Although a reduction in BMR after CPAP predisposes to a positive energy balance, dietary intake and eating behavior had greater impacts on weight change. These findings highlight the importance of lifestyle modifications combined with CPAP. Clinical trial registered with http://www.umin.ac.jp/english/ (UMIN000012639).

Notwithstanding the cross-sectional design, SDB and obesity, but not short sleep duration, were independently associated with diabetes and hypertension, with gender and menopausal status-related differences in risk emerging.

It is well known that the prevalence of sleep disordered breathing (SDB) is increased in patients with obesity or metabolic comorbidities. However, the way in which the prevalence of SDB increases in relation to comorbidities according to the severity of obesity remains unclear.This cross-sectional study evaluated 7713 community participants with nocturnal oximetry ≥2 nights. SDB was assessed by the 3% oxygen desaturation index corrected for sleep duration obtained by wrist actigraphy (Acti-ODI3%). SDB severity was defined by Acti-ODI3%. Obesity was defined as body mass index ≥25 kg·/m−2.The prevalence of SDB was 41.0% (95% CI 39.9–42.1), 46.9% (45.8–48.0), 10.1% (9.5–10.8), and 2.0% (1.7–2.3) in normal, mild, moderate, and severe SDB, respectively, with notable sex differences evident (men >post-menopausal women >pre-menopausal women). Comorbidities such as hypertension, diabetes, and metabolic syndrome were independently associated with the prevalence of moderate-to-severe SDB, and coincidence of any one of these with obesity was associated with a higher probability of moderate-to-severe SDB (OR 8.2, 95% CI 6.6–10.2; 7.8, 5.6–10.9; 6.7, 5.2–8.6, respectively). Dyslipidemia in addition to obesity was not additively associated with the prevalence of moderate to-severe SDB. The number of antihypertensive drugs was associated with SDB (p for trend <0.001). Proportion of a high cumulative percentage of sleep time with SpO2 <90% increased even among moderate-to-severe SDB with increases in obesity.Metabolic comorbidities contribute to SDB regardless of the degree of obesity. We should recognise the extremely high prevalence of moderate-to-severe SDB in patients with obesity and metabolic comorbidities.

OSA is associated with elevated serum levels of the incretin hormones GLP-1 (fasting) and GIP (post-prandial) in patients without diabetes. A significant association between body mass index and DPP-4, which is said to exist in healthy persons, was not found in the patients with OSA. Fasting GLP-1 in patients without diabetes with OSA may influence fasting glucose levels.

No abstract

Sarcopenia has been associated with several conditions relevant to obstructive sleep apnea (OSA), such as aging and obesity, but a direct relationship between OSA and skeletal muscle alterations has not been identified. This study investigated associations between computed tomography (CT)-measured skeletal muscle indices and OSA severity. Analyzed were 334 patients who underwent polysomnography to diagnose OSA. Lumbar skeletal muscles were assessed with CT for the skeletal muscle mass index (SMI, cross-sectional area, normalized for height squared) and skeletal muscle density (SMD, fat infiltration). The apnea-hypopnea index (AHI) correlated positively with the SMI and negatively with SMD in both men and women. The AHI was weakly associated with SMI only in men (β = 0.11, P = 0.017) after adjustment for the body mass index (BMI) (BMI: β = 0.61, P < 0.001 in men, β = 0.65, P < 0.001 in women). The association of AHI and SMD was not significant after adjustment for BMI (BMI: β = −0.42, P < 0.001 in men, β = −0.64, P < 0.001 in women). Severity of OSA correlated with increases in skeletal muscle mass rather than muscle depletion and skeletal muscle adiposity. These associations were limited compared with the stronger associations between obesity and skeletal muscles.

No abstract

Endogenous carbon monoxide (CO) levels are recognized to be a surrogate marker of oxidative stress. No study has evaluated both exhaled and blood CO at the same time in obstructive sleep apnea (OSA) patients. Here we provide evidence that exhaled CO levels positively correlated with hypoxia during sleep in OSA patients, but blood CO levels did not, and that continuous positive airway pressure therapy significantly decreased exhaled CO levels in the OSA group, but did not significantly affect blood CO.