The use of intensive lifestyle intervention for weight loss in patients with type 2 diabetes has been shown to reduce the overall severity of obstructive sleep apnea (OSA), according to study results published in the American Journal of Respiratory and Critical Care Medicine.
Researchers conducted the longitudinal randomized controlled Sleep AHEAD study (ClinicalTrials.gov Identifier: NCT00194259) — an ancillary study of Look AHEAD (Action for Health in Diabetes) — enrolled participants from 4 of the 16 Look AHEAD sites.
Investigators sought to establish whether initial benefit of intensive lifestyle intervention for weight loss on OSA severity would be maintained at 10 years. The primary study objective was to determine whether the Look AHEAD intervention was associated with improvements in apnea-hypopnea index (AHI) at 10 years and during the 10-year follow-up. Secondary objectives included determining whether this effect was independent of weight change and whether the intervention had an effect on changing an individual’s OSA category.
Primary study inclusion criteria of Look AHEAD (and, thus, of Sleep AHEAD) were being between ages 45 and 7, having a body mass index (BMI) of ≥25 kg/m2 (or 27 kg/m2 if taking insulin), physician-verified type 2 diabetes, and hemoglobin A1c of <11%. Participants received either intensive lifestyle intervention for weight loss or diabetes support and education (DSE). Of the 264 participants, 38.7% had mild OSA, 35.2% had moderate OSA, and 26.1% had severe OSA at baseline.
At 10 years, polysomnograms were obtained in 54% of those in the intensive lifestyle intervention group and in 48% of those in the DSE group. Mean weight losses in the intensive lifestyle intervention group at 1, 2, 4, and 10 years were 10.7±0.7 kg, 7.4±0.7 kg, 5.1±0.7 kg, and 7.1±0.8 kg, respectively. These weight losses were all significantly higher than the 1-kg weight loss at 1, 2, and 4 years, and the 3.5±0.8 kg weight loss at 10 years in the DSE group (P ≤.0001).
The AHI was lower with intensive lifestyle intervention compared with DSE — by 9.7±2.0, 8.0±2.0, and 7.9±2.2 events per hour at 1, 2, and 4 years, respectively (P ≤.0004), and by 4.0±2.5 events per hour at 10 years (P =.109). Changes in AHI over time were associated with the amount of weight loss, baseline AHI, and year of the visit (P <.0001), as well as with the intervention independent of change in weight (P =.01). At 10 years, OSA remission occurred in more participants in the intensive lifestyle intervention compared with participants in DSE group (34.4% vs 22.2%, respectively).
The investigators concluded that although the greater improvement in OSA severity with intensive lifestyle intervention in the initial 4 years was no longer present at the 10-year follow-up and the greater weight loss in the intensive lifestyle intervention group also diminished at 10 years, overall OSA severity decreased across the 10-year study period with intensive lifestyle intervention. This improvement was associated with changes in body weight, greater severity of baseline OSA, and lifestyle intervention unrelated to weight change.
Kuna ST, Reboussin DM, Strotmeyer ES, et al; for the Sleep AHEAD Research Subgroup of the Look AHEAD Research Group. Effects of weight loss on obstructive sleep apnea severity: 10-year results of the Sleep AHEAD study. Am J Respir Crit Care Med. Published online July 28, 2020. doi:10.1164/rccm.201912-2511OC