Effect of CPAP vs Control on Nocturnal Dipping in Normotensive Patients With Obstructive Sleep Apnea

The Effect of CPAP on Nocturnal Dipping in Normotensive Patients With Moderate-severe Obstructive Sleep Apnoea, a Multicentre Randomised Controlled Trial

This is an open-label, parallel, prospective, randomised control trial evaluating the effect of Continuous Positive airway pressure (CPAP), the standard treatment for obstructive sleep apnea (OSA) versus control (diet and lifestyle advice) on dipping status and blood pressure parameters in 100 non-dipper normotensive patients with moderate to severe obstructive sleep apnea and without established cardiovascular or metabolic disease.

Inclusion Criteria:

• Newly diagnosed moderate-severe OSA (by standard criteria)
• Absence of known hypertension and antihypertensive medication
• Office blood pressure <140/90mmHg
• Age 18 - 70 years
• Able to provide written, informed consent

Exclusion Criteria:

• Pregnancy
• Previous diagnosis of OSA or previous CPAP treatment
• Diagnosis of Diabetes Mellitus
• Active treatment for malignancy or severe psychiatric disorder
• History of cardiovascular disease or cerebrovascular disease
• Moderate or severe chronic kidney disease (CKD) defined as a eGFR of ≤ 44mL/min/1.73m2
• Dipper on ABPM
• Morbid obesity, defined as BMI ≥40
• Professional drivers or drivers with a history of road-traffic accident due to sleepiness
• Severe excessive daytime sleepiness defined as Epworth sleepiness scale (ESS) >15