Nearly half of people hospitalized with bipolar disorder also have high blood pressure (hypertension), according to a study presented in May at the 2010 American Psychiatric Association annual meeting.

A number of studies have linked bipolar disorder with conditions that affect heart health, including cardiovascular disease and diabetes. What hasn’t been well explored, however, is whether hypertension is more common in people with bipolar disorder.

To examine the potential link, Dale D’Mello, MD, from the Michigan State University Department of Psychiatry in East Lansing, and his colleagues conducted mood assessments and took mental health histories and blood pressure readings from 99 people who were hospitalized for bipolar disorder between 2002 and 2006.

D’Mello’s team found that 45 of the study participants had hypertension when they were hospitalized. What’s more, those with hypertension had more severe manic symptoms, and an earlier onset of the disorder, than the participants who did not have hypertension.

“There is a large clinical relevance to the finding hypertension could be linked to the severity of bipolar disorders,” D’Mello said. “There is some similarity to the pathology of the two conditions; they both can be triggered by stress and are tied to the excretion of norepinephrine, a hormone affecting how the brain reacts to stress.”

While it is not clear what the underlying causes of hypertension in people with bipolar disorder might be, pinpointing the link could benefit the treatment for both disorders.

“These findings show that we should look to treat hypertension more aggressively in bipolar patients,” D’Mello concluded. “There also is some evidence hypertension may lead to brain lesions; diagnosing high blood pressure and treating it earlier may change the medical outcomes for people battling bipolar disorders.”