Abnormalities Of Serum Cortisol And ACTH In Patients With Central Obesity In Relation To Leptin And Plasma Glucose

Objective1. To evaluate the abnormalities of serum cortisol and ACTH in patients with central obesity of different serum glucose.2. To evaluate the abnormalities of serum cortisol and ACTH in relation to serum leptin and glucose.MethodsFifty central obese subjects were grouped to obese diabetic patients and obese non-diabetic patients according to their serum glucose. Waist circumference(WC),waist-to-hip ratio (WHR),body mass index(BMI),serum cortisol and ACTH at 8am and 4pm,morning serum leptin, fasting plasma glucose(FPG),GHbA1c and some other related index were measured in the subjects. To compare the difference of serum cortisol and ACTH among the groups and the abnormalities of serum cortisol and ACTH in relation to serum leptin and glucose.Results1. Obese non-diabetic patients displayed lower plasma cortisol concentrations and higher plasma ACTH compared to normal control. The lower plasma cortisol concentrations was negtively associated with serum leptin, WC ,WHR, BMI and systolic blood pressure. Further analysis revealed that WC is the strongest factor associated with serum cortisol.2. In Obese diabetic patients, both cortisol and ACTH concentrations are higher than normal control, and the high level of cortisol and ACTH was positively associated with hyperglycemia.3. All the patients with central obesity display abnormal circadian rhythms of cortisol and ACTH secretion.ConclusionsAll the patients with central obesity display abnormal circadian rhythms of cortisol and ACTH secretion, regardless of the level of serum glucose. Obese non-diabetic patients displayed lower serum cortisol concentrations and higher serum ACTH compared to normal control, which reflect the abnormal feedback regulation of the pituitary- adrenal axis and inhibition of leptin on hypothalamus-pituitary-adrenal axis (HPAA). The close association between low cortisol level and WC indicated the important role which abnormality of HPAA played in the formation of central obesity. Obese diabetic patients displayed higher serum cortisol concentrations and higher serum ACTH compared to normal control, and the high level of cortisol and ACTH was closely associated with hyperglycemia.