Title:Nocturnal Hypertension, Nondipping Phenomenon and Target Organ Damage in Obstructive Sleep Apnea Patients - The Bad and the Worse
Volume: 10
Issue: 3
Author(s): Radostina Vlaeva Cherneva, Ognian Borisov Georgiev, Daniela Stoichkova Petrova, Emil Ivanov Manov, Dinko Georgiev Valev and Julia Ivanova Petrova
Affiliation:
Keywords:
Cardiac damage, hypoxia, sleep disordered breathing.
Abstract: Background: Nocturnal blood pressure (NBP) abnormalities are often encountered in obstructive sleep apnea
(OSA) patients. Both phenomena are associated with increased cardiovascular morbidity and mortality in general
hypertensives. The aim of the study was to determine the prevalence of target organ damage (TOD) in different nighttime
blood pressure patterns of newly diagnosed OSA patients with early hypertension.
Materials and Methods: Seventy-four patients participated in the study. OSA was verified by a polysomnography. All
patients had controlled hypertension. 24-hour BP monitoring divided participants into: 39 (NH) - nocturnal hypertensives;
18 NND - nocturnal normotensive dippers, (NBP fall>10%, NBP<120/70mmHg); 17 (NNN) - nocturnal normotensive
non-dippers (NBP fall<10%, NBP<120/70mmHg). Anthropological glucometabolic and sleep study characteristics were
collected. Cardiac damage (left ventricular mass index - LVMI, relative wall thickness - RWT) was assessed by a standard
echocardiography; renal damage by microalbuminuria and vascular damage by ultrasonography of the carotid vessels.
Results: Left ventricular hypertrophy (LVH) was met in 33% of the dippers, 64.7% of NNN and in 62.6% of NH. LVMI
in non-dippers was higher when compared to dippers (127.71± 8.71 vs 109.1± 4.9g/m2, p=0.03) and nearly identical to
those in patients with NH (127.71± 8.71 vs 124.18 ± 5.92g/m2, p=0.42). Microalbuminuria was present in 3% and 6% of
dippers/non-dippers and in 51% of NH. IMT and RWT were within the same range in the three groups. Multivariate
regression analysis showed that: LVMI correlated positively to age and sleep time at SaO2<90%; RWT correlated
positively to BMI, age and AHI. IMT and microalbuminuria correlated to none of the parameters.
Conclusion: In newly diagnosed OSA patients with early hypertension (duration <3 years) TOD was detected mostly at
cardiac level. It was presented by an increased LVMI, that was associated with the age and the sleep time at SaO2<90%.
