Prevalence of the metabolic syndrome in moderately-severely obese subjects with and without growth hormone deficiency

Background and aim: There is a considerable heterogeneity in metabolic phenotype among equally obese subjects. Impaired GH secretion is frequent in obese patients, with GH secretion reduced up to levels that are comparable to those found in adult patients with organic GH deficiency (GHD). Low GH status exerts detrimental effects on metabolic abnormalities in organic GHD patients. The aim of this observational, retrospective study was to investigate the prevalence of the metabolic syndrome (MetS) in moderately-severely obese subjects who met criteria for GDH (GHD) and in those with normal GH status (GH sufficient: GHS). Methods and results: One-hundred and ninety-five moderately-severely obese individuals partecipated, 149 women and 46 males [body mass index (BMI) 43.0±4.4 kg/m2 aged 34.3±11.8 yr]. Main outcome measures were: GH peak after GHRH plus arginine test, IGF-I, MetS parameters according to National Cholesterol Education Program criteria. Fifty-five subjects (27.3%) were GHD (49 females and 6 males). The prevalence of MetS parameters was 70.9% in GHD subgroup vs 52.9% in GHS (χ2=5.281; p=0.02) and the likelihood of MetS was highest in GHD subgroup (odds ratio: 2.174; 95% confidence interval 1.113 to 4.248). At the multiple regression analysis either GH peak or IGF-I were the major determinants of waist circumference (β=-0.380, t=−6.110 and β=-0.326, t=−4.704, respectively; p<0.001), while age and IGF-I were the major determinants of MetS (β=0.255, t= 3.342, and β=−0.282, t=−3.270; p=0.02, respectively). Conclusions: Among moderately-severely obese individuals the prevalence of the MetS was higher in GHD than in GHS subjects. Thus, in obese subjects, GH status investigation might be considered in the clinical evaluation of their metabolic risk profile.