Study: The Relationship Between Obesity, Lung Diseases, and Pulmonary Hypertension in Transplant Patients

The United States is coping with an obesity epidemic. It is therefore critical to understand the distribution of body fat and its effect on treatment.

A recent article in Healio suggests that the hormonal component of body fat (visceral adipose tissue), presents certain characteristics that have an influence on various processes in the body. If levels are abnormally high, it is known as visceral obesity.

Visceral adipose tissue is associated with several medical disorders, namely cardiovascular disease, metabolic syndrome, and malignancies of the breast, prostate, and colon.

An Elevated Risk

Adipose tissue is a connective tissue with the primary function of storing lipid “energy.” A recent study found that patients being evaluated for lung transplantation were considered to have an increased risk of pulmonary hypertension (high blood pressure affecting arteries) due to thoracic visceral adipose tissue in the lower thorax (chest cavity).

A Cross-Sectional Analysis

A human has several layers of skin. The outer layer is the epidermis. The loose irregular connective tissue containing fat cells, just beneath the epidermis, is the subcutaneous tissue.

One of the research goals of the study was to examine the association of subcutaneous adipose tissue, thoracic visceral (deep) adipose tissue, and pulmonary hypertension.

399 patients who were scheduled for lung transplants were evaluated. The patients were diagnosed with COPD, interstitial lung disease, pulmonary arterial hypertension, sarcoidosis, and other lung diseases.

Note that 34% of patients in the study were diagnosed with pulmonary hypertension.

The term “interstitial” describes many lung disorders often caused by years of exposure to asbestos and other hazardous materials. Rheumatoid arthritis and other autoimmune diseases are also considered to be a cause of these lung diseases.

Most interstitial lung diseases cause scarring of the lung tissue that subsequently creates an inability to provide sufficient oxygen into the bloodstream. It is usually irreversible. Some medications may slow its progression, but a lung transplant is generally considered an option.

Sarcoidosis, a disease that causes the growth of tiny inflammatory cells in most parts of the body, most often affects the lungs and lymph nodes.

Post Transplantation

Obesity has been associated with a higher risk of primary graft disruption post lung transplant. It is not known if there is any relationship to an adipose tissue site (fat storage).

Researchers in the Lung Transplant Body Composition study have concluded that it is the subcutaneous, not the visceral, obesity that creates an increased risk of primary graft dysfunction after a lung transplant.

Research is Ongoing

Additional research is being conducted for a better understanding of the results of this study and to personalize therapies for the patients.