Is physical activity associated with the risks of hospitalization for common health conditions?

By Bhavana KunkalikarReviewed by Danielle Ellis, B.Sc.Feb 20 2023

In a recent study published in JAMA Network Open, researchers assessed the relationship between physical activity levels and hospitalization risk.

Background

Evidence indicates that higher physical activity levels are connected with reduced risks of cancer, cardiovascular disease, and diabetes. Yet, the connections between physical activity and hospitalization risks are not well understood for many common and frequently less severe illnesses.

Accelerometers monitor the frequency, intensity, and timespan of physical activity and record the entirety of activities performed throughout the day, which serve as a significant factor in total physical activity energy expenditure. Large-scale prospective studies of physical activities and disease risk have relied almost exclusively on self-reported physical activities. Hence, they are vulnerable to errors in measurements and biases, resulting in uncertainty about the correlation between health outcomes and physical activity.

About the study

In the present study, researchers explored the relationship between physical activity measured by accelerometers and hospitalization risk associated with 25 common reasons for hospitalization.

The team invited almost 9.2 million individuals for study participation. Between 13 March 2006 and 1 October 2010, a total of 502,625 participants aged between 40 and 69 joined the study cohorts and attended one of 22 assessment sites in England, Scotland, and Wales. Using a self-administered touch-screen questionnaire and a computer-assisted personal interview, participants provided data on various sociodemographic, health, and lifestyle-related factors. The assessment center also measured the height and weight of the participants.

Subjects who provided a verified email address were randomly selected to receive invitations via email to use a wrist-worn accelerometer for seven days to estimate physical activity levels. Before accelerometer measurements, participants' characteristics were gathered for an average of 5.7 years. During accelerometer evaluations, the final cohort involved 81,717 people aged between 42 and 78.

The average vector magnitude was used to characterize the entire volume of physical activity. Time spent performing sedentary activities such as watching television or driving, light physical activity (LPA) such as self-care or cooking, moderate to vigorous physical activity (MVPA) such as jogging or walking the dog, and sleep was measured with machine learning models trained using time-use diaries and wearable cameras in 152 persons residing in free-living conditions.

The outcomes involved the most prevalent primary reasons for non-cancer-related hospitalization mentioned in the UK Biobank. After completing the accelerometer assessment, national health data were linked to initiate follow-up. Incident cases were detected from the primary cause for hospital admission, surgical operation, or death only. Individuals hospitalized during follow-up due to any of the 25 reasons contributed to the follow-up time related to all other conditions evaluated until the end of follow-up, death, or hospitalization for the condition under investigation.

Results

The average age of 81,717 participants at accelerometer evaluations was 61.5 years, most of whom were women and White. The follow-ups lasted for a median of 6.8 years, while the median time passed till the first incidence of each event ranged between 2.6 years in female genital prolapse cases and 4.1 years in ischemic stroke cases. Ischemic heart disease was the most serious condition, while several other illnesses did not cause deaths directly. Furthermore, people with greater levels of overall physical activity were younger and reported a lower body-mass index (BMI), while participants with greater proportions were female.

Greater total physical activity correlated with a decreased likelihood of first hospitalization following the accelerometer evaluation. In addition, a higher level of physical activity was connected with a lower incidence of nine conditions, including gallbladder disease, urinary tract infections, diabetes, venous thromboembolism, ischemic stroke, pneumonia, iron-deficiency anemia, diverticular disease, and colon polyps. Nevertheless, higher levels of physical activity were related to increased risks of carpal tunnel syndrome, osteoarthritis, and inguinal hernia.

When inverse correlations were noted between disease risk and average total physical activity, higher sedentary time generally had positive correlations with these diseases when the 1-factor models were employed. On the other hand, higher sedentary time was related to a lower risk of inguinal hernia, osteoarthritis, and female genital prolapse.

Furthermore, isotemporal models found that replacing 20 minutes of inactive time every day with 20 minutes of MVPA was related to lower hospitalization rates for all diseases that displayed an inverse correlation with overall physical activity. However, replacing 20 minutes of LPA every day produced fewer consistent connections.

Increasing MVPA by 20 minutes every day was associated with fewer hospitalizations, especially for diabetes, gallbladder disease, pneumonia, iron deficiency anemia, gastroesophageal reflux disease, diverticular disease, cellulitis, and colon polyps, according to population-attributable risk estimates.

Conclusion

Overall, the study findings identified protective relationships between physical activities and the risks of gallbladder disease, diabetes, and cardiopulmonary diseases, as well as unique correlations with other diseases across various physiological systems.

These findings imply that increasing MVPA by 20 minutes daily could reduce hospitalization rates. The team believed that the study findings might be an effective non-pharmaceutical intervention for reducing healthcare burdens and enhancing the quality of life.