Additive effect of interleukin-6 and C-reactive protein (CRP) single nucleotide polymorphism on serum CRP concentration and other cardiovascular risk factors

BACKGROUND: Serum C-reactive protein (CRP) levels, closely associated with cardiovascular disease (CVD) risk are influenced by CRP or interleukin-6 (IL-6) single nucleotide polymorphism (SNPs). However, it is still controversial. Therefore, we investigated the association of IL-6/CRP SNPs and serum CRP levels or other CVD risk factors in healthy adult Korean men. METHODS: In healthy adult men (age>or=20 years, n=677), we genotyped IL-6-572C>G and CRP SNPs (-717G>A, 1444C>T, 2147A>G) and measured anthropometric parameters, lipid profile, serum levels of CRP and IL-6 and insulin resistance. RESULTS: At IL-6-572C>G (n=677), subjects with G/G genotype (n=42) showed higher concentrations of CRP (P=0.027) and IL-6 (P=0.028) as compared with C allele carriers after age-adjustment (C/C: n=371, C/G: n=264). Fasting insulin and homeostatis model assessment insulin resistance (HOMA-IR) were also higher in G/G genotype. However, there were no significant differences in other metabolic biomarkers. Among 677 study subjects, 676 were genotyped at CRP-717G>A (G/G: n=513, G/A: n=150, A/A: n=13), 672 at CRP+1444C>T (C/C: n=580, C/T: n=85, T/T: n=7), and 668 at CRP+2147A>G (A/A: n=273, A/G: n=296, G/G: n=99). There were no significant differences in CRP concentrations and other markers related to CVD risk according to each CRP SNP genotype. However, we could find the additive gene-gene interaction between IL-6-572C>G and CRP SNPs on CRP concentration; subjects with the 'G/G' at IL-6-572 showed the highest CRP levels when they have variant allele at CRP SNPs after adjusted for age, body mass index, cigarette smoking and alcohol drinking (-717G>A: F=7.806, P=0.005; CRP+1444C>T: F=8.398, P=0.004; and CRP+2147A>G: F=7.564, P=0.006, respectively) Particularly, G allele carriers at CRP+2147A>G in subjects with IL-6-572G/G showed highest HOMA-IR (F=9.092, P=0.003). CONCLUSION: The present data showed that serum CRP levels and other CVD risk factors appeared more influenced by IL-6-572C>G rather than CRP SNPs (-717G>A, 1444C>T, and 2147A>G), however CRP levels and insulin resistance may be additively affected by IL-6-572 and CRP SNP, particularly when subjects with G/G genotype at IL-6-572 have allele variant at CRP SNPs.     

白细胞介素-6基因多态性与冠心病的相关性研究及其对血脂的影响

目的 探讨白细胞介素6（IL-6） 基因启动子区基因-572位点和-634位点多态性与冠心病的关系,及其对血脂、脂蛋白、载脂蛋白水平的影响.方法 采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法,检测165例冠心病（冠心病组）患者和170名健康人（对照组） 的IL-6基因型;按常规方法测定血脂、脂蛋白、载脂蛋白水平.结果 冠心病组总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）水平均明显高于对照组（P均〈0.05）;IL-6基因-634位点多态性在冠心病组和对照组的分布差异无显著性（P〉0.05）,而IL-6基因-572位点多态性在两组人群中的分布差异存在显著性（P〈0.05）;等位基因频率的相对风险分析发现,G等位基因携带者患冠心病的风险是C等位基因的1.652倍[相对比值比（OR）=1.652,95%可信区间（CI）：1.137～2.401],携带G等位基因的冠心病个体血清TC水平显著高于不携带者（P〈0.05）.结论 IL-6基因-572位点多态性与冠心病的发病具有相关性,其中G等位基因是冠心病重要的遗传标记;IL-6基因-572位点多态性可能通过影响血脂水平而影响冠心病的发生.     

