Association of KLOTHO gene variants with metabolic and renal function parameters in Mexican patients living with type 2 diabetes.

Objective: Type 2 diabetes (T2D) and high blood pressure are the main causes of chronic kidney disease (CKD) in adulthood. Both metabolic and oxidative stresses driven by hyperglycemia as well as genetic factors have been suggested as pathogenic causes of renal failure. Some single nucleotide variants (SNVs) on gene coding KLOTHO (KL) have been implicated in several clinical scenarios including hypertension, diabetes, and cardiovascular disease. The aim of this study was to analyze the association of rs1207568 (-395G > A), rs953614 (+ 1062T > G) and rs564481 (+ 1818 C > T) SNVs with metabolic and renal function parameters in Mexican patients living with type 2 diabetes. Methods: A cross-sectional study was conducted in 637 Mexican patients with T2D, and/or hypertension without previous diagnosis of CKD. Anthropometric, metabolic, and renal function parameters were determined. Patients were genotyped for rs1207568, rs953614 and rs564481 SNVs and associations under a dominant genetic model were analyzed by logistic regression. Results: For rs9536314, G-allele showed to be protective for hypo-HDL-C, albuminuria, and CKD. Carriers of minor allele of rs564481 had low odds for high glucose levels. No differences in genotype nor allele frequencies between the patients and the reference population were observed. Conclusion: In Mexican patients living with type 2 diabetes, KL variant rs9536314 was found associated with low odds of hypo-HDL cholesterol, albuminuria and presence of CKD. Meanwhile the consensus of soluble KLOTHO measurement is reached, genetic variants in the KL gene could be considered as genetic markers for CKD susceptibility in patients at high-risk of vascular complications.

Sex differences in fetal kidney reprogramming: the case in the renin-angiotensin system.

During the early stages of the development of the living multiorgan systems, genome modifications other than sequence variation occur that guide cell differentiation and organogenesis. These modifications are known to operate as a fetal programming code during this period, and recent research indicates that there are some tissue-specific codes in organogenesis whose effects may persist after birth until adulthood. Consequently, the events that disrupt the pre-established epigenetic pattern could induce shifts in organ physiology, with implications on health from birth or later in adult life. Chronic kidney disease (CKD) is one of the main causes of mortality worldwide; its etiology is multifactorial, but diabetes, obesity, and hypertension are the main causes of CKD in adults, although there are other risk factors that are mainly associated with an individual's lifestyle. Recent studies suggest that fetal reprogramming in the developing kidney could be implicated in the susceptibility to kidney disease in both childhood and adulthood. Some epigenetic modifications, such as genome methylation status, dysregulation of miRNA, and histone coding alterations in genes related to the regulation of the renin-angiotensin axis, a common denominator in CKD, may have originated during fetal development. This review focuses on epigenetic changes during nephrogenesis and their repercussions on kidney health and disease. In addition, the focus is on the influence of environmental factors during pregnancy, such as maternal metabolic diseases and dietary and metabolic conditions, as well as some sex differences in fetal kidney reprogramming during which dysregulation of the renin-angiotensin system is involved.

Association of Serum Fibroblast Growth Factor 23 and FGF23 Gene Variants with Chronic Kidney Disease in Patients with Type 2 Diabetes and Essential Hypertension.

