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Rethinking Sleep Apnea: Dr. Atul Malhotra on Remote Patient Monitoring, Central Apnea, and the Future of GLP-1 Therapy
This article highlights why multi-night, airflow-based sleep testing outperforms single-night studies, with insights from Dr. Atul Malhotra on CSA, hypoxic burden, and GLP-1 therapy.
Why isn’t one night of sleep testing enough?
Diving in, Dr. Malhotra warns that “single-night polysomnography gives you a snapshot—nothing more.” Sleep quality fluctuates dramatically between nights due to factors like body position, REM cycles, alcohol intake, or even minor illnesses such as colds. Such variability can lead to significant misclassification. For example, a recent study in Sleep observed night-to-night AHI variability of ≥10 events/hour in over one-third of adults, driven by variations in REM sleep and posture. Large-scale home testing has shown that relying on only the first night misclassifies moderate OSA in about 20% of cases, disproportionately affecting women and REM-predominant OSA patients.
Further, in a separate cohort of more than 12,000 adults monitored over hundreds of nights, individuals with high night-to-night AHI variability exhibited a 50–70% higher risk of uncontrolled hypertension, regardless of their average AHI. RPM—by enabling repeated measurements over multiple nights—offers a more accurate assessment of OSA severity and associated vascular risk, reducing the chance of false negatives or inappropriate treatment initiation.
What does “hypoxic burden” mean, and why is it important?
“The AHI is the best we have, but it’s nowhere near perfect,” Dr. Malhotra observes, noting that two patients may show identical event counts yet differ drastically in the depth and duration of hypoxic episodes, arousal frequency, and cardiovascular risk. Advanced metrics like hypoxic burden—which integrates the duration and severity of oxygen desaturations—have demonstrated stronger predictive power for cardiovascular outcomes than AHI alone. Analyses from the Sleep Heart Health and MrOS cohorts showed that higher hypoxic burden independently predicted heart failure risk, with each incremental increase associated with a 45% higher incidence. Since AHI fails to capture these critical dimensions, RPM systems that routinely track hypoxic burden can improve risk stratification and support more targeted interventions.
How is Wesper different than other at-home sleep tests?
Dr. Malhotra cautions against overvaluing the number of channels in a home sleep testing device, emphasizing instead the importance of validating against in-lab polysomnography. Many RPM systems use PPG or oximetry to infer breathing, but those systems tend to systematically overestimate oxygen saturation in individuals with darker skin—a phenomenon confirmed by a 2024 Duke cohort study. Recognizing this racial bias, the FDA issued draft guidance in January 2025 mandating inclusive validation across different skin tones. In contrast, airflow-based sensors bypass this issue and are particularly effective in detecting central apnea. RPM devices like Wesper, equipped with airflow and respiratory effort channels, thus deliver more equitable and accurate monitoring, especially in diverse patient populations.
What is Central Sleep Apnea (CSA), and how is it different from Obstructive Sleep Apnea (OSA)?
“If you miss central sleep apnea, you may pick the wrong treatment—some patients actually feel worse on CPAP,” Dr. Malhotra warns. Central sleep apnea (CSA) is prevalent among patients with systolic heart failure—affecting up to 40%—and if left untreated, elevated sympathetic tone can exacerbate cardiac dysfunction. Phrenic-nerve stimulation has emerged as a promising therapy: clinical trials demonstrate a halving of AHI and improvements in heart rate variability and sleep architecture over 3–12 months. Adaptive servo-ventilation (ASV), once labeled unsafe following SERVE-HF, has been shown to be neutral in cardiovascular outcomes in more recent trials such as ADVENT-HF. RPM systems optimized for airflow and effort detection can effectively screen for CSA, allowing clinicians to guide patients toward appropriate—often non-CPAP—treatments with better outcomes.
How do GLP-1 medications like tirzepatide affect sleep apnea?
