Amerindians normalized waist circumference and obesity diagnosis standarized by biochemical and HLA data

Interaction between non-alcoholic fatty liver disease and obesity on the risk of developing cardiovascular diseases

BACKGROUNDS

This investigation seeks to explore the correlation between nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs), and to to provide evidence for the prevention and treatment of CVDs.

METHODS

This study utilized data from the Jinchang cohort platform, including 19,399 participants without pre-existing major CVDs. Based on the general population and gender stratification, Cox models were used to analyze the risk of NAFLD for CVDs. The combined effect of NAFLD and different obesity indicators on CVDs was analyzed by additive and multiplicative interaction models and subgroups.

RESULTS

There were 3129 NAFLD patients out of 19399 subjects, and 723 (23.11%) of them had the CVD. After adjusting for multiple confounding factors, the Cox model revealed a 1.17-fold increase in the risk of CVDs among patients with NAFLD compared to those without NAFLD. Moreover, there was no notable disparity in CVDs risk among most NAFLD patients at the same level of obesity. The results indicated no additive interaction between NAFLD and obesity concerning CVDs risk, but rather a positive multiplicative interaction. Using the normal population as a reference, it was found that people with both obesity and NAFLD significantly increased the risk of developing CVDs, with HRs and 95% CIs of 1.790 (1.508, 2.126), 1.356 (1.213, 1.517), and 1.807 (1.503, 2.174), respectively, for BMI, WC, and the combination of BMI and WC.

CONCLUSIONS

NAFLD and obesity are independent risk factors for CVDs. The synergy of obesity and NAFLD implies that NAFLD patients should control weight gain. Larger BMI and WC values may increase the CVDs risk for NAFLD patients, especially women.

HLA-DMB in Amerindians: Specific linkage of DMB*01:03:01/DRB1 alleles

BACKGROUND

HLA-DMB proteins are important for intracellular microbial metabolism in order other major histocompatibility complex (MHC) molecules present peptides to lymphocytes. In addition, HLA-DMB alleles have been found linked to diseases in some ethnic groups and HLA-DMB molecules may be important to explain HLA disease association.

OBJECTIVE

To detect HLA-DMB alleles profile in Amerindians for the first time and compare them to other populations. This will establish the bases to study HLA-DMB linkage to disease in Amerindians.

METHOD

A group of 168 voluntary Amerindians have been typed for HLA-DMB alleles. They have been characterized both, by genetic and genealogical bases. Cloning and automated HLA-DMB DNA (exons 2, 3 and 4) sequencing have been performed for allele assignation.

RESULTS

HLA-DMB*01:01:01 and HLA-DMB*01:03:01 show the highest frequencies. These have been compared to other World wide populations. HLA-DMB*01:03:01 is tightly associated to certain specific HLA-DRB1 alleles in Amerindians.

CONCLUSION

The specific Amerindian HLA-DMB allele frequencies and their linkage disequilibrium with other MHC alleles may be crucial to determine HLA-DMB World wide variation, evolution and specific linkage to disease in Amerindians and other populations.

Amerindians show association to obesity with adiponectin gene SNP45 and SNP276: population genetics of a food intake control and "thrifty" gene

Adiponectin gene polymorphisms SNP45 and SNP276 have been related to metabolic syndrome (MS) and related pathologies, including obesity. However results of associations are contradictory depending on which population is studied. In the present study, these adiponectin SNPs are for the first time studied in Amerindians. Allele frequencies are obtained and comparison with obesity and other MS related parameters are performed. Amerindians were also defined by characteristic HLA genes. Our main results are: (1) SNP276 T is associated to low diastolic blood pressure in Amerindians, (2) SNP45 G allele is correlated with obesity in female but not in male Amerindians, (3) SNP45/SNP276 T/G haplotype in total obese/non-obese subjects tends to show a linkage with non-obese Amerindians, (4) SNP45/SNP276 T/T haplotype is linked to obese Amerindian males. Also, a world population study is carried out finding that SNP45 T and SNP276 T alleles are the most frequent in African Blacks and are found significantly in lower frequencies in Europeans and Asians. This together with the fact that there is a linkage of this haplotype to obese Amerindian males suggest that evolutionary forces related to famine (or population density in relation with available food) may have shaped world population adiponectin polymorphism frequencies.

Amerindians show no association of PC-1 gene Gln121 allele and obesity: a thrifty gene population genetics

PC-1 Gln121 gene is a risk factor for type 2 diabetes, obesity and insulin resistance in European/American Caucasoids and Orientals. We have aimed to correlate for the first time this gene in Amerindians with obesity and their corresponding individuals genotypes with obesity in order to establish preventive medicine programs for this population and also studying the evolution of gene frequencies in world populations. Central obesity was diagnosed by waist circumference perimeter and food intake independent HDL-cholesterol plasma levels were measured. HLA genes were determined in order to more objectively ascertain participants Amerindians origin. 321 Amerindian blood donors who were healthy according to the blood doning parameters were studied. No association was found between PC-1 Gln121 variant and obesity. Significant HDL-cholesterol lower values were found in the PC-1 Lys121 bearing gene individuals versus PC-1 Gln121 bearing gene ones (45.1 ± 12.7 vs. 48.7 ± 15.2 mg/dl, p < 0.05). Population analyses showed a world geographical gradient in the PC-1 Gln121 allele frequency: around 9% in Orientals, 15% in European Caucasoids and 76% in Negroids. The conclusions are: (1) No association of PC-1 Gln121 gene is found with obesity in Amerindians when association is well established in Europeans. (2) PC-1 Gln121 gene is associated to higher levels of HDL-cholesterol than the alternative PC-1 Lys121 allele. This may be specific for Amerindians. (3) Amerindians have an intermediate frequency of this possible PC-1 Gln121 thrifty gene when compared with Negroid African Americans (78.5%) or Han Chinese (7.5%, p < 0.0001). Historical details of African and other groups may support the hypothesis that PC-1 Gln121 is indeed a thrifty gene.