INTRODUCTION: Fibroblast growth factor 23 (FGF23) gene variants could influence the production of FGF23 in subjects at risk for chronic kidney disease (CKD). Our purpose was to analyze the association of serum levels of FGF23 and two FGF23 gene variants with metabolic and renal function parameters in Mexican patients with Type 2 Diabetes (T2D) and/or essential hypertension (HTN). MATERIALS/METHODS: The study included 632 individuals diagnosed with T2D and/or HTN, of which 269 (43%) were diagnosed with CKD. FGF23 serum levels were determined and FGF23 gene variants rs11063112 and rs7955866 were genotyped. Genetic association analysis included binary and multivariate logistic regressions adjusted for age and sex. RESULTS: Patients with CKD were older, had higher systolic blood pressure, uric acid, and glucose levels than those without CKD. Also, patients with CKD had higher FGF23 levels (106 vs. 73 pg/mL p = 0.003). No correlation of any gene variants with FGF23 levels was found, but minor allele for rs11063112 and haplotype rs11063112A-rs7955866A were associated with low probability of CKD (Odds Ratio [OR] = 0.62 and 0.58, respectively). Conversely, the haplotype rs11063112T-rs7955866A was associated with increased FGF23 levels and risk for CKD (OR = 6.90). CONCLUSIONS: In addition to the traditional risk factors, levels of FGF23 are higher in Mexican patients with diabetes and/or essential hypertension and CKD, compared to those without renal damage. In contrast, the two minor alleles of two variants of the FGF23 gene, rs11063112 and rs7955866, as well as the haplotype carrying these two alleles, were found to be protective against renal disease in this Mexican patients' sample.

Transcription factor NRF2 as potential therapeutic target for preventing muscle wasting in aging chronic kidney disease patients.

Increased muscle protein catabolism leading to muscle wasting is a prominent feature of the syndrome of protein-energy wasting (PEW) in patients with chronic kidney disease (CKD). PEW and muscle wasting are induced by factors such as inflammation, oxidative stress and metabolic acidosis that activate the ubiquitin-proteasome system, the main regulatory mechanism of skeletal muscle degradation. Whether deficiency of nuclear factor erythroid 2-related factor 2 (NRF2), which regulates expression of antioxidant proteins protecting against oxidative damage triggered by inflammation, may exacerbate PEW has yet to be examined in aging patients with CKD. This review focuses on the hypothesis that NRF2 is involved in the maintenance of muscle mass and explores whether sustained activation of NRF2 by non-pharmacological interventions using nutraceutical activators to improve redox homeostasis could be a plausible strategy to prevent skeletal muscle disorders, including muscle wasting, sarcopenia and frailty associated with PEW in aging CKD patients.

Association of Variants of the NFE2L2 Gene with Metabolic and Kidney Function Parameters in Patients with Diabetes and/or Hypertension.

Background: Type 2 diabetes mellitus (T2DM) and high blood pressure (HBP) are the main risk factors for chronic kidney disease (CKD). Relationships between variants within the NFE2L2 gene and the presence of environmental risk factors for CKD, such as HBP and hyperglycemia have been suggested; however, their interactions remains unclear. Aim: To analyze the association of NFE2L2 variants with metabolic and kidney parameters. Materials and Methods: Six-hundred and fifty-one patients grouped according to the diagnosis of T2DM (n =166), T2DM+HBP (n =348) and HBP (n =137) were included. Metabolic characteristics were evaluated to identify risk factors and presence of CKD. Genotyping was performed by polymerase chain reaction (PCR) using two pairs primers for rs35652124 and rs6721961 and by real-time PCR for rs2364723. Logistic regression analyses, adjusted for confounding factors and correction for multiple tests were performed. Results: Significant associations between decreased risk for presenting with CKD and the rs35652124 (A allele) and the rs2364723 (G allele) variants were detected. Other variables consistently associated with these alleles were HBP, BMI, waist circumference, uric acid and triglycerides. Haplotypes AAC and GCG (loci order: rs35652124-rs6721961-rs2364723) showed similar trends. After adjustment for age and sex and correction for multiple tests, only rs35652124 (Odds Ratio [OR] = 0.5; Confidence Interval at 95% (CI95%), 0.3-0.9; p = 0.04) and rs2364723 (OR = 0.3; CI95%, 0.1-0.8; p = 0.009) variants remained associated with deceased risk for CKD in T2DM patients. Conclusion: This study showed for the first time that NFE2L2 variants are associated with decreased risk for CKD in the presence of environmental/metabolic risk factors related to kidney damage, including HBP, hyperuricemia and albuminuria in Mexican patients with diabetes.

