The relation of autonomic function to physical fitness in patients suffering from alcohol dependence

Pupillary response to percutaneous auricular vagus nerve stimulation in alcohol withdrawal syndrome: A pilot trial

BACKGROUND

Autonomic symptoms in alcohol withdrawal syndrome (AWS) are associated with a sympathetic-driven imbalance of the autonomic nervous system. To restore autonomic balance in AWS, novel neuromodulatory approaches could be beneficial. We conducted a pilot trial with percutaneous auricular vagus nerve stimulation (pVNS) in AWS and hypothesized that pVNS will enhance the parasympathetic tone represented by a reduction of pupillary dilation in a parasympatholytic pharmacological challenge.

METHODS

Thirty patients suffering from alcohol use disorder, undergoing AWS, and stable on medication, were recruited in this open-label, single-arm pilot trial with repeated-measure design. Peripheral VNS (monophasic volt impulses of 1 msec, alternating polarity, frequency 1 Hz, amplitude 4 mV) was administered at the left cymba conchae for 72 h, followed by pupillometry under a tropicamide challenge. We assessed craving with a visual analog scale. We used pupillary mean as the dependent variable in a repeated-measures ANOVA (rmANOVA).

RESULTS

A repeated-measures ANOVA resulted in a significant difference for pupillary diameter across time and condition (F(2,116) = 27.97, p < .001, ηp2 > .14). Tukey-adjusted post hoc analysis revealed a significant reduction of pupillary diameter after pVNS. Alcohol craving was significantly reduced after pVNS (p < .05, Cohen's d = 1.27).

CONCLUSION

Our study suggests that pVNS activates the parasympathetic nervous system in patients with acute AWS, and that this activation is measurable by pupillometry. To this end, pVNS could be beneficial as a supportive therapy for AWS. Potential confounding effects of anti-craving treatment should be kept in mind.

Cardiorespiratory Fitness Predicts Higher Inhibitory Control in Patients With Substance Use Disorder

Impaired inhibitory control has been shown in individuals with substance use disorder (SUD). Cardiorespiratory fitness has been described as a potential factor to improve inhibitory control; however, the benefits in individuals with SUD are unclear. The aim of this study was to investigate the relationship between cardiorespiratory fitness with general and drug-specific inhibitory control in individuals with SUD. Sixty-two male participants under treatment for SUD performed a general and drug-specific inhibitory control test (go/no-go) and a cardiorespiratory fitness test. Cardiorespiratory fitness, age, and years of drug use were inversely associated with reaction time for both general and drug-specific inhibitory control. In addition, the regression models showed that cardiorespiratory fitness predicts general and drug-specific inhibitory control adjusted for age and time of drug use. However, cardiorespiratory fitness predicts equally both general and drug-specific inhibitory control. These findings suggest that increasing cardiorespiratory fitness could provide benefits in the inhibitory function of individuals with SUD.

Effect of chronic alcohol intake on motor functions on the elderly

Alcohol use disorder (AUD) is a chronic and progressive disease influenced by genetic, psychosocial, and environmental factors. The consequences of alcohol consumption involve alterations in neural circuits of emotion and cognition, as well as in the motor planning circuit. Furthermore, during the natural aging process, several biochemical and functional alterations are also observed with neurological consequences. Thus, considering the consequences of chronic alcohol consumption on neural systems and natural aging process, we aimed to analyze the degree of motor and functional impairment in elderly with chronic alcohol consumption. Sixty elderly underwent an analysis of alcohol consumption profile (Alcohol Use Disorders Identification Test - AUDIT) that divided them into a control group (CON) and an alcohol group (ALC). The analysis of quality of life was performed using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), the analysis of motor function was performed using the Borg Scale, the Six-Minute Walk Test (6MWT) and the Motor Scale for Elderly (MSE). We were able to conclude that the misuse of alcohol by the elderly promotes significant physical limitations. These limitations result in a worsening of functional capacity of walking and various dimensions of motor ability: fine motor skill, global coordination, balance, body scheme, spatial organization, temporal organization, and general motor aptitude. Besides the physical limitations caused by alcohol use, the quality of life in their physical, mental, and social aspects was reduced. Thus, actions are required to help the elderly understand these losses and exercise control over alcohol misuse.

