Diuretic or sodium-restricted diet for obstructive sleep apnea-a randomized trial

Area of Science:

• Sleep Medicine
• Cardiology
• Nephrology

Background:

• Obstructive sleep apnea (OSA) severity is linked to fluid retention.
• Previous studies suggest interventions reducing leg fluid can improve OSA.

Purpose of the Study:

• To evaluate the effectiveness of fluid-reducing interventions on OSA severity in a randomized trial.
• To compare the impact of diuretics and dietary changes on OSA metrics.

Main Methods:

• Men with severe OSA were randomized into three groups: diuretics (spironolactone + furosemide), sodium-restricted diet, or placebo.
• All participants underwent home sleep apnea testing at baseline and after one week.
• The primary outcome was the change in the apnea-hypopnea index (AHI).

Main Results:

• The diuretic group showed a 14.4% reduction in AHI, and the diet group showed a 22.3% reduction, versus 0.8% in the placebo group (p = .001).
• Significant reductions in total body water were observed in both the diuretic (2.2 L) and diet (1.0 L) groups.
• Sleepiness and neck circumference improved significantly only in the diet group.

Conclusions:

• Interventions aimed at reducing body fluid content offer a limited improvement in apnea frequency for men with severe OSA.
• Rostral fluid displacement appears to be only a partial contributor to OSA severity.
• Other factors likely play a more dominant role in pharyngeal collapsibility and OSA.