EMPOWER: Effects of Weight Loss and Exercise Post-stroke

With a surviving cohort of nearly 7 million individuals, stroke is the leading cause of long-term disability in the United States. Of the ~795,000 new strokes occurring in the U.S. each year, approximately two-thirds of survivors will have some degree of long term disability, and less than half will progress to independent community ambulation. Even among those who do achieve independent ambulation, significant residual deficits persist, with more than 60% of persons post-stroke reporting limitations in mobility related to walking. Concurrently, obesity is highly prevalent in stroke survivors (~30-45% of stroke survivors have BMI>30) and is associated with increased levels of disability as well as risk for numerous adverse health-related outcomes; including re-occurrence of stroke and all-cause mortality.8 The neurological sequelae following stroke result in a myriad of residual impairments that contribute to significant reductions in physical activity, which further increase the risk for obesity. The alarmingly high (and increasing) rates of obesity amongst stroke survivors represents an area of critical clinical need and, despite an abundance of information regarding weight loss approaches in neurologically healthy individuals, there is a lack of information regarding the impact of intentional weight loss on obese survivors of stroke.

The proposed approach is an opportunity to address the all-to-common problem of post-stroke obesity. In an effort to reduce the long-term risk for disability and development or worsening of comorbid conditions, we propose the Enhancing Mobility and Psychosocial function in Obese Chronic Stroke Survivors via Weight loss and ExeRcise (EMPOWER) trial. This trial leverages a 15-week multidisciplinary approach to weight loss, via an existing lifestyle and weight management program at MUSC Weight Management Center. We will study the effects of this weight loss program delivered with or without concurrent supervised exercise training as the catalyst by which remediation of physical and psychosocial impairments promote enhanced recovery. Intentional weight loss in individuals who are obese (non-stroke) has been repeatedly shown to increase functional capacity, reduce risk of cardiovascular event and improve health related quality of life. However, a knowledge gap currently exists related to the efficacy of weight loss strategies for stroke survivors who are obese. Several lines of evidence suggest the potential impact of successful treatment for obesity following stroke, including: a) pathophysiological consequences of obesity, b) epidemiological evidence that obesity increases disability and reduces quality of life following stroke and c) well-established benefits of weight loss in neurologically health individuals. In response, we seek to create an environment suitable for stroke survivors who are obese to participate in and realize the benefits from a comprehensive lifestyle and weight management program. The proposed lifestyle management program incorporates a highly structured dietary caloric restriction intervention, consisting primarily of meal replacements, integrated with education and behavior modification strategies. In addition, the proposed exercise training program has demonstrated efficacy for improving post-stroke functional performance. It is our expectation that results of the proposed trial will catalyze change in post-stroke rehabilitation and recovery care for local stroke survivors who are obese, as well as the ~800,000 stroke survivors/year worldwide, thereby reducing the global burden of post-stroke disability.

Inclusion criteria

• age 35-85
• stroke at least 6-months prior
• residual paresis in the lower extremity (Fugl-Meyer LE motor score <34)
• ability to walk without assistance and without an AFO during testing and training at speeds ranging from 0.2-0.8 m/s
• body mass index (BMI) greater than 25
• provision of informed consent. All subjects who meet criteria for training must complete an exercise tolerance test and be cleared for participation by the study physician.

Exclusion criteria

• unable to ambulate at least 150 feet prior to stroke, or experienced intermittent claudication while walking
• history of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during ADL's
• history of COPD or oxygen dependence
• preexisting neurological disorders, dementia or previous stroke
• history of major head trauma
• legal blindness or severe visual impairment
• history of psychosis or other Axis I disorder that is primary
• life expectancy <1 yr
• severe arthritis or other problems that limit passive ROM
• history of DVT or pulmonary embolism within 6 months
• uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions
• severe hypertension with systolic >200 mmHg and diastolic >110 mmHg at rest
• history of seizures or currently prescribed anti-seizure medications
• current enrollment in a clinical trial to enhance motor recovery
• persons with child-bearing potential.