白细胞介素6基因-174G/C和-634C/G多态性与冠心病的相关性研究

目的探讨白细胞介素6(interleukin6,IL6)基因启动子上游174G/C和634C/G基因多态性,在冠心病患者和正常人群中的分布及与冠心病的相关性。方法应用聚合酶链反应限制性片断长度多态性技术,对汉族199例冠心病患者及189名正常人群,白细胞介素6基因174G/C、634C/G位点进行研究,同时结合血脂、脂蛋白和载脂蛋白水平,探讨两者之间的关系。结果正常人群和冠心病患者的174G等位基因频率均为0.99。174C等位基因频率均为0.01。634C等位基因频率在正常人群和冠心病患者分别为0.82和0.76,G等位基因频率分别为0.18和0.24,两者差异有统计学意义(P<0.05)。冠心病患者634GG基因型频率(0.08)明显高于对照组(0.02)(P<0.05)。结论白细胞介素6基因174位点多态性与冠心病无关,而634位点多态性与冠心病有相关性。G等位基因可能是汉族人群冠心病的易感性标志。     

Genetic determination of plasma lipids and insulin in the Czech population

OBJECTIVES: To evaluate the association between plasma lipids and insulin and variation in the genes for apolipoproteins (APO) E (CfoI), B (insertion/deletion), C1 (HpaI), and C3 (C-482T, C3238G) in a population-based Czech Slavonic study. DESIGN AND METHODS: In 131 men and 154 women, polymorphisms were investigated using PCR. In the same subjects plasma lipid levels and insulin were measured. RESULTS: In the women, carriers of the e4 allele had higher apoB (p = 0.03) and triglyceride (p = 0.03) compared to e3 homozygotes, whereas in the men, the effect of the e4 allele was seen on total cholesterol (p = 0.02), LDL cholesterol (p = 0.003) and apoB (p = 0.001). Compared with SP27 (insertion) homozygotes of the APOB polymorphism, women SP24 (deletion) homozygotes had higher levels of total (p = 0.003) and LDL cholesterol (p = 0.007) and apoB (p = 0.05). No significant effect was seen in the men. Women homozygous for the APOC3 -482T allele had higher insulin levels than -482C homozygotes (p = 0.03). Men homozygous for APOC3 -482T allele have the highest plasma triglyceride level (p = 0.02). The APOC1 polymorphism exhibited no significant effect on any of the parameters studied. CONCLUSIONS: In this sample, variation at the APOE, APOB and APOC3 genes play a role in determining plasma levels of insulin and lipids, and emphasize the importance of gender-associated effects in the genetic determinations.     

The effect of novel polymorphisms in the interleukin-6 (IL-6) gene on IL-6 transcription and plasma IL-6 levels,and an association with systemic-onset juvenile chronic arthritis.

During active disease, patients with systemic-onset juvenile chronic arthritis (S-JCA) demonstrate a rise and fall in serum interleukin-6 (IL-6) that parallels the classic quotidian fever. To investigate the possibility that this cytokine profile results from a difference in the control of IL-6 expression, we examined the 5'' flanking region of the IL-6 gene for polymorphisms. A G/C polymorphism was detected at position -174. In a group of 383 healthy men and women from a general practice in North London, the frequency of the C allele was 0.403 (95% confidence interval 0.37-0.44). In comparison, 92 patients with S-JCA had a different overall genotype frequency, especially those with onset of disease at < 5 yr of age. This was mainly due to the statistically significant lower frequency of the CC genotype in this subgroup. When comparing constructs of the 5'' flanking region (-550-+61 bp) in a luciferase reporter vector transiently transfected into HeLa cells, the -174C construct showed 0.624+/-0.15-fold lower expression than the -174G construct. After stimulation with LPS or IL-1, expression from the -174C construct did not significantly change after 24 h, whereas expression from the -174G construct increased by 2.35+/-0.10- and 3.60+/-0.26-fold, respectively, compared with the unstimulated level. Plasma levels of IL-6 were also measured in 102 of the healthy subjects, and the C allele was found to be associated with significantly lower levels of plasma IL-6. These results suggest that there is a genetically determined difference in the degree of the IL-6 response to stressful stimuli between individuals. The reduced frequency of the potentially protective CC genotype in young S-JCA patients may contribute to its pathogenesis. Similarly the individual''s IL-6 genotype may be highly relevant in other conditions where IL-6 has been implicated, such as atherosclerosis.     

