October 23, 2017
Can Lack Of Sleep Cause Type 2 Diabetes?
By Michael D. Shaw
According to a CDC report released last July, more than 100 million U.S. adults are now living with diabetes or prediabetes. Among other findings, figures in 2015 indicate that 30.3 million Americans—a shocking 9.4 percent of us—have diabetes. The rest are in the prediabetic category. Making matters worse, of those 30.3 million, 7.2 million are undiagnosed.
Notwithstanding that these statistics are likely inflated, the numbers are nothing short of appalling. World estimates for 2015 ring in at over 400 million adults, with a goodly number of them being undiagnosed, as well. To put things in perspective, in 1980 the number of diabetics worldwide was around 108 million.
So, what happened? Most experts point to the staggering rise in obesity. After all, insulin resistance can be considered a mechanism in controlling excessive weight. The trouble, of course, is that this “weight” in the form of glucose remains in the blood, creating hyperglycemia, and thus diabetes.
However, not all overweight people are diabetics, and how does one explain the ten percent or so of type 2s who are of normal weight? “Genetics” is the most common—if specious—response. What, pray tell is the mechanism whereby this gene, or genes, creates hyperglycemia? Don’t hold your breath waiting for an answer.
Instead, consider the notion that lack of sleep could be a factor. Experts cite various aspects that might be in play here:
1. Several key hormonal processes can be affected by short sleep duration. Moreover, glucose tolerance (the ability to maintain proper blood glucose levels) varies in a circadian rhythm, including during the different stages of sleep.
2. In a nasty twist, being hyperglycemic can cause poor sleep. Talk about your vicious circle. For one thing, high glucose levels will prompt more frequent urination; and few things interrupt a good night’s sleep more than having to awaken for that reason—perhaps multiple times per night.
3. Then, if that poor sleep makes you feel tired during the day, you might be inclined to munch on carb-laden snacks or comfort foods—triggering a nice spike in blood glucose. What about coffee? Some research suggests that for type 2s, caffeine can also raise glucose levels.
To be sure, individual sleep needs vary, and with so many metabolic processes being involved—not to mention stress and aging—determining your ideal is far from easy. According to Mark Mahowald, MD, director of the Minnesota Regional Sleep Disorders Center in Hennepin County:
“On average, we need 7.5 hours per night, but your sleep requirement is genetically determined and varies. It can be about four hours on the short end to 10 or 11 on the long end.” OK, but how do you know if you’re sleep-deprived? Mahowald says, “If you use an alarm clock, you are. If you were getting adequate sleep, your brain would awaken you before the alarm goes off.”
Sorry doc, but I’ll have to respectfully disagree. As many of us know, waking up without an alarm, or before the alarm sounds, could be a function of stress, anticipation of an important event during the day such as a big meeting or an out-of-town journey, or just the force of habit.
Back in August, 2011, a superb review article entitled “Does lack of sleep cause diabetes?” was published in the Cleveland Clinic Journal of Medicine. As the authors put it…
“Several lines of evidence indicate that chronic lack of sleep may contribute to the risk of type 2 diabetes mellitus. Adequate sleep and good sleep hygiene should be included among the goals of a healthy lifestyle, especially for patients with diabetes.”
Finally, for those wondering whether strategic naps can make up for lack of nighttime sleep, the answer seems to be “sort of.” I fear that perfect sleep, along with perfect health and a perfect diet, are benchmarks that will continue to elude most of us.