"The HPA axis provides the metabolic fuel for the reaction of the brain, muscles and heart against psychological and physical distress," said Vittorio Coiro, aggregate professor in internal medicine at the University of Parma, Italy. "In previous research, tests with psychological and physical challenging stimuli - such as operative traumata, hyperthermia, cold-pressor and public-speaking stress - have shown a deficient HPA reactivity in abstinent alcoholics. However, none of these studies has established a time course of HPA failure during abstinence or has shown the time needed for a possible recovery."
"The HPA axis is an exquisitely sensitive system triggered physiologically by a wide range of psychological and physical stressors," remarked Cristiana Di Gennaro, research doctor at the University of Parma. "A rise in plasma ACTH and cortisol are considered good markers of stress, in terms of both acute reaction and of chronic exposure to stressful situations. An impaired function of HPA axis is well known in alcoholics," she added, "and it has been suggested that a blunted HPA axis responsiveness plays a role in early alcohol relapse following detoxification in alcoholics."
Researchers recruited two groups of males: 10 recently abstinent alcoholics 33 to 45 years of age; and 10 age-matched healthy controls. All participants exercised on a bicycle ergometer for approximately 15 minutes to a workload gradually increased at three-minute intervals until exhaustion (considered a highly reproducible and reliable form of stress). The alcoholics were tested at three time points: four, six and eight weeks after alcohol withdrawal. The controls were tested only once.
Results indicate an only slight ACTH/cortisol response to physical exercise among alcoholics after four weeks of abstinence, returning to near-normal levels at eight weeks.
This means, said Coiro, that not only did his group establish a time course of HPA failure during abstinence, but they also found that physical exercise among abstinent alcoholics may not always be a good thing.
"Guidelines for recovery from alcoholism attribute an important role to physical activity and sport," he said. "Exercise is included in many rehabilitation programs, because it produces physical and emotional effects that benefit the alcohol-dependent subjects during early abstinence. However, in the absence of HPA reactivity, exercise until exhaustion may produce stressful deleterious effects, because alcohol-dependent subjects are more vulnerable to relapse during early abstinence."
"Given that the HPA axis remains 'stunned' for at least one month from withdrawal, with a full functional recovery only after two months," said Di Gennaro, "caution is to be recommended for patients in rehabilitation programs that include stressful physical exercise. However, since physical activity has been found to be an important therapeutic tool for early alcohol-withdrawing patients, it should be included in treatment even during the first eight weeks of abstinence, albeit mild at the beginning, with a slight progressive increase of physical activity during the first and the second month of abstinence."
"From a research perspective," said Coiro, these results help us to understand entity and time of the effects of alcohol in the central nervous system as ACTH/cortisol measurements represent a 'window' through which we can evaluate alcohol damage in central nervous transmission. Practically speaking, guidelines for alcohol-rehabilitation programs should take into account these observations for a better programming of physical exercise and therapeutic follow up. Furthermore, readers should be aware of the increased vulnerability of alcohol-dependent subjects, particularly during the first two months of abstinence, when physical and psychological stress should be absolutely avoided."
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Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "ACTH/Cortisol Response to Physical Exercise in Abstinent Alcoholics," were: Amos Casti of the Department of Experimental Medicine; Gloria Saccani Jotti of the Department of Public Health; Pasquale Rubino and Guido Manfredi of the Department of Internal Medicine and Biomedical Sciences; Maria Ludovica Maffei of the Department of Cardiology; and Andrea Melani, Elio Volta and Paolo Chiodera of the Graduate School in Physical Exercise and Sport Sciences; all of the University of Parma in Italy. The study was funded by the Italian University and Research Ministry.
Contact:
Vittorio Coiro, M.D.
University of Parma
Cristiana Di Gennaro, M.D.
University of Parma
Alcoholism: Clinical & Experimental Research
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Spousal Choices Can Influence The Risk Of Developing Alcoholism
* Alcohol dependence (AD) is more common among partners of alcoholics than among partners of non-alcoholics.
* A new study examines two kinds of spousal similarity for influence on AD risk: assortative mating (like marries like), and reciprocal spousal interaction (an individual's behavior directly influences his/her spouse's behavior).
* Assortative mating is reflected in an increased frequency of spousal AD; but spousal interaction seems to protect against spousal AD after accounting for assortative mating.