Heart rate variability as a potential biomarker for alcohol use disorders: A systematic review and meta-analysis

BACKGROUND

Alcohol use disorders (AUDs) have been found to be associated with elevated cardiovascular risk. The autonomic nervous system is considered to play a role in this association. Heart rate variability (HRV) has been employed to measure parasympathetic activity in AUDs patients in some studies; however, the results are not consistent, and the adopted HRV indices vary across studies. A meta-analysis should be helpful for clarifying this topic.

METHODS

We gathered studies about measuring HRV in AUDs patients and healthy participants from databases. HRV was analyzed in several ways: parasympathetic function in hierarchical order (main analysis), total variability, and specific parasympathetic indices. Specific parasympathetic indices were further separated into high-frequency power (HF) and root mean square of the successive differences (RMSSD). For comparing the above values in patients with AUDs and in healthy individuals, we adopted the random effects model to calculate the standardized mean difference.

RESULTS

Of the 144 screened studies, 15 were included in the quantitative analysis. In the comparison of parasympathetic function in hierarchical order, HRV in AUDs patients was significantly lower than in healthy individuals (Hedges'g = -0.4301, 95% CI [-0.7601 to -0.1000], p=0.0106, I² = 83.8%). Regarding total variability and RMSSD, AUDs patients also had significantly lower values than healthy controls. However, the differences of specific parasympathetic indices and HF were not significantly different.

CONCLUSION

Our results support the view that AUDs patients have reduced parasympathetic activity. Total variability and RMSSD are suitable indices for presenting reduced HRV in patients with AUDs.

Alcohol-induced autonomic dysfunction: a systematic review

Purpose

Autonomic dysfunction is a known consequence of chronic and excessive alcohol consumption. The aim of this systematic review was to characterise this phenomenon, describe the frequency at which it occurs and to explore the best management strategies.

Methods

A systematic, computer-based search was conducted using the PubMed database. All studies identified by the search were evaluated independently by at least three authors. For inclusion, studies had to report human subjects consuming ethanol in excess. Case reports and non-original studies were excluded from this review.

Results

A total of 55 studies were included in this review. According to cardiovascular reflex tests, 16–73% of chronic alcohol abusers suffer from autonomic dysfunction. The most commonly occurring symptom is erectile dysfunction, whilst other features such as postural dizziness are rare. The most important risk factor for this condition is total lifetime dose of ethanol, although there is mixed evidence supporting the role of other risk factors. The only management strategy currently explored in the literature is abstinence, which appears to lead to significant improvement in autonomic investigations.

Conclusion

Current literature includes studies of highly heterogeneous populations, consuming differing volumes of alcohol over variable periods of time and utilising a number of different autonomic test batteries and criteria to diagnose autonomic dysfunction. Therefore, further research using homogeneous methods for measuring autonomic dysfunction in the field is needed. Despite this limitation, our review demonstrated that autonomic dysfunction is very common among alcohol abusers.

Physical exercise in the treatment of alcohol use disorder (AUD) patients affects their drinking habits: A randomized controlled trial

AIM

The aim of this study is to compare the effect of exercise training on physical capacity and alcohol consumption in alcohol use disorder (AUD) patients.

METHODS

One hundred and five AUD patients were randomly assigned to treatment as usual combined with running and brisk walking for 30-45 min twice a week, either in small supervised groups (GR) or individually (IND), or to a control group with no running (C). Assessments were made after 6 and 12 months of training.

RESULTS

Training volume was estimated as 36 min per training bout at an intensity of 78% of HR_max with no differences between GR and IND ( p>.05). A highly significant reduction in training frequency was seen in both training groups after the first month ( p<.0001). Only IND increased VO_2max, by 5.7% ( p<.05), while no differences were seen between GR, IND and C. Alcohol intake decreased from 219 to 41 units per 30 days as the average for the entire sample with no significant difference of drinking outcomes between groups ( p<.0001).

CONCLUSIONS

We saw an effect on drinking habits after running in both groups. However, no additional effect was seen when compared with the control group. A drop in the training frequency during the intervention might have resulted in an insignificant training stimulus.

Physical activity as treatment for alcohol use disorders (FitForChange): study protocol for a randomized controlled trial

BACKGROUND

Help-seeking for alcohol use disorders (AUDs) is low and traditional treatments are often perceived as stigmatizing. Physical activity has positive effects on mental and physical health which could benefit this population. We propose to compare the effects of aerobic training, yoga, and usual care for AUDs in physically inactive Swedish adults.

