The Effects of Treating Insomnia on Behavioral Weight Loss Outcomes in Survivors of Breast Cancer

Overweight and obesity are highly prevalent in the U.S. and are associated with increased breast cancer risk, reduced treatment efficacy, and increased risk of recurrence, medical comorbidity and mortality. Breast cancer survivorship is increasing, and is associated with weight gain, increased fat mass, insomnia, and disease risk, making breast cancer survivorship a major healthcare priority. Weight loss is a standard treatment guideline for individuals with breast cancer with overweight/obesity; however, achieving clinically significant and sustained weight loss is challenging in general, and particularly for those who have undergone breast cancer treatment. While several trials have tested the effects of behavioral weight loss (BWL) in breast cancer survivors, a significant percentage of patients do not achieve clinically significant weight loss. Insomnia disorder is also highly prevalent in individuals with breast cancer and, like obesity, predicts breast cancer risk, progression and death. Research demonstrates that inadequate sleep may directly contribute to obesity and impair weight loss efforts via many behavioral and biological pathways. Several studies demonstrate that cognitive-behavioral therapy for insomnia (CBT-I) is efficacious in treating breast cancer survivors. One approach that has yet to be tested in a large scale study, however, is adding an intervention to improve sleep quality before a BWL intervention. Our preliminary data suggest that CBT-I may enhance weight loss outcomes in women with early stage breast cancer (ESBC). Although the complex, inter-related mechanisms linking sleep, obesity and dietary/physical activity behaviors are only beginning to be explored, we hypothesize that improving insomnia will catalyze weight loss efforts and enhance the effects of BWL on dietary and physical activity behaviors. We propose a randomized controlled clinical trial to test whether a 6-session CBT-I intervention delivered over 8-weeks combined with a one-year BWL intervention (CBT-I+BWL) delivered via telehealth (audio-video) is superior to a sleep education control condition (EDU) combined with BWL (EDU+BWL) among 250 adult female survivors of ESBC who are overweight or obese and have insomnia. Assessments will be conducted at randomization, after CBT-I/EDU, and at 3-, 6-, and 12-months of BWL. We have the following aims: Aim 1: Evaluate the short (3 mo), intermediate (6 mo), and long-term (12-mo) effects of CBT-I+BWL compared to EDU+BWL on weight loss (% TWL 12-months, primary) and body composition (secondary). Aim 2: Evaluate the extent to which 12-month weight loss is mediated by pre to post sleep treatment changes in sleep parameters (Sleep Efficiency, SE; Total Sleep Time, TST). Exploratory Aim 3: Determine whether CBT-I+BWL alters caloric intake, diet quality and/or physical activity relative to EDU+BWL and evaluate the extent to which these factors are associated with sleep continuity and weight loss at 3, 6 and 12-months. This novel approach to addressing sleep disturbances in weight loss treatment has the potential to substantially impact the treatment of obesity and to advance the management of survivors of ESBC.