PHYSBE – Physical fitness and Brain – Epidemiological and Interventional studies

Effects of exercise on symptoms of anxiety, cognitive ability and sick leave in patients with anxiety disorders in primary care – study protocol for PHYSBE, a randomized controlled trial.

Background

Anxiety disorders are common and associated with reduced quality of life, impaired physical and mental health and an increased economic burden for society. While evidence exists for the effectiveness of exercise treatment for depression, there is a need for high-quality randomized clinical trials (RCT) with a focus on anxiety disorders. Further research is also warranted regarding outcomes of cognitive function, other health-related variables, dose-response effects, work ability and potential mechanisms. 

Method/Design

Using a parallel RCT design with three assessment points (baseline, post-intervention and one-year follow-up), we aim to assess the effect of a 12-week exercise intervention in primary care patients with anxiety disorders (n=180), diagnosed using the Mini International Neuropsychiatric Interview (M.I.N.I; Swedish version 6.0.0d DSM-IV). Participants are randomly assigned to three physical exercise groups: one low-intensity training group, one moderate-to high intensity training group and one control non-exercise group. Assessments include measures of anxiety symptoms, cognitive function, physical health variables such as cardiovascular fitness, sick-leave and levels of hormones/cytokines in blood samples.

Discussion

Findings from this study will provide novel insights regarding the effects of exercise treatment on not only anxiety symptoms but also other outcomes including mental and physical health, cognitive function, dose-response effects, work ability/sick leave and on biomarkers that may help explain underlying mechanisms.

Trial registration

The trial was registered at ClinicalTrial.gov NCT03247270 August 8, 2017.

Chronic cerebral and heart diseases are main contributors to the global burden of illness and to premature death. To a large extent, these conditions are preventable, with risk factors accumulating over the life course. Adolescence is a transitional phase of life of intense physical and psychological development. The brain is not fully developed until 25 years of age and previous studies have shown that the teenage years are a crucial time for the development of higher brain functions. However, because several of these disorders become predominant in later life, most studies on causal factors are conducted in older populations where potentially important influences from early life can usually not be adequately captured.

Analyzing data from a unique and very large population, the Swedish Conscript Register which comprises more than 1.8 million men examined in late adolescence, and linking this to several other nationwide registries including health profiles later in life, primary care data and the Twin Register, we have access to very detailed phenotype data, as well as near-complete outcome data for a range of serious disorders. In our research group we have explored the impact of physical fitness, IQ and mental illness in adolescence on the risk of dementia, stroke, epilepsy, anxiety and depression later in life, in addition to several factors related to early heart failure.

In several ongoing projects we are now investigating the importance of physical and mental ability for the development of neurological (Parkinson’s disease and ALS), psychiatric (suicidal behavior) and heart (cardiomyopathy) diseases later in life. Data in young women will be available through the Swedish Medical Birth Register.

Background

In Sweden, suicide rates for adult men and women have remained constant for the past two decades despite the governments “zero vision” for suicide adopted in 2008. Several international studies have identified associations between suicide risk and certain occupations, such as work in agriculture, construction industry and medicine. However, in a Swedish setting, there is no corresponding recent data and it appears crucial identifying psychosocial workplace exposures in order to develop preventive actions.

Aims

1) To investigate suicidal behavior (attempted and completed suicides) among all Swedish males born in 1950-1983 over time in relation to occupational group and psychosocial workplace exposures. 

2) Using survey data to determine individual-level psychosocial job exposures for suicidal behavior among male construction workers in Sweden. 

 3) To investigate the risk of suicidal behavior in Swedish women in relation to occupation and psychosocial workplace exposures.

Implementation

To address these aims we will utilize:

1) The Swedish Conscript Register which comprises more than 1.6 million men examined in late adolescence during 1968-2001 and followed for suicidal behavior during 2002-2018.

 2) The construction workers (n=370,000 men) that were recruited through healthcare examinations from 1971–1993 and followed regarding suicidal behavior during 1972-2018.

 3) A cohort of 1.6 million women aged 18–45 years in the Swedish Medical Birth Register who gave birth during 1982-2016 followed for suicidal behavior during 2002-2018.

These three cohorts are linked to other nationwide registries including international standard classification of occupations, job-exposure matrices and National Patient and Death Registers. Hence, we have access to very detailed phenotype data, as well as outcome data for suicidal behavior during follow-up.

Impact

These findings could inform occupation- or work context specific interventions to prevent suicide in the working population.

Background: Coronavirus disease 2019 (COVID-19) has spread rapidly worldwide, with serious consequences for the community. There have been a number of reports and cross-sectional studies regarding risk factors for severe COVID-19. However, large prospective cohort studies identifying exposures that are important for understanding the course of the disease are lacking.

Aims: Our overall aim is to investigate prospectively the extent to which early cardiovascular disease, body weight, physical fitness, and muscle strength, as well as occupational exposures and socioeconomics can predict risk of severe COVID-19. In addition, we aim to investigate the interplay between socio-occupational factors and potentially modifiable risk factors.

Implementation:

To address these aims we will utilize:

1) The Swedish Conscript Register which comprises more than 1.5 million men examined in late adolescence during 1968-2005 who were alive on January 1, 2020, with current age in the range of 33–70 years. Information is available on weight, height, blood pressure, muscle strength, cognitive ability and results of fitness tests on a bicycle. For a sub-cohort of 416,735 men, we have linked supplementary data from health profile assessments.

2) A cohort of 4.2 million women who gave birth in Sweden, alive on January 1, 2020, with current age in the range of 18–100 years.

These two cohorts are linked to other nationwide registries including international standard classification of occupations, job exposure matrices, National Patient and Death Registers and the Swedish Intensive Care Register. Hence, we have access to very detailed phenotype data, as well as COVID-19 outcomes, and both cohorts will be followed until the end of the pandemic.

Impact: The results will be of importance for understanding the effects of early risk factors and social inequalities on the course of COVID-19 disease, to design preventative measures, and may be applicable to other viral respiratory infections.