METHODS

This is a three-group, parallel, single-blind, randomized controlled trial (RCT). In total, 210 adults (aged 18-75 years) diagnosed with an AUD will be invited to participate in a 12-week intervention. The primary study outcome is alcohol consumption measure by the Timeline Follow-back method and the Alcohol Use Disorders Identification Test (AUDIT). Secondary outcomes include: depression, anxiety, perceived stress, sleep quality, physical activity levels, fitness, self-efficacy, health-related quality of life, and cognition. Blood samples will be taken to objectively assess heavy drinking, and saliva to measure cortisol. Acute effects of exercise on the urge to drink alcohol, mood, and anxiety will also be assessed.

DISCUSSION

The treatment potential for exercise in AUDs is substantial as many individuals with the disorder are physically inactive and have comorbid health problems. The study is the first to assess the effects of physical activity as a stand-alone treatment for AUDs. Considerable attention will be given to optimizing exercise adherence. Both the feasibility and treatment effects of exercise interventions in AUDs will be discussed. The Ethical Review Board (EPN) at Karolinska Institutet has approved the study (DNR: 2017/1380-3).

TRIAL REGISTRATION

German Clinical Trials Register, ID: DRKS00012311. Registered on 26 September 2017.

The prevalence of diabetes mellitus type 2 in people with alcohol use disorders: a systematic review and large scale meta-analysis

Type 2 Diabetes Mellitus (T2DM) is highly predictive of cardiovascular diseases and is associated with worse quality of life and increased healthcare utilisation. The current meta-analysis aimed to (i) describe the pooled prevalence of T2DM in people with alcohol use disorders (AUDs), (ii) investigate the impact of demographic, clinical and treatment factors, and (iii) compare T2DM prevalences in AUDs versus the general population. The trim and fill adjusted pooled T2DM prevalence among 3998 people with AUDs (age range 34.8-51.1 years; 76.6% male) (N studies=7) was 12.4% (95%CI=11.8-13.9%). Higher T2DM prevalences were observed in studies with a higher mean age and a higher percentage of male participants, and in studies with self- or physician reported T2DM assessment. A trend for higher T2DM prevalences was found in inpatient settings, in studies assessing T2DM with the gold-standard oral glucose tolerance test compared with fasting glucose only, and with studies including patients with a higher percentage of physical co-morbidity. Although healthy control data are lacking, the pooled prevalence is similar to that observed in people with severe mental illness who are considered a high-risk group. Routine screening and multidisciplinary management of T2DM in people with AUDs is needed.

Sitting time, physical fitness impairments and metabolic abnormalities in people with bipolar disorder: An exploratory study

A sedentary lifestyle is an independent risk factor for cardiovascular disease and mortality. Little is known however about sedentary behavior in people with bipolar disorder (BD). The primary aim of this study was to explore associations between sitting time (as a proxy for a sedentary lifestyle) and physical fitness and metabolic parameters in BD. A secondary aim was to investigate associations between psychiatric symptoms, psychotropic medication use and sitting time. Thirty-nine (21♀) participants (43.7±12.4 years) completed a full metabolic screening, the sitting time item of the International Physical Activity Questionnaire, the Quick Inventory of Depressive Symptomatology self-report and the Hypomania Checklist-32. Additionally participants performed the Eurofit-test battery and 6-min walk test. The mean time spent sitting per day for the entire sample was 7.0±3.0h. A higher body mass index, worse physical fitness and higher antipsychotic medication dose were identified as independent predictors of higher levels of sitting behavior. The model explained 76.5% of the variability in the sitting time. Given that a sedentary lifestyle is an independent predictor of cardiovascular disease, future interventions specifically targeting time spend sitting are warranted in BD, with a particular emphasis on those with high body mass index and low fitness levels.

The Prevalence of Metabolic Syndrome in Alcohol Use Disorders: A Systematic Review and Meta-analysis

AIMS

People with alcohol use disorders (AUDs) have a double increased risk for cardiovascular diseases (CVD) and associated premature mortality. Metabolic syndrome (MetS) and its components are highly predictive of CVD. The primary aim of this meta-analysis was to describe pooled rates of MetS and its components in people with AUDs taking into account variations in demographic and clinical variables.

