SHBG gene polymorphism (rs1799941) associates with metabolic syndrome in children and adolescents

Deciphering key genes in cardio-renal syndrome using network analysis

Cardio-renal syndrome (CRS) is a rapidly recognized clinical entity which refers to the inextricably connection between heart and renal impairment, whereby abnormality to one organ directly promotes deterioration of the other one. Biological markers help to gain insight into the pathological processes for early diagnosis with higher accuracy of CRS using known clinical findings. Therefore, it is of interest to identify target genes in associated pathways implicated linked to CRS. Hence, 119 CRS genes were extracted from the literature to construct the PPIN network. We used the MCODE tool to generate modules from network so as to select the top 10 modules from 23 available modules. The modules were further analyzed to identify 12 essential genes in the network. These biomarkers are potential emerging tools for understanding the pathophysiologic mechanisms for the early diagnosis of CRS. Ontological analysis shows that they are rich in MF protease binding and endo-peptidase inhibitor activity. Thus, this data help increase our knowledge on CRS to improve clinical management of the disease.

Association between sex hormone binding globulin gene polymorphism and type 2 diabetes mellitus

This study aims to investigate the relationship between single nucleotide polymorphisms (SNPs) of sex hormone binding globulin (SHBG) and type 2 diabetes mellitus (T2DM) in an Uighur population. One hundred and fourteen T2DM male patients (with a history of diabetes or diagnosed as diabetic by the oral glucose tolerance test) and 173 healthy males from the Uighur ethnic group were included in the study to test the following SNPs of SHBG: rs727428, rs1799941, rs6259, rs6257, rs858521, rs858518, rs3760213, and rs11078701. The body mass index (BMI), blood pressure, and waist circumference, and lipid, glucose, HbA1c, insulin, HOMA-IR, testosterone, and SHBG levels of enrolled individuals were measured. We used the t-test or rank sum test and Chi-square test to analyze the difference and compare numeration data, respectively, between the case and control groups. Comparisons among multiple groups were carried out using analysis of variance, and the correlation between variables was determined by nonparametric Spearman rank correlation analysis; multivariate logistic regression analysis was used to assess the risk of abnormal glucose in the two groups. There was a significant difference (P < 0.05) in BMI, blood pressure, and waist circumference, and lipid, glucose, HbA1c, insulin, and HOMA-IR levels between the case and control groups. The risk factors for diabetes included testosterone (P = 0.042) and SHBG (P = 0.001). The distribution of rs858521 (P = 0.001), rs1799941 (2.3%, P = 0.032), rs6259 (2.5%, P = 0.040), and rs727428 (3.4%, P = 0.016) was significantly different between the case and control groups (P < 0.05). In the control group, there was linkage disequilibrium (LD) between rs727428 and rs6259, while in the case group LD was found among rs858518, rs3760213, rs1799941, and rs6257. The frequency of rs858518-rs3760213-rs1799941-rs6257 haplotype TCGC was significantly different between the two groups (P = 0.033). Both testosterone and SHBGwere found to be risk factors of diabetes in the Uighur population, and SNPs of SHBG may contribute to T2DM.

Genetic polymorphisms of the SHBG gene can be the effect on SHBG and HDL-cholesterol levels in Coronary Heart Disease: a case-control study

Sex hormone binding globulin (SHBG) level is positively associated with the high-density lipoprotein cholesterol (HDL-C) levels. The aim of this study was to investigate the effects of the SHBG gene variations (D356N, rs1799941, and P156L) on SHBG and HDL-C levels and Coronary Heart Disease (CHD) risk. The SHBG D356 N (rs6259,G > A), P156L (rs6258,C > T), and rs1799941(G > A) polymorphisms were determined in 131 male CHD patients and 55 male controls by PCR-RFLP and real-time PCR techniques. SHGB levels were measured by Electro-chemiluminescence immunoassay (ECLIA). In the patients who had SHBG levels lower than threshold 35 nmol/l value, the risk of being HDL-C levels lower than threshold 0.90 mmol/l value was observed statistically significant (p = 0.017; OR 2.522, 95% CI 1.170-5.438). The rs1799941 GG was associated with increased CHD risk when compared with the A allele carriers (GA + AA) (p = 0.019, OR 2.222, 95% CI 1.130-4.371). In addition, the rs1799941 GG genotype and D356 N N allele were associated with lower SHBG in the CHD group (p < 0.01). The logistic regression analysis also revealed the rs1799941 GG genotype was significantly associated with low SHBG in CHD patients. It was observed that Haplotype-1(rs1799941 G allele-P156L P allele-D356 N D allele) was associated with increased CHD risk, while Haplotype-2 (rs1799941 rare A allele-P156L C allele- D356 N G allele) was correlated with the decreased CHD risk (p = 0.0167). Our findings suggest that there is a positive correlation between SHBG and HDL-C levels in CHD patients, and this association might be affected by SHBG gene variations.

