Effectiveness of an intensive weight-loss program for severe OSA in patients undergoing CPAP treatment: a randomized controlled trial

Abstract

Study objectives: To determine whether an intensive weight-loss program (IWLP) is effective for reducing weight, the severity of obstructive sleep apnea (OSA), and metabolic variables in patients with obesity and severe OSA undergoing continuous positive airway pressure treatment.

Methods: Forty-two patients were randomized to the control (CG, n = 20) or the intervention group (IG, n = 22), who followed a 12-month IWLP. The primary outcome was a reduction in the apnea-hypopnea index (AHI) as measured at 3 and 12 months by full polysomnography. Metabolic variables, blood pressure, body fat composition by bioimpedance, carotid intima media thickness, and visceral fat by computed tomography were also assessed.

Results: Mean age was 49 (6.7) years, body mass index 35 (2.7) kg/m², and AHI 69 (20) events/h. Weight reduction was higher for the IG than the CG at 3 and 12 months, -10.5 versus -2.3 kg (P < .001), and -8.2 versus -0.1 kg (P < .001), respectively, as was loss of visceral fat at 12 months. AHI decreased more in the IG at 3 months (-23.72 versus -9 events/h) but the difference was not significant at 12 months, though 28% of patients from the IG had an AHI < 30 events/h compared to none in the CG (P = .046). At 12 months, the IG showed a reduction in C-reactive protein (P = .013), glycated hemoglobin (P = .031) and an increase in high density lipoprotein cholesterol (P = .027).

Conclusions: An IWLP in patients with obesity and severe OSA is effective for reducing weight and OSA severity. It also results in an improvement in lipid profiles, glycemic control, and inflammatory markers.

Clinical trial registration: Registry: ClinicalTrials.gov; Title: Effectiveness of an Intensive Weight Loss Program for Obstructive Sleep Apnea Syndrome (OSAS) Treatment; Identifier: NCT02832414; URL: https://ichgcp.net/clinical-trials-registry/NCT02832414.

Keywords: apnea-hypopnea index; intensive weight-loss program; obesity; obstructive sleep apnea syndrome; weight loss.

© 2020 American Academy of Sleep Medicine.

Figures

Figure 1. Study flowchart.

ITT = intention-to-treat, PP = per-protocol.

Figure 2. Change in weight and change in AHI.

(A) Change in weight over the follow-up period. The mean values are represented by dots. (B) Change in apnea-hypopnea index over the follow-up period. AHI = apnea-hypopnea index.

Figure 3. Association between AHI and weight reduction at 3 and 12 months.

AHI = apnea-hypopnea index.

Figure 4. 3D surface plot contrasting apnea-hypopnea index change, weight change, and time in supine change at 3 and 12 months.

It can be observed that both weight change and supine change have a certain effect on the change in AHI. On the one hand, with an equal weight loss, AHI improvement is higher the less time is spent in the supine position, while, on the other hand, despite no weight loss, AHI improvement occurs if there is a reduction in the time spent in the supine position. AHI = apnea-hypopnea index.