Role of -675 4G/5G in the plasminogen activator inhibitor-1 gene and -308G/A tumor necrosis factor-α gene polymorphisms in obese Argentinean patients

Genetic factors associated with obesity risks in a Kazakhstani population

Objectives

There is limited published literature on the genetic risks of chronic inflammatory related disease (eg, obesity and cardiovascular disease) among the Central Asia population. The aim is to determine potential genetic loci as risk factors for obesity for the Kazakhstani population.

Setting

Kazakhstan.

Participants

One hundred and sixty-three Kazakhstani nationals (ethnic groups: both Russians and Kazakhs) were recruited for the cross-sectional study. Linear regression models, adjusted for confounding factors, were used to examine the genetic associations of single nucleotide polymorphisms (SNPs) in 19 genetic loci with obesity (73 obese/overweight individuals and 90 controls).

Results

Overall, logistic regression analyses revealed genotypes C/T in CRP (rs1205), A/C in AGTR1 (rs5186), A/G in CBS (rs234706), G/G in FUT2 (rs602662), A/G in PAI-1 (rs1799889), G/T (rs1801131) and A/G (rs1801133) in MTHFR genes significantly decrease risk of overweight/obesity. After stratification for ethnicity, rs234706 was significantly associated with overweight/obesity in both Russians and Kazakhs, while rs1800871 was significant in Kazakhs only.

Conclusions

This study revealed that variations in SNPs known to be associated with cardiovascular health can also contribute to the risks of developing obesity in the population of Kazakhstan.

The -308 G/A polymorphism in the tumor necrosis factor-α gene is not associated with development and progression of rheumatoid arthritis in Argentinean patients

AIM

A polymorphism in the tumor necrosis factor-alpha (TNF-α) promoter region has been associated with disease susceptibility and progression in rheumatoid arthritis (RA). The presence of an adenosine (TNF2 allele) instead of a guanine (TNF1 allele) at position -308 may be responsible for a general increase in the transcriptional activity of the TNF-α gene. Our aim was to evaluate the association of the TNF2 allele with the risk of disease development and/or progression of RA in an Argentine population cohort.

METHODS

Two hundred and twenty-three consecutive patients with RA according to the 1987 criteria of the American College of Rheumatology were included in the study. Clinical variables, Disease Activity Score 28, Health Assessment Questionnaire and Rheumatoid Arthritis Quality of Life were recorded. The radiographic erosions were determined by the method of Sharp/van der Heijde. A group of 111 healthy subjects matched by sex and age was used as a control. All samples were genotyped for the -308 G/A TNF-α polymorphism.

RESULTS

No significant differences were observed either in the frequency of the TNF2 allele or in the genotypic distributions of the -308 G/A TNF-α polymorphism (P > 0.05) between the control group and the RA patients. No association was found between the TNF2 allele and the variables related to the course and outcome of the disease (P > 0.05).

CONCLUSION

In this cohort of Argentinean patients with RA, the TNF2 allele was neither associated with susceptibility to the disease nor was it associated with the variables related to the course and outcome of the disease.

Supplementation with L-arginine favorably influences plasminogen activator inhibitor type 1 concentration in obese patients. A randomized, double blind trial

BACKGROUND

Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients.

MATERIAL/SUBJECTS AND METHODS

A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eightyeight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique.

RESULTS

We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found.

CONCLUSIONS

The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.