白介素6基因启动子区多态性与体重指数和炎症因子等生化指标的相关性及与冠心病发生发展关系的探索

本研究旨在通过对中国北方地区汉族人IL-6基因启动子区-572G／C，-597G／A多态性与体重指数（BMI）和炎症因子等生化指标的相关性的调查，探索基因多态性与冠心病（CHD）发生发展的关系。采用荧光杂交探针、以荧光共振能量转移原理和熔点曲线分析技术，测定了194例冠心病患者和123例健康对照者的IL-6基因型，同时测定BMI、超敏C反应蛋白（hsCRP）、血脂、载脂蛋白等指标，并通过建立逻辑回归（Logistic regression）模型分析CHD发生的危险因素。结果表明，在所有观察对象中发现中国北方汉族人IL-6基因启动子区-597位点有7例为GA型．其余均为GG型，尚未发现AA型，未发现其多态性与BMI和炎症因子等生化指标的相关性。冠心病（cor—onary heart disease，CHD）组与对照组-572G／C基因型频率和等位基因频率分布差异无统计学意义，但是CHD组和对照组携带G等位基因和非G等位基因频率相比差异有统计学意义（P=0，0425）。正常对照组中携带G等位基因者收缩压中位数水平明显高于非G等位基因者（P=0、02）。在所有研究对象中，与非G等位基因组相比，携带G等位基因组的体重指数、超敏C反应蛋白、收缩压中位数水平显著升高（P值分别为0、026、0．022、0、005）。经Logistic逐步回归分析显示，年龄、血清甘油三脂、性别、高血压、载脂蛋白C2、血清总胆固醇、脂蛋白a是冠心病发生的危险因子，而载脂蛋白A1是保护因子（P〈0．05），未见-572G／C的G等位基因是一独立的危险因素。结论：IL-6基因启动子区-597G／A多态性和CHD的易感性无关，而-572G／C多态性与CHD的易感性有关，其机制可能与-572G／C多态性可导致BMI、hsCRP和血压的变化有关。     

IL-6基因启动子区域-572C>G和-174G>C多态性与江苏宿迁汉族人群冠心病的相关性

目的 探讨白细胞介素6(interleukin-6,IL-6)基因启动子区域-572C>G和-174G>C基因多态性与宿迁汉族人群冠心病(coronary heart disease,CHD)的关系。方法 参考2010卫生部CHD诊断标准(WS319-2010),选择2017年1～12月在宿迁市第一人民医院心内科确诊的CHD患者,应用聚合酶链-限制性片段长度多态性(Polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)方法检测266例CHD患者和192例体检健康人群(对照组),分析其IL-6-572C>G和IL-6-174G>C基因多态性,并进行Hardy-Weinberg平衡检验,检测血糖、血脂等生化指标。结果 IL-6-572C>G基因型和等位基因频率在两组间分布差异有统计学意义(χ2=11.1,19.5,22.4,均P<0.05),CHD组GG型和CG型OR值分别是CC型的4.88倍(95%CI:2.31～10.31)和1.96倍(95% CI:1.32～2.91); -174G>C基因型和等位基因频率在两组间分布差异无统计学意义(χ2=0.024,0.027,均P>0.05)。结论 IL-6-572G等位基因可能是宿迁汉族CHD的易感基因,IL-6-174G>C基因多态性可能与宿迁汉族人群CHD没有相关性。     

Interleukin-6 gene promoter -174G/C polymorphism and insulin resistance: a pilot study.

