WEDNESDAY, March 7 (HealthDay News) -- An experimental drug called pasireotide reduced levels of the "stress hormone" cortisol and improved symptoms in patients with Cushing's disease, a new study found.

Cushing's disease is a rare (three to five cases per million people) hormonal disorder that causes a wide range of health problems and, if untreated, significantly increases a patient's risk of dying at a much younger age than normal, researchers said in a news release.

Weight gain, high blood pressure, mood swings, irregular or absent menstrual periods, insulin resistance, glucose intolerance and type 2 diabetes are among the symptoms of Cushing's disease. It is a form of Cushing's syndrome, which is caused by prolonged exposure of the body's tissues to high levels of the hormone cortisol.

This phase 3 study of 162 patients in 18 countries found that treatment with pasireotide reduced cortisol secretion by an average of 50 percent and returned some patient's cortisol levels to normal.

A phase 3 study means that a drug is in the final stages of testing that drugs undergo before they can be approved for treatment of a specific disease.

The study, funded by Novartis Pharma, appears in the March 8 issue of the New England Journal of Medicine.

Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City, is not associated with the study but is familiar with its findings.

Mezitis said the study showed that the experimental treatment "improved metabolic abnormalities and emotional difficulties. Therefore, pasireotide injections become an alternative to surgical resection of the pituitary ACTH-secreting tumor, and may be shown to work with the FDA-approved mifepristone, which blocks the action of cortisol at receptors in the body."

Elevated blood sugar (glucose) levels occurred in 73 percent of the patients who took the drug, a side effect that requires close attention, according to senior study author Dr. Beverly Biller, of Massachusetts General Hospital.

Cushing's patients already have difficulty processing glucose, she noted.

"Those patients who already were diabetic had the greatest increases in blood sugar, and those who were prediabetic were more likely to become diabetic than those who began with normal blood sugar," Biller said in the hospital news release. "So this is real and needs to be monitored carefully."

Mezitis agreed that careful patient monitoring is important. "Blood-sugar elevations are dose-dependent with pasireotide and will need to be managed as indicated for diabetes," he said.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about Cushing's syndrome.