The prevalence of central hypertension defined by a central blood pressure type I device and its association with target organ damage in the community-dwelling elderly Chinese: The Northern Shanghai Study

Highlights

• Central hypertension is considerably prevalent (69.3%) in the elderly.

• Brachial and central combined hypertension significantly relates to organ damage.

• Both brachial and central blood pressure need to be considered for managing hypertension.

Abstract

We aimed to investigate the prevalence of central hypertension and its association with target organ damage (TOD). 1983 community-dwelling elderly Chinese people were recruited for this analysis. Brachial and central blood pressure (BP) were measured by an oscillometric device and SphygmoCor (type I device), respectively. Brachial hypertension was defined by brachial systolic BP/diastolic BP ≥140/90 mmHg or using antihypertensive medications. Central hypertension was defined by central systolic BP/diastolic BP ≥130/90 mmHg or using antihypertensive medications. TOD included left ventricular hypertrophy and diastolic dysfunction, carotid-femoral pulse wave velocity, and urinary albumin-creatinine ratio. In this cohort, there were 563 (28.4%) brachial and central consistent normotension, 46 (2.3%) isolated brachial hypertension, 27 (1.4%) isolated central hypertension, and 1347 (67.9%) brachial and central combined hypertension (BCCH). In analysis of variance, BCCH showed significantly higher levels in all TOD than brachial and central consistent normotension. In multiple logistic regression, all TOD were significantly associated with BCCH (left ventricular hypertrophy: adjusted odds ratios [95% confidence interval] = 2.03 [1.55, 2.68]; left ventricular diastolic dysfunction: 2.29 [1.53, 3.43]; carotid-femoral pulse wave velocity >10 m/s: 3.41 [2.55, 4.58]; urinary albumin-creatinine ratio >30 mg/g: 1.97 [1.58, 2.44]), rather than isolated brachial hypertension or isolated central hypertension. In conclusion, central hypertension was prevalent (69.3%) in this elderly cohort. BCCH was independently and significantly associated with cardiac, arterial, and renal damage. This finding implies that both brachial and central BPs need to be considered for managing hypertension.

Introduction

Hypertension is a prevalent and modifiable risk factor for cardiovascular diseases. Blood pressure (BP) measurement is fundamental in the diagnosis and management of hypertension. Traditionally, BP is noninvasively measured at brachial artery using cuff-based devices. However, it is well recognized that arterial BP varies along arterial tree due to BP amplification from proximal to distant artery and augmentation of reflected wave.¹ Thus, brachial BP actually is an inaccurate surrogate for central BP, which is thought to be more closely associated with target organ damage (TOD) because central BP rather than peripheral BP is the load that target organs directly confront. In the past decades, the development of noninvasive measurement accelerated the investigation on and deepened our understanding on central BP and its waveforms. A body of evidences indicate that central BP was superior to brachial BP in predicting hypertensive target organ damage2, 3, 4, 5 and cardiovascular events and mortality.2, 6, 7, 8, 9 In addition, several studies have been devoted to establish reference values for central BP, which could help to assess patient's status and to promote its clinical application.10, 11 Moreover, a recent study made the first attempt at establishing the diagnostic threshold for central BP.¹² In this study, based on a derivation cohort of 1272 individuals with a median follow-up of 15 years and a validation cohort of 2501 individuals with median follow-up of 10 years, Cheng et al. proposed the cutoff value of 130/90 mmHg as the diagnostic threshold for abnormal central BP.¹² Although this threshold still needs further verification, it provides us possibility to define and investigate “central hypertension”. In the present study, we measured central BP using a type I device¹³ and aimed to investigate the prevalence of central hypertension defined by central BP of 130/90 mmHg and its association with TOD, in an elderly community-based cohort derived from the Northern Shanghai Study (NSS).