Effect of Exercise on Elevated C-reactive Protein Concentrations in Formerly Inactive Adults
Effect of Exercise on Elevated C-reactive Protein Concentrations in Formerly Inactive Adults
The purpose of this study is to determine the effect of exercise training on elevated
 C-reactive protein (CRP) concentrations, an indicator of inflammation, in initially inactive
 women and men.
BACKGROUND:

 CRP, a marker of systemic inflammation, has been reported to be an independent predictor of
 cardiovascular disease in both women and men. Recently published data from cross-sectional
 analyses showed that CRP is inversely related to cardiorespiratory fitness, and that this
 association is independent of body mass index. Regular exercise may affect CRP levels, and
 can possibly be used as a means of reducing elevated CRP levels. Though there are a number of
 studies focusing on related topics, there are no published reports from randomized clinical
 trials on the effect of exercise training alone on CRP levels.

 DESIGN NARRATIVE:

 An estimated 200 individuals will be randomly assigned to either a no exercise control group
 or an exercise group. Exercising individuals will participate in 3 or 4 training sessions
 each week for 4 months, and will progress to a total energy expenditure of 16 kcal [kg(-1),
 week(-1)], which is an exercise dose at the upper end of current public health
 recommendations for physical activity. The target exercise intensity will be 50-70% of
 baseline volume of oxygen consumed (V02 max). VO2 max is the maximal rate of oxygen
 consumption during exercise, and is a measurement of fitness. The primary outcome measure
 will be plasma CRP concentration. Secondary outcomes will be changes in variables that are
 potential mechanisms through which regular exercise might reduce CRP. These variables include
 visceral adiposity, the cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha
 (TNF-alpha), and heart rate variability as a measure of autonomic balance. Although the
 primary outcome is CRP level, this study will also contribute significantly to the limited
 body of literature examining the effect of exercise on the variables of visceral adiposity,
 cytokines, and heart rate variability.
Inclusion Criteria:

 -  Physically inactive

 -  C-reactive protein level at least 2.0 mg/L but less than 10.0 mg/L upon study entry

 -  Body mass index between 18.5 kg/square meter and 40.0 kg/square meter as measured at
 study entry

 -  Does not smoke

 -  Total cholesterol at least 240 mg/dl with LDL-C at least 160 mg/dl OR LDL less than
 190 mg/dl and Framingham less than 10%

 -  Triglyceride levels no higher than 300 mg/dl

 -  Fasting glucose level less than 126

 -  Systolic blood pressure less than 140 mm Hg and/or diastolic blood pressure less than
 90 mm Hg as measured at study entry

 -  If taking an oral contraceptive, aspirin, ibuprofen, or other anti-inflammatory
 medications, must be on a stable dose for 6 months prior to study entry

 -  If taking a cholesterol medication, including statins, blood pressure medication
 (including ace inhibitors), or multi-vitamins, must be on a stable dose for 2 months
 prior to study entry

 Exclusion Criteria:

 -  Using a beta blocker, hormone replacement therapy, or corticosteroids (except
 inhalers)

 -  Any rheumatologic, orthopedic, neurological, or autoimmune diseases, or seizure
 disorder

 -  Any significant cardiovascular disease or disorders including, but not limited to,
 stent or coronary artery bypass grafting

 -  Cardiac dysrhythmias including, but not limited to, left bundle branch block, atrial
 fibrillation, pacemaker, or automatic implantable cardioverter defibrillator

 -  Any surgery, broken bones, blood donation, or anaphylactic shock within 6 months of
 study entry

 -  Any sprain or strain, removal of wisdom teeth, or use of antibiotics within 3 months
 of study entry

 -  History of stroke or TIA

 -  History of cancer within at least 5 years of study entry

 -  Diabetes or glucose intolerance

 -  Planning on participating in any other research trials during the next year

 -  Currently pregnant

 -  Planning to becoming pregnant during the next year