METHODS

Medline, Embase and CINAHL were searched until 03/2016 for cross-sectional and baseline data of longitudinal studies in adults with AUDs. Two independent reviewers extracted data. Random effects meta-analysis with a relative risk, subgroups and meta-regression analyses were employed.

RESULTS

The pooled MetS prevalence after adjusting for publication bias was 21.8% (95% CI = 19.1%-24.8%; N studies = 5; n participants = 865; age range = 34.8-51.1 years). Abdominal obesity was observed in 38.3% (N = 4, n = 389; 95%CI = 30.2%-47.0%), hyperglycemia in 14.3% (N = 4, n = 389; 95% CI = 3.7%-42.3%), hypertriglyceridemia in 43.9% (N = 4, n = 389; 95% CI = 31.7%-56.8%), low high-density lipoprotein cholesterol in 7.6% (N = 4, n = 389; 95% CI = 4.3%-13.2%) and hypertension in 46.5% (95% CI = 21.7%-73.1%). The MetS prevalence was similar across settings. A separate meta-regression analysis revealed that a higher MetS frequency was moderated by a higher percentage of psychiatric co-morbidity (coefficient = 3.651; standard error = 1.10, 95% CI = 1.50 to 5.80, z = 3.3, P < 0.001), CONCLUSIONS: Routine screening and multidisciplinary management of metabolic abnormalities in people with AUD is needed. Special attention should be given to people with AUDs with psychiatric co-morbidities. Future research should focus on how cardio-metabolic outcomes are moderated by clinical characteristics.

SHORT SUMMARY

The metabolic syndrome (MetS) and its components are highly predictive of cardiovascular diseases. Our meta-analysis demonstrates that more than 1 in 5 persons with alcohol use disorder (AUDs) has the MetS. Routine screening and multidisciplinary management of metabolic abnormalities should be an integral part of the multidisciplinary treatment of AUDs.

Autonomic nervous system dysfunction in psychiatric disorders and the impact of psychotropic medications: a systematic review and meta-analysis

BACKGROUND

Autonomic nervous system (ANS) dysfunction is a putative underlying mechanism for increased cardiovascular disease risk in individuals with psychiatric disorders. Previous studies suggest that this risk may be related to psychotropic medication use. In the present study we systematically reviewed and analyzed published studies of heart rate variability (HRV), measuring ANS output, to determine the effect of psychiatric illness and medication use.

METHODS

We searched for studies comparing HRV in physically healthy adults with a diagnosed psychiatric disorder to controls and comparing HRV pre- and post-treatment with a psychotropic medication.

RESULTS

In total, 140 case-control (mood, anxiety, psychosis, dependent disorders, k = 151) and 30 treatment (antidepressants, antipsychotics; k = 43) studies were included. We found that HRV was reduced in all patient groups compared to controls (Hedges g = -0.583) with a large effect for psychotic disorders (Hedges g = -0.948). Effect sizes remained highly significant for medication-free patients compared to controls across all disorders. Smaller and significant reductions in HRV were observed for specific antidepressants and antipsychotics.

LIMITATIONS

Study quality significantly moderated effect sizes in case-control analyses, underscoring the importance of assessing methodological quality when interpreting HRV findings.

CONCLUSION

Combined findings confirm substantial reductions in HRV across psychiatric disorders, and these effects remained significant even in medication-free individuals. Reductions in HRV may therefore represent a significant mechanism contributing to elevated cardiovascular risk in individuals with psychiatric disorders. The negative impact of specific medications on HRV suggest increased risk for cardiovascular disease in these groups, highlighting a need for treatment providers to consider modifiable cardiovascular risk factors to attenuate this risk.

Diverse autonomic regulation of pupillary function and the cardiovascular system during alcohol withdrawal

BACKGROUND

Previous research indicated the complexity of autonomic dysfunction during acute alcohol withdrawal. This study aimed to investigate the pupillary light reflex as an indicator of midbrain and brainstem regulatory systems in relation to cardiovascular autonomic function.

METHODS

Thirty male patients were included in the study. They were investigated during acute alcohol withdrawal syndrome and 24h later during clomethiazole treatment and compared to healthy controls. Parameters of pupillary light reflex of both eyes as well as heart rate variability, blood pressure variability and baroreflex sensitivity (BRS) were studied.

