All consented subjects following exercise treadmill testing will undergo initial laboratory assessment to include fasting lipid panel (LDL-C, HDL-C, and triglycerides), C-reactive protein, fasting blood glucose, creatinine, thyroid stimulating hormone (TSH) and urine pregnancy test (for females). Approximately 15 mL (3 teaspoons) of blood will be drawn by the central laboratory, the clinical laboratory at Walter Reed Army Medical Center. Excess blood will be discarded by the central laboratory according to their standard protocol. All laboratory values will be processed through this central laboratory.