Divorce may be linked to a higher risk for heart attack, especially in women.

Researchers used a nationally representative sample of 15,827 adults ages 45 to 80, all of whom were married or had been previously. The study, published in Circulation: Cardiovascular Quality and Outcomes, began in 1992, and the participants were interviewed every two years through 2010. About one-third were divorced at least once.

During the follow-up, 1,211 of the participants — about 8 percent — had a heart attack. The researchers found that compared with a woman who was continuously married, a woman who had been divorced once had a 24 percent higher risk of heart attack. Those who had been divorced twice had a 77 percent higher risk, and remarried a 35 percent higher risk.

Among men, only those who had divorced more than once had an higher risk of heart attack, about 30 percent.

"Divorce isn't a classical risk factor, like smoking or high blood pressure," said the lead author, Matthew Dupre, an associate professor of sociology at Duke. "But we hope that caretakers and the general public will have a greater understanding of how the stress of divorce can affect their lives."

Sleep apnea tied to memory decline

Breathing problems during sleep may be linked to early mental decline and Alzheimer's disease, a study suggests. But treating apnea with a continuous positive airway pressure machine can delay the onset of cognitive problems.

In a group of 2,470 people, average age 73, researchers gathered information on the incidence of sleep apnea, a breathing disorder marked by interrupted breathing and snoring, and the incidence of mild cognitive impairment and Alzheimer's disease. They found that people with disordered breathing during sleep became cognitively impaired about 10 years sooner than those without the disorder.

But compared with those whose sleep disorder was untreated, those using CPAP machines delayed the appearance of cognitive impairment by an average of 10 years — making their age of onset almost identical to those who had no sleep disorder.

The lead author, Dr. Ricardo S. Osorio, a research professor of psychiatry at NYU Langone Medical Center, said the analysis, published online in Neurology, was an observational study that did not prove cause and effect. "But," he added, "we need to increase the awareness that sleep disorders can increase the risk for cognitive impairment and possibly for Alzheimer's."

Depression, diabetes, dementia

It's known that people with Type 2 diabetes and those with depression each face a greater risk of dementia. But a study published online in JAMA Psychiatry says people with both conditions face a risk of dementia higher than expected.

"Depression and diabetes mellitus were independently associated with a greater risk for dementia, and the combined association of both exposures with the risk for all-cause dementia was stronger than the additive association," the study concludes.

Type 2 diabetes and depression go hand-in-hand. Poorly managed blood-glucose levels can lead to depression while inactivity from depression raises the risk of diabetes. Type 2 diabetes brings a 20 percent higher risk of dementia; depression is associated with an 83 percent higher risk of dementia.

A study of 2.5 million Danes, age 50 and older, found that people younger than 65 with both diabetes and depression represented 25 percent of all dementia cases in that age group. Six percent of all dementia cases among people 65 and older had both conditions.

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