Analysis of 3,635 U.S. adults revealed that elevated remnant cholesterol-to-HDL-C ratios increase obstructive sleep apnea risk by 23% per unit increase, with the highest quartile showing 49% greater odds. The relationship exhibits a clear threshold at 0.232 ratio units—below this point, each 0.1-unit increase raises risk by 54%, while above it the effect plateaus. However, central adiposity mediated 82.7% of this association, particularly in women where the indirect pathway was 2.8 times stronger. This finding adds nuance to emerging research linking lipid metabolism dysfunction to sleep-disordered breathing. While previous studies identified various lipid ratios as OSA predictors, this work pinpoints a specific actionable threshold and reveals that abdominal fat accumulation—not lipid abnormalities per se—drives most of the relationship. The modest discrimination power (AUC 0.564) suggests limited clinical utility as a standalone screening tool. Important limitations include reliance on questionnaire-based OSA diagnosis rather than gold-standard polysomnography and cross-sectional design preventing causal inference. As an unreviewed preprint, these exploratory findings require validation in prospective cohorts with objective sleep measurements before clinical application.