Obstructive sleep apnea (OSA) is a type of sleep disorder characterized by a decrease in or a complete lack of airflow to your lungs. This decrease or stoppage in airflow happens repeatedly during sleep and is caused by the collapse of soft tissues in the upper airway. Anything that narrows the airway can lead to this collapse but the more common causes are obesity, age, menopause, upper airway anatomy and being male.
In this article we’ll look at the relationship between weight, OSA and Continuous Positive Airway Pressure (CPAP) therapy, the gold standard of treatment for OSA. We’ll examine the connection between sleep apnea and weight gain and answer the burning question, “Can CPAP help you lose weight?”
Sleep Apnea and Weight Gain
The relationship between sleep apnea and weight is a complicated one and the answer to the question, can sleep apnea cause you to gain weight involves understanding how sleep affects weight. Obesity is a major risk factor for OSA and as much as 45% of obese individuals suffer from OSA.1 However, OSA can also lead to weight gain as less sleep and poor sleep quality contributes to hormonal changes that can make it easier to gain weight.
Sleep apnea results in shorter sleep duration and poor sleep because the body is in a constant state of sympathetic activation, or stress. When you receive less airflow, your blood oxygen levels drop, causing the body to react by constricting blood vessels to raise blood pressure, and increasing your heart rate to try to deliver more oxygen to your organs. Your brain will wake you up from sleep just enough so you take in a breath, causing you to gasp, choke and/or snort in your sleep. This results in shorter sleep and an overall poor sleep quality.
A lack of sleep not only makes you feel fatigued and irritable, it can also lead to weight gain. Sleep deprivation affects the body’s ability to produce hormones such as melatonin and leptin and also increases the risk of insulin resistance. 1,2. Decreased melatonin levels are associated with an increase in appetite, making weight gain more likely especially if your lifestyle doesn’t involve much physical activity.3 Similarly, insulin resistance has a strong association with weight gain when accompanied by poor diet and lack of exercise.
Leptin is a hormone produced by fat tissue which gives you that feeling of satiety. When you don’t get enough sleep, your body produces less leptin and you run the risk of overeating.1 It’s interesting to note that although having more fat means you produce more leptin, obese individuals actually develop leptin resistance and don’t benefit as much from the effects of this hormone.
Can CPAP Help You Lose Weight?
We’ve all heard a CPAP machine weight loss story that happened to a friend of a friend. But what exactly is the relationship between CPAP and weight loss? Can using a sleep apnea machine really help you shed those extra pounds?
In theory, yes. Research shows that sleep apnea and the poor sleep quality it creates have a strong correlation with weight gain. Therefore, it might seem reasonable to expect that by treating sleep apnea with CPAP, we’d be removing a major factor in weight gain. Surprisingly though, recent research on CPAP and weight loss paints a somewhat different picture.
CPAP and Weight Loss: The Findings
A study by Drager et al. involving 3181 patients provides strong evidence that CPAP therapy actually leads to weight gain.4 This meta-analysis (a study that examines the data from various independent studies with the same research topic) looked at 25 randomized trials which measured the effect of CPAP on weight. The study actually concludes that OSA patients experience an increase in BMI and weight after starting CPAP therapy.
So what causes weight gain with CPAP use? Again, the answer is complicated, with multiple theories at play. One such therapy is that our bodies use less energy when we sleep, but people with obstructive sleep apnea actually use more energy.5 This is because OSA causes periods of hypoxia, or low blood oxygen levels, which increase the body’s sympathetic tone, also known as the fight-or-flight response. By this logic, sleep apnea treatment should decrease the amount of energy the body uses during sleep, leading to weight gain.
Another theory that explains why OSA patients experience weight gain with CPAP use is related to leptin, the hormone responsible for satiety. Research shows that CPAP therapy causes leptin levels to decrease significantly in OSA patients with a BMI<30 kg/m2 .6 Since leptin helps inhibit appetite, a lower amount is logically linked to weight gain.
Hormones and metabolism aside, the most obvious reason why that CPAP machine weight loss story should be taken with a grain of salt is that a lot of different factors influence weight. Everything from exercise to eating healthy, getting enough sleep, managing stress and treating sleep apnea plays a role. People gain weight with CPAP use because they often don’t make any other lifestyle adjustments. Therefore, doctors stress the importance of an active weight loss plan alongside CPAP therapy for OSA patients looking to lose weight.
CPAP and Weight: Achieving a Balance
We all struggle to make healthy choices. When life gets hectic, it can be hard to resist reaching for that second slice of cheesecake or prioritize watching funny cat videos over getting enough sleep. However, in the long run, these short term pleasures take a toll on our health, our waistline and increases our chance of developing obstructive sleep apnea.
Here are some tips to help you lose weight and keep those pounds off:
Adopt a Healthy Eating Pattern
In order to lose weight, one needs to eat less calories. However, if your goal is to lose weight and keep it off, it’s important to adopt a healthy eating pattern. A healthy eating pattern means eating a diet that involves all food groups—fruits, vegetables, grains, protein foods, and dairy—within your calorie limits. It also involves choosing more nutrient-dense versions of foods. For example, instead of eating a fruit flavored yogurt loaded with added sugars, choose low-fat plain yogurt and add some fresh fruits to it.7 Or, replace the sour cream with greek yogurt the next time you make french onion dip.
It’s also important to limit foods that are high in sugar, sodium, cholesterol, saturated and trans fats. Common foods to avoid are sugary drinks such as soda and juice, all forms of junk food and highly processed foods including cured, smoked and salted meats. Sauces, dressings, and gravies packed with unhealthy fats, sugar and sodium should be indulged in limited quantities. Some examples include ranch dressing, honey mustard, ketchup, tartar sauce, and sausage gravy.