RESULTS

We observed significantly reduced sympathetic (small diameter, e.g., left eye: 5.00 in patients vs. 5.91 mm in controls) and vagal modulation (e.g., prolonged latencies, left eye: 0.28 vs. 0.26 ms) regarding both pupils during acute alcohol withdrawal syndrome. Cardiovascular parameters showed reduced vagal modulation (e.g., b-slope of BRS: 7. 57 vs. 13.59 ms/mm Hg) and mixed results for sympathetic influence. After 24h, autonomic dysfunction improved significantly, both for the pupils (e.g., left diameter: 5.38 mm) and the heart (e.g., b-slope of BRS: 9.34 ms/mm Hg). While parameters obtained from the pupil correlated with cardiac autonomic function (e.g, BRS and left diameter: r=0.564) in healthy controls, no such pattern was observed in patients.

CONCLUSION

Results obtained from the pupil during acute alcohol withdrawal do not simply mirror autonomic dysfunction regarding the heart. Pupillary and cardiovascular changes after 24h indicate state dependencies of the results. The findings are discussed with respect to autonomic mechanisms and potentially involved brain regions.

Health-related quality of life and aerobic fitness in people with schizophrenia

The purpose of this cross-sectional study was to investigate whether aerobic fitness contributes to the health-related quality of life (HRQoL) in people with schizophrenia, while adjusting for other previously-established contributory factors. Thirty-four male (34.1 ± 12.0 years) and 13 female (34.3 ± 9.2 years) participants performed a submaximal Astrand-Rhyming cycle ergometer test and completed the 36-item Short-Form Health Survey, the International Physical Activity Questionnaire, and the Psychosis Evaluation tool for Common Use by Caregivers. After controlling for age and sex, illness duration (12.4 ± 11.2 years, r(2) = 0.38, P < 0.001), fewer positive (9.3 ± 4.3, r(2) = 0.30, P = 0.006) and cognitive (8.4 ± 3.8, r(2) = 0.28, P = 0.011) symptoms, and higher aerobic fitness (34.5 ± 8.7 ml O2  min(-1) kg(-1), r(2) = 0.36, P = 0.001) were found to be independent significant predictors of physical HRQoL (mean score 66.6 ± 18.5). However, when all variables were included in the same regression model, only illness duration (P = 0.004) and positive symptoms (P = 0.045) remained significant predictors, while there was a trend (P < 0.10) for age and aerobic fitness. The final model explained 54% of the variability in physical HRQoL. No significant correlates for mental HRQoL (54.9 ± 18.5) were found. People with schizophrenia might improve their physical HRQoL by improving their aerobic fitness. Mental health nurses should assist in facilitating improvements in aerobic fitness through facilitating physical activity participation in patients with schizophrenia.

The functional exercise capacity in patients with bipolar disorder versus healthy controls: A pilot study

The aim of the current study was to compare the functional exercise capacity of patients with bipolar disorder with age-, gender- and body mass index (BMI)-matched healthy controls. Thirty patients (16 ♂, 40.8±11.6 years) and healthy controls (16 ♂, 40.5±10.8 years) were included. All participants performed a 6-min walk test to assess the functional exercise capacity and completed the International Physical Activity Questionnaire. Patients were screened for psychiatric symptoms using the Quick Inventory of Depressive Symptomatology and Hypomania Checklist-32. Results demonstrated that patients with bipolar disorder demonstrated a significantly poorer functional exercise capacity (590.8±112.6 versus 704.2±94.3m). A backward stepwise regression analyses showed that the level of depression and existing foot or ankle static problems and back pain before the test explained 70.9% of the variance in the distance achieved on the 6-min walk test (functional exercise capacity). The current study demonstrates that foot and back pain appear to be important negative predictors of functional exercise capacity in patients with bipolar disorder. Physical activity interventions delivered by physical therapists may help ameliorate pain symptoms and improve functional exercise capacity.

A systematic review of physical activity correlates in alcohol use disorders

BACKGROUND

Physical activity might promote mental and physical health in persons with alcohol use disorder. Understanding the barriers and facilitators of participation in physical activity in persons with alcohol use disorder is an essential first step in order to devise effective physical activity interventions.

OBJECTIVE

The present review provides a systematic quantitative review of the correlates of physical activity in people with alcohol use disorder.

METHODS

Major electronic databases were searched by two independent authors from inception until June 2014. Keywords included 'physical activity' or 'exercise' and 'alcohol dependence' or 'alcohol abuse' or 'alcohol use disorders' or 'alcoholism'.