Interactions Between Diet Quality and Interleukin-6 Genotypes Are Associated With Metabolic and Renal Function Parameters in Mexican Patients With Type 2 Diabetes Mellitus.

OBJECTIVE: The aim of this study was to evaluate the interaction between diet quality and interleukin (IL)-6 genotypes and its association with metabolic and renal function parameters in Mexican patients with type 2 diabetes mellitus (T2DM). DESIGN AND METHODS: Using an analytical cross-sectional design, 219 patients with T2DM (92 men; age 62 ± 10 years) were evaluated for selected metabolic and renal function parameters. Diet quality according to the Healthy Eating Index was evaluated and classified as good diet or poor diet in all patients. IL-6 serum concentrations and genotypes and haplotypes for IL6-597G > A (rs180097), -572G > C (rs180096), and -174G > C (rs180095) polymorphisms were determined. RESULTS: Eighty-two percent of patients reported having a poor diet. Carriers of alleles -572C and -174C showed higher high-density lipoprotein cholesterol levels (44 ± 12 vs. 40 ± 9 mg/dL; P = .01) and lower total cholesterol levels (184 ± 33 vs. 197 ± 42 mg/dL; P = .03) than did those homozygous for G/G. Neither IL6 genotypes nor haplotypes were significantly associated with serum concentrations of IL-6. Some significant interactions between IL6 genotypes/haplotypes and diet quality were associated with body mass index, waist circumference, high-density lipoprotein cholesterol levels, and estimated glomerular filtration rate. CONCLUSIONS: Interactions between diet quality and IL6 genotypes/haplotypes were associated with the main metabolic and renal function parameters in Mexican patients with T2DM. It will be important to consider genetic profiles in designing dietary portfolios and nutritional interventions for the management of such patients.

Relación entre el índice lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) con enzimas antioxidantes y el índice oxLDL/HDL.

INTRODUCTION: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. OBJECTIVE: To assess the association of the index with oxidative stress markers. METHODS: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. RESULTS: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). CONCLUSIONS: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

INTRODUCCIÓN: El índice de lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) es un factor predictivo de aterosclerosis, la cual está asociada con modificaciones oxidativas. OBJETIVO: Evaluar la asociación del índice con marcadores de estrés oxidativo. MÉTODO: Se incluyeron 444 sujetos, caracterizados clínica, antropométrica y bioquímicamente; se cuantificó superóxido dismutasa, glutation peroxidasa 3 (GPx3), magnesio e índice LDL oxidadas (oxLDL/HDL). RESULTADOS: La disminución en 1.014 unidades del índice LDL/HDL se asoció con aumento de 1 unidad/mL de superóxido dismutasa (p = 0.030) y la de 0.023 unidades con aumento de 1 nmol/minuto/mL de GPx3 (p < 0.0005). El aumento en 1 unidad del índice se asoció con aumento de 0.831 unidades en el índice oxLDL/HDL (p < 0.05). Después de controlar el efecto del sexo, edad, fumar, obesidad y resistencia a la insulina, la reducción de 0.001 por unidad del índice se asoció con aumento de 1 µg/g de magnesio en uñas (p = 0.020). CONCLUSIONES: El índice LDL/HDL presenta relación inversa con el estado antioxidante y relación directa con el estado de oxidación, independientemente de otros factores de riesgo cardiovascular y de estrés oxidativo.

No association of HLA-DRB1 and TNF alleles in Mexican patients with autoimmune hepatitis.

