Cortisol Binding Capacity in Plasma of the Patients with Diabetes Mellitus

Abstract

Cortisol binding capacity (C. B. C.) in plasma was measured in 51 diabetics (32 male, 19 female) and 32 healthy subjects (23 male, 9 female) with the aid of Doe and Seals' method.
Diabetic group showed a significantly lower C. B. C. values than the healthy group (p<0.01), which was more prominent in male patients.
In order to explore the cause of such decline in C. B. C. in diabetic patients, various possible factors were correlated with C. B. C.
No direct relationship was established between C. B. C. levels and plasma cortisol concentrations, fasting blood sugar levels or degree of excess in body weight. Also, there was no tendency that lowering of C. B. C. was predominant among patients with diabetic heredity.
There was a linear relationship between C. B. C. and serum albumin in the diabetic patients (y=4.05x+13.7, p<0.01). Furthermore, there exhibited a tendency that the more the patients suffered from diabetic complications (nephropathy, retinopathy and neuropathy), the lower C. B. C. as well as serum albumin concentration they had.
The results of these studies indicate that hypoalbuminemia due to diabetic nephropathy, through an unknown mechanism, may play a leading role in lowering C. B. C. in the diabetic patients. Alternatively, however, there still exists a possibility that inborn impairment of C. B. C. in diabetic patients was accompanied by increment of native free cortisol, which in turn deteriorates the diabetic compications.