BACKGROUND: The aim of this pilot study was to evaluate the relationship between interleukin-6 promoter -174G/C (IL-6 -174G/C) polymorphism and insulin resistance (IR) in obese patients with coronary heart disease (CHD). METHODS: Twenty obese male patients with CHD were selected from a larger database of patients (n=606). IL-6 -174G/C genotype was previously analysed and only homozygotes with the CC genotype (n=10) or GG genotype (n=10) were selected. IR was measured using the homeostasis model assessment for IR (HOMA-IR) method. RESULTS: Differences in age, body mass index, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), hypertension, IL-6, C-reactive protein and HOMA-IR were not significant between the genotypes (p>0.05), but analysis of a homogeneity-of-slopes model showed that genotype had a significant influence on HOMA-IR (p=0.037), and the interaction between genotype and HDL-C had a pronounced tendency to affect HOMA-IR (p=0.058). Using multiple regression analysis, we found that HDL-C had a significant effect on HOMA-IR (p=0.023), and TG had a tendency to affect HOMA-IR (p=0.066) only in the CC genotype. CONCLUSIONS: Our data show that IL-6 -174G/C polymorphism may have a significant effect on IR. A comparison between the effects of various cardiovascular risk factors showed that HDL-C may have a significant effect on HOMA-IR in the CC genotype but not in the GG genotype. Further research is needed to test the preliminary results.     

IL-6基因-572C／G多态性对2型糖尿病患者血清IL-6水平的影响

【目的】探讨白介素-6（IL-6）基因-572C／G多态性对2型糖尿病患者血清IL-6水平的影响。【方法】应用聚合酶链反应-限制性片段长度多态性方法检测358例初发2型糖尿病患者IL-6基因-572C／G多态性,用ELISA方法检测不同基因型患者的IL-6水平【结果】2型糖尿病患者IL-6基因-572CC,CG,GG基因型人数分别为212,129,17;血清IL-6水平分别为（61．32±16．98）pg／mL,（64．98±15．19）pg／mL和（92．18±25．36）pg／mL,血清IL-6水平在CC,CG基因型间差异无显著性,两种基因型与GG基因型相比,血清IL-6水平差异均有显著性（P〈0．05）。【结论]IL-6基因572C／G多态性可能具有功能性,572GG基因型分泌IL-6能力可能较CC及CG基因型强,IL-6基因572GG基因型可能是2型糖尿病的危险因素之一。     

Polymorphism of the tumor necrosis factor-alpha receptor 2 gene is associated with obesity, leptin levels, and insulin resistance in young subjects and diet-treated type 2 diabetic patients

OBJECTIVE: Mice lacking the tumor necrosis factor-alpha receptor 2 (TNFR2) gene fed a high-fat diet gain less weight and display reduced leptin and insulin levels. In humans, plasma levels of the soluble fraction of TNFR2 (sTNFR2) circulate in proportion to the degree of insulin resistance. The purpose of this study was to evaluate a polymorphism in the 3' untranslated region of the TNFR2 gene on chromosome 1 in relation to BMI, leptin levels, and insulin resistance. RESEARCH DESIGN AND METHODS: Using single-strand conformation polymorphism, the polymorphism was analyzed in 107 nondiabetic subjects (60 women, 47 men) and in 110 consecutive patients with type 2 diabetes (79 women, 31 men). In a subset of 33 healthy subjects, insulin sensitivity (minimal model analysis) was also evaluated. RESULTS: Four alleles of the TNFR2 gene were identified (A1, A2, A3, and A4). BMI and serum leptin levels were significantly increased in young carriers of the A2 allele. Plasma sTNFR2 levels were similar among the different TNFR2 gene variants. However, in subjects who did not carry the A2 allele, in young subjects, and in women, plasma sTNFR2 levels were proportional to BMI and leptin levels. In the study sample, carriers of the A2 allele (n = 18) showed significantly increased BMI, fat mass, waist-to-hip ratio, serum total and VLDL triglyceride levels, and leptin levels and had a lower insulin sensitivity index than noncarriers of the A2 variant (n = 15). The frequency of the different alleles among diabetic subjects was similar to that in the control population. However, diet-treated diabetic subjects (n = 49) who were carriers of the A2 allele exhibited significantly higher BMI and leptin levels than diet-treated noncarriers of the A2 allele. CONCLUSIONS: The presence of the A2 allele in the TNFR2 gene may predispose subjects to obesity and higher leptin levels, which may in turn predispose them to insulin resistance or vice versa. The TNFR2 gene may be involved in weight-control mechanisms.     