HLA-DRB1 alleles has been found implicated in susceptibility to autoimmune hepatitis (AIH) in populations from different genetic backgrounds. In Mexicans, HLA-DRB1*04:04 is recognized as a risk allele for AIH but, to date, there is no high-resolution data supporting this association. Also, the association of other nonclassical HLA genes, such as TNF-LTA locus, have not, to our knowledge, been evaluated in this population. The association of HLA-DRB1 alleles determined by sequence-based typing and two polymorphisms in the TNF locus with AIH in a sample of Mexican patients was evaluated. Fifty-six patients from Guadalajara, Mexico, diagnosed with AIH and 115 age-gender matched healthy volunteer blood donors, were genotyped for HLA-DRB1 by the sequencing exon 2 and for TNFA-308G>A and LTA + 252A>G polymorphisms. Increased frequencies of both HLA-DRB1*04:04:01 and *16:02:01:01 alleles (OR = 2.91; 95% CI = 1.08-7.84) and the haplotype (DRB1-TNFA-LTA) *04:04:01-G-A (OR = 5.33; 95% CI = 1.32-21.49) were observed in AIH patients. However, after corrections for multiple comparisons, associations were not significant. In conclusion, our study does not support the association of HLA-DRB1*04:04:01 with the susceptibility to AIH in Mexican population. More studies including patients from other Mexican regions and considering other genetic, immunological, and environmental factors should be performed.

Relationship of the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index with antioxidant enzymes and with the oxLDL/HDL index

Introduction: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. Objective: To assess the association of the index with oxidative stress markers. Methods: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. Results: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). Conclusions: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

Interleukin-1 Alpha Polymorphisms Are Associated With Body Mass Index in Male But Not in Female Adolescents.

BACKGROUND: The Interleukin (IL)-1 family of cytokines plays a key role in the inflammatory response. Genes coding for IL-1α, IL-1ß, and IL-1Ra are located together as a block gene known as the IL-1 cluster. This genomic region shows wide nucleotide variability, and some polymorphisms have been widely studied and associated with features related to the metabolic syndrome. METHODS: Eight polymorphisms within three genes of the IL-1 cluster, including IL1A (rs3783553, rs17561, and rs1800587), IL1B (rs1143634, rs1143627, and rs16944) and IL1RN (rs419598 and rs2234663) were genotyped in 460 Mexican adolescents. Genotype and haplotype frequencies are reported, as well as the linkage disequilibrium analysis. Genetic associations with some anthropometric and metabolic traits were evaluated. RESULTS: Allele frequencies were similar to those found in other populations, and genotype proportions were according to the Hardy-Weinberg equilibrium. Seven haplotypes were observed at frequencies ≥5%. Of the entire cluster, only the rs17561-rs1800587 and rs1143627-rs16944 pairs showed highest and significant linkage disequilibrium values. An haplotype of IL1A, rs17561T-rs1800587T, was significantly associated with increase in body mass index in males (p <0.008), whereas IL1B and IL1RN variants showed associations with insulin, and hs-CRP (p <0.05). CONCLUSIONS: Some MetS parameters seem to be influenced by variations in the IL-1 gene cluster in Mexican adolescents. These variations may confer risk for metabolic alterations from early ages, and and these risks may be different when variables such as sex are considered. Strategies leading to generate protective behaviors could be designed to take into account specific variations in the IL-1 gene cluster and biological conditions such as sex.

KIR/HLA Gene Profile Implication in Systemic Sclerosis Patients from Mexico.

