Physical Activity Benefits Based by Duration in the Prevention, Diagnosis, and Cardiovascular Complications of Type 2 Diabetes 

 The importance of moderate and vigorous physical activity is often underestimated in patients at risk of or diagnosed with type 2 diabetes. 

By 2045, the International Diabetes Federation projects almost 630 million people to be diagnosed and living with diabetes mellitus. Physical activity is a crucial modifiable factor that has been found to deter the natural course of diabetes and mortality risks in past studies. The intensity and length of exercise had yet to be studied in an unbiased manner over greater than ten years, which this study sought to remedy.   

For approximately 27 years, London servants were followed from the Whitehall II study to primarily examine the role of moderate to vigorous physical activity in the frequency of type 2 diabetes. Secondly, the investigation’s purpose was to study the relationship between physical activity post-diagnosis of diabetes and the subsequent risks, along with the mortality of patients with cardiovascular disease.  

Between 1985 and 1988, the Whitehall II cohort began with 9987 subjects free of type 2 diabetes. The baseline participants who were followed to observe the incidence of the disease were over 67% male and had an average age of 44.9 with a standard deviation of six. The study continued until March 31, 2017, in which a questionnaire was used to measure the correlation between physical activity and type 2 diabetes incidence. The survey was completed every four to five years for a total of seven times during the follow–up period. Physical activity was divided into three categories: mild, moderate and vigorous. Mildly energetic activities included house chores while moderate physical activity was defined as cycling, dancing, swimming or walking at leisure and vigorous exercise was seen as running or playing a game of squash. The competing risk analysis utilized was the illness-death model for interval-censored data. A secondary analysis focused on the participants with type 2 diabetes was studied using a Cox regression model with inverse probability weighting. The reports were adjusted for multiple factors including behavioral, health-related, and sociodemographic.  

Within the follow up study, 1553 patients developed type 2 diabetes. In comparison to the subjects who were completely inactive from 1985 to 1988, the subjects who partook in moderate to vigorous physical activity of any duration had a decreased risk of developing type 2 diabetes HR 0.85 [95% CI 0.75, 0.97], p = 0.02). Among those who were diagnosed with type 2 diabetes during the follow up period, 1026 patients produced data valuable to examining the activity post-diabetes diagnosis. In almost 9 (SD= 6.1) years, there was a recording of 55 deaths related to cardiovascular complications and 165 deaths due to other reasons. The mortality of those diagnosed with cardiovascular disease was distinct in patients who committed to less than the recommended two and a half hours per week of moderate activity or one hour and 15 minutes of vigorous physical exercise per week (HR 0.40 [95% CI 0.16, 0.96], p = 0.04). Any duration of moderate or vigorous activity post-diabetes diagnoses was observed to promote lower mortality rates by all causes (HR 0.61 [95% CI 0.41, 0.93], p = 0.02). 

Both diagnosis and prognosis in type 2 diabetes are positively impacted by moderate to vigorous exercise. Statistically significant data supported the duration of physical activity as negligible. Any patients who exercised the recommended amount by the World Health Organization (WHO) guidelines were observed to have additional benefits. Mortality declined in those subjects who partook in any duration of moderate to vigorous physical activity. However, the recommended length of the exercise was found necessary for the prevention of disease-related cardiovascular complications. Future opportunities to further this line of research could include monitored physical activity by the researchers instead of self-reported, using decimals when logging duration of action instead of rounding to the nearest whole number, or enlarging the study to encompass the effects of moderate to vigorous physical activity in those who have cardiovascular disease at baseline and develop type 2 diabetes.  

Practice Pearls: 

• The decreased incidence of type 2 diabetes was found in any duration of moderate to vigorous physical activity compared to inactivity. 
• Any duration of moderate to vigorous physical activity was also found to reduce all mortalities. 
• Implementing moderate to vigorous exercise in patients diagnosed with type 2 diabetes can also decrease the incidence and mortality rates of cardiovascular complications. 

Yerramalla, Manasa S et al. “Association of moderate and vigorous physical activity with incidence of type 2 diabetes and subsequent mortality: 27–year follow-up of the  Whitehall II study.” Diabetologia vol. 63,3 (2020): 537-548. doi:10.1007/s00125-019-05050-1 

Mia Flowers, PharmD. Candidate of Florida Agricultural & Mechanical University School of Pharmacy 

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