Alcohol dependence (AD) is more common among partners of alcoholics than among partners of non-alcoholics. A new examination of spousal similarity for alcohol consumption and AD risk reveals that while one type of association, assortative mating, results in an increased frequency of AD in partners, another type, spousal interaction, may diminish AD risk for spouses.
Results are published in the May issue of Alcoholism: Clinical & Experimental Research.
"We know that AD runs in families, and that genetic influences explain about 50 percent of the variation in risk for AD," explained Julia D. Grant, research assistant professor in the department of psychiatry at Washington University School of Medicine. "Not surprisingly, spouses are positively correlated for AD. Our goal was to better understand the processes that may explain this association."
Grant, who is also the study's corresponding author, explained that the commonly used phrase, "like marries like," describes assortative mating, a type of behavioral similarity by which individuals seek partners with whom they share certain characteristics. Another process that she and her colleagues examined is called spousal interaction, in which an individual's drinking behavior has an impact on his or her partner's drinking behavior.
"Phenotypic assortment for alcoholism risk is part of a much larger phenomenon, having deep evolutionary roots," commented Michael Vanyukov, associate professor of pharmaceutical sciences, psychiatry and human genetics at the University of Pittsburgh. "Selecting a phenotypically similar spouse increases the chances that offspring will inherit one's genes related to AD risk inasmuch as the spouse shares them. A closer phenotypic and genetic similarity may translate into higher social cohesion and thus benefit the group, and perhaps the whole species. Similar mechanisms likely work with peer affiliation, such as selection of friends. Unfortunately, as with many other benefits, there is a downside to that, the price paid by our species when these mechanisms extend to those traits considered antisocial."
Researchers used telephone interviews to assess AD-related criteria of 5,974 twin participants in the Australian Twin Register who were born in the years 1902 through to 1964, as well as 3,814 spouses of the twins. Statistical modeling was used to determine the extent to which variability in risk for AD was influenced by genetic factors, the extent of spousal association for AD, and whether any association was attributable to assortative mating, reciprocal spousal interaction, or both.
Results revealed that, when examined separately, both assortative mating and spousal interaction effects were "positive," meaning that those with an AD partner appear to be at increased risk of developing AD themselves. However, when examined simultaneously, only assortative mating remained positive while spousal interaction effects appeared to be protective.
"This means that after controlling for assortative mating," said Grant, "having an AD spouse reduces the likelihood of an individual developing AD. This is consistent with a scenario in which an individual with an AD partner reduces his or her consumption in reaction to the other's excess. The suggestion of a protective spousal interaction effect after accounting for assortative mating highlights the importance of examining both processes simultaneously, as it was missed when we analyzed spousal interactions separately."
Grant and her colleagues also assessed potential gender differences in the direction and magnitude of spousal influence, but found none. "This is quite interesting," noted Grant, "because it suggests that men and women are equally susceptible to the influences of their partner."
Both Grant and Vanyukov noted that assortative mating is likely to result in an increased proportion of offspring who will be exposed to the genetic liability of two alcoholic parents. "The offspring will have a greater chance to inherit such genes than in the case of random or non-assortative mating," said Vanyukov, "and on the population level, this would lead to an increased frequency of genotypes associated with extreme phenotypes, such as those related to an increased risk for alcoholism."
Furthermore, added Grant, clinicians need to be aware that in addition to an increased genetic risk, children with AD parents are more likely to be exposed to a high-risk environment and less likely to experience protective environmental influences.
"Detrimental environmental characteristics associated with AD include reduced educational attainment and income, fewer social and neighborhood support networks, higher rates of divorce and single parenthood, and exposure to other psychiatric disorders," she said. "These environmental factors not only increase the risk of AD for the partner of an AD individual, but also for any children in the household." She added that education is key: incorporating parental monitoring and involvement, providing coping mechanisms for when alcohol is available, educating offspring about specific risks, and discussing guidelines about responsible alcohol consumption.
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Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "Spousal Concordance for Alcohol Dependence: Evidence for Assortative Mating or Spousal Interaction Effects?," were: Andrew C. Heath, Kathleen K. Bucholz, Pamela A.F. Madden, and Arpana Agrawal of Washington University School of Medicine; and Dixie J. Statham and Nicholas G. Martin of Queensland Institute of Medical Research. The study was funded by the National Institute on Alcohol Abuse and Alcoholism.
Contact:
Julia D. Grant, Ph.D.
Washington University School of Medicine
Michael Vanyukov, Ph.D.
University of Pittsburgh
Alcoholism: Clinical & Experimental Research |
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