Kanjana Suriyaprom

Measurement of the levels of leptin, BDNF associated with polymorphisms LEP G2548A, LEPR Gln223Arg and BDNF Val66Met in Thai with metabolic syndrome

BackgroundMetabolic syndrome is a cluster of metabolic risk factors including dyslipidemia, impaired glucose tolerance, hypertension and central obesity. BDNF (Brain-derived neurotrophic factor) and leptin have been implied in the energy homeostasis. The purposes of this study were to examine concentrations of leptin, BDNF and biochemical parameters in metabolic-syndrome subjects and healthy controls, and also to search for associations of leptin gene (LEP) G2548A, leptin receptor gene (LEPR) Gln223Arg, and BDNF gene (BDNF) Val66Met polymorphisms with leptin levels, BDNF levels and metabolic syndrome among Thais.MethodsThe case-controlled design was performed using 322 Thai volunteers (160 metabolic-syndrome subjects; 162 controls) during the health screening program. Metabolic syndrome was assessed by using the modified National Cholesterol Education Program, Adult Treatment Panel III criteria. The levels of leptin, BDNF, insulin, glucose and lipids were measured in samples. Genotyping of LEP G2548A, LEPR Gln223Arg and BDNF Val66Met was carried out using polymerase chain reaction-restriction fragment length polymorphism technique.ResultsSerum leptin levels were significantly higher in the metabolic-syndrome group than the control group (p < 0.01), but the BDNF difference between them was not significant. Significant associations of LEPR Gln223Arg polymorphism were found with leptin and glucose levels (p < 0.05), after adjusting for potential covariates. This LEPR polymorphism in the metabolic-syndrome group was also significantly more frequent than in the control group (p < 0.05). However, other gene polymorphisms, LEP G2548A and BDNF Val66Met, showed no significant relationship with leptin levels, BDNF levels or metabolic syndrome.ConclusionThese findings suggest leptin levels are linked with metabolic syndrome. LEPR Gln223Arg polymorphism impacted leptin concentrations, and this gene polymorphism may influence susceptibility to metabolic syndrome among Thais.

Association of adiponectin gene -11377C>G polymorphism with adiponectin levels and the metabolic syndrome in Thais

The metabolic syndrome is related to increased risk of developing cardiovascular disease and type 2 diabetes. Adiponectin is an adipocyte-secreted protein with insulin-sensitizing and anti-atherogenic properties. The aims of this study were to evaluate adiponectin levels and biochemical parameters in metabolic-syndrome subjects and healthy controls. The study also sought to identify links between two polymorphisms, -11377C>G (rs266729) and +45T>G (rs2241766) of the adiponectin gene, in relation to adiponectin levels and the metabolic syndrome. Three hundres and thirty-two Thai volunteers: 164 metabolic-syndrome subjects and 168 healthy control subjects were investigated. The adiponectin and HDL-C levels of the metabolic-syndrome group were significantly lower than the control group (p<0.001). Decreased concentration of adiponectin was associated with -11377C>G polymorphism (p<0.001); this polymorphism was significantly more frequent in the metabolic syndrome group than in the control group (p<0.001). However, +45T>G polymorphism of the adiponectin gene was found not to be related to adiponectin level or metabolic syndrome. Therefore, -11377C>G polymorphism was related to the metabolic syndrome susceptibility, and this polymorphism impacted on circulating adiponectin concentrations among Thais.

