Characteristics of the increased adrenocortical function observed in many obese patients.

Evidence of increased adrenal cortical function has been found in 30 to 60q' of obese people. In a group of obese individuals reported by US,^ those with increased adrenal cortical function manifested high urinary 17-hydroxycorticosteroids (17-OHCS) and high cortisol secretion rates (CSR). However, plasma 17-OHCS were lower than normal, and more of the secreted cortisol was converted to Porter and Silber chromogens (expressed as the ratio of CSR to U17-OHCS). Obese patients also present higher than normal cortisol turnover rates (TABLE 1). In our study, neither the high urinary 17-OHCS nor the elevated CSR showed any correlation with either absolute body weight or with degree of obesity. Similarly, others' have been unable to correlate the high urinary 17-OHCS and CSR with body surface in obesity. From these and other s t~dies , ' ,~ it appears that some obese patients exhibit a rapid rate of cortisol turnover, which is associated with an increased excretion of cortisol metabolites (measured as urinary 17-OHCS, 17-KS, or 17-ketogenic steroids). This should lead to lowering of the plasma 17-OHCS level and a compensatory feedback increase in cortisol secretion. The present study shows a relationship between excessive protein intake, increased glomerular filtration rate (GFR) and adrenal cortical overactivity in obesity.