Older men who are light sleepers are at increased risk for developing high blood pressure, according to a study that adds to the growing body of research about the importance of a good night’s rest. Men who spent the least amount of time in slow-wave sleep, marked by synchronized brain waves and a deep sleep from which it’s hard to wake up, were 83 percent more likely to develop hypertension during the three-year study. The findings remained consistent even after the researchers took weight, race and age into account, according to the report in Hypertension: Journal of the American Heart Association.