白细胞介素-18基因-607C/A多态性与2型糖尿病的相关性

目的研究白细胞介素-18（interleukin 18,IL-18）基因单核苷酸多态性与河北唐山地区人群2型糖尿病（T2DM）的相关性。方法应用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法对122名T2DM患者和161名健康对照者（NC）行IL-18启动子-607C/A基因型检测,并测定血清hs-CRP。结果糖尿病与对照组比较,IL-18基因-607C/A多态性分布差异有统计学意义（P〈0.05）,C等位基因携带者患T2DM的风险是A等位基因的1.883倍（OR=1.883,95%CI：1.28-2.771）。两组人群中CC和CA基因型个体CRP浓度均显著高于AA基因型个体（P〈0.05）。结论IL-18基因-607C/A多态性与T2DM的发病具有相关性,其中C等位基因可能是T2DM的遗传易感基因,并导致血清CRP浓度升高。     

The effect of the Interleukin-6-174G > C promoter gene polymorphism on endothelial function in healthy volunteers

AIMS: Atherosclerosis is a chronic inflammatory condition, manifest in its early stages by endothelial dysfunction. Interleukin-6 (IL6) plays a key role in driving this process through stimulation of acute phase protein synthesis. We have examined the effect of the IL6 gene -174G > C promoter polymorphism on endothelial function in a group of healthy subjects. METHODS: 248 adults aged 20-28 years participated. Polymerase chain reaction was performed for the -174G > C polymorphism. Brachial artery diameter was measured at rest and after forearm cuff occlusion by high-resolution ultrasound. Responses were represented as absolute flow mediated dilatation (FMDA). RESULTS: Overall there was a trend towards greater FMDA for genotype CC, P = 0.14. No effect was seen in women; however, in men, following multivariate analysis, there was a significant association between genotype and FMDA, P = 0.04. In addition, a significant detrimental effect of smoking on FMDA was only seen in males of genotype CC (P < 0.05) when compared to nonsmokers of the same genotype. CONCLUSION: IL6-174G > C promoter polymorphism influences endothelial function in healthy male subjects. The detrimental effect of smoking on endothelial function is most clearly seen in men of genotype -174 CC, suggesting a genotype-specific interaction with smoking.     

Different susceptibility to insulin resistance and fatty liver depending on the combination of TNF-α C-857T and adiponectin G+276T gene polymorphisms in Japanese subjects with type 2 diabetes

The C-857T promoter polymorphism of TNF-α gene is associated with obese type 2 diabetes, while the adiponectin G+276T gene polymorphism in intron 2 may influence the fat accumulation in the liver. In this study, we examined effects of these polymorphisms on clinical markers of insulin resistance and fatty liver (a liver/spleen CT ratio < 0.9). These polymorphisms were determined in 342 Japanese subjects with type 2 diabetes. The liver/spleen CT ratio was lower in the subjects with the adiponectin +276G/G genotype than that in the subjects with the +276T allele (P < 0.05), indicating that fat accumulation in the liver is associated with the +276G/G genotype. Multiple comparisons among the 4 combinations of each polymorphism of the TNF-α and adiponectin genes revealed a significant difference in the liver/spleen CT ratio (P < 0.05) among the 4 groups, indicating that the gene combinations influence the degree of fat accumulation in the liver. The subjects carrying the TNF-α -857T allele (C/T or T/T genotype) and the adiponectin +276G/G genotype had greater risks for fatty liver and insulin resistance that was evaluated by higher levels of fasting insulin and homeostasis model assessment of insulin resistance, as compared with the other groups. Therefore, Japanese subjects with the TNF-α -857T allele and the adiponectin +276G/G genotype may be more susceptible to insulin resistance and fatty liver. The present study provides the evidence for the interaction between TNF-α and adiponectin genes in the insulin resistance and fatty liver in Japanese subjects with type 2 diabetes.     

