During the early stages of recovery, alcoholics have abnormalities in a key hormonal system that regulates responses to psychological and physical stress, but the system returns to normal after about eight weeks of abstinence, Italian researchers report.

These findings show that "alcoholics should avoid physical and psychological stress during early alcohol withdrawal," Dr. Vittorio Coiro of the University of Parma, the study's lead author, told Reuters Health in an e-mail interview. "In this period, abstinent alcoholics are particularly fragile. They do not have protection against stress because of deficient function of the hypothalamic-pituitary-adrenal axis."

In addition to handling stress, the hypothalamic-pituitary-adrenal (HPA) axis -- the system of interactions between the hypothalamus in the brain, the pituitary gland, and the adrenal glands -- helps regulate mood, the immune system and other functions.

A number of studies have shown changes in the HPA axis in alcoholics, Coiro's team notes in the journal Alcoholism: Clinical and Experimental Research. Specifically, their adrenocorticotropic hormone (ACTH) and cortisol secretion in response to various stresses appears to be reduced.

To determine how stress from physical exercise affects activation of the HPA axis, the researchers had 10 alcoholic men ride an exercise bike to exhaustion at four, six and eight weeks after they stopped drinking. The men had been dependent on alcohol for four to six years. Ten nonalcoholic men who were matched to the subjects for age, served as a comparison group.

While exercise produced a spike in blood levels of ACTH and cortisol among the men in the comparison group, the hormone levels rose only slightly among the alcoholic men after four weeks of abstinence.

However, hormone responses were significantly increased post-exercise after six weeks of abstinence; and after eight weeks of abstinence, hormonal levels returned to normal.

Although recovering alcoholics should avoid stress during their first few weeks of abstinence, they should not avoid physical exercise, Coiro and his colleagues note in their report. "Exercise produces many physical and emotional effects that could benefit the alcohol-dependent subject in early abstinence," they write.

Nevertheless, Coiro added, "careful control of patient's activity during early abstinence should be established in a rehabilitation program," and alcoholics should take precautions to avoid excessive stress.