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A Cross-sectional Study of the Occurrence and Effect of Obstructive Sleep Apnea in Subjects With Resistant Hypertension

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ClinicalTrials.gov Identifier: NCT00843583
Recruitment Status : Completed
First Posted : February 13, 2009
Last Update Posted : May 3, 2017
Sponsor:
Information provided by:
The University of Hong Kong

Tracking Information
First Submitted Date February 12, 2009
First Posted Date February 13, 2009
Last Update Posted Date May 3, 2017
Study Start Date February 2009
Actual Primary Completion Date December 2012   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures
 (submitted: December 29, 2014)
ambulatory blood pressure [ Time Frame: 24 hour ]
Original Primary Outcome Measures Not Provided
Change History
Current Secondary Outcome Measures Not Provided
Original Secondary Outcome Measures Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title A Cross-sectional Study of the Occurrence and Effect of Obstructive Sleep Apnea in Subjects With Resistant Hypertension
Official Title A Cross-sectional Study of the Occurrence and Effect of Obstructive Sleep Apnea in Subjects With Resistant Hypertension
Brief Summary This study aims to investigate the prevalence of obstructive sleep apnea (OSA) in subjects with resistant hypertension and to evaluate the relationship between parameters of OSA severity and blood pressure control
Detailed Description

Obstructive sleep apnea (OSA) is characterized by intermittent upper airway collapse during sleep, which results in hypoxia, arousals and surge in sympathetic activity. There is robust evidence to support a contributing role of OSA in hypertension (HT). The Sleep Heart Health Study (1), which recruited more than 6000 subjects having polysomnogram at home, found an independent association between OSA and HT. The adjusted odds ratio was 1.37 for subjects with and apnea-hypopnea index >= 30/hour compared to those without apnea. The Wisconsin Sleep Cohort Study , which provided prospective longitudinal follow-up for OSA subjects over 4 years, have shown dose dependency of the severity of OSA and the risk of development of HT. Current available data suggests that in hypertensive patients with severe OSA, there is a BP drop of about 10mmHg with CPAP treatment (2-5). The blood pressure (BP) lowering effect of CPAP treatment in the group with mild asymptomatic OSA is less consolidated.

The relationship between BP and risk of cardiovascular events is continuous, consistent, and independent of other risk factors. A strict blood pressure control is imperative in subjects with diabetes mellitus or renal impairment. Resistant hypertension is defined as blood pressure that remains above goal in spite of concurrent use of 3 antihypertensive agents of different classes. (6) Resistant hypertension is defined in order to identify patients who are at risk of having secondary causes of hypertension, and who may benefit from specific diagnostic and therapeutic applications. Despite the fact that OSA is listed as one of the causes of resistant HT (6), paucity of works has demonstrated the scale of problems of untreated OSA in subjects with resistant HT. (7-9) There is so far one study demonstrating the beneficial effect of CPAP treatment in subjects with resistant HT, though no randomization was implemented and the sample size was limited (n=11). (10) We aim at conducting a cross-sectional study to explore the situation which would guide further clinical trial.

Study Type Observational
Study Design Observational Model: Case-Only
Time Perspective: Cross-Sectional
Target Follow-Up Duration Not Provided
Biospecimen Retention:   Samples Without DNA
Description:
Blood test for glucose, lipid, vascular and metabolic markers
Sampling Method Non-Probability Sample
Study Population Consecutive sampling of subjects who attend Hypertension clinic , Department of Medicine, Queen Mary Hospital, and who fulfill the inclusion criteria.
Condition
  • Obstructive Sleep Apnea
  • Resistant Hypertension
Intervention Not Provided
Study Groups/Cohorts resistant hypertension subjects
subjects with resistant hypertension
Publications *

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status Completed
Estimated Enrollment
 (submitted: February 12, 2009)
96
Original Estimated Enrollment Same as current
Actual Study Completion Date December 2012
Actual Primary Completion Date December 2012   (Final data collection date for primary outcome measure)
Eligibility Criteria

Inclusion Criteria:

  • ≧ 3 anti-HT drugs
  • age 18-65
  • mentally fit for signing an informed written consent

Exclusion Criteria:

  • moderate renal impairment (glomerular filtration rate <30 mL/min/m2 )
  • endocrine/renal/cardiac causes of secondary HT
  • congestive heart failure and clinically fluid overloaded
  • On drugs that elevate BP e.g. alcohol, NSAID, steroid
Sex/Gender
Sexes Eligible for Study: All
Ages 18 Years to 65 Years   (Adult, Older Adult)
Accepts Healthy Volunteers No
Contacts Contact information is only displayed when the study is recruiting subjects
Listed Location Countries Hong Kong
Removed Location Countries  
 
Administrative Information
NCT Number NCT00843583
Other Study ID Numbers Not Provided
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement Not Provided
Responsible Party Professor Ip, Sau Man Mary, Department of Medicine, The University of Hong Kong, Queen Mary Hospital
Study Sponsor The University of Hong Kong
Collaborators Not Provided
Investigators
Principal Investigator: Sau Man Mary Ip, MD Department of Medicine, The University of Hong Kong
PRS Account The University of Hong Kong
Verification Date May 2017