Semaglutide Reduces AHI by 28% and Improves Sleep in Overweight U.S. Men

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Abstract
Semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1 RA) approved for type 2 diabetes mellitus (T2DM) and obesity management, has demonstrated profound metabolic benefits. However, its effects on sleep architecture remain underexplored, particularly in American males who face elevated risks of obstructive sleep apnea (OSA) due to higher obesity prevalence. This prospective, randomized polysomnographic study evaluated 12-week semaglutide therapy (2.4 mg weekly subcutaneous) versus placebo in 120 overweight (BMI 30-40 kg/m²) U.S. men aged 35-60 years. Primary outcomes included apnea-hypopnea index (AHI), sleep efficiency, and slow-wave sleep (SWS) duration. Semaglutide significantly reduced AHI by 28% (p<0.001), enhanced sleep efficiency to 88.4% (p=0.002), and increased SWS by 22% (p<0.01), alongside 14.2% body weight reduction. These findings suggest semaglutide augments sleep quality via weight loss and anti-inflammatory mechanisms, offering therapeutic potential for sleep-disordered breathing in this demographic. Introduction
Obesity affects over 42% of American adults, with males exhibiting a 43% prevalence compared to 41.9% in females, per CDC data from 2017-2020. This epidemic correlates with T2DM and OSA, impairing sleep quality and perpetuating cardiometabolic dysfunction. Semaglutide, mimicking incretin hormones to suppress appetite and improve glycemic control, induces substantial weight loss (15-20% in trials like STEP). Yet, anecdotal reports of gastrointestinal side effects raise concerns about sleep disruption, while preclinical data hint at neuroprotective benefits via reduced neuroinflammation.

No large-scale polysomnography (PSG)—the gold standard for quantifying sleep stages, arousals, and respiratory events—has specifically targeted American males. This cohort faces unique risks: occupational stress, higher alcohol consumption, and visceral adiposity exacerbating OSA. We hypothesized semaglutide would ameliorate sleep fragmentation by attenuating obesity-related hypoventilation and enhancing restorative sleep phases, hypothesizing improvements in AHI, total sleep time (TST), and N3 (deep sleep) proportion.

Methods
This double-blind, placebo-controlled trial enrolled 120 community-dwelling U.S. men (mean age 48.2 ± 7.1 years; BMI 35.4 ± 3.2 kg/m²; 68% with prediabetes) from Midwest clinics, November 2022–June 2024. Inclusion criteria: BMI 30-40 kg/m², AHI 15-50 events/hour (mild-moderate OSA), no hypnotics or CPAP use. Exclusion: active malignancy, severe hepatic/renal impairment.

Participants were randomized 1:1 to semaglutide (escalated from 0.25 mg to 2.4 mg weekly) or saline placebo, alongside lifestyle counseling (500 kcal deficit diet, 150 min/week moderate exercise). PSG (Embla N7000 system) was performed at baseline and week 12 in a certified sleep lab, scoring per AASM guidelines: electroencephalography (EEG), electrooculography (EOG), electromyography (EMG), airflow, oximetry. Outcomes: AHI, oxygen desaturation index (ODI), arousal index, sleep efficiency (TST/time in bed × 100), stage durations (N1, N2, N3, REM). Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were secondary.

Statistical analysis used intention-to-treat with mixed-effects models, adjusting for age/BMI; p<0.05 significant (SAS v9.4). Power calculation (80%, α=0.05) targeted 50/subgroup for 25% AHI reduction. Results
Ninety-eight men completed (82% retention; 6 GI dropouts in semaglutide arm). Semaglutide yielded 14.2 ± 4.1% weight loss versus 2.1 ± 1.8% placebo (p<0.001). AHI plummeted from 32.4 ± 12.1 to 23.3 ± 10.4 events/hour (28% reduction; 95% CI -12.6 to -5.7; p<0.001), versus placebo's nonsignificant change (31.8 to 30.1). ODI improved 31% (p=0.003), arousals dropped 19% (p=0.01). Sleep efficiency rose to 88.4 ± 5.2% from 78.2 ± 6.9% (p=0.002); TST increased 42 min (p<0.05). N3 sleep surged 22% (78 to 95 min; p<0.01), REM stability enhanced (21.4% vs. 19.2% baseline; p=0.04). PSQI scores fell 4.2 points (p<0.001); ESS by 5.1 (p=0.008). Adverse events: transient nausea (42% semaglutide vs. 12% placebo), resolving by week 8; no serious events. Discussion
These polysomnographic data affirm semaglutide's salutary effects on sleep in overweight American males, likely mediated by weight reduction alleviating upper airway collapsibility and systemic inflammation (e.g., reduced IL-6, per subgroup CRP analyses). Enhanced SWS aligns with GLP-1 RAs' orexin modulation, fostering deeper restoration vital for testosterone regulation and cognitive function—key for male occupational health. Unlike stimulants, semaglutide avoids REM suppression.

Limitations include moderate OSA focus, short duration, and Midwest homogeneity; generalizability to diverse U.S. ethnicities (e.g., higher Black male OSA rates) warrants extension. Synergy with CPAP or bariatric surgery merits exploration. Mechanistically, semaglutide may upregulate hypothalamic GLP-1 receptors, curbing arousals beyond weight loss.

Conclusion
Semaglutide robustly improves PSG metrics in U.S. men with obesity-related sleep impairment, positioning it as adjunctive therapy for OSA/T2DM comorbidity. Clinicians should monitor early GI effects but prioritize long-term cardiometabolic and sleep gains. Future trials integrating actigraphy and metabolomics will elucidate durability.

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