Objectives: Several studies suggest a link between circulating 25-hydroxyvitamin D (25(OH)D) and metabolic risk factors. However, this relation has been mainly studied in elderly and/or obese subjects. In addition, the relation between 25(OH)D and adiponectin is unclear. The purpose of this study is to look at these relations in non-obese young individuals. Design: We investigated the relation between serum 25(OH)D and adiposity, blood pressure, glucose metabolism, lipid profile, and adiponectin in 381 randomly selected university students (201 males and 180 females, mean age 23.9G3.9). Results: In the overall population, 25(OH)D is significantly inversely correlated with body mass index (BMI), systolic blood pressure (SBP), waist circumference (WC), fasting plasma glucose (FPG), insulin levels, and homeostasis model assessment of insulin resistance (HOMA index) and positively correlated with adiponectin and high density lipoprotein-cholesterol (P!0.01 for all variables). In males, these correlations are still significant for BMI, SBP, WC, and adiponectin (PZ0.02, PZ0.01, PZ0.04 and PZ0.01 respectively); also, 25(OH)D is inversely correlated with low density lipoprotein (LDL)-cholesterol (PZ0.007). In females, 25(OH)D is only inversely correlated with FPG and HOMA index (P!0.001 and PZ0.03 respectively). In multivariate regression analysis models, after adjustment for sex and BMI, 25(OH)D is an independent predictor of FPG and SBP (PZ0.032 and PZ0.05 respectively) in the overall population, while in males 25(OH)D is a predictor of LDL-cholesterol and SBP independently of BMI (PZ0.007 and PZ0.035 respectively). Conclusion: In non-obese young subjects, we observe new relationships between 25(OH)D and several metabolic risk factors and adiponectin. Further research is needed to elucidate the gender differences and to look at the relation between 25(OH)D and adiponectin.European Journal of Endocrinology 160 965-971

The proximal intestine of neonatal rats expresses a specific receptor (RFcn) that binds immunoglobulin G (IgG) and is no longer expressed after weaning. The aim of this study was to quantify and compare the intestinal transport and processing of IgG in intestinal fragments with or without RFcn, with the fluid-phase transport of horseradish peroxidase (HRP). The mucosal to serosal transport and degradation of IgG and HRP were measured in neonatal and adult rats in vitro in Ussing chambers. IgG transcytosis occurred without degradation in the proximal intestine of neonatal rats, where RFcn is expressed, up to a luminal concentration of 300 μg/ml. At higher mucosal IgG concentrations, a degradative pathway was also involved. The immunoreactive IgG fluxes across the proximal intestine of neonatal rats were higher than those observed in the distal neonatal intestine or those in the proximal and distal adult intestine. The rate of HRP transcytosis was higher than that of IgG but it involved a mainly degradative pathway. These results suggest that in the proximal intestine of the neonatal rat, where RFcn is expressed, the transcytotic rate for IgG is not increased, but the nondegradative transport of immunoreactive IgG is favored, especially at low luminal concentrations.

Our study demonstrated a gender-specific difference between VDR SNPs and various cardiovascular risk factors and adiponectin.

Our results suggest that SHBG is independently associated with HOMA-IR, adiponectin, hs-CRP and triglycerides. A gender difference in these associations is observed. Further studies are needed to elucidate these findings.