Does sleep promote recovery after bone marrow transplantation?--A hypothesis

Bone marrow transplantation is increasingly being used for treatment of patients with malignant and hematologic disorders. The process requires 4-6 wk of waiting for recovery from conditioning regimens and for engraftment. Patients undergo intensive monitoring and supportive care, yet their requirements for deep uninterrupted sleep often go unrecognized. We suggest that deep sleep may promote recovery and stem cell proliferation through production of growth hormone and melatonin, and through other mechanisms. Growth hormone production occurs primarily during deep, rapid-eye-movement (REM) sleep. Growth hormone promotes nutritional recovery, mucosal healing, cellular uptake of amino acids, and promotes proliferation of bone marrow cell lines in animal models. Melatonin is also secreted during nighttime and during sleep. Melatonin increases immune response, inhibits tumor growth, counteracts stress-induced immunosuppression, protects against viral infections, stimulates GM-CSF, salivary IgA, antioxidant properties and enhances sleep. In our preliminary studies, we have found that most patients undergoing bone marrow transplantation complain of sleep disturbances related to laminar air flow noise-beepers, and lights. We recommend several simple methods of enhancing sleep and for more research in the pathophysiology of sleep and bone marrow transplantation.