ECE2007 Poster Presentations (1) (659 abstracts)
Abdominal obese (AO) women might have a hyperactivation of the HPA axis. The limitations of previous studies have been often represented by the limited and heterogeneous number of patients enrolled. Our aim was to asses urinary free cortisol (UFC) output during daily and nightly hours in a large cohort of AO women vs. normal weight controls (CT). 107 AO women and 37 CT were enrolled in the study. In basal condition, each subject underwent OGTT, biochemical determinations. Each subject collected daily (from 0800 AM to 0800 PM, dUFC) and nightly (from 0800 PM to 0600 AM of the day after, nUFC) urine.
Cholesterol and triglycerides levels were significantly higher (P<0.001) in the AO, whilst HDL were significantly (P<0.01) lower than in CT. AO had significantly higher HOMA index than CT. There were no differences neither in dUFC nor in the nUFC between the groups. On the contrary, AO had significantly lower dUFC/nUFC than CT.
There was a negative and significant correlation between dUFC/nUFC and waist and BMI in all subjects. When AO were analyzed separately, the correlation between dUFC/nUFC and anthropometric variables was still present. Moreover, the ratio was also positively correlated to HOMA index (P<0.05).
In order to assess the linkage between HPA axis activity and metabolic syndrome, a multiple regression was performed in AO. dUFC/nUFC was still negatively and significantly correlated to BMI, while the correlation with waist circumference was lost. Interestingly, dUFC/nUFC was still positively and significantly correlated to HOMA index and systolic blood pressure. On the contrary, a negative and significant correlation was found between dUFC/nUFC and both HDL and diastolic blood pressure.
In conclusion, obesity by itself is characterized by high nightly UFC excretion. The HPA axis dysregulation is strictly associated to the abnormalities of the metabolic syndrome, particularly to glucose-insulin homeostasis, dyslipidemia and hypertension.