In a study about massage therapy conducted by Tiffany Field, PhD executive director of the Touch Research Institute at the University of Miami Miller School of Medicine in Miami they focused on the effects of massage therapy on breast cancer patients. Field concluded that massage therapy increases the number of natural killer cells that are known to destroy cancer cells, bolstering immune function. Other research has shown that massage improves sleep patterns and decreases pain, fatigue, anxiety, depression and stress hormone (cortisol)levels in adults with fibromyalgia and decreased diastolic blood pressure, and reduces anxiety and cortisol levels in adults with hypertension. It has also been found that glucose levels of diabetic children decreased to the normal range after just one month of receiving massage.