INTRODUCTION: Systemic Sclerosis (SSc) is an autoimmune, inflammatory, and multisystemic disease characterized by the presence of autoantibodies and fibrosis. The pathogenesis involves the interaction between immune system cells such as macrophages, NK cells, T cells, and B cells. Killer-cell Immunoglobulin-like Receptors (KIR) are expressed in NK cells and some T cell subsets that recognize HLA class I molecules as ligands and are involved in regulating the activation and inhibition of these cells. The KIR family consists of 14 genes and two pseudogenes; according to the gene content, the genotype could be AA and Bx. The aim of this study was to evaluate the association between KIR/HLA genes and genotypes with SSc and the clinical characteristics. METHODS: We included 50 SSc patients and 90 Control Subjects (CS). Genotyping of KIR, HLA-C, -Bw4, and -A ∗ 03/ ∗ 11 was made by SSP-PCR. RESULTS: In SSc patients, a higher frequency of KIR2DL2 (p = 0.0007, p' = 0.011), KIR2DS4del (p = 0.001, p' = 0.021), and HLA-C2 (p = 0.02, p' = 0.09) was found. This is the first study to evaluate the frequency of HLA-A ∗ 03/ ∗ 11 in SSc patients, of which a low frequency was found in both groups. Compound genotypes KIR2DL2+/HLA-C1+ or KIR2DL2+/HLA-C2+ have a higher frequency in SSc patients. The Bx genotype was the most frequent and was associated with risk to SSc (p = 0.007, OR = 3.1, 95% CI = 1.4-7.9, p' = 0.014). The genotypes with a higher iKIR number than aKIR (iKIR > aKIR) were found in all individuals; genotypes with 7-8 iKIR genes were increased in SSc patients. We do not find an association between the KIR genes with the clinical characteristics. CONCLUSION: The results suggest that KIR2DL2 and 2DS4del could have a risk role in the development of SSc, but not with clinical manifestations.

Relationship of the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index with antioxidant enzymes and with the oxLDL/HDL index.

INTRODUCTION: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. OBJECTIVE: To assess the association of the index with oxidative stress markers. METHODS: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. RESULTS: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). CONCLUSIONS: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

Metabolic and genetic markers' associations with elevated levels of alanine aminotransferase in adolescents.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in adolescents, is a feature of metabolic syndrome (MetS). Obesity and insulin resistance (IR) are risk factors for NAFLD, as well as inflammation-related genetic markers. The relationship between metabolic or inflammation-related genetic markers and alanine aminotransferase (ALT) is not fully understood. We examined the relationship of MetS, metabolic and inflammation-related genetic markers with elevated ALT in adolescents. METHODS: A total of 674 adolescents participated in a cross-sectional study in Guadalajara, Mexico. Elevated ALT (>40 IU/L), a surrogate marker of NAFLD, and MetS (International Diabetes Federation definition) were evaluated. Obesity, IR, lipids, C-reactive protein (CRP) and genetic markers (TNFA-308G>A, CRP+1444C>T, IL1RN and IL6-597/-572/-174 haplotype) were evaluated. Multivariate logistic regression was performed. RESULTS: Elevated ALT was observed in 3% and 14.1% (total and obese, respectively) of the adolescents. Obesity (odds ratio [OR], 5.86; 95% confidence interval [95% CI], 1.16-25.89), insulin (OR, 8.51; 95% CI, 2.61-27.71), IR (OR, 9.10; 95% CI, 2.82-29.38), total cholesterol (TC) (OR, 3.67; 95% CI, 1.25-10.72), low-density lipoprotein-cholesterol (LDL-C) (OR, 3.06; 95% CI, 1.06-8.33), non-high-density lipoprotein-cholesterol (HDL-C) (OR, 3.88; 95% CI, 1.27-11.90) and IL1RN (OR, 4.64; 95% CI, 1.10-19.53) were associated with elevated ALT. Among males, ≥2 MetS criteria were associated with elevated ALT (OR, 4.22; 95% CI, 1.14-15.71). CONCLUSIONS: Obesity, insulin, IR, high TC, high LDL-C, high non-HDL-C and IL1RN polymorphism were associated with elevated ALT. Among males, ≥2 MetS criteria were associated with elevated ALT. There is an urgent need to reduce obesity and IR in adolescents to prevent NAFLD.

Circulating Levels of Soluble Klotho and Fibroblast Growth Factor 23 in Diabetic Patients and Its Association with Early Nephropathy.

