Obesity could alter circulating ghrelin profile, and relative A-Ghr excess could contribute to obesity-associated insulin resistance in metabolic syndrome.

Metabolic syndrome is characterized by increased cardiovascular risk. Pentraxin 3 (PTX3), an acute phase protein, is involved in atherosclerosis. No information is available on PTX3 plasma concentrations in metabolic syndrome and on its associations with metabolic alterations and subclinical atherosclerosis. The aim of this study was to assess PTX3 plasma levels in metabolic syndrome patients compared to control subjects and their potential associations with anthropometric and clinical components of the syndrome as well as with carotid artery intima-media thickness (cIMT), a marker of subclinical atherosclerosis. Plasma was obtained from metabolic syndrome patients (NCEP-ATP III criteria n = 41, 20 M/21F) and by age-matched control subjects (n = 32, 16 M/16F). PTX3 was measured using sandwich ELISA and cIMT with ultrasound. Compared to those of the control subjects, plasma levels of PTX3 were higher (? * 100%, P = 0.0009) in metabolic syndrome patients. In univariate analysis, plasma PTX3 was negatively (P = 0.005) associated with high-density lipoprotein (HDL) cholesterol and positively (P = 0.046) with plasma triglycerides and with cIMT (P = 0.045) in the patients (n = 41). In multivariate analysis the direct association between PTX3 and cIMT was no longer significant after correction for HDL. None of these associations were detected in the control patients. These data demonstrate that PTX3, a novel marker of vascular disease, is higher in patients with metabolic syndrome associated with subclinical atherosclerosis. In addition, PTX3 is significantly independently correlated with low HDL cholesterol, but not with cIMT, suggesting a novel association between PTX3 and atherogenic lipid profile.

The data show that following GBP, early T-Ghr stability masks elevation of A/T-Ghr, that is stabilized after later increments of both T- and A-hormones. GBP does not normalize the obesity-associated elevated A/T-Ghr ratio, instead resulting in enhanced A-Ghr excess. Excess A-Ghr is unlikely to contribute to, and might limit, the common GBP-induced declines of appetite, body weight, and insulin resistance.

Objective: Gastric bypass (GBP) lowers food intake, body weight, and insulin resistance in severe obesity (SO). Ghrelin is a gastric orexigenic and adipogenic hormone contributing to modulate energy balance and insulin action. Total plasma ghrelin (T-Ghr) level is low and inversely related to body weight and insulin resistance in moderately obese patients, but these observations may not extend to the orexigenic acylated form (A-Ghr) whose plasma concentration increase in moderate obesity. Design and Methods: We investigated the impact of GBP on plasma T-, A-, and A/T-Ghr in SO patients (n ¼ 28, 20 women), with measurements at baseline and 1, 3, 6, and 12 months after surgery. Additional cross-sectional comparison was performed between nonobese, moderately obese, and SO individuals before GBP and at the end of the follow-up period. Results: Before GBP, SO had lowest T-Ghr and highest A/T-Ghr profile compared with both nonobese and moderately obese individuals. Lack of early (0-3 months from GBP) T-Ghr changes masked a sharp increase in A-Ghr and A/T-Ghr profile (P < 0.05) that remained elevated following later increments (6-12 months) of both T-and A-Ghr (P < 0.05). Levels of A-Ghr and A/T-Ghr at 12 months of follow-up remained higher than in matched moderately obese individuals not treated with surgery (P < 0.05). Conclusions: The data show that following GBP, early T-Ghr stability masks elevation of A/T-Ghr, that is stabilized after later increments of both T-and A-hormones. GBP does not normalize the obesity-associated elevated A/T-Ghr ratio, instead resulting in enhanced A-Ghr excess. Excess A-Ghr is unlikely to contribute to, and might limit, the common GBP-induced declines of appetite, body weight, and insulin resistance.

The present study analysed the effect of protein restriction on serum insulin and leptin levels and their relationship with energy balance during lactation. Four groups of rats received isocaloric diets containing 170 g protein/kg or 60 g protein/kg from pregnancy until the 14th day of lactation: control non-lactating, control lactating (both fed a control diet), low-protein non-lactating and low-protein lactating. Energy intake, body composition, energy balance, serum insulin and leptin concentrations and the relationship between these hormones and several factors related to obesity were analysed. Low-protein-intake lactating rats exhibited hypoinsulinaemia, hyperleptinaemia, hypophagia and decreased energy expenditure compared with control lactating rats. The protein level in the carcasses was lower in the low-protein lactating group than in the control lactating group, resulting in a higher fat content in the first group compared with the latter. Body fat correlated inversely with serum insulin and positively with serum leptin level. There was a significant negative correlation between serum leptin and energy intake, and a positive relationship between energy intake and serum insulin level in lactating rats and in the combined data from both groups. Energy expenditure was correlated positively with serum insulin and negatively with serum leptin in lactating rats and when data from control non-lactating and lactating rats were pooled. Lactating rats submitted to protein restriction, compared with lactating control rats, showed that maternal reserves were preserved owing to less severe negative energy balance. This metabolic adaptation was obtained, at least in part, by the hypoinsulinaemia that resulted in increased insulin sensitivity favouring enhanced fat deposition, hyperleptinaemia and hypophagia.Low-protein diet: Serum leptin: Serum insulin: Energy balance: Lactation