To hammer home a point we at Van Winkle’s regularly make: Sleep patterns tend to say more about people than whether they're owls or larks. Public health studies have linked sleep and related health issues to a host of demographic characteristics including income, ethnicity and education level. It’s one big, and not particularly fair, web. But, as a new study on geographic variations in sleep quantity shows, it’s not always easy to predict the connections inside that web.
For the study, a multi-university research team used data from the CDC’s 2009 Behavioral Risk Factor Surveillance Survey (BRFSS) to map out county-by-county differences in rates of poor sleep, and published their findings in the journal Sleep Health.
Analyzing 2,231 counties across the country, researchers identified poor-sleep “hotspots,” which have the highest percentage of sleep-starved residents, and “coldspots” where rates of solid rest are highest.
To determine hot and cold spots, they categorized people based on whether they’d slept poorly for greater or fewer than 15 days during the previous month.
The 15-day mark jibes with diagnostic criteria for insomnia. To reach clinical significance, people must report symptoms of the sleep disorder on at least half of the nights during a given time period. In hotspots, at least 34 percent of residents had to hit the 15-day mark, whereas coldspot counties boast poor-sleep rates of four to 22 percent.
Here’s what they found:
The prevalence of poor sleep doesn’t follow an especially clear pattern.
Researchers found 84 hotspots across the southeast, southwest and midwest. Tossing and turning appears to be disproportionately common in one region: Appalachia, home to the 17 egregious hotspots in the mountainous intersection of Kentucky, Tennessee, Virginia and West Virginia.
But, some of the hotspot-ridden states, including Alabama, Georgia and Illinois, are also home to coldspots, of which researchers found 45.
They aren’t quite sure why Appalachia is a bastion of insomnia. But, they mention a few issues that might be related:
- Extraordinary rates of obesity, poverty and unemployment
- Elevated risk for cardiovascular disease, diabetes, lung disease, and several types of cancer;
- Lack of healthcare access and infrastructure.
Yup, that could do it. To the healthcare access point, the multi-state Appalachian region has about 18 accredited sleep centers (within a hundred-plus-mile radius of one West Virginia town). By contrast, there are 52 within 20 miles of midtown Manhattan.
While, in general, hotspot populations skewed young, poor and unhealthy, coldspots proved harder to predict. Interestingly, researchers noted, the findings didn’t link poor-sleep rates and racial or ethnic minority groups, whereas a strong link has emerged in a number of epidemiological studies on sleep health. We would've guessed otherwise. But you know what they say about assuming.