Nutrition and Aerobic Exercise in Chronic Stroke

Strokes are very common in the United States and occur more in the elderly. The number of strokes is likely to double in the next 50 years. Many stroke survivors are sedentary and have a poor dietary intake, which results in abnormalities in fuel utilization (eg carbohydrate versus fat). This study will examine the effects of dietary modification and treadmill training on fuel utilization and physical function. We will study skeletal muscle oxidative stress in chronic stroke patients and the ability to employ dietary modification and exercise training to reverse these abnormalities in this ethnically diverse population.

In acute stroke settings, it is known that energy imbalance is associated with poorer rehabilitation and functional outcomes, and importantly, increased risk of institutionalization. However, nutrition and eating habits of chronic stroke rehabilitative care have received very little consideration, especially if the survivor is living in a free living environment. Studies have shown deficiencies in energy and protein intake versus recommendations in chronic stroke survivors. Perry et al. found \~7% of chronic stroke survivors were at moderate and \~5% at high nutritional risk. Although little is known regarding total daily energy expenditure and dietary intake in chronic stroke, energy and macronutrient imbalance may have a profound impact on stroke recovery and risk of development of chronic disease and recurrent stroke by altering substrate oxidation and result in systemic and tissue level oxidative stress. Conversely, cardiovascular disease risk increases with excess calorie and fat intake and two-thirds of stroke survivors are overweight or obese. In obese, non-stroke populations, energy dense, high fat meals are associated with increases in plasma oxidative stress markers. Oxidative stress can lead to mitochondrial damage and abnormal accumulation of metabolite intermediates and lipid accumulation in non-adipose tissues, which can impair heart function, increasing CVD and stroke recurrence risk.

Eligibility Criteria:
Inclusion Criteria:

* Veteran
* Adequate language and neurocognitive function to safely participate in informed consent, and exercise testing and training
* Under the care of a primary care medical provider.
* Age greater than 20 years
* Body mass index between 20 to 50 kg/m2
* Already completed all conventional inpatient and outpatient physical therapy.
* Ischemic or hemorrhagic stroke greater than or equal to 6 months prior.

Exclusion Criteria:

* Already performing aerobic exercise 3 x / week.
* Increased alcohol consumption defined as greater than 2 oz. liquor or 2 times 4 oz. glasses of wine or 2 x 12 oz. cans of beer per day
* Cardiac history of: a) unstable angina, b) recent (less than 3 months prior to study entry) myocardial infarction, congestive heart failure (NYHA category II-IV); c) hemodynamically significant valvular dysfunction.
* Muscle Biopsy Exclusion Criteria: a) anti-coagulation therapy with heparin, warfarin, or lovenox (anti-platelet therapy is permitted), b) bleeding disorder c) allergy to lidocaine
* Medical History: a) recent hospitalization (less than 3 months prior to study entry) for severe medical disease, b) peripheral arterial disease with vascular claudication, c) orthopedic or chronic pain condition restricting exercise, d) pulmonary or renal failure, e) active cancer, f) untreated poorly controlled hypertension measured on at least 2 occasions (greater than 160/100) g) type I diabetes mellitus, untreated and / or poorly controlled diabetes with fasting blood glucose of greater than 170 and HbA1c greater than 10.0, h) medications: heparin, warfarin, lovenox, oral steroids i) currently pregnant.
* Neurological history of: a) dementia with Mini-Mental Status Score less than 23 (less than 17 if education level at or below 8th grade), and diagnostic confirmation by neurologist or psychiatrist, b) severe receptive or global aphasia which confounds testing and training, operationally defined as unable to follow 2 point commands, c) neurologic disorder restricting exercise, such as Parkinsons Syndrome or myopathy, d) untreated major depression.