The -11377C > G Adiponectin Gene Polymorphism Alters the Adiponectin Concentration and the Susceptibility to Type 2 Diabetes in Thais

The aims of this study were first to detect the levels of adiponectin, insulin, albumin, glucose, alanine aminotransferase (ALT), lipids, homeostasis model assessment for insulin resistance (HOMA-IR), and anthropometric variables in type 2 diabetes mellitus (T2DM) as well as healthy control groups, and to determine whether two adiponectin gene polymorphisms, at the position -11377C > G as well as +45T > G, are associated with serum levels of adiponectin and other variables; then to search for the association between these two single nucleotide polymorphisms (SNPs) of the adiponectin gene and T2DM. We investigated 93 T2DM patients and 90 healthy volunteers. Compared with the healthy control group, the T2DM group had significantly lower adiponectin levels. Waist circumference, total cholesterol, ALT, glucose, insulin, and HOMA-IR scores were significantly higher in the T2DM group than in the control group. The polymorphism of the adiponectin gene at position -11377C > G among type 2 diabetes subjects showed that the adiponectin concentration was significantly lower in CG/GG genotypes (6.2 μg/mL) than the CC genotype (7.8 μg/mL), whereas SNP +45T > G was not associated with adiponectin levels. Adiponectin gene polymorphisms at position -11377C > G and +45T > G were significantly more frequent in type 2 diabetes patients than in the control group (p = 0.022; p = 0.045, respectively). However, multivariate logistic regression analysis showed that the strong impact on T2DM was found for -11377C > G gene polymorphism (p = 0.023) and waist circumference (p < 0.001). Therefore, the single nucleotide polymorphism of -11377C > G in adiponectin promoter region has impact on the lower adiponectin concentrations, and may influence susceptibility to T2DM in Thais.

The +299(G>A) Resistin Gene Polymorphism and Susceptibility to Type 2 Diabetes in Thais

The prevalence of type 2 diabetes has been increased in Thais. Resistin is an adipokine that involve in glucose homeostasis and is a candidate gene for type 2 diabetes. We performed a case-control study in representative sample of 200 Thai volunteers, 105 controls and 95 type 2 diabetes subjects. The purposes of the present study were to investigate the association between two SNPs (single nucleotide polymorphisms) in the resistin gene, at positions +299(G>A) and −420(C>G), and biochemical parameters; to determine whether these polymorphisms are linked to increased risk of type 2 diabetes. At position +299(G>A) of the resistin gene, the resistin concentration among type 2 diabetes subjects was significantly higher in GA/AA genotypes (3.40 ng/ml) than the GG genotype (1.99 ng/ml). Resistin gene polymorphism at position +299(G>A) in type 2 diabetes patients was significantly more frequent than in the control group (p = 0.004). Polymorphism at position −420(C>G) showed no significant relationship with type 2 diabetes (p = 0.095). Logistic regression analysis was shown that +299(G>A) gene polymorphism was increased risk factors for type 2 diabetes (p = 0.013). In conclusion, these finding suggest that resistin gene polymorphism at position +299(G>A) has impact on the increased resistin concentrations and may influence susceptibility to type 2 diabetes in Thais.

BDNF Val66Met polymorphism and serum concentrations of BDNF with smoking in Thai males.

Many studies have suggested that brain-derived neurotrophic factor (BDNF) is involved in the reward system of addiction, and that nicotine may induce alterations in BDNF gene expression and its protein level within the mesocorticolimbic system. We investigated the BDNF levels and biochemical-hematological parameters of smoker and non-smoker groups, and examined the association of the Val66Met BDNF gene polymorphism with BDNF serum levels and cigarette smoking. The study sample comprised 311 Thai volunteers (200 smokers; 111 non-smokers). The levels of serum BDNF and biochemical-hematological parameters were determined. The Val66Met BDNF polymorphism was genotyped by the polymerase chain reaction-restriction fragment length polymorphism technique. The smoker group had significantly higher serum BDNF levels than the non-smoker group (8.3 vs 6.5 ng/mL, P < 0.05). BDNF concentrations correlated positively with hemoglobin, hematocrit, red blood cell count, white blood cell count, platelet count, number of cigarettes smoked, and thiocyanate level (P < 0.05). No association was found between the BDNF Val66Met genotype and the serum BDNF level. The BDNF Val66Met polymorphism was not significantly associated with the smoking status of the Thai males in this study. Cigarette smoking may be one factor that determines the serum BDNF level, but the BDNF Val66Met polymorphism probably does not influence susceptibility to smoking among Thai males.

