Psychological Stress, Activities of Natural Killer Cells and Bone Strength in Young Women.

Abstract

Low activities in natural killer(NK) cell in depressive patients are reported. Also low bone mineral density in these patients are reported. To evaluate whether the young women who show lower NK. activity after restriction-stress will show lower bone strength and higher depressive tendency, we measured calcaneum bone density by using both of ultra-sound bone densitometer and DXA in 17 healty young women. The subjects who showed lower NK activity after stress, showed lower Speed of Ultrasound(SOS) in ultrasound method and lower BMD compared with the expected values from 236 age-matched normal women. They also showed higher depression-tendency scores. The study supports the hypothsis that stress-dependent hormonal changes have influences not only upon immune system but also bone densities.