Dr. Malhotra highlights a paradigm shift: “Tirzepatide cut AHI almost two-thirds in the SURMOUNT‑OSA trials. But as patients lose weight, their physiology moves—so you need RPM at every major milestone.” The 52-week SURMOUNT-OSA Phase III trials in NEJM showed ≥20 events/hour reductions in AHI with tirzepatide versus ~5 events/hour reduction with placebo. Moreover, there were marked improvements in hypoxic burden, systolic blood pressure, inflammatory markers, and patient-reported outcomes. The FDA’s December 2024 approval of Zepbound (tirzepatide) for moderate-to-severe OSA in adults with obesity further confirms its clinical relevance. Since weight loss alters upper airway dynamics, scheduled RPM at baseline, 3 months, and after each 10% weight loss increment is critical to re-evaluate disease severity, adjust PAP settings, and detect emergent CSA.
Integrating RPM with Wesper
| Feature | Supported By |
|---|---|
|
AHI variability and hypertension risk |
|
Mortality/CVD prediction |
|
Equity and CSA detection |
|
Guides phrenic-nerve stimulation/ASV |
|
Tracks physiology during weight loss |
Wesper’s RPM platform—powered by its multi-night, airflow-validated patch—captures a range of clinically meaningful signals, including positional variability, respiratory effort, and hypoxic burden. This continuous, at-home data collection bridges the diagnostic gaps left by single-night tests and PPG-based systems. Its alignment with emerging evidence is clear: multi-night monitoring has been shown to improve detection of AHI variability and hypertension risk, with studies across PMC, PubMed, Nature, and Archivos de Bronconeumología consistently demonstrating the clinical value of repeated sleep measurements. Hypoxic burden tracking, another core capability, has been repeatedly validated as a stronger predictor of cardiovascular and all-cause mortality than AHI alone. Wesper’s use of airflow-based sensing also addresses equity concerns associated with pulse oximetry, which can misread in individuals with darker skin tones—ensuring more accurate apnea detection, including central events. For CSA, Wesper supports early identification and treatment guidance, aligning with recent trials on phrenic-nerve stimulation and ASV. And for patients undergoing GLP-1 therapy, its serial testing capabilities track physiologic changes during weight loss, enabling timely therapy adjustments.
In short, Wesper delivers what the latest science demands: “Tailored, dynamic care—enabled by platforms like Wesper—is how we unlock better outcomes.” (Dr. Atul Malhotra)
Frequently Asked Questions (FAQ)
1: Why isn’t one night of sleep testing enough?
A single-night study can be misleading due to natural fluctuations in sleep patterns caused by posture, REM cycles, environmental factors, and illness. Research has shown significant variability in AHI scores from night to night, which can lead to misdiagnosis or inappropriate treatment plans. Multi-night testing helps create a more reliable average and reduces the risk of false negatives.
2: What does “hypoxic burden” mean, and why is it important?
Hypoxic burden refers to the total amount of time a patient spends in low-oxygen states during sleep. Unlike AHI, which simply counts breathing interruptions, hypoxic burden accounts for the depth and duration of desaturations. It has been shown to be a more powerful predictor of cardiovascular events and overall health risks.
3: How is Wesper different from other home sleep tests?
Many home sleep test systems use optical sensors (PPG) to estimate oxygen levels, which can be inaccurate, especially in individuals with darker skin tones. Wesper uses airflow-based measurement validated against in-lab polysomnography. This allows for more accurate detection of apneas, including central events, and eliminates much of the racial bias found in standard oximetry.
4: What is Central Sleep Apnea (CSA), and how is it different from Obstructive Sleep Apnea (OSA)?
CSA occurs when the brain temporarily stops sending signals to the muscles that control breathing, as opposed to OSA, where the airway becomes physically blocked. CSA is common in patients with heart failure, opioid use, or stroke, and requires a different treatment strategy. CPAP may not be effective or could worsen symptoms in CSA patients.
5: What treatments are available for CSA?
