Maury E, Ehala-Aleksejev K, Guiot Y, Detry R, Vandenhooft A, Brichard SM. Adipokines oversecreted by omental adipose tissue in human obesity. Am J Physiol Endocrinol Metab 293: E656-E665, 2007. First published June 19, 2007 doi:10.1152/ajpendo.00127.2007.-Central-omental obesity plays a causative role in the pathogenesis of the metabolic syndrome. Adipokines are involved in the pathogenesis of this syndrome. However, adipokines secreted by omental adipose tissue (OAT) are still poorly characterized in human obesity. Therefore, we searched for novel adipokines abnormally secreted by OAT in obesity and examined their relationships with some features of metabolic syndrome and the respective contribution of adipocytes vs. stromal-vascular cells. OAT from obese and nonobese men was fractionated into adipocytes and SV cells, which were then cultured. Medium was screened by medium-scale protein arrays and ELISAs. Adipokine mRNA levels were measured by real-time RT-qPCR. We detected 16 cytokines secreted by each cellular fraction of lean and obese subjects. Of the 16 cytokines, six adipokines were newly identified as secretory products of OAT, which were dysregulated in obesity: three chemokines (growth-related oncogen factor, RANTES, macrophage inflammatory protein-1␤), one interleukin (IL-7), one tissue inhibitor of metalloproteinases (TIMP-1), and one growth factor (thrombopoietin). Their secretion and expression were enhanced in obesity, with a relatively similar contribution of the two fractions. The higher proportion of macrophages and endothelial cells in obesity may contribute to this enhanced production as well as changes in intrinsic properties of hypertrophied adipocytes. Accordingly, mRNA concentrations of most of these adipokines increased during adipocyte differentiation. Eventually, expression of the investigated adipokines did correlate with several features of the metabolic syndrome. In conclusion, six adipokines were newly identified as oversecreted by OAT in obesity. These adipokines may link obesity to its cardiovascular or metabolic comorbidities.

This study aimed to determine the effect of metabolic syndrome (MS) on the reproductive function in fertile (FM) and male partners of infertile couples (MPIC). We performed a cross-sectional study formatting two study groups: partners of pregnant women (n = 238; mean age 32.0) as FM and male partners of infertile couples (n = 2642; mean age 32.6) as MPIC. A standard semen analysis was performed and clinical, laboratory and lifestyle data were analysed. The adapted NCEP-ATPIII criteria were used to define MS. 12.2% of FM and 17.8% of MPIC had MS. In both groups, men with MS were older, they were centrally obese and had higher triglycerides, systolic and diastolic blood pressure and decreased HDL cholesterol values as compared to men without MS. However, glucose concentrations as well as fasting insulin levels were significantly higher only in the MPIC-MS+ group. MS was not associated with semen parameters. Testosterone levels were negatively correlated to MS in both groups. This negative association persisted within the BMI categories between MPIC-MS- and MPIC-MS+ groups. LH was negatively correlated to MS but only in MPIC. FSH and oestradiol were not correlated to MS. Smoking and alcohol consumption were higher among men with MS. This study shows that except for testosterone, MS has no independent effect on major fertility parameters in different subgroups of men.

SUMMARYThe objective of this study was to investigate the relations of basic semen parameters and reproductive hormones with different surrogate measures of adiposity: body mass index (BMI), body fat percentage (BF%), waist circumference (WC) and waist-to-height ratio (WHtR). Standard semen analysis was performed and serum levels of reproductive hormones were measured in 260 male partners of pregnant women at a university hospital andrology centres in Estonia. Quartile analysis revealed that all adiposity markers were negatively related to sex hormone-binding globulin and total testosterone levels. After adjustment for covariates a high BF%, WC and WHtR were negatively associated with total sperm count. The BF% was also negatively related to semen volume. These significant changes occurred from a BF% ≥ 23.4%, WC > 98 cm and WHtR > 0.54. Next to these changes the BMI was not related to sperm parameters. This study shows that semen quality is affected by central adiposity and confirms earlier findings that adiposity markedly changes serum sex hormone levels. Further studies are required to find out what is the best body composition marker showing most clearly the relationships between adiposity, semen characteristics and sex hormone levels.

The objective of this study was to investigate the relationships between total testicular volume (TTV), reproductive parameters and adiposity measures: body mass index, waist circumference and waist-to-height ratio. Semen analysis was performed, and reproductive hormone levels were measured in 2,672 male patients (mean age 32.6) due to couple's infertility. Significant, positive correlations between semen parameters and the TTV were found. Gonadotrophins were negatively related to the TTV, and testosterone was not related to the TTV. Three anthropometric parameters were negatively correlated to the total sperm count, and sperm concentration seen in men with a TTV of ≤46 ml. In the case of a TTV >46 ml, only the semen volume was inversely correlated with WC and WHtR. These changes occurred from a WHtR ≥0.56, WC ≥102 cm and BMI ≥29 and were more pronounced between WHtR and the TTV. Adiposity was associated with a significant testosterone level decline but did not have a major impact on the gonadotrophin levels. This study shows the divergent results in sperm parameters in different TTV groups in the presence of central adiposity.

SUMMARYThe aim of this study was to investigate the relations of basic semen parameters and reproductive hormones with alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). In addition, to examine possible interaction between adiposity, alcohol consumption, and liver tests in relation to male reproductive health, standard semen analysis was performed and serum levels of reproductive hormones and liver tests were measured in 245 male partners of pregnant women at a University Hospital Andrology Centres in Estonia. Quartile analysis revealed that after adjustment for covariates GGT was negatively related to sperm concentration and total sperm count. These significant changes appeared from a GGT >35.5 U/L. Next to these changes ALT was not related to sperm parameters. Both enzymes, GGT and ALT, were not related to reproductive hormones. Alcohol consumption was positively related to GGT and in cases with elevated GGT alcohol use was negatively related to sperm concentration and total sperm count. Alcohol consumption was positively related to body mass index (BMI) and waist circumference (WC). Our findings also confirm results of previous studies that BMI and WC are associated positively with ALT and GGT. According to the study, increased GGT activity might represent a possible connection between adiposity, alcohol consumption, and semen quality.