Hormonal responses to cold exposure in subjects with vibration syndrome.

Responses of the autonomic nervous system and the endocrine system to cold exposure were investigated. The subjects were all males, between 41 and 69 years of age. Seventy subjects with the vibration syndrome and vibration-induced white finger (VWF(+) group), 70 subjects with the vibration syndrome without VWF (VWF(-) group) and 70 healthy subjects (control group) were individually matched according to age. The subjects remained in a cold room at 7 C for 30 minutes. Catecholamines, cyclic nucleotides, thyroid hormones, ACTH and cortisol were measured before and during cold exposure. The VWF(+) group and the VWF(-) group had larger % increases of plasma norepinephrine, cyclic AMP, cyclic GMP, T3 and T4 levels than the control group. These findings indicate that the responses of the autonomic nervous system and the thyroid system to cold exposure are greater in the subjects with the vibration syndrome.