June 6, 2013
Poor Sleep More Harmful For Female Heart Patients
redOrbit Staff & Wire Reports - Your Universe Online
Women with coronary heart disease could be at risk for elevated levels of inflammation if they aren´t getting enough sleep, according to new research published online Wednesday in the Journal of Psychiatric Research.
The study was conducted by investigators at the University of California, San Francisco (UCSF) and found that poor sleep patterns — in particular, waking up too early — appears to play “a significant role” in raising inflammation levels among female coronary heart disease patients.
However, the phenomenon was observed only in women, not in male patients. The authors report that their research points to the existence of potentially important gender differences in heart patients, and that their findings suggest that inflammation could “serve as a key biological pathway through which poor sleep contributes to the progression of heart disease in women.”
“Inflammation is a well-known predictor of cardiovascular health,” said lead author assistant professor of psychiatry at UCSF Dr. Aric Prather. “Now we have evidence that poor sleep appears to play a bigger role than we had previously thought in driving long-term increases in inflammation levels and may contribute to the negative consequences often associated with poor sleep.”
Previous research has illustrated that sleeping fewer than six hours each night is a risk factor for coronary heart disease and other chronic medical conditions, and has also linked a lack of sleep with elevation in biomarkers of inflammation. The UCSF researchers set out to examine the link between self-reported sleep quality and changes in inflammation levels in older patients with stable coronary heart disease over a five-year span.
Prather and his colleagues started their work in 2000, and recruited nearly 700 participants — all of whom had coronary heart disease. Subjects were recruited from the university, the Veterans Affairs Medical Centers in San Francisco and Palo Alto, and nine public health clinics in the Community Health Network of San Francisco.
The average age of male patients was 66, while the average age of female patients was 64. Furthermore, the women tended to have a higher systolic blood pressure, were more likely to be using antidepressants, and were less likely to be using statins, beta-blockers, or other drugs that treat blood pressure or other heart-related conditions.
“Participants were asked when they first enrolled and five years later: ℠During the past month, how would you rate your overall sleep quality?´ Their choices were ℠very good,´ ℠fairly good,´ ℠good,´ ℠fairly bad,´ or ℠very bad.´ Biomarkers assessed in the study were Interleukin-6, C-reactive protein, and Fibrinogen,” the researchers said.
“The researchers found that poor sleep quality was significantly associated with five-year increases in the biomarkers in women but not men: Women who reported very poor or fairly poor sleep quality showed a percent increase in markers 2.5 times that of men who said they slept poorly,” they added. “The association remained statistically significant after adjustment for characteristics such as lifestyle, medication use and cardiac function.”
Many of the women who took part in the study were post-menopausal, leading the researchers to surmise that reduced estrogen levels could be a factor in the inflammatory activity associated with poor sleep. They added that it could be possible that testosterone could have helped ward off the effects of poor sleep quality in men.
“The researchers note that men comprised the majority of the study subjects, but point out that their findings may actually underestimate the real effects given the limited sample size,” UCSF explained. “They say that further investigation is needed to explain the gender-specific associations between poor sleep quality and markers of inflammation which could help clarify gender disparities in coronary heart disease.”