INTRODUCTION: Diabetic nephropathy is a leading cause of chronic kidney disease (CKD). In diabetes, changes in serum levels of both soluble alpha Klotho (sKL) and fibroblast growth factor 23 (FGF-23) have been associated with CKD progression. OBJECTIVE: To evaluate the associations of circulating levels of sKL and FGF-23 with the presence of early nephropathy (EN) in diabetic patients. METHODS: A cross-sectional study in 136 Mexicans with type 2 diabetes mellitus (T2DM). Early nephropathy was defined as an estimated glomerular filtration rate (≥60 ml/min) and urinary albumin excretion (≥30 mg/g). Serum concentrations of sKL and FGF-23 were measured using ELISA. Associations were evaluated with multiple logistic regression. RESULTS: Fifty-two subjects had EN. Median values of sKL and FGF-23 for all individuals were 244 pg/mL (interquartile range [IQR]: 201-402) and 92 pg/mL (IQR: 39-507), respectively. A positive correlation was found between levels of sKL and FGF-23 (r = 0.38; p <0.001). FGF-23 levels correlated negatively with angiotensin-II receptor blocker therapy (ARB, r = 0.24; p <0.01). Subjects without EN were younger (59 vs. 63 years old, p = 0.02). Elevated concentrations of FGF-23 were negatively associated with EN (Odds Ratio [ORadjusted] = 0.29, 95% Confidence Interval [95% CI] = 0.13, 0.65). CONCLUSIONS: In Mexican diabetic patients, serum levels of FGF-23 were positively correlated with sKL but negatively correlated with ARB therapy. In addition, a higher concentration of FGF-23 reduced the odds of early nephropathy in patients with T2DM.

Analysis of cytokine gene polymorphisms in Mestizo and native populations from Mexico.

OBJECTIVES: To determine whether the well-known genetic structure of the Mexican population observed with other multiallelic markers can be detected by analyzing functional polymorphisms of cytokine and other inflammatory-response-related genes. METHODS: A total of 834 Mestizo individuals from five Mexican cities and 92 Lacandonians - an Amerindian group from southeastern Mexico - were genotyped for 14 polymorphisms in the CRP, IL10, IL6, TGFB1, TNFA, LTA, ICAM1 IFNG, and IL1RN genes. Allele and haplotype frequencies were used for genetic structure analysis using F-statistics pairwise distances and multidimensional scaling plot. Ancestry analysis was performed, as well. RESULTS: Significant interpopulational differences at the allele and haplotype frequency level were observed, mainly between Northern (Guadalajara, Monterrey, and Culiacan) and Southern (Tierra Blanca and Puebla) Mexican populations. Also, low but significant substructure was detected between some populations from these two broad regions. Interestingly, both Lacandonian populations were highly differentiated from each other and with respect to Mestizos. Consistent with previous data, Amerindian ancestry in the Southern Mexican groups was higher compared to Northern ones. CONCLUSIONS: The Mexican population exhibits regional differences in functional polymorphisms of inflammatory-response genes, as observed for other genetic markers. This information constitutes a reference for epidemiological studies that include these genetic markers to assess the susceptibility of the Mexican population to several immune-response-related diseases, such as diabetes, obesity, and renal disease, which have been shown to be common in the Mexican population but with prevalence differences within this country.

CYP2C9 and CYP2C19 Allele and Haplotype Distributions in Four Mestizo Populations from Western Mexico: An Interethnic Comparative Study.

AIMS: Polymorphisms in the CYP2C9 and CYP2C19 genes confer potential risk for specific adverse drug reactions and therapeutic effect failure. Their frequencies differ among ethnic groups. This study was aimed to describe the distribution of CYP2C9 and CYP2C19 alleles and haplotypes in four Mestizo populations from Western Mexico and their comparison with the reported data from other ethnic groups. METHODS: The CYP2C alleles (CYP2C9*2, CYP2C9*3, CYP2C19*2, and CYP2C19*3) were genotyped using polymerase chain reaction-restriction fragment length polymorphisms analyses using DNA samples from 477 healthy Mestizo individuals of Colima (n = 100), Jalisco (n = 147), Michoacán (n = 117), and Nayarit (n = 113). RESULTS: Frequencies ranged from 2.2-3.0% and 4.8-8.9% for CYP2C9*3 and CYP2C9*2 alleles, respectively, and 5.4-12.0% for CYP2C19*2, whereas the CYP2C19*3 allele was not found. Haplotype GACA, which harbors the loss-of-function allele CYP2C19*2, was the second most frequent (8.7%). Genetic heterogeneity between the Western Mexican populations studied here and the global population was evident (p < 0.05), except for most American populations and other Mexican Mestizo populations. CONCLUSION: Our findings increase the evidence for genetic variability at relevant pharmacogenetic loci and could be useful in association studies involving drugs that are substrates for CYP2C enzymes in the Western Mexican population.

