Factors associated with diastolic dysfunction in patients with resistant hypertension: resist-POL study

Abstract

Background: Diastolic dysfunction has been shown to be an independent factor of cardiovascular diseases in patients with hypertension. Very often, obstructive sleep apnea (OSA) and metabolic syndrome (MS) coexist with resistant hypertension (RHTN) and may lead to diastolic dysfunction. Thus, the purpose of this study was to investigate whether OSA and MS are associated with diastolic dysfunction in patients with RHTN independently from other factors, including age, left ventricular mass index (LVMI), and blood pressure (BP).

Methods: Data from 155 patients (n = 92 men and 63 women) were analyzed. All patients underwent thorough examination, including biochemical evaluations, ambulatory blood pressure monitoring, polysomnography with assessment of apnea/hypopnea index (AHI), and echocardiography. LVMI and diastolic function parameters were obtained.

Results: Patients were divided into 2 groups based on the presence or absence of diastolic dysfunction: group 1 (E' < 10cm/second; n=87) and group 2 (E' > 10cm/second; n = 68). AHI, LVMI, and 24-hour systolic BP/diastolic BP values were higher in group 1. E' correlated with AHI (r = -0.25; P < 0.001), LVMI (r = -0.36; P < 0.0001), 24-h systolic BP/24-h diastolic BP (r = -0.28, P < 0.001; r = -0.30, P < 0.001, respectively), glucose level (r = -0.26; P < 0.01), and abdominal obesity (r = -0.28; P < 0.0001). In multivariable models decreased E' was independently related to the presence of MS or abdominal obesity when separate components of MS were included in the model. Age and 24-hour systolic BP were independently associated with decreased E'. However, the relationship of decreased E' with 24-hour systolic BP was nonsignificant if LVMI was included in the multivariable model.

Conclusions: MS and abdominal obesity were independently associated with diastolic dysfunction in patients with RHTN. OSA was not confirmed to be an independent factor of diastolic dysfunction.

Keywords: blood pressure; diastolic function; echocardiography; hypertension; metabolic syndrome; obstructive sleep apnea; resistant hypertension..