Impact of COMT Val 108/158 Met and DRD2 Taq1B gene polymorphisms on vulnerability to cigarette smoking of Thai males.

The nicotine in cigarette smoke can stimulate the dopaminergic reward pathways. The catechol O-methyltransferase gene (COMT) and dopamine receptor 2 gene (DRD2) are dopamine-related genes. Genetic polymorphisms in these two genes are potential candidates in determining an individuals predisposition to cigarette smoking. The purposes of this study were to examine the association between two polymorphisms in COMT Val 108/158 Met and DRD2 Taq1B and anthropometric–biochemical parameters and to ascertain the association between these polymorphisms and cigarette smoking. The levels of anthropometric–biochemical parameters were determined. COMT Val 108/158 Met and DRD2 Taq1B polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism technique. With regard to COMT Val 108/158 Met and DRD2 Taq1B polymorphisms, no differences were found in anthropometric–biochemical variables, except for thiocyanate concentration. Smoking status was significantly associated with COMT Val 108/158 Met polymorphism, but not associated with DRD2 Taq1B polymorphism. Logistic regression analysis showed that COMT Val 108/158 Met gene polymorphism, educational status, parental smoking, and alcohol consumption had statistically significant impacts on cigarette smoking. The results suggest that COMT Val 108/158 Met genetic polymorphisms, but not DRD2 Taq1B, may influence susceptibility to cigarette smoking among Thai males.

Homocysteine but not Serum Amyloid A, Vitamin A and E Related to Increased Risk of Metabolic Syndrome in Post-Menopausal Thai Women

This study aims to investigate serum amyloid A, homocysteine, and biochemical-anthropometric measurements in post-menopausal women with and without metabolic syndrome (MS), and determine whether serum amyloid A and homocysteine are linked to MS among this group. This study was performed with 405 post-menopausal Thai volunteers with a mean age of 57.95±5.90 years (135 subjects with MS and 270 subjects without MS). The levels of serum amyloid A, homocysteine, vitamins, glucose, and lipids were measured. Homocysteine levels were significantly higher in the group with MS than in that without MS (p<0.001), whereas for serum amyloid A, vitamin A, vitamin E and vitamin B12, there were no significant differences. There were significant differences between the groups in folate, HDL-C, and anthropometric measurements (p<0.001). Thirty seven percent of the group with MS and 14.1% of the group without MS were classified as having hyperhomocysteinemia (p<0.001). Furthermore, logistic regression analysis revealed that hyperhomocysteinemia (odds ratio (OR): 2.67, 95% confidence interval (95%CI): 1.57-4.58), low folate (OR: 1.79, 95%CI: 1.11-2.89), and BMI (OR: 1.25, 95%CI: 1.16-1.33) were significantly related to MS. These findings suggest that increased homocysteine levels and decreased folate concentrations may influence susceptibility to MS and this effect may be an early event in the development of cardiovascular diseases among post-menopausal women. Therefore, there is a need to evaluate homocysteine levels, especially among post-menopausal Thai women.

Homocysteine and vitamin status in healthy Thai smokers

Purpose. Cigarette smoking is considered to increase morbidity and the mortality risk of cardiovascular diseases. B vitamins regulate the metabolism of homocysteine via remethylation and trans‐sulfuration pathways. The purpose of this study was to investigate homocysteine concentrations, vitamin status, anthropometric and haematological measurements of healthy smokers compared with healthy non‐smoking subjects.Design. This cross‐sectional study was carried out among smokers and non‐smokers from suburban and urban residential areas in Bangkok, Thailand.Materials and methods. 174 smokers and 97 non‐smokers (aged 19–62), who participated voluntarily in the study, were investigated. Total homocysteine, folate, vitamin B2, B6, B12, and C concentrations were measured.Results. Total homocysteine concentrations in plasma were significantly higher in smokers than non‐smokers. Vitamin B2, folate, B12 and C concentrations were significantly lower among smokers than non‐smokers but vitamin B6 was not significantly di...