Skin thickness in patients with acromegaly and Cushing's syndrome and response to treatment.

Radiological assessment of skin thickness (ST) was assessed in 22 patients with acromegaly and 17 patients with Cushing's syndrome. The age ranges of the patients studied and the 55 individuals in the control group were comparable. The skin thickness in males was significantly greater than in females (P less than 0.01). Mean skin thickness in patients with acromegaly and Cushing's syndrome was significantly greater and less respectively than the mean skin thickness of the normal controls (P less than 0.02). Following successful treatment of acromegaly (growth hormone less than 5 micrograms/l) there was a significant reduction in skin thickness (P less than 0.02 males: P less than 0.01 females). The skin thickness declined at approximately 0.3 mm/year for the first two years and more slowly thereafter. A highly significant correlation was observed between the logarithm of the pre and post treatment plasma GH concentrations and ST values. With one exception, all patients with growth hormone (GH) levels greater than 5 micrograms/l had ST values above the normal range. At an average of 4.5 years after successful treatment of Cushing's syndrome the average increase in ST was 0.23 mm (P less than 0.01). It is concluded that the measurement of skin thickness is a useful screening test for both acromegaly and Cushing's syndrome and provides an objective assessment of the clinical response to treatment.