Depression, Insomnia and Your Heart

Resistant hypertension and poor sleep associated

(RxWiki News) Management of high blood pressure is usually accomplished with medication and salt restriction. But treating depression or insomnia might help with the management of more difficult cases.

A recent unpublished study presented at a heart conference found that poor sleep quality and persistent high blood pressure are linked.

The link is especially evident among those who are depressed.

"Talk to your doctor if you can't get good sleep."

The study, presented by Dr. Rosa Maria Bruno from the University of Pisa in Italy, involved 234 individuals who were outpatients for high blood pressure.

The researchers assessed the patients' sleep quality, levels of anxiety or depression and cardiovascular risk factors and compared this data among those who did or didn't have resistant hypertension.

The patients were considered to have "resistant hypertension" if their blood pressure remained over 140/90 mmHg even if they were taking three or more drugs for hypertension. A total of 15 percent of the study participants had resistant hypertension.

The sleep quality and anxiety/depression were measured with two standard questionnaire assessments.

The study group included half women and half men, and patients who had sleep apnea were not included in the analysis.

The average amount of sleep among the patients was 6.4 hours, and 49 percent of them got less than 6 hours of sleep regularly. However, the study focused on the quality of that sleep.

Overall, the women experienced poorer sleep quality and had worse scores on the sleep index used in the study compared to the men.

Women also had more than twice as many symptoms of depression and scored more than twice as high on the depression assessment scale.

The patients with resistant hypertension had poorer sleep quality scores than those without it, but the difference was much more dramatic in women and only slightly different in men.

Similarly, women with resistant hypertension were far more likely to be depressed than women without resistant hypertension, but there was no difference in depression scores among the men with or without resistant hypertension.

"In women, we found that poor sleep quality was associated with a fivefold increase in the probability of having resistant hypertension, even after adjustment," said Dr. Bruno.

Still, when the researchers took into account the participants' age, gender, obesity, diabetes status, past cardiovascular health conditions or events, number of hours of sleep and use of hypnotic drugs, they still found that resistant hypertension was linked to poor sleep quality.

Sleep can be measured based on its quantity — how many hours of sleep a person gets — or its quality. In this study, it was the quality of sleep — how well the patients slept — that appeared to have the most significant link to high blood pressure.

When the researchers took into account the patients' levels of depression, however, the link between poor sleep quality and resistant hypertension vanished.

Because the study only established an association between poor sleep and high blood pressure, the researchers cannot determine from the results whether one caused the other or not.

"This needs to be confirmed in a prospective study," said Dr. Bruno. "It could also be that the hypertension is causing the insomnia, but we believe that the insomnia is making the hypertension worse."

William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill, Florida, said the study is still valuable in pointing out the association with not getting good sleep.

"This study provides additional information showing the association between poor quality of sleep or insufficient sleep and medical consequences, in this case hypertension," Dr. Kohler said.

As the study points out, however, there is only an association established here, not a cause-effect relationship, he said.

"A prospective study needs to be performed to show a more causal relationship," he said. A prospective study is a different design where the researchers can control the variables to determine whether one thing causes another.

The study was presented on September 21 at the American Heart Association High Blood Pressure Research 2012 Scientific Sessions. The study was funded by the University of Pisa. The authors reported no conflicts of interest.

Because the study has not yet been published in a peer-reviewed journal, its results should be regarded as preliminary and still require review by researchers in the field. No information was available regarding funding or disclosures.

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Review Date: 
September 24, 2012