Extremely high interleukin-6 blood levels and outcome in the critically ill are associated with tumor necrosis factor- and interleukin-1-related gene polymorphisms

OBJECTIVE: To determine the allelic frequencies of interleukin (IL)-6-, IL-1-, and tumor necrosis factor-alpha (TNF)-related gene polymorphisms in critically ill patients with extremely high IL-6 blood level and to examine the genetic effects on their clinical courses. DESIGN: Population-based association study. SETTING: A general intensive care unit in a university teaching hospital. PATIENTS: A total of 150 consecutive critically ill patients recruited at admission to the intensive care unit, regardless of diagnosis, and 150 healthy volunteers. MEASUREMENTS AND MAIN RESULTS: IL-6 blood levels were measured daily with chemiluminescence immunoassay. The IL-6 peak levels were significantly correlated with simultaneously measured TNF (r = .659, p < .0001) and IL-1beta levels (r = .518, p < .0001), respectively. Single nucleotide polymorphism at position -174 and -596 sites of the IL-6 (IL6-174*G/C and IL6-596*G/A), -308 site of the TNF (TNF-308*G/A), and -511 site of the IL-1beta (IL1B-511*C/T) were identified with real-time polymerase chain reaction assay using specific fluorescence-labeled probe. Within the IL-1 receptor antagonist intron 2, a various number of tandem repeat polymorphisms (IL1RN*1-5) were identified after polymerase chain reaction with gel electrophoresis. Allelic frequencies of patients with IL-6 peak levels of > or =10,000 pg/mL (group A) were compared with those of patients with IL-6 peak levels of <10,000 pg/mL (group B). Neither IL6-174*C nor IL6-596*A were recognized in all the subjects; however, group A showed a higher frequency of TNF-308*A (p = .054), IL1B-511*T (p = .013), and non-IL1RN*1 (p = .008) allele compared with group B. TNF-308*A, IL1RN*2 or IL1RN*3 allele carriers of group A showed sustained high IL-6 levels, despite countermeasures against hypercytokinemia, and their survival rate was lower than that of the noncarriers of those high-risk alleles (p = .025). CONCLUSIONS: TNF-308*A, IL1RN*2, and IL1RN*3 alleles were associated with the prevalence of the extremely high IL-6 blood level in the critically ill, their uncontrollable blood IL-6 kinetics, and outcome.     

Genetic predisposition of the interleukin-6 response to inflammation: implications for a variety of major diseases?

BACKGROUND: A single-nucleotide polymorphism (SNP) in the promoter region of the interleukin-6 (IL-6) gene at position -174 (G>C) has been reported to be associated with a variety of major diseases, such as Alzheimer disease, atherosclerosis, and cardiovascular disease, cancer, non-insulin-dependent diabetes mellitus, osteoporosis, sepsis, and systemic-onset juvenile chronic arthritis. However, authors of previous in vitro and in vivo studies have reported conflicting results regarding the functionality of this polymorphism. We therefore aimed to clarify the role of the -174 SNP for the induction of IL-6 in vivo. METHODS: We vaccinated 20 and 18 healthy individuals homozygous for the -174 C and G alleles, respectively, with 1 mL of Salmonella typhii vaccine. IL-1beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) were measured in the blood at baseline and up to 24 h after vaccination. RESULTS: Individuals with the G genotype had significantly higher plasma IL-6 values at 6, 8, and 10 h after vaccination than did individuals with the C genotype (P <0.005). There were no differences between the two genotypes regarding serum concentrations of IL-1beta and TNF-alpha before or after vaccination. CONCLUSIONS: The -174 G>C SNP in the promoter region of the IL-6 gene is functional in vivo with an increased inflammatory response associated with the G allele. Considering the central role of IL-6 in a variety of major diseases, the present finding might be of major relevance.     

Cytokine promoter polymorphisms in Taiwanese patients with Graves' disease

OBJECTIVES: This study aimed to examine the association between promoter polymorphisms of Th1 and Th2 cytokine genes [interleukin-4 (IL-4 T-34C, A-81G, C-285T and T-589C), IL-6 (G-174C), IL-10 (A-592C and T-819C) and tumour necrosis factor-alpha (TNF-alpha G-238A and G-308A)] and Graves' disease (GD) in Taiwanese population. DESIGN AND METHODS: Genomic DNA was extracted from peripheral blood cells of 137 GD patients and 189 control subjects. Cytokine gene polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: Genotype frequencies of TNF-alpha G-238A or G-308A between control and GD subjects were significantly different. Frequencies of the high TNF-alpha secreting alleles (-238*A and -308*A) and IL-10 -819*C allele were significantly increased in GD patients. No significant differences regarding IL-4 or IL-6 gene polymorphisms between GD patients and control subjects were found. CONCLUSIONS: Our data demonstrated that TNF-alpha G-238A and G-308A genotypes were strongly associated with GD incidence.     