Association of rs6259 polymorphism with SHBG levels and Poly Cystic Ovary Syndrome in Indian population: a case control study

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. PCOS reflects a number of possible etiologies but its pathophysiology is still unclear. The principal abnormality of the syndrome is hyperandrogenism (70-80%). The access of androgens to target tissues is regulated by sex hormone-binding globulin (SHBG), a transport protein secreted by liver i.e. specific for androgens. Present study was done to find the association of rs6259 polymorphism with SHBG levels and Poly Cystic Ovary Syndrome in Indian population. Present study was a case control study. 400 subjects were enrolled for the study and serum SHBG levels and D327N polymorphism were measured. The D327N polymorphism (wild-type and variant allele) was detected using PCR-RFLP method (restriction enzyme Bbs-I). PCOS group was found to have significantly lower SHBG levels than healthy controls. There was no significant difference in genotype distribution between PCOS and controls (χ² = 1.0335, p = 0.59). Significant difference in SHBG levels of PCOS and control group highlights the potential of SHBG as a biomarker for PCOS. However, no significant difference in genotype distribution between PCOS and controls provided an insight that rs6259 polymorphism is not associated with the risk of PCOS and SHBG levels.

Sex Hormone-Binding Globulin in Children and Adolescents

Sex hormone-binding globulin (SHBG) is a circulating glycoprotein that transports testosterone and other steroids in the blood. Interest in SHBG has escalated in recent years because of its inverse association with obesity and insulin resistance, and because many studies have linked lower circulating levels of SHBG to metabolic syndrome, type 2 diabetes, nonalcoholic fatty liver disease, polycystic ovary syndrome, and early puberty. The purpose of this review is to summarize molecular, clinical, endocrine, and epidemiological findings to illustrate how measurement of plasma SHBG may be useful in clinical medicine in children.

Nutritional habits, lifestyle, and genetic predisposition in cardiovascular and metabolic traits in Turkish population

OBJECTIVES

Cardiovascular and metabolic traits (CMT) are influenced by complex interactive processes including diet, lifestyle, and genetic predisposition. The present study investigated the interactions of these risk factors in relation to CMTs in the Turkish population.

METHODS

We applied bootstrap agglomerative hierarchical clustering and Bayesian network learning algorithms to identify the causative relationships among genes involved in different biological mechanisms (i.e., lipid metabolism, hormone metabolism, cellular detoxification, aging, and energy metabolism), lifestyle (i.e., physical activity, smoking behavior, and metropolitan residency), anthropometric traits (i.e., body mass index, body fat ratio, and waist-to-hip ratio), and dietary habits (i.e., daily intakes of macro- and micronutrients) in relation to CMTs (i.e., health conditions and blood parameters).

RESULTS

We identified significant correlations between dietary habits (soybean and vitamin B12 intakes) and different cardiometabolic diseases that were confirmed by the Bayesian network-learning algorithm. Genetic factors contributed to these disease risks also through the pleiotropy of some genetic variants (i.e., F5 rs6025 and MTR rs180508). However, we also observed that certain genetic associations are indirect since they are due to the causative relationships among the CMTs (e.g., APOC3 rs5128 is associated with low-density lipoproteins cholesterol and, by extension, total cholesterol).

CONCLUSIONS

Our study applied a novel approach to integrate various sources of information and dissect the complex interactive processes related to CMTs. Our data indicated that complex causative networks are present: causative relationships exist among CMTs and are affected by genetic factors (with pleiotropic and non-pleiotropic effects) and dietary habits.