There's growing evidence that people who regularly sleep too little and at the wrong time suffer long-lasting consequences including an increased risk of diabetes and heart disease.
Studies have long shown that people who sleep fewer than five hours a night have an increased risk of developing Type 2 diabetes, the kind that tends to strike later in life.
Rotating shift work -- three or more night shifts a month interspersed with day or evening hours -- also raises the risk.
That's according to a recent report from researchers who analyzed years of medical records from the huge Nurses' Health Study.
But a study published last week shows sleep plays a more complex role than that.
As sleep drops and normal biological rhythms are disrupted, the body physically changes in ways that can help set the stage for diabetes.
That's according to researchers at Boston's Brigham and Women's Hospital.
Up to 70 million Americans are estimated to suffer from chronic problems with sleep, from insomnia to sleep apnea.