Risk Factors for Cardiovascular Diseases

**77**

**Chapter 5**

**Abstract**

target organs.

cardiovascular

**1. Introduction**

several criteria which may or may not overlap.

Ambulatory Isolated Systolic

*Muzi Maseko, Bongubuhle Mlambo, Edgar Phukubje* 

African Ancestry

*and Thamsanqa Nyundu*

Hypertension and Cardiovascular

Target Organ Damage in People of

Isolated systolic hypertension (ISH) is a major contributor to cardiovascular disease morbidity and mortality worldwide, however, diagnosis of ISH is mainly dependent on conventional blood pressure (BP) techniques. Studies that have used ambulatory blood pressure monitoring (ABPM) were only limited to 24-hour BP. To date ambulatory isolated BP subtypes have never been identified. Therefore, the prevalence of ambulatory subtypes of ISH unknown. Conventional and ambulatory BP was measure in 549 participants and based on the results, they were stratified into ISH subtypes (Conventional, Daytime, Night-time and 24-hour ISH). Participants further underwent measurements of pulse wave velocity (PWV) and left ventricular mass index (LVMI) to determine the extent of arterial stiffness and left ventricular hypertrophy. We further assessed whether the target organ changes are associated with any ISH subtype. The prevalence of Conventional ISH (ISHC), 24-hour ISH (ISH24), Night-time ISH (ISHN) and Daytime ISH (ISHD) was 7.5%, 7.1%, 7.7% and 7.5% respectively. Compared to normotensives, all ISH subtypes had higher PWV and LVMI. These target organ changes were similar to those observed in hypertensives. Our results indicate that isolated systolic hypertension, whether conventional or ambulatory, is as detrimental as hypertension on cardiovascular

**Keywords:** hypertension, hypertrophy, ambulatory nocturnal, conventional,

By definition, hypertension is a chronic condition characterised by persistent elevated blood pressure [1]. Traditionally, the term hypertension has been used to describe a condition in which systolic BP (SBP) is equal or above 140 mm Hg and/ or a diastolic BP (DBP) is equal or above 90 mm Hg [2]. The term Systolic-diastolic hypertension (SDH) is slowly replacing 'hypertension' in this regard as the latter becomes a broader term describing a large number of classes/categories of persistent high BP [3–5]. Thus hypertension can be divided into several types based on
