African American Cancer Survivor’s BMI Linked with Neighborhood Walkability

Among African American cancer survivors, a higher neighborhood walkability was linked with a lower body mass index (BMI), according to a recent study out of Detroit.

As part of the Detroit Research on Cancer Survivors Study, researchers looked at data from 2,089 African American cancer survivors. Self-reported height and weight were used to calculate BMI. Associations were then analyzed between neighborhood walkability index (NWI) quartiles, BMI, and cancer type.

NWI was created by assessing four aspects used by planners and designers to promote walking: population density, access to public transit as measured by bus-stop density, street connectivity, and destination accessibility.

The median age of survivors at diagnosis was 60, with a median time since diagnosis of 20 months. Median BMI at enrollment was 29.5 kg/m2.

After adjusting for survivor- and neighborhood-level characteristics, the survivor BMI in neighborhoods with the highest NWI score quartile was 1.70 kg/m2 lower than survivor BMI in neighborhoods with the lowest NWI score (P for trend <0.01).

“Stratified findings indicated that this overall relationship likely reflected an association in men, and this suggests that the influence of neighborhood walkability on postdiagnosis body size may differ by gender as well as a relationship among survivors regularly engaged in physical activity,” the researchers wrote. “However, in formal tests of whether the association of the NWI score with BMI differed by cancer type, sex, or regular engagement in physical activity, we did not observe evidence of statistically significant differences.”

Similar trends were noted for prostate cancer survivors and a non-significant trend was noted for colorectal cancer survivors. No apparent trend of lower BMI with higher NWI was noted for breast cancer survivors. The researchers noted that the findings should be interpreted with some limitations in mind included self-report of weight and height.

“Future research is critical and should be performed in African American cancer survivor populations from different geographic regions,” the researchers concluded. “Additionally, because both the obesity burden and the influence of neighborhood walkability features on obesity-related health likely differ between men and women in this patient population, a better understanding of gender-by-environment interactions and driving mechanisms may be crucial to producing truly translational findings and to supporting health systems’ neighborhood-level engagement with cancer survivors and their surrounding community.”