The insertion/deletion polymorphism of the ACE gene is related to insulin sensitivity in overweight women

OBJECTIVE: The ACE insertion/deletion (I/D) polymorphism has been identified as a genetic risk factor for coronary heart disease (CHD). The deletion (D) allele of the ACE gene may be associated with higher insulin sensitivity. Individuals who are homozygous for the DD allele have higher ACE levels and possibly more angiotensin II, which, when infused exogenously, causes an increase in insulin sensitivity. The purpose of this study was to investigate the association of the I/D polymorphism of the ACE gene with insulin sensitivity and CHD risk factors. RESEARCH DESIGN AND METHODS: The study included 66 women (ages 57 +/- 1 years) who were overweight or obese (means +/- SEM, BMI = 33 +/- 1 kg/m(2)) and sedentary (VO(2max) = 19.6 +/- 0.4 ml. kg(-1). min(1)). Total body fat mass and percent fat were determined by dual-energy X-ray absorptiometry, and abdominal fat was by computed tomography. Insulin sensitivity was measured during the last 30 min of 3-h hyperinsulinemic-euglycemic clamps (40 mU. m(-2). min(-1)). Comparisons were made among women with the II (n = 9), ID (n = 36), and DD (n = 21) genotypes. RESULTS: Age, percent body fat, waist-to-hip ratio, visceral and subcutaneous abdominal fat areas, plasma lipid levels, and systolic and diastolic blood pressures did not differ by ACE genotype. Fasting glucose and 2-h glucose levels were similar among genotypes, but fasting plasma insulin levels were lower in DD women than in ID women (P < 0.05). Glucose utilization was higher in women with the DD genotype than in women with the II genotype (53.1 +/- 3.9 vs. 36.0 +/- 3.8 micromol. kg(-1) FFM. min(-1), P = 0.01) and was higher in ID women than in II women (48.5 +/- 2.5 micromol. kg(-1) FFM. min(-1), P = 0.04). CONCLUSIONS: These data suggest that the I/D polymorphism is not associated with risk factors for CHD in overweight sedentary women; however, women who are homozygous for the D allele of the ACE gene are more insulin sensitive, whereas women who are homozygous for the I allele of the ACE gene have greater insulin resistance and potential risk for type 2 diabetes.     

Association of methylenetetrahydrofolate reductase T677 allele with early development of chronic allograft nephropathy

OBJECTIVES: The aim of this study was to evaluate the role of genetic polymorphisms on the development of chronic allograft nephropathy (CAN). DESIGN AND METHODS: Using the polymerase chain reaction (PCR), polymorphisms of methylenetetrahydrofolate reductase (MTHFR C677T), interleukin-6 (IL-6 G-174C) and CD14 (C-260T) were evaluated in 92 kidney transplant recipients with stable renal graft function and no signs of acute rejection in a protocol that included graft biopsy at 12 months after kidney transplantation. A normal population sample (n = 365) was also included. Multivariate analysis was used to evaluate the effect of different variables on the CAN appearance. RESULTS: There were no differences in alleles and genotypes distribution between transplant group and normal population sample. The CAN+ group (n = 69) significantly differed from CAN- (n = 23) in both MTHFR (P < 0.05) and IL-6 (P < 0.01) genotype distribution. Using logistic regression multivariate analysis, MTHFR T677 allele (OR: 3.91, CI: 1.11-13.8; P < 0.05), patient age (OR: 0.94, CI: 0.88-0.98; P < 0.01) and proteinuria (OR: 3.63, CI: 1.25-10.6; P < 0.05) were associated with CAN. Although the IL-6 G-174 allele was shown to be associated with CAN development in univariate analysis (P < 0.01), the multivariate analysis did not show an association. There was no relation between CD14 gene polymorphism and CAN. CONCLUSION: The MTHFR T677 allele is associated with the presence of CAN in kidney graft biopsies 12 months after transplantation.