above were recruited into the study from two centers in Ibadan, Nigeria. Hypertension was identified using JNCVII definition and was further grouped into four subtypes: controlled hypertension (CH), isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH). Results. Systolic-diastolic hypertension was the most prevalent. Whereas SDH (77.6% versus 73.5%) and IDH (4.9% versus 4.7%) were more prevalent among females, ISH (10.1% versus 6.2%) was higher among males (P = 0.048). Female subjects were more obese (P < 0.0001) and SDH was prevalent among the obese group. Conclusion. Gender and obesity significantly influenced the distribution of the hypertension subtypes. Characterization of hypertension by subtypes in genetic association studies could lead to identification of previously unknown genetic variants involved in the etiology of hypertension. Large-scale studies among various ethnic groups may be needed to confirm these observations.