Jennifer Middleton, MD, MPH
Posted on January 2, 2023
The first study examined older adults’ step counts in relation to risk of future dementia. Using data from the United Kingdom’s Biobank, researchers correlated step counts from more than 78,000 adults 40 to 79 years of age with the risk of a dementia diagnosis over, on average, the next 6.9 years. Participants wore wrist accelerometers to measure their daily steps. The researchers found that the more steps participants took, the lower their risk of developing dementia:
The optimal dose (ie, exposure value at which the maximum risk reduction was observed) was 9826 steps (hazard ratio [HR], 0.49; 95% CI, 0.39-0.62) and the minimal dose (ie, exposure value at which the risk reduction was 50% of the observed maximum risk reduction) was 3826 steps (HR, 0.75; 95% CI, 0.67-0.83).
The researchers controlled for multiple potential confounding factors, including socioeconomic status, educational attainment, gender, and ethnicity. Although an increased benefit was noted at nearly 10,000 steps per day, it’s also encouraging that some risk reduction was noted at the more modest 4,000 steps per day.
In the second study, a separate research team used the United States National Institutes of Health All of Us database to examine how daily step counts correlated with risk of developing type 2 diabetes. These researchers looked at data from more than 5,600 adult participants, the majority of whom identified as White (89%) and female (74%), who also wore wrist accelerometers to track their daily steps over a median period of 3.8 years. They found that “[i]n models adjusted for age, sex, and race, the hazard of incident diabetes was reduced by 44% (95% CI, 15%-63%; P = 0.01) when comparing those with an average daily step count of 10 700 to those with 6000.” Interestingly, they found “no evidence for effect modification by age, sex, BMI, or sedentary time.” Hopefully, future studies will include a more diverse group of participants.
Although both studies were observational (and can therefore show only correlation, not causation), their findings still add to the body of evidence regarding walking. Walking can ease chronic low back pain, slow functional decline in persons with peripheral arterial disease, and reduce the risk of hip fracture in older women. Walking can be done indoors if outdoor safety and/or weather is a concern, although family physicians can also advocate for decreasing environmental barriers to walking in their communities. Collaborating with our patients to write an exercise prescription that includes walking is a tangible way to support patients who are resolving to increase their physical activity in 2023. More resources can be explored in the AFP By Topic on Health Maintenance and Counseling.
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