Stress Raises Belly Fat, Heart Risks
Study Shows Monkeys Under Long-Term Stress Put on Belly Fat, Get Heart Disease
Stress Strips Females of Heart Protection
All of the monkeys in the Shively study were female. One way monkeys are like humans is that females are less likely to get heart disease than males. Yet stressed female monkeys that put on belly fat are at least as likely to get heart disease as are male monkeys.
"So this is a good model for women with heart disease. When women get visceral fat and the metabolic syndrome, that completely abolishes the female protection," Shively says. "Any edge they get for being female is totally gone. And in fact it may even be a worse disease for women than men, because they get complications and die faster when they have heart disease."
Shively and colleagues found that the stressed monkeys had abnormal menstrual cycles. Compared to the unstressed monkeys, they were much less likely to ovulate. This was linked to abdominal fat -- but not to body mass index or other kinds of fat.
"We don't know about ovarian function in women with metabolic syndrome, but probably this is something we should look into," Shively says. "Because the menstrual system protects against osteoporosis and loss of cognitive function. Depressed ovarian function in women is not a good thing."
Bays says he's not surprised by this finding.
"All these things are interconnected," he says. "The central theme is it just shouldn't be a mystery why, if you gain weight, you get metabolic disease."
The Shively study appears in the current issue of the journal Obesity.