Glutathione peroxidase 3 serum levels and GPX3 gene polymorphisms in subjects with metabolic syndrome.

BACKGROUND AND AIMS: Glutathione peroxidase 3 (GPx3) plays a main role in removing hydro- and lipoperoxides from the body. Changes in concentration and several single-nucleotide polymorphisms (SNP) at the GPX3 gene have been associated with vascular diseases, but the relationship of GPx3 with metabolic syndrome (MetS) remains unexplored. We undertook this study to determine the association of GPx3 serum levels and several GPX3 SNPs with the presence of MetS in Mexican subjects. METHODS: Clinical, biochemical, and anthropometric evaluation were conducted in 426 subjects assigned to three groups: control (n = 42); risk group (RG, n = 200), and MetS group (n = 184). Insulin sensitivity (IS) and cardiovascular risk were determined by the QUICKI and TG/HDL-C index, respectively. Serum GPx3 was determined by enzyme immunoassay and polymorphisms within GPX3 gene were identified by nucleotide sequencing. RESULTS: MetS group showed low IS and increased cardiovascular risk with respect to controls as well as higher GPx3 serum levels (172.9 ± 32.2 vs. 145.6 ± 24.8 ng/dL; p <0.05). Only three of the ten GPX3 SNPs screened were polymorphic with two haplotypes observed (CCT and TTA-rs8177404, rs8177406, and rs8177409), indicating tight linkage disequilibrium in this genetic region. No differences for either genotype or allele frequencies among groups were observed, but rs8177409 (allele T) was associated with cardiovascular risk (odds ratio [OR], 4.5; p = 0.0125). CONCLUSION: This study shows that serum levels of GPx3 are increased in subjects with MetS and that rs8177409 SNP was associated with cardiovascular risk in a Mexican population.

Low prevalence of interleukin-6 haplotypes associated with a decreased risk of type 2 diabetes in Mexican subjects with a family history of type 2 diabetes.

BACKGROUND AND AIMS: There is evidence that family history of type 2 diabetes (FHT2D) and single nucleotide polymorphisms (SNP) on the IL-6 gene promoter region are separately associated with the risk of developing type 2 diabetes. However the relationship between adult Mexican subjects with FHT2D and genotypes/haplotypes for IL-6 gene has not been explored. The aim of the present work was to study the prevalence of IL-6 -598G>A-572G>C-174G>C haplotypes among subjects with FHT2D and to determine whether their presence influences the relationship between FHT2D and risk factors for diabetes. METHODS: Two hundred fifty eight nondiabetic subjects participated in this study; 153 with and 105 without FHT2D. Polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) was used for genotyping. Logistic regression analysis was employed to assess the impact of IL-6 haplotypes on FHT2D per se and hyperinsulinemia and insulin resistance as risk factors for diabetes. RESULTS: Subjects with FHT2D showed a higher prevalence of hyperinsulinemia and insulin resistance (IR) than those without FHT2D (14.4 vs. 5.7%, p = 0.029, and 14.2 vs. 7.0% p = 0.050, respectively). Lower prevalence of -598 -572-174 (AGC)-haplotype (19%) in subjects with FHT2D was observed as well as a lower prevalence of hyperinsulinemia and IR among AGC haplotype carriers (12 and 14%, respectively). The relationship between FHT2D and IR was modified by the presence of AGC haplotype (from OR, 2.70; 95% CI, 0.99-7.36; p = 0.050 OR, 30.08; 95% CI, 0.58-1,568.06; p = 0.092). CONCLUSIONS: IL-6 -598/-572/-174 (AGC) haplotype has a low prevalence among first-degree relatives of subjects with type 2 diabetes. Our results suggest that this haplotype is associated with decreased risk of type 2 diabetes in Mexican subjects with FHT2D.

