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So integrating OSA into cardiac metabolic risk assessment. So this is the first polling question. In your patients with obesity and resistant hypertension, when do you usually initiate OSA screening? A routinely as part of cardio metabolic review, B only when sleep symptoms are reported, C only after bed partner concerns, D, only when clinician requests, or E really or never. There's no real right or wrong answer here, but just a kind of an assessment of your current clinical practice. Thank you very much for your replies. OK, I'm gonna talk about a patient now. This is gonna be a patient focused talk. So patient case 1, 56-year-old woman with obesity, resistant hypertension, type 2 diabetes and dyslipidemia with a BMI of 36. She's hypertensive on three anti-hypertensive medications, so resistant hypertension. She's got an elevated hemoglobin A1C and dyslipidemia. She reports fatigue, morning headaches, nocturia, and her partner reports loud snoring. Cardiometabolic therapy is intensified but no sleep history, OSA screen or diagnostic referral documented. So RSA is a common and serious medical condition. It's associated with intermittent hypoxia, sleep fragmentation, and daytime sleepiness, and poor sleep, and it's associated with upper airway collapse during sleep. It's very common, and up to a billion adults, million adults, a billion million adults aged between 30 and 69 may be affected by this condition. Most studies suggest the male to female ratio of 2:1 to 3:1 in the general population, but there are differences in presentation that we'll discuss later on. And sleep apnea is significantly influenced by socioeconomic status, although this association may vary across different populations. So if you look at the global presentation of OSA AHI greater than 5, and I'll talk about what AHA is, this is kind of the world presentations and it varies depending on where you live. In Australia, maybe 18%. But the figures probably underestimate the true prevalence, particularly in regions with limited access to sleep medicine facilities and awareness of sleep apnea. So what is the mechanism of sleep apnea and why do we worry about it? So I get asked this all the time. The mechanism of sleep apnea is collapsible upper airway. It also may involve collapsing of the muscles or relaxation of the muscles at nighttime that keep the airway open. There may be changes in arousal threshold and ventilation control as well. So it's a mixture of these kind of mechanisms that lead to sleep apnea, and that's derived a lot of interest in the research world that you can endotype these types of mechanisms. Maybe you can target therapy. Nonetheless, if you've got moderate to severe obstructive sleep apnea, it may be associated with significant health consequences, and we know the associations with cardiovascular disease, particularly arrhythmias and hypertension, even heart failure, metabolic disruptions, particularly dyslipidemia and diabetes, and even cognitive dysfunction which has gained a lot of interest in the sleep apnea world. And don't forget psychiatric conditions as well, such as depression and anxiety are commonly associated with obstructive sleep apnea. So not only are there medical and psychiatric complications you get with sleep apnea, but there's also a large socioeconomic costs. And this may be related to medical treatments and assessments. It may be associated with loss of productivity and high predilection to accidents, including driving and even work-related accidents as well. And not achieving your potential in terms of, I guess, cognition may be an important factor, particularly in students or people trying to get promotions in their job. The important thing is that most patients with sleep apnea, particularly moderate to severe sleep apnea, underdiagnose, and we've actually got studies that show that. This may be due to lots of different reasons low awareness rates, lack of adequate screening programs in most areas, particularly in low resource settings, the evolving diagnostic criteria which can be a little bit confusing, polysommography, which is the gold standard treatment, is resource intensive, and many long waitlists and also unavailable in many regions around the world. And also the treatment compliance with CPAP. That may be an issue that you may have patients that said I've been down the CPAP pathway, I don't want to use it. Leave me alone. And also inequalities in access to healthcare across systems as well. So we know that sleep apnea is common. We know it can be associated with significant complications and comorbidities, but a lot of it remains underdiagnosed. So when should we be thinking about sleep apnea? What are the triggers? So patients at high risk include obesity. We'll talk more about that. Patients with established cardio metabolic complications, a family history, patients who have post-op complications, cranial facial abnormalities, large neck circumference, and even pregnancy. Obesity is one of the major modifiable risk factors for sleep apnea, and there are population studies that suggest that maybe 70% of patients with sleep apnea are overweight or obese. And if you look at clinic populations that patients presenting with sleep apnea, maybe up to 80% of patients are overweight or obese. So there lies a very important modifiable risk factor. We also know from large cohort studies that with weight gain, a 10% weight gain is associated with a 32% increase in AHI based on population studies, and a 10% weight loss is associated with about a 30% reduction in AHI. So it's a modifiable risk factor that we need to think about. So high risk patients with cardio metabolic disease should undergo OSA screening. As I mentioned, the OSA is commonly associated with hypertension, atrial fibrillation, heart failure, ischemic heart disease, CVA, pulmonary hypertension, metabolic syndrome, diabetes and cardiovascular morbidity and mortality. And it has a negative feedback. So you think about sleep apnea untreated, it's associated with arousals and awakenings, hypoxia, and that causes more stress on the heart, the sympathetic activity, endoferial dysfunction, and also inflammation as well. It's also satiated with what we call poor brain. Cleaning. So we know that during the day we have buildup of products that are usually cleared at nighttime, but if you've got sleep apnea that may affect that clearance at nighttime and may predispose patients to developing complications and neurocognitive issues such as mild cognitive impairment and even dementia. If you look at the American Heart Association's statement in RSA and cardiovascular states, the high prevalence and comorbidity of OSA in patients with cardiovascular disease coupled with evidence of improved patient centered outcomes uh with RSA and treatment in patients with cardiovascular disease provide a rationale for OSA screening. So I think screening in high risk cardiovascular population is strongly recommended by expert guidelines, but it's probably not implemented commonly in the real world in clinical practice. So what are the things that we need to think about when we're asking about sleep apnea? We all know about snoring, we all know about gasping and apneas at nighttime and feeling fatigued and sleepy during the day and having periods of drowsy driving. Also think about decreased memory and concentration and lower mood. And there are what we call screening questionnaires that you can use. These screening questionnaires are all available to GPs and they can also guide you in terms of which patients should be having sleep studies. So common ones are stop bang, which you can see on the slide here in the Berlin questionnaire. And if you're squirm high in these questionnaires, that may be associated with having a high risk of developing sleep apnea. There are some caveats though. A lot of these screening questionnaires have been focused on males, and we know that women or females may have more slightly different symptomatology. Fatigue, insomnia, poor sleep, tiredness may be more common in females than males. And I think that's important when we're thinking about sleep apnea in this population. So let's talk about a positive screen. So you've got a patient who's got a positive RSA screen, be it the stop bang or Berlin or OSA 50, which we'll talk about later on. What's the next step? So the next step is to confirm the diagnosis with a sleep study. And it's important to do that. You cannot diagnose the sleep apnea based on symptoms and screening questionnaires by itself. So what is a sleep study? Essentially there's various types of sleep studies out there. We have the gold standard polysommography, which is an in-lab sleep study, and it measures lots of different things at nighttime. So from a sleep apnea point of view, we want to know the AHI, this is the standard metric that we use to gauge sleep apnea severity. AHI means apnea hypopnea index. That's the numbers of times where patients stop breathing.