Improved Sleep Quality Is Associated with Reduced Insulin Resistance in Cancer Survivors Undertaking Circuit,...

Cancer patients often experience poor sleep quality, typically induced by cancer-related treatments, a sedentary lifestyle, and psychological distress, leading to an increased risk of metabolic dysregulation such as obesity and insulin resistance. In this novel 16-week pilot study, we examined the effect of a circuit-based aerobic and resistance exercise intervention on self-reported sleep quality in breast, prostate, and colorectal cancer survivors and explored the association between changes in sleep quality and insulin resistance.

Survivors of breast, prostate or colorectal cancers who were sedentary, overweight or obese (BMI>25.0 kg/m2) were randomized to exercise (n=60) or usual care (n=30). The 16-week intervention included supervised moderate-vigorous aerobic (65-85% of VO2max) and resistance (65-85% of 1-repetition maximum) exercise performed in a circuit, interval fashion three times per week. Patient-reported sleep quality and insulin resistance were assessed at baseline and post-intervention using Pittsburgh Sleep Quality Index (PSQI) and Homeostasis Model of Assessment (HOMA-IR), respectively. Mean changes in PSQI score that are negative demonstrate improvements in sleep. Between-group differences were determined using repeated-measures analysis of variance. Associations between changes in PSQI and insulin resistance were computed using Pearson correlations.

Participants were 63.2±10.8 years old, obese (87%), female (55%), and completed chemotherapy + radiation therapy (75%). Adherence to the intervention was 92% and the retention rate was 100%. Post-intervention, the PSQI global score improved significantly in the exercise group when compared to usual care (mean between-group difference, -2.7; 95% CI, -4.2 to -0.6). Change in PSQI was inversely associated with change in HOMA-IR (r=-0.91; p<0.01) among the exercise group.

A circuit, interval-based aerobic and resistance exercise intervention improved patient-reported sleep quality in breast, prostate, and colorectal cancer survivors. Additionally, this exercise-induced improvement in sleep-quality may result in reduced insulin resistance.