Stay Active
According to the CDC, a minimum of 150 minutes of moderate intensity aerobic activity per week is needed for most people to maintain their weight. This includes hiking, walking briskly, doing light yard work and biking casually. If you’re hoping to achieve weight loss, combining exercise with calorie restriction is key, as studies show that exercise alone isn’t a guaranteed path to success.8
Plan Your Meals
You can make healthier food choices by planning ahead for your meals. Bringing a packed lunch helps you avoid eating unhealthy fast food at work or grabbing a bite from that conveniently located sandwich shop. If you’re trying to lose weight, meal planning is crucial to help you stay on track of your goals, which will keep you motivated.
Additionally, it’s important to limit certain foods that can make your sleep apnea symptoms worse. Foods packed with unhealthy fats, sodium and sugar can increase inflammation and promote weight gain, increasing your sleep apnea severity. Learn more about how you can improve sleep apnea symptoms by changing your diet.
Get Enough Sleep
Research indicates that people who chronically sleep less than or equal to 6 hours per night are more likely to be obese.9 When we don’t sleep enough, our bodies not only produce less leptin, the hormone that tells us we’re full, but also produce more ghrelin, the hunger hormone. We also produce more cortisol, the stress hormone, which increases our craving for high energy foods.
This is because cortisol increases your energy level by metabolizing carbohydrates and fats. Unfortunately, while increased cortisol is a great response when you’re having a standoff with your neighbor’s aggressive dog, it’s not as beneficial when you’re trying to meet your weight loss goals.
If you find it hard to fall asleep or stay asleep, here are some sleep hygiene tips that will help improve your sleep quality.
CPAP and Weight: The Takeaway
Can a CPAP cause you to gain weight? Or does it help with weight loss? Unfortunately, recent research says yes to weight gain. While scientists have for years theorized that CPAP therapy should lead to weight loss by improving sleep quality, a closer look reveals that most people experience weight gain with CPAP use.
Sleep apnea therapy leads to weight gain by decreasing the body’s energy expenditure during sleep and decreasing the amount of the satiety hormone, leptin. This means the body burns fewer calories while also feeling less full, making it easier to consume more. So if you’ve been diagnosed with OSA, it’s important to keep in mind that weight gain is a possibility with CPAP therapy, especially if you don’t make any lifestyle changes once after starting treatment.
OSA patients looking to lose weight or avoid weight gain with CPAP should adopt a balanced approach that goes beyond just using their sleep apnea machines. In addition to CPAP use, it’s a good idea to develop healthy eating patterns, increase or maintain your level of physical activity, plan your meals and try to get enough sleep.
References
- Romero-Corral, A., Caples, S. M., Lopez-Jimenez, F., & Somers, V. K. (2010). Interactions between obesity and obstructive sleep apnea: implications for treatment. Chest, 137(3), 711–719. https://doi.org/10.1378/chest.09-0360
- Punjabi, N. M., Shahar, E., Redline, S., Gottlieb, D. J., Givelber, R., Resnick, H. E., & Sleep Heart Health Study Investigators (2004). Sleep-disordered breathing, glucose intolerance, and insulin resistance: the Sleep Heart Health Study. American journal of epidemiology, 160(6), 521–530. https://doi.org/10.1093/aje/kwh261
- Walecka-Kapica, E., Klupińska, G., Chojnacki, J., Tomaszewska-Warda, K., Błońska, A., & Chojnacki, C. (2014). The effect of melatonin supplementation on the quality of sleep and weight status in postmenopausal women. Przeglad menopauzalny = Menopause review, 13(6), 334–338. https://doi.org/10.5114/pm.2014.47986
- Drager, L. F., Brunoni, A. R., Jenner, R., Lorenzi-Filho, G., Benseñor, I. M., & Lotufo, P. A. (2014). Effects of CPAP on body weight in patients with obstructive sleep apnoea: a meta-analysis of randomised trials. Thorax, 70(3), 258–264. https://doi.org/10.1136/thoraxjnl-2014-205361
- Redenius, R., Murphy, C., O’Neill, E., Al-Hamwi, M., & Zallek, S. N. (2008). Does CPAP lead to change in BMI? Journal of Clinical Sleep Medicine, 04(03), 205–209. https://doi.org/10.5664/jcsm.27181
- Harsch, I. A., Konturek, P. C., Koebnick, C., Kuehnlein, P., Fuchs, F. S., Schahin, S. P., Wiest, G. H., Hahn, E. G., Lohmann, T., & Ficker, J. H. (2003). Leptin and ghrelin levels in patients with obstructive sleep apnoea: effect of CPAP treatment. The European Respiratory Journal, 22(2), 251–257. https://doi.org/10.1183/09031936.03.00010103
- Agriculture, U. S. D. O., & Agriculture, U. S. D. O. (2020). Dietary Guidelines for Americans 2020 – 2025 (9th ed.). https://www.dietaryguidelines.gov
- Cox, C. (2017). Role of physical activity for weight loss and weight maintenance. Diabetes Spectrum, 30(3), 157–160. https://doi.org/10.2337/ds17-0013
- Papatriantafyllou, E., Efthymiou, D., Zoumbaneas, E., Popescu, C. A., & Vassilopoulou, Ε. (2022). Sleep deprivation: Effects on weight loss and weight loss maintenance. Nutrients, 14(8), 1549. https://doi.org/10.3390/nu14081549