Interleukin-6 polymorphisms are associated with obesity and hyperglycemia in Mexican adolescents.

BACKGROUND AND AIMS: Interleukin-6 is an inflammatory response mediator used as a metabolic marker of obesity. Polymorphisms IL6 -597C>A, -572G>C, and -174G>C modify the production of this protein. The associations between these haplotypes and obesity or metabolic markers have not been studied in adolescents, so an analysis of these associations was performed. METHODS: The cross-sectional study included 745 apparently healthy 14- to 19-year-old adolescents. Obesity, serum glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol (HDL-C), and high-sensitivity C-reactive protein (hs-CRP) were evaluated, and IL6 -597G>A, -572G>C and -174G>C polymorphisms determined. The associations were analyzed using multivariate logistic regression models. RESULTS: The allele frequencies were 0.15 for -597A and -174C and 0.30 for -572C. Genotypes were in Hardy-Weinberg equilibrium. IL-6(-597/-572/-174) haplotypes GGG, GCG, and AGC comprised 99.74% of the total haplotypes. The associations were significant between genotype GCG/GCG and hyperglycemia (OR = 2.86, 95% CI = 1.02-7.97); between GCG/GCG and high hs-CRP (OR = 6.17, 95% CI = 1.13-33.77); between AGC/AGC and obesity (OR = 4.42, 95% CI = 1.40-14.01); and between GGG/GCG and low HDL-C (OR = 1.53, 95% CI = 1.03-2.28). CONCLUSIONS: Genotypes of the IL6(-597/-572/-174) polymorphisms are associated with metabolic risk factors in Mexican adolescents.

Serum levels of glutathione peroxidase 3 in overweight and obese subjects from central Mexico.

BACKGROUND AND AIMS: Overweight and obesity are considered complex entities in which there are alterations in the concentration of antioxidant enzymes. It has been reported that glutathione peroxidase 3 (GPx3), an extracellular enzyme involved in the reduction of both hydro- and lipoperoxides, shows changes both in gene expression and protein concentration in animal models for type 2 diabetes (T2D) and obesity, but the variability of GPx3 levels in different human populations and under different health conditions are currently unclear. We undertook this study to determine the GPx3 levels in overweight and obese subjects from central Mexico. METHODS: Biochemical profile (serum glucose, insulin and lipid profile) and GPx3 concentrations were determined in 28 healthy subjects (control) and 133 subjects who were overweight or obese (OW-OB). RESULTS: The OW-OB group had a higher concentration of triacylglycerides (TAG) compared with the control group (201.2 ± 88.7 vs. 100.3 ± 46.4 mg/dL, p <0.05) and the TAG/high density lipoprotein-cholesterol (HDL-C) index (5.6 ± 2.8 vs. 2.1 ± 1.2, p <0.05), whereas the concentration of HDL-C decreased (38.2 ± 8.7 vs. 50.1 ± 14.5 mg/dL, p <0.05). Serum GPx3 was significantly higher in the OW-OB group than in the control group (175.4 ± 25.4 vs. 143.5 ± 23.1 ng/dL). GPx3 concentration correlated with insulin sensitivity (IS) and the TAG/HDL-C index (Rho = -0.2336 and Rho = 0.2275) (p <0.01). CONCLUSIONS: The TAG/HDL-C index and serum GPx3 concentration increased in the OW-OB group. In addition, GPx3 had a significant correlation with IS, weight, and the TAG/HDL-C index.