Obese patients with obstructive sleep apnea have been noted to have increased insulin resistance. So researchers in university hospitals who have to urgently get some publications out there to ensure that the year-end allocation of research funds don't go elsewhere, do the easy thing and get some healthy people to sleep on the job literally. They then measured how easily their glucose is made short work of, by the insulin. Apparently they go ahead and suggest that if you sleep more, you reverse the insulin resistance that built up when you were not sleeping. Depends on the sins you did when you were awake if you ask me.
Lack of sleep = Reduced insulin sensitivity
Increased sleep = Increased insulin sensitivity
So sleep more?? Next thing you know, the americans are likely to suggest that sleeping is exercise. Obese patients everywhere will chant "I told you so"..
Recommending a confounding condition as a solution for an unrelated problem is meaningless. Try driving a lorry at night to london. Try staying awake in the truck for six hours at a stretch. Easy? Yes, if you take three breaks, one at Macdonalds, one at Burger King and then one to polish off the Extra Big Burger with extra cheese that you bought at the Macdonalds. Arrive at London. Have your insulin sensitivity checked. Yes, Lack of sleep causes hyperglycaemia, recorded as increased insulin resistance. Now sleep it off in London. Bingo. Sleep helps you to keep your mouth shut and improves insulin action. Just one word of advice. Please dont lose any sleep over this hypothesis. Instead do the healthy thing and sleep on it.