Disease of the veins include blood clots, varicose veins, leg swelling, and sores on the legs. Venous disease is more common in overweight patients, but little is known as to why this is the case. This research project is investigating the relationship between body weight and function of the leg veins using a special non-invasive technique known as venous plethysmography. We hope to investigate the reason for the relationship between body weight and higher risk of vein problems.

Approximately 45 people will take part in this study. Patients will be recruited from among three groups: normal weight people, overweight people, and obese people.

Resting ankle-brachial index will be measured in both lower extremities to exclude the presence of peripheral arterial disease. Venous physiologic study using air plethysmography with positional maneuvers will be performed. Parameters to be measured will be outflow time, passive draining and refill time, and exercise venous plethysmography. All studies will be performed with the Phlebotest system (Osborn Medical).

All study procedures will be done during one visit, and no further follow-up is required.

• Obesity
• Peripheral Arterial Disease

• Normal Body-Mass Index: 18.5-24.9
• Obese Body-Mass Index: 30.0-39.9
• Morbidly Obese Body-Mass Index: ≥ 40

Inclusion Criteria:

• Age between 18-60 years old
• BMI within one of three strata (Normal: 18.5-24.9, Obese: 30.0-39.9, Morbidly Obese: ≥ 40)

Exclusion Criteria:

• Prior diagnosis of chronic venous insufficiency or venous stasis ulceration
• Prior diagnosis of lymphedema
• Significant lower extremity edema as determined by study investigators. Lipidemia (in the absence of venous or lymphatic related edema) is acceptable.
• Varicose veins (subcutaneous dilated vein > 3 mm in diameter measured in upright position). Subjects with telangiectasias and/or mild reticular veins will be eligible (CEAP C1)
• Patients who have been prescribed compression stockings by a health care provider at any time in the past, aside from prophylactic use during prior hospitalization to prevent VTE
• Patients who have undergone any procedure for treatment of lower extremity varicose veins, including: sclerotherapy, venous ablation, phlebectomy, or a stripping procedure
• History of DVT or SVT
• Pregnancy
• Active malignancy
• Documented hypercoagulable state
• Body weight exceeds weight limit of the venous air plethysmograph chair equipment (approximately 375 lbs)
• Clinical diagnosis of lower extremity peripheral arterial disease or abnormal ankle-brachial index (ABI) in either lower extremity
• History of surgical intervention involving pelvis or lower extremities
• Pelvic or lower extremity radiation