Role of Sleep Apnea and Sympathetic Activity in Resistant Hypertensive Patients.

Summary

Hypertension is highly prevalent in type 2 diabetic patients (NIDDM) with nephropathy, and is the single most important determinant of the rate of renal function loss. In many of these patients, hypertension is resistant to therapy. Although increased sympathetic activity is also highly prevalent in NIDDM patients with nephropathy and chronic renal insufficiency, little attention has been paid to sleep apnea as the cause of both resistant hypertension and sympathetic hyperactivity in this population. Since the prevalence of sleep apnea is increased in patients with either NIDDM, or resistant hypertension, or chronic renal insufficiency, it is almost certain that sleep apnea has a high prevalence in patients in whom all three states co-exist, i.e. NIDDM patients with nephropathy and hypertension resistant to therapy. As a consequence of undetected and untreated sleep apnea, resistant hypertension, nocturnal hypertension, and sympathetic hyperactivity likely contribute to accelerated loss of renal function and increased cardiovascular morbidity and mortality in these patients.

Hypothesis: A. Sleep apnea is highly prevalent in type 2 diabetic patients with diabetic nephropathy and hypertension resistant to therapy. Treatment with nasal continuous positive airway pressure (NCPAP) will result in a decrease in blood pressure and restore normal diurnal blood pressure pattern.

B. Sleep apnea-caused hypertension is mediated by sympathetic hyperactivity and increased activity of the renin-angiotensin-aldosterone system (RAAS) in type 2 diabetic patients with nephropathy. A decrease in sympathetic hyperactivity in response to NCPAP therapy will result in a decrease in plasma renin activity and plasma aldosterone concomitant with decreases in blood pressure.

Randomized, double blind, parallel comparative (two groups) one center trial.

Therapeutic treatment with nasal continuous positive airway pressure (NCPAP) Sub-therapeutic treatment with nasal continuous positive airway pressure

Conditions

• Type 2 Diabetes
• Diabetic Nephropathy
• Hypertension
• Sleep Apnea

Interventions

DEVICE

NCPAP; Nasal continuous positive airway pressure.

Patients will be randomized to receive either therapeutic or sub-therapeutic NCPAP; Nasal continuous positive airway pressure treatment. In patients randomized to therapeutic NCPAP, treatment pressures will be increased until apneas and hypopneas are prevented during all sleep stages. In the sub-therapeutic treatment group, pressure will be left unchanged at the lowest possible value for the NCPAP device. Pressure settings for NCPAP therapy will be determined by Dr. J. Leech, collaborator and specialist in sleep disorders. Treatment will be continued for a total of 6 weeks.

DEVICE

NCPAP Nasal Continuous Positive Airway Pressure-sub-therapeutic treatment group

In the sub-therapeutic treatment group, pressure will be left unchanged at the lowest possible value for the NCPAP device. Pressure settings for NCPAP therapy will be determined by Dr. J. Leech, collaborator and specialist in sleep disorders. Treatment will be continued for a total of 6 weeks.

Sponsors & Collaborators

• Ottawa Hospital Research Institute

  lead OTHER

Principal Investigators

• Marcel Ruzicka, Dr. · Ottawa Hospital Research Institute

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2004-12-31

Primary Completion

2015-02-28

Completion

2015-02-28

Countries

• Canada

Study Locations