RESULTS

Five papers evaluating 14 correlates were included. Three studies reported that alcohol dependence was unrelated to physical activity behavior, while alcohol abuse showed positive associations in 2 studies. No demographic variable was related with physical activity participation. Functional impairments and distress associated with alcohol use disorders including increased smoking rates, obesity, anxiety, depression and a lower self-efficacy may limit one's ability to be physically active. Data on social, environmental and policy related factors are currently lacking. No included study assessed physical activity levels utilizing objective measurements (e.g. pedometers, accelerometers).

CONCLUSION

Although the literature on physical activity correlates in persons with alcohol use disorder still is equivocal, our varied findings support the hypothesis that the participation in physical activity by people with alcohol use disorder is determined by a range of complex factors.

Cardiac autonomic function during sleep: effects of alcohol dependence and evidence of partial recovery with abstinence

Chronic alcoholism is associated with the development of cardiac and peripheral autonomic nervous system (ANS) pathology. The aim of the present study was to evaluate the extent to which recovery in ANS function could be demonstrated over the first 4 months of abstinence. Fifteen alcoholics (7 women) were studied on three occasions: within a month of detoxification, at approximately 2 months post-detox, and at 4 months post-detox. Thirteen control subjects (6 women) were also studied on three occasions with inter-study intervals matching those of the alcoholics. Six alcoholics relapsed, 48.7 ± 27.9 days following the initial PSG session. ANS function was assessed in the first part of stable non-rapid eye movement sleep. Frequency-domain power spectral analysis of heart rate variability (HRV) produced variables including: heart rate (HR), total power (TP; an index representing total HR variability), High Frequency power (HFa; an index reflecting cardiac vagal modulation), HF proportion of total power (HFprop sympathovagal balance), and HF peak frequency (HFpf; an index reflecting respiration rate). Overall, high total and high frequency variability and low sympathovagal balance and myocardial contractility are considered as desired conditions to promote cardiovascular health. At initial assessment, alcoholics had a higher HR (p < 0.001) and respiratory rate (p < 0.01), and lower vagal activity (HFa; p < 0.01) than controls. Alcoholics showed evidence of recovery in HR (p = 0.039) and HFa (p = 0.031) with 4 months of abstinence. Alcoholics with higher TP at the initial visit showed a greater improvement in TP from the initial to the 4 month follow-up session (r = 0.75, p < 0.05). Alcoholics showed substantial recovery in HR and vagal modulation of HRV with 4 months of abstinence, with evidence that the extent of recovery in HRV may be partially determined by the extent of alcohol dependence-related insult to the cardiac ANS system. These data support other studies showing recovery in a number of ANS, central nervous system, and behavioral domains with abstinence, even in those with long-term dependence.

Health-related physical fitness in patients with bipolar disorder vs. healthy controls: an exploratory study

BACKGROUND

Low physical fitness has been recognized as a prominent behavioral risk factor for cardiovascular diseases and an independent risk factor for all-cause mortality. To date, no studies have systematically assessed physical fitness in patients with bipolar disorder. The aim of the current study was to assess and compare the physical fitness in patients with bipolar disorder against healthy controls.

METHODS

Thirty patients with bipolar disorder (16♂, 40.8±11.6 years) and 30 age-, gender- and body mass index (BMI)-matched healthy controls were included. All participants performed the Eurofit test battery and the International Physical Activity Questionnaire. Patients were screened for psychiatric symptoms using the Quick Inventory of Depressive Symptomatology and Hypomania Checklist-32.

RESULTS

Patients with bipolar disorder had a reduced speed of limb movement (15.8±5.7 vs. 11.8±2.2s; p<0.001), explosive leg muscle strength (134.9±49.0 vs. 167.6±32.3cm; p=0.003) and abdominal muscular endurance (11.5±7.8 vs. 18.3±7.6; p<0.001). Backward regression analyses demonstrated that longer illness duration, higher body mass index, higher levels of depression and a lower physical activity level explained the variance in physical fitness.

LIMITATIONS

Our data are cross-sectional and cannot establish cause and effect.

CONCLUSIONS

The current findings suggest that a lower physical fitness is emerging as an eminent modifiable risk factor for somatic co-morbidity in people with bipolar disorder. In particular less physically active persons, those with a longer illness duration and those with higher levels of depression might benefit from specific rehabilitation interventions aimed at increasing physical fitness.