The effect of exercise as adjunctive treatment on quality of life for individuals with alcohol use disorders: a randomized controlled trial

Alcohol use disorder (AUD) is a preventable and treatable disorder, yet the prevalence of alcohol dependency and hazardous use is high in the Danish population [1]. Moreover, it is estimated that only 10 % of alcohol-dependent individuals receive treatment [2], even though treatment is publicly financed and free at the point of use. Further, treatment of AUD is associated with a range of compliance factors, which means that even when an individual enters the treatment facility, his/her risk of treatment interruption and relapse remains high [3]. Research in the AUD treatment area suggests several interventions to support adherence to treatment and better treatment outcome. Particularly in the later stages of treatment, focusing on reintegration into society and restoration of normal functioning, including the adoption of a healthy lifestyle has been found important [4]. One aspect of a healthy lifestyle is physical activity [5, 6]. Interventions involving physical exercise as an adjunct to treatment for alcohol use disorder are therefore suggested to have promising effects [7‐11].

Previous studies of the use of exercise in AUD treatment have shown positive effects on treatment outcome; both in regard to alcohol-specific outcomes, such as intake, craving and withdrawal symptoms, and in regard to other health-related outcomes, such as mood, cognitive function and quality of life [8, 12]. Quality of life has been shown to be significantly impaired in those with alcohol abuse and dependence [13‐16], particularly in the domains of mental health and social functioning [17]. But although favorable effects of exercise on quality of life were found, the evidence for the efficacy of exercise in alcohol and drug treatment is weak [7]. Methodological limitations, such as too small sample sizes, non-generalizable populations and the lack of intention-to-treat-analyses to correct for the high number of dropouts were some of the factors limiting the strength of the evidence [7]. Preliminary evidence for the role of exercise as an adjunctive tool in the treatment of AUDs and substance use disorders (SUDs) is, however, promising [18, 19].

Recently, two feasibility studies of exercise as an adjunctive treatment for AUD and SUD, respectively, showed significant improvements in both physical activity levels and quality of life for the participants [12, 20]. Regular exercise was also found to be a significant predictor of health-related quality of life (HRQoL) and substance use dependence [21], and exercise, along with other health-related behaviors, was found to be strongly associated with HRQoL among veterans in addictions treatment [22]. Bearing in mind that the evidence is still somewhat limited, exercise appears to be an alternative and effective substance-free activity and a relapse prevention strategy in the treatment of both AUDs and SUDs [23, 24]. Consequently, implementing exercise into the existing treatment of AUDs and SUDs may be a promising strategy for improving the quality of life of participants, which may in turn support the outcome of treatment on other parameters. However, well-designed and carefully performed randomized controlled trials of exercise as an adjunct to treatment of AUD are needed. Furthermore, information on how exercise may affect secondary outcomes of the treatment, such as patients’ quality of life, is not sufficiently covered in the available literature so far.

Several theoretical and practical factors provide further support for exercise-based treatments for AUDs and SUDs, including the psychological, behavioral, and overall positive health effects [18]. The psychological mechanisms of exercise on individuals with SUDs include, for example, the reduction of cravings and withdrawal symptoms, and may thus prevent relapse both acute and long term [25‐27]. An example of the effect of the behavioral mechanisms of exercise for alcohol- or other substance-dependent individuals is that when urges arise, engaging in an alternative behavior such as physical activity instead of drinking or using drugs may help reduce relapse [18]. Furthermore, psychobiological research has demonstrated that both exercise and commonly abused substances activate the same reward areas in the brain [28, 29]. This so far small but growing body of research supports the relevance of using exercise as a treatment for substance use disorder. Theoretically, exercise programs can be lifestyle interventions that provide people with AUDs with skills to undertake a positive health promoting behavior, in addition to simultaneously provide self-control strategies, coping strategies and an alternative to drinking [30, 31]. The concept Runner’s high, which is the feel-good effect of running due to release of endorphins that has been considered as natural painkillers [32], may also have potential to substitute alcohol with exercise [33]. Therefore, randomized controlled trials with appropriate sample sizes, which are also more generalizable to populations with alcohol dependence, are needed to evaluate the effect of exercise-based interventions on alcohol use and related outcomes.

The Healthy Lifestyle Study, conducted in a Danish outpatient alcohol treatment setting, investigated the effect of physical exercise on alcohol use disorder [34‐36]. Data were collected on primary outcomes, in terms of alcohol consumption, amount and frequency, and secondary outcomes, including quality of life, depression, and interpersonal problems were investigated. Regarding the primary outcomes, no direct effect of physical exercise on alcohol consumption was found, probably due to low adherence to the exercise intervention. However, supplementary findings of the study were quite promising. The intervention effect on primary outcome which was consumed amount of alcohol per week showed an OR of 0.99 [95% CI: 0.46; 2.14], p = 0.976 for excessive drinking in the group exercise condition, and 1.02 [95% CI: 0.47; 2.18], p = 0.968 in the individual exercise condition, which, when compared to the control group as reference, did not differ statistically significantly. This may indicate that the AUDs treatment itself is successful regardless of the intervention. However, participants with moderate level general physical activity had lower odds for excessive drinking OR = 0.12 [0.05; 0.31], p < 0.001 than participants with low level general physical activity. Furthermore, the amount of alcohol consumption in the intervention groups decreased by 4% [95% CI: 0.03; 6.8], p = 0.015 for each increased exercising day. This suggests a dose-response effect of exercise on drinking outcome and supports the need for implementing physically active lifestyles for patients in treatment for alcohol use disorder [34].

