Obstructive Sleep Apnea, Glucose Tolerance, and β-Cell Function in Adults With Prediabetes or Untreated Type 2 Diabetes in the Restoring Insulin Secretion (RISE) Study
Authors: Mokhlesi Babak , Tjaden Ashley H. , Temple Karla A. , Edelstein Sharon L. , Sam Susan , Nadeau Kristen J. , Hannon Tamara S. , Manchanda Shalini , Mather Kieren J. , Kahn Steven E. , Ehrmann David A. , Van Cauter Eve ,   RISE Consortium, Temple Karla A. , Tjaden Ashley H. , Atkinson Karen M. , Barengolts Elena , Hannon Tamara S. , Mather Kieren J. , Utzschneider Kristina M. , Edelstein Sharon L. , Ehrmann David A. , Mokhlesi Babak , Ehrmann David A. , Temple Karla A. , Rue Abby , Barengolts Elena , Mokhlesi Babak , Van Cauter Eve , Sam Susan , Miller M. Annette , Kahn Steven E. , Atkinson Karen M. , Palmer Jerry P. , Utzschneider Kristina M. , Gebremedhin Tsige , Kernan-Schloss Abigail , Kozedub Alexandra , Montgomery Brenda K. , Morse Emily J. , Mather Kieren J. , Garrett Tammy , Hannon Tamara S. , Lteif Amale , Patel Aniket , Chisholm Robin , Moore Karen , Pirics Vivian , Pratt Linda , Nadeau Kristen J. , Gross Susan , Zeitler Philip S. , Williams Jayne , Cree-Green Melanie , Reyes Yesenia Garcia , Vissat Krista , Arslanian Silva A. , Brown Kathleen , Guerra Nancy , Porter Kristin , Caprio Sonia , Savoye Mary , Pierpont Bridget , Buchanan Thomas A. , Xiang Anny H. , Trigo Enrique , Beale Elizabeth , Hendee Fadi N. , Katkhouda Namir , Nayak Krishan , Martinez Mayra , Montgomery Cortney , Wang Xinhui , Edelstein Sharon L. , Lachin John M. , Tjaden Ashley Hogan , Marcovina Santica , Harting Jessica , Albers John , Hill Dave , Savage Peter J. , Leschek Ellen W. 
Published: February 2021

OBJECTIVE
Obstructive sleep apnea (OSA) is associated with insulin resistance and has been described as a risk factor for type 2 diabetes. Whether OSA adversely impacts pancreatic islet β-cell function remains unclear. We aimed to investigate the association of OSA and short sleep duration with β-cell function in overweight/obese adults with prediabetes or recently diagnosed, treatment-naive type 2 diabetes.

RESEARCH DESIGN AND METHODS
Two hundred twenty-one adults (57.5% men, age 54.5 ± 8.7 years, BMI 35.1 ± 5.5 kg/m2) completed 1 week of wrist actigraphy and 1 night of polysomnography before undergoing a 3-h oral glucose tolerance test (OGTT) and a two-step hyperglycemic clamp. Associations of measures of OSA and actigraphy-derived sleep duration with HbA1c, OGTT-derived outcomes, and clamp-derived outcomes were evaluated with adjusted regression models.

RESULTS
Mean ± SD objective sleep duration by actigraphy was 6.6 ± 1.0 h/night. OSA, defined as an apnea-hypopnea index (AHI) of five or more events per hour, was present in 89% of the participants (20% mild, 28% moderate, 41% severe). Higher AHI was associated with higher HbA1c (P = 0.007). However, OSA severity, measured either by AHI as a continuous variable or by categories of OSA severity, and sleep duration (continuous or &lt;6 vs. ≥6 h) were not associated with fasting glucose, 2-h glucose, insulin sensitivity, or β-cell responses.

CONCLUSIONS
In this baseline cross-sectional analysis of the RISE clinical trial of adults with prediabetes or recently diagnosed, untreated type 2 diabetes, the prevalence of OSA was high. Although some measures of OSA severity were associated with HbA1c, OSA severity and sleep duration were not associated with measures of insulin sensitivity or β-cell responses.