(Rochester, MN)  —  Most states turned the clocks back an hour overnight, a task that comes with some health concerns.  Sleep disorder specialists at the Mayo Clinic say turning the clocks back and forth twice a year causes disruptions in the brain’s circadian rhythms.  Researchers at Harvard Medical School and Massachusetts General Hospital have found that in mice, disrupted sleep causes an increase in heart disease.  Another study in people shows a 24-percent increase in heart attacks after moving clocks forward an hour in the spring and the opposite they “fall back” in November.