Sleeplessness and Aging
Insomnia, which often accompanies menopause, has a clear association with age acceleration, according to UCLA researchers.
The investigators also said that menopause increases biological aging.
The dual findings suggest both factors could increase women’s risk for aging-related diseases and earlier death. The two studies, published in separate journals, contribute to increasing evidence of the biological clock’s variability.
The menopause study was published in the Proceedings of the National Academy of Sciences.
“For decades, scientists have disagreed over whether menopause causes aging or aging causes menopause,” said Steve Horvath, a professor of human genetics and biostatistics in the David Geffen School of Medicine at UCLA, and senior author on both studies. “It’s like the chicken or the egg: which came first? Our study is the first to demonstrate that menopause makes you age faster.”
The sleep study was published in the online issue of the journal Biological Psychiatry.
Not getting restorative sleep may do more than just affect our functioning the next day, said Judith Carroll, an assistant professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior and the Cousins Center for Psychoneuroimmunology, and first author of the sleep study.
“It might also influence the rate at which our biological clock ticks,” Carroll said. “In the women we studied, those reporting symptoms such as restless sleep, waking repeatedly at night, having difficulty falling asleep, and waking too early in the morning tended to be older biologically than women of similar chronological age who reported no symptoms.”
For their findings, both studies used a genetic “biological clock” developed by Horvath, which has become a widely used method for tracking the epigenetic shift in the genome. Epigenetics is the study of changes to DNA packaging that influence which genes are expressed but don’t affect the DNA sequence itself.
In the menopause study, Horvath and first author Morgan Levine tracked methylation, a chemical biomarker linked to aging, to analyze DNA samples from more than 3,100 women enrolled in four large studies. The DNA samples included those from women participating in the Women’s Health Initiative a 15-year research program that addressed the most common causes of death, disability and poor quality of life in postmenopausal women. The researchers measured the biological age of cells from blood, saliva and inside the cheek, from all 3,100 women to explore the relationship between each woman’s chronological age and her body’s biological age.
“We discovered that menopause speeds up cellular aging by an average of 6 percent,” said Horvath, who is also a professor in the UCLA Fielding School of Public Health. “That doesn’t sound like much but it adds up over a woman’s lifespan.”