Recently completed research examines the effect of consistent cycling on all-cause and cardiovascular mortality in type 2 diabetes.
Exercise is integral to a healthy lifestyle, especially in those with Type 2 Diabetes (T2DM). In 2016 the American Diabetes Association (ADA) guidelines were updated to recommend at least 2.5 hours a week of moderate to vigorous-intensity exercise. In addition, the guideline recommends two to three sessions of resistance training on nonconsecutive days and two to three sessions of flexibility and balance training for older patients with diabetes. However, the duration may be decreased in young, healthy patients with diabetes if they wish to increase the intensity of their workouts. Cycling may be a good candidate in these areas. Cyclists can modify the level of resistance and intensity, and cycling requires the person to have balance.
People with diabetes have a higher incidence of premature death from cardiovascular disease (CVD) and all-cause. Ried-Larsen and his team sought to examine the association between duration of cycling and all-cause and CVD death among people who have diabetes. They also wanted to assess the association between change in time spent cycling and the risk of CVD-related death and all-cause mortality. The study was a multi-national prospective cohort composed of 7459 persons with diabetes. The pool of participants came from ten Western European countries and specifically from the European Prospective Investigation into Cancer and Nutrition study (EPIC). Just over half of the adults were women, and the mean age was 56 years old. There were 110,944 person-years of follow-up.
The primary and secondary outcomes of the study were death from CVD and all-cause mortality. These outcomes were adjusted for how long patients had diabetes, social factors, sociodemographic characteristics, and other physical activities. The primary exposure was how much time was spent cycling each week at the baseline of the study. The secondary exposure focused on the adjustment in cycling status between baseline and the next check-in.
There were 1673 reported deaths from all causes in the 110,944 person-years of follow-up; 811 of the deaths were due to CVD. This study showed that people with diabetes who did any cycling over five years were associated with at least a 24% reduced risk from any cause death versus those that reported doing no cycling. Known confounders were considered, such as gender, age, diet, comorbidities, and educational level. The most significant risk reduction, especially in CVD death, was seen in the people that cycled between 150-299 minutes each week. There was a sub-analysis of 5,423 people that had 10.7 years of follow-up. This comparison was independent of other physical activities. From this group, there were 975 all-cause mortalities, and 429 of those were CVD deaths. Sub-analysis showed that those who started or continued to cycle during follow-up experienced reductions of approximately 35% for CVD mortality and all-cause death compared to those who did not cycle at all.
In conclusion, cycling could be an activity for persons with diabetes to reduce the risk of premature death. Ried believes that persons without diabetes also may have similar benefits from cycling. JAMA editors insist that the data from this study has strengthened the data from prior studies that showed the benefits of cycling relative to other physical activities. They also state that cycling is more eco-friendly than different types of transportation, especially those that include exhaust pipes. In recent years, access to bike paths has increased. There have been more and more bicycle lanes constructed in the United States and throughout Europe.
Limitations of the study are that it was observational in design, and there was a potential for selection bias. People had to be able to cycle to be included in the study. Additionally, for people to cycle, they must have a good balance and have sufficient resources to be able to buy a bicycle. Access to bike paths has increased, but not everywhere. Potential cyclists need to live in an area with cycling paths or parks, or other safe areas to cycle.
- Cycling may contribute directly to the longer and healthier lives of people with T2DM.
- Benefits seen with cycling in patients with T2DM could potentially be generalized to the general population.
- To cycle, people need to have a good balance, a certain level of fitness, live in an area that is safe to ride a bicycle, and have the means to afford a bike.
American Diabetes Association. Standards of Medical Care in Diabetes—2021 Abridged for Primary Care Providers. Retrieved from https://clinical.diabetesjournals.org/content/39/1/14. 2021.
Ried-Larsen M, Rasmussen MG, Blond K, et al. Association of Cycling With All-Cause and Cardiovascular Disease Mortality Among Persons With Diabetes: The European Prospective Investigation Into Cancer and Nutrition (EPIC) Study. JAMA Intern Med. Published online July 19, 2021. doi:10.1001/jamainternmed.2021.3836
Ashley Ball, LECOM PharmD Candidate