Introduction/purpose: Exercise interventions among Native American cancer survivors are lacking, despite major cancer health disparities in survivorship. The purpose of this study was to evaluate a 12-week randomized controlled trial (RCT) of culturally tailored exercise on cancer risk biomarkers and quality of life among Native American cancer survivors and family members.
Methods: Participants were randomized to immediate start versus 6-week waitlist control at two rural and two urban sites. Participants enrolled in a small feasibility pilot study (only cancer survivors evaluated, n=18; cohort 1) or larger efficacy pilot study where cancer survivors (n=38; cohort 2) and familial supporters (n=25; cohort 3) were evaluated concurrently. Resistance, aerobic, flexibility, and balance exercises were tailored by cultural experts representing ten tribes. Exercises was supervised on-site one day per week and continued in home-based settings two to five days per week. Fat mass, blood pressure, hemoglobin A1c, 6-min walk, sit-to-stand test, and quality of life (Patient-Reported Outcomes Measurement Information System Global Health short form and isolation subscale) were measured. Mixed effects models evaluated differences between RCT arms from baseline to 6 weeks, and 12-week intervention effects in combined arms.
Results: There were no consistent differences at 6 weeks between randomized groups. Upon combining RCT arms, 6-min walk and sit-to-stand tests improved in all three cohorts by 12 weeks (both survivors and familial support persons, p<0.001); social isolation was reduced in all three cohorts (p≤0.05). Familial support persons additionally improved blood pressure and HbA1c (p≤0.05).
Conclusion: Exercise improved cardiorespiratory fitness and physical function among Native American cancer survivors and familial supporters. A longer intervention may influence other important health outcomes among Native American survivors. Additional improvements demonstrated among Native American family members may have a meaningful impact on cancer prevention in this underserved population with shared heritable and environmental risks.
Keywords: American Indian/Alaskan Native; cultural tailoring; exercise; exercise oncology; randomized controlled trial.