Diuretic or sodium-restricted diet for obstructive sleep apnea—a randomized trial
What this study found
After 1 week, AHI reductions differed by group (p = 0.001). Diuretic group: ΔAHI −7.3 events/hour (−14.4%); sodium-restricted diet group: ΔAHI −10.7 events/hour (−22.3%); placebo: minimal change. None achieved normal AHI. Diet improved Epworth Sleepiness Scale and neck circumference; total body water decreased in both intervention groups (diuretic −2.2 L; diet −1.0 L). 24-h urinary sodium decreased most with the diet. Conclusion: Reducing bodily fluid content modestly lowers OSA frequency in men with severe OSA, implying rostral fluid displacement contributes but is not the sole determinant;…
- Study & population
- Three-arm, parallel, placebo-controlled randomized clinical trial in 54 men aged 18–60 with severe obstructive sleep apnea (AHI >30/h; BMI <35 kg/m^2).
- Intervention
- Spironolactone 100 mg + furosemide 20 mg daily for 7 days (taken in the morning).
- Key limitation
- Short duration (1 week); small, male-only sample (n=54) limits generalizability; Diet not blinded; home sleep apnea testing used instead of full polysomnography; bioelectrical impedance for total body water has limited accuracy; no long-term outcomes.
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Open PDFOriginal abstract
Study Objectives Interventions that decrease leg fluid retention reduce obstructive sleep apnea (OSA) severity in nonrandomized experiments. We aimed to investigate in a randomized trial the effect of interventions that reduce fluid volume on OSA severity. Methods Men diagnosed with severe OSA were randomized to receive daily spironolactone 100 mg + furosemide 20 mg or nutritional counseling to sodium-restricted diet plus placebo pill or placebo pill. All participants underwent home sleep apnea testing at baseline and after 1 week follow-up. The change in apnea-hypopnea index (AHI) was the primary outcome. Results The study included 54 participants and all were assessed at follow-up. The average baseline value of the AHI was similar among groups and from baseline to follow-up the AHI reduced 14.4 per cent (δ value -7.3 events per hour; 95% confidence interval, -13.8 to -0.9) in the diuretic group, 22.3 per cent (-10.7; 95% CI, -15.6 to -5.7) in the diet group, and 0.8 per cent (0.4; 95% CI, -2.5 to 3.2) in the placebo group (p = .001 for time × group interaction). None of the patients had their AHI returned to normal. The reduction in the total body water was 2.2 ± 2.2 L in the diuretic group (p < .001) and 1.0 ± 1.6 l in the low salt diet group (p = .002). Sleepiness and neck circumference were significantly reduced only in the diet group (p = .007 and p < .001 for the time × group interactions, respectively). Conclusions Interventions to reduce bodily fluid content in men with severe OSA promoted a limited decrease of apnea frequency. This finding suggests that rostral fluid displacement affects only partially the OSA severity and/or that other factors prevail in determining pharyngeal collapsibility. Clinical Trial Sodium-Restricted Diet and Diuretic in the Treatment of Severe Sleep Apnea (DESALT), https://clinicaltrials.gov/ct2/show/NCT01945801 ClinicalTrials.gov number: NCT01945801.