CSA can be treated with adaptive servo-ventilation (ASV), phrenic-nerve stimulation, and in some cases, medications that influence respiratory drive. Phrenic-nerve stimulation has shown promise in improving sleep architecture and reducing cardiovascular risk. Wesper's platform can help identify CSA patterns early to guide these specialized treatments.
6: How do GLP-1 medications like tirzepatide affect sleep apnea?
GLP-1 medications lead to significant weight loss, which can reduce or even resolve OSA in some patients. In the SURMOUNT-OSA trials, tirzepatide reduced AHI by up to 63%. However, as patients lose weight, their sleep patterns and physiology shift, making serial monitoring essential to guide therapy changes.
7: When should sleep be retested during GLP-1 therapy?
Dr. Malhotra recommends retesting at baseline, after 3 months, and at each 10% body weight milestone. This ensures therapy is adjusted as the patient's physiology evolves. Wesper enables this easily through wearable, longitudinal monitoring.
8: Is Wesper suitable for patients on CPAP or oral appliance therapy?
Yes. Wesper's multi-night data collection allows clinicians to evaluate how well a treatment is working and make adjustments over time. It also helps detect residual events or emerging issues, such as central apneas, that may not have been present during initial diagnosis.
9: Why is racial equity an issue in sleep diagnostics?
PPG-based pulse oximeters have been shown to overestimate oxygen levels in people with darker skin tones. This can lead to underdiagnosis of sleep apnea. Airflow-based sensors, like those used in Wesper, eliminate this bias and provide more equitable care.
10: How can I integrate Wesper into my sleep practice?
Wesper is designed to seamlessly fit into both primary care and specialist workflows. With AI-powered reports, easy setup, and ongoing support, it empowers clinicians to deliver precise, patient-specific care across time.
Sources
- Hynes DJ, et al. Night-to-night variability in obstructive sleep apnea severity. Sleep. 2025. pubmed.ncbi.nlm.nih.gov
- Punjabi NM, et al. Variability and Misclassification of Sleep Apnea Severity Based on Multi-Night Testing. Chest. 2020. pmc.ncbi.nlm.nih.gov
- Azarbarzin A, et al. Hypoxic burden predicts cardiovascular mortality. Eur Heart J. 2019. pubmed.ncbi.nlm.nih.gov
- Hao S, et al. Utility of Skin Tone on Pulse Oximetry in Critically Ill Patients. Crit Care Explor. 2024. pmc.ncbi.nlm.nih.gov
- U.S. FDA. Draft Guidance on Pulse-Oximeter Performance Across Skin Tones. Press release, 6 Jan 2025. fda.gov
- Hodossy K, et al. Central Sleep Apnea Syndrome in Chronic Heart Failure. Cardiol Rev. 2023. pubmed.ncbi.nlm.nih.gov
- Costanzo MR, et al. Phrenic-Nerve Stimulation for Central Sleep Apnea. Eur J Heart Fail. 2018. pubmed.ncbi.nlm.nih.gov
- Perger E, et al. ADVENT-HF: Adaptive Servo-Ventilation in Heart Failure—Outcome Analysis. J Card Fail. 2024. pubmed.ncbi.nlm.nih.gov
- Eli Lilly & Co. Tirzepatide Reduced OSA Severity by up to 62.8 % in SURMOUNT-OSA. Press release, 2024. prnewswire.com
- PR Newswire. FDA Approves Zepbound® (tirzepatide) for Moderate-to-Severe OSA in Adults with Obesity. 6 Dec 2024.
Article by Brett Figliozzi
Brett Figliozzi is the Marketing Manager at Wesper, where he leads brand strategy, content development, and digital communications for one of the most innovative companies in sleep technology. With a background in visual design and a focus on clinical storytelling, Brett oversees everything from social strategy to conference branding and blog development. He collaborates closely with Wesper’s clinical team to craft campaigns that are not only engaging but clinically meaningful—bridging the gap between science and audience with precision and purpose.