Effects of caloric restriction and low glycemic index diets associated with metformin on glucose metabolism and cortisol response in overweight/obese subjects: a case series study.
BACKGROUND
To determine whether cortisol secretion and glucocorticoid receptors in lymphocytes and monocytes are altered in patients with impaired glucose tolerance, and whether treatment with a hypocaloric diet and metformin could interfere with these aspects.


METHODS
This is an analytical, interventional, case series study. Patients with impaired glucose tolerance were included. They received 500 mg of metformin twice daily and followed a low glycemic index diet for 16 weeks. Cortisol levels were assessed at 8:00 A.M. before and after use of 0.25 mg of dexamethasone at 11:00 P.M. the day before.


RESULTS
Sixteen subjects (9 men) were included. Normal basal levels of cortisol and adequate responses to the low dose of dexamethasone were observed before and after treatment. There was no significant correlation between the parameters evaluated and cortisol levels. Nevertheless, there was a strong correlation between the number of glucocorticoid receptors, BMI (r = 0.88; p = 0.02), and insulin AUC (r = 0.94; p = 0.005) before treatment; after treatment, all these associations ceased to exist.


CONCLUSIONS
The cortisol secretion remained normal in the group of patients with impaired glucose tolerance. Treatment with metformin and diet did not change this condition. However, glucocorticoid receptor number had a strong correlation with insulin, due to insulin resistance, but this characteristic was lost after treatment.
Unit of Endocrinology, University Hospital Brasilia, University of Brasilia, Brasilia, Brazil ; CLINEN - Clínica de Neurologia e Endocrinologia. SCN quadra 1, bloco F, Ed. America Office Tower, sala 1111, Brasília, DF 70711-905 Brazil.
Luiz Augusto
LA
Casulari
Dipartimento di Scienze Farmacologiche e Biomolecolari, Sezione di Biomedicina ed Endocrinologia, Università di Milano, Milan, Italy.
Donatella
D
Dondi
Dipartimento di Scienze Farmacologiche e Biomolecolari, Sezione di Biomedicina ed Endocrinologia, Università di Milano, Milan, Italy.
Fabio
F
Celotti
Postgraduate course in Health Sciences, University of Brasilia, Brasilia, Brazil.
Fábio Vinicius Pires
FV
da Silva
Postgraduate course in Health Sciences, University of Brasilia, Brasilia, Brazil.
Caio Eduardo Gonçalves
CE
Reis
Department of Nutrition, School of Health Sciences, University of Brasilia, Brasilia, Brazil.
Teresa Helena Macedo
TH
da Costa
Calorie-restricted diet; Cortisol; Diabetes; Glucose intolerance; Metformin; Receptor