Reduced plasma concentrations of transforming growth factor beta1 (TGF-beta1) in obese women

To evaluate Transforming Growth Factor beta1, (TGF-beta1) plasma concentrations and the possible relationship between this growth factor and various hormones in obese women.

Case-control study.

Outpatient's Service for the Prevention and Treatment of Obesity at the University Hospital.

Twenty-five women with mild to moderate obesity, and 15 non-obese healthy women were used as controls.

Evaluation of TGF-beta1, insulin, prolactin, sex-hormone binding globulin, androstenedione, free triiodothyronine, free tetraiodothyronine, thyroid-stimulating hormone, dehydroepiandrosterone-sulfate, testosterone, insulin-like growth factor 1, cortisol and adrenocorticotropic hormone plasma concentrations in obese women. Blood samples were taken from fasting subjects for the determination of the above parameters.

In obese women plasma TGF-beta1 concentrations were lower than in controls. The obese subjects also had lower GH, IGF-1 and SHBG plasma concentrations and increased insulinaemia. A positive correlation was found between TGF-beta1 and both IGF-1 (r = 0.52; P < 0.01) and DHEA-S (r = 0.43; P < 0.05), while a negative correlation was found between TGF-beta1 and SHBG (r = -0.49; P < 0.05).

The reduction in TGF-beta1, an antilipogenic factor, may play a role in the pathogenesis of obesity and could be involved in the development of some obesity-related endocrine alterations.