protests in the U.S.

Hawaii and most of Arizona don’t make the spring switch, sticking to standard time year-round along with Puerto Rico, American Samoa, Guam and the U.S. Virgin Islands. Worldwide, dozens of countries also observe daylight saving time, starting and ending at different dates.Some people try to prepare for daylight saving time’s sleep jolt by going to bed a little earlier two or three nights ahead. With a third of American adults already not getting the recommended seven hours of nightly shuteye, catching up can be difficult.

This article is part of AP’s Be Well coverage, focusing on wellness, fitness, diet and mental health.The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert. The patterns change with age, one reason that early-to-rise youngsters evolve into hard-to-wake teens.Morning light resets the rhythm. By evening, levels of a hormone called melatonin begin to surge, triggering drowsiness. Too much light in the evening — that extra hour from daylight saving time — delays that surge and the cycle gets out of sync.

Sleep deprivation is linked to heart disease, cognitive decline, obesity and numerous other problems. And that circadian clock affects more than sleep, also influencing things like heart rate, blood pressure, stress hormones and metabolism.Fatal car crashes temporarily jump the first few days after the spring time change, according to a study of U.S. traffic fatalities. The risk was highest in the morning, and researchers attributed it to sleep deprivation.

Then there’s the cardiac connection. The American Heart Association points to studies that suggest an uptick in heart attacks on the Monday after daylight saving time begins, and in strokes for two days afterward.

Doctors already know that heart attacks, especially severe ones, are a bit more common on Mondays generally — and in the morning, when blood is more clot-prone.Oklahoma overall has a maternal mortality rate of about

live births, significantly higher than the national average of about 23. But in Jackson’s quarter-century tenure, she said, there have been no maternal deaths among clients.Pivotal to Healthy Start’s success are care coordinators like Krystal Keener, a social worker based at Oklahoma State University’s obstetrics and gynecology clinic, where clients get prenatal care. One of her responsibilities is to educate clients about health issues, like how to spot the signs of preeclampsia or how much bleeding is too much after delivery.

She also helps with practical matters: Many clients don’t have cars, so they call Keener when they need a ride to a prenatal visit, and she assists in scheduling one.With doctors, Keener serves as a patient advocate. On a recent afternoon, Keener sat in on a prenatal appointment for Areana Coles. A single mom, Coles was joined by her 5-year-old daughter, who was born prematurely and spent time in intensive care.