This paper aims to evaluate the effect of the intervention on quality of life for subjects who participated in the Healthy Lifestyle Study.

In 39 (33.3%) cases, follow-up information was missing. Last observation carried forward (LOCF) was conducted to address the problem of missing data in an intention-to-treat analysis.

Differences between the control and intervention groups on the five quality of life dimensions were investigated using Fisher’s exact test to analyze the distribution of participants in each degree of disability.

Baseline demographic and clinical characteristics of the sample are presented in Table 1. No statistically significant differences in demographic and clinical characteristics between the completers and non-completers of the EQ-5D and EQ-VAS questionnaires were observed, except for the alcohol composite score calculated using the ASI. The non-completers had higher alcohol composite scores on average, which means that they had more severe alcohol problems than the completers.

The intention to treat analyses of intervention effect on quality of life showed no statistically significant difference between intervention groups in EQ-5D at follow-up. Figure 1 illustrates the frequency of participants in each group rating their level of function in each dimension and assessing their degree of disability as “none”, 6 months after treatment start and thereby end of intervention. Here 62% of the participants in the individual exercise condition reported that they had no pain or discomfort compared to 38% of the controls reporting the same (p = 0.078). This indicates a trend towards an exercise intervention effect on pain and discomfort for patients in treatment for AUD.

Self-rated health status, as assessed by the EQ-VAS, did not differ at a statistically significant level between intervention groups at follow-up as analyzed by ANCOVA (Table 2). Neither did the change in mean EQ-VAS from baseline to follow-up across the total sample.

Similarly to the primary outcome analysis [34], the present study found no significant differences in quality of life dimensions between the groups participating in the exercise intervention and the controls. Quality of life for individuals with alcohol use disorders is generally suggested to improve during treatment, as patients may experience better control and fewer problems in everyday life while staying abstinent or drinking sensibly. Moreover, the very fact of measuring and monitoring QoL itself during assessment and treatment may add important value to patient recovery [17]. However, no significant change in the present study was observed. It is also suggested that alcohol-dependent individuals experience improvements in QoL across treatment with both short-term and long-term abstinence, and even in the absence of complete abstinence, a marked reduction in drinking is associated with significant increases in QoL [13].

Results of the present study can therefore not support earlier findings in that that individuals with alcohol use disorders included in this study did not increase their quality of life. Unlike earlier studies, our study had a longer follow-up period, but we found no effect of the intervention on primary outcome at the six months follow-up, which supports the findings of Brown et al. [41]. This means that the potential effect of adding exercise interventions to treatment as usual may dissolve on long term. Probably participants’ motivation and adherence to exercise declines in the months after initiation, maybe due to the lack of social support and individually tailored exercise programs, which we found were important reasons to drop out [42], and this may explain why no intervention effect was observed at six months follow-up.

Furthermore, the dropout rate in our study was 37.1%, which is a little lower than the 40% reported in a recent meta-analysis by Hallgren et al. [8]. However, a slight tendency towards better outcome among participants allocated to individual exercise is seen, especially in the pain dimension. A large body of research on physical exercise for pain management suggests that exercise has a pain-reducing effect [43‐46]. Therefore, although not significant, a substantial portion of the participants in the individual exercise condition reporting that they have no pain or discomfort compared to the controls is interesting, as this finding supports the suggested pain reducing effect of exercise demonstrated in prior research. As suggested by Roessler [47], physical exercise can provide important support in the treatment of drug abuse. In terms of quality of life dimensions, pain is an important dimension which should be further studied for this particular target group.

In addition, it is not surprising that there was no difference between the groups in the mobility and self-care dimensions. This is mainly because the study was conducted in an outpatient treatment center, where patients in general are expected to have a relatively high degree of independency and high level of physical function [48]. If participants were inpatients, the picture would probably be different.

Regarding the effect of exercise on quality of life for the study participants, it is interesting that no significant differences between intervention and control groups were observed at follow-up. This may be due to a relatively high number of participants not exercising as much as expected, as discussed elsewhere in relation to the primary outcomes of the study [34]. It may also partially be explained by a relatively high dropout rate from the study, since one third of the included participants did not return the follow-up questionnaire [43]. Consequently, baseline values of quality of life were used to determine follow-up values for one third of the study sample. This may have affected the analyses and results conservatively, thus explaining why we could not observe any improvement in quality of life.

No improvements in quality of life were observed when adding physical exercise to treatment of alcohol use disorder, but a trend towards reduction in pain and discomfort among participants who exercised individually was observed. Future research will seek to further investigate and advance the quality of life for individuals with alcohol use disorder and make suggestions of how to improve the quality of life for this population group.