With so many sleep apnea sufferers undiagnosed, it’s important that people who are at high risk understand their risk factors and seek screening. This includes people whose parents had (or might have had) sleep apnea. In the past, genetic analysis focused on risk factors for obesity and apnea, but new genetic evidence makes it very clear that there are multiple genetic factors involved in sleep apnea risk which could transmit susceptibility from parents to children, independent of obesity.
The Obesity-Apnea Connection
Earlier genetic evidence of sleep apnea heritability discovered many overlapping genetic markers for obesity and apnea. Evidence looking at certain pieces of genetic code (known as genetic loci) related to sleep apnea identified that about half of the genetic variability associated with sleep apnea could be accounted for by obesity-linked loci.
This makes sense, given the strong links between obesity and sleep apnea. But the heritability of obesity is itself dubious. There are many factors that cause obese parents to have obese children, and many of them are cultural, rather than genetic. Eating habits, shopping habits, tendency to exercise, and more are cultural and educational factors from parents that influence a child’s obesity, independent of genetics.
But if a person breaks the cycle of obesity by unlearning lessons taught by parents, controlling weight and exercising regularly, are they still at risk for sleep apnea?
Independent Risk for Apnea
Researchers sought to determine whether they could find genetic loci that were independently associated with sleep apnea, not obesity. To focus their genetic search and to help vulnerable people understand their risks, they focused on the Hispanic population. This was a good population to choose because they had access to large numbers of recent individuals surveyed in three prior studies: the Hispanic Community Health Study/Study of Latinos, the Multi-Ethnic Study of Atherosclerosis, and the Starr County Health Study. These current studies were valuable because they contained both genetic information and detailed sleep studies of over 12,000 individuals. Researchers noted that a limitation of previous studies was that they only focused on apnea-hypopnea index (AHI), so they looked at oxygen saturation levels and apnea event duration as well as AHI.
Using this data, they identified two key genetic loci that were significant for sleep apnea risk and seven additional loci that might be significant. It’s important that these aren’t loci associated with obesity, but relate to systemic inflammation, the body’s system for sensing and responding to oxygen shortages, and control of sleep.
Your Risk Is Independent of Obesity
Many people think that sleep apnea is something that people only have to worry about if they’re overweight or obese, but that’s not true. This study reminds us that sleep apnea is a complex phenomenon, and it’s important not to ignore your potential risk. If your parents were diagnosed with sleep apnea, or if they were snorers that died of health conditions linked to sleep apnea (such as heart attack and stroke), then it’s important to get screened for apnea, even if you maintain a healthy weight and lifestyle.