醛糖还原酶基因(AC)n串联重复序列多态性与糖尿病视网膜并发症的相关性

高血糖一直被视作导致糖尿病慢性并发症 (ＤＣＣ)的主要因素 ,而多元醇 (主要是山梨醇 )通路在高糖状况下过度激活对ＤＣＣ的发生、发展起着重要的作用。醛糖还原酶 (ＡＲ)是多元醇代谢途径的限速酶 ,与ＤＣＣ的发生发展密切相关〔1〕。ＡＲ活性的改变除与高血糖相关外 ,遗传因素也是不可忽略的原因。在不同人群中 ,ＡＲ基因转录起始点上游 -2 .1ｋｂ处有 (ＡＣ) ｎ 二核苷酸重复序列标记与ＤＣＣ之间的关联性存在争议〔2〕。本文研究中国大陆人群中该重复序列标记与 2型糖尿病性视网膜病变之间的关系。一、对象和方法选取并发视网膜病变的 …     

Aldose reductase (AC)n gene polymorphism and susceptibility to diabetic retinopathy in Type 2 diabetes in Caucasians

Genetic factors are implicated in the development of diabetic retinopathy, and the aldose reductase (AC)n gene is a candidate gene for the development of diabetic retinopathy in patients with Type 2 diabetes. In the association study, a relationship between the aldose reductase (AC)n gene polymorphism and the development of diabetic retinopathy in patients with Type 2 diabetes were studied. We tested the hypothesis whether the Z-2 allele of the aldose reductase gene is a risk factor for the development of diabetic retinopathy in a group of Caucasian participants with Type 2 diabetes. Two hundred and five participants with Type 2 diabetes were enrolled in the study: 124 participants with Type 2 diabetes with diabetic retinopathy were compared with 81 diabetic participants without retinopathy with diabetes duration of more than 10 years. Eight alleles of the aldose reductase (AC)n gene polymorphism were detected: Z+6, Z+4, Z+2, Z, Z-2, Z-4, Z-6, and Z-8. An increased frequency of the Z-2 allele was found in the patients with diabetic retinopathy compared with the patients without diabetic retinopathy (39.1% vs. 26.5%; P value=.009, chi2=6.9). Our results suggest that the Z-2 allele of the aldose reductase gene is a risk factor for the development of diabetic retinopathy in a group of Caucasian participants with Type 2 diabetes.     

醛糖还原酶基因5’端(AC)n多态性对2型糖尿病患者红细胞醛糖还原酶活性的影响

目的　探讨醛糖还原酶 (AR)基因 5’端 (AC) n 的多态性对 2型糖尿病 (DM )红细胞AR活性的影响。方法　 16 3例 2型DM分为无微血管病变 (NDC)组 (6 6例 )和微血管病变 (DMAP)组(97例 ) ,正常对照 (CON)组 42例 ;另按AR基因 5’端 (AC) n 的等位基因类型分为DM携带Z 2等位基因 (DZ 2 )组 (5 4例 )、DM携带Z - 2等位基因 (DZ - 2 )组 (35例 )、DM同时携带Z 2和Z - 2等位基因 (Z 2 /Z - 2 )组 (18例 )、DM不携带Z 2和Z - 2等位基因 (X/X)组 (5 6例 )、对照者携带Z 2等位基因 (NZ 2 )组 (2 1例 )和对照者携带Z - 2等位基因 (NZ - 2 )组 (7例 )。用改良Sriratava法测定AR活性并比较其在各组间的差异。结果　DMAP组、NDC组和CON组间的AR活性 (ARA)差异有显著性 ,DMAP组最高 ,NDC组次之 ,CON组最低 (P <0 .0 0 1)。DM组携带Z - 2和Z 2等位基因各亚组中 ,DZ - 2组ARA最高 ,Z - 2 /Z 2和X/X组居中 ,DZ 2组最低 ,差异有显著性统计学意义(P <0 .0 0 1)。DZ - 2和NZ - 2组的ARA分别高于DZ 2和NZ 2组 ,DZ - 2和DZ 2组的ARA分别高于NZ - 2和NZ 2组 (P均 <0 .0 0 1)。结论　AR的激活对DMAP的发生和发展起重要作用。Z - 2等位基因可能是AR的激活因子 ,Z 2等位基因则为其抑制因子。     

Angiotensin-converting enzyme gene polymorphism and microvascular complications in Turkish type 2 diabetic patients

The aim of this study was to investigate whether an association exists between the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism and microvascular complications of type 2 diabetes mellitus in Turkish patients. A total of 239 type 2 diabetic patients and 138 sex and age matched control subjects were included into the study. The I/D polymorphism was determined by polymerase chain reaction (PCR). Nephropathy status was determined according to urinary albumin/creatinine ratio (microg/mg) (<30 normoalbuminuria, 30-300 microalbuminuria, >300 macroalbuminuria) and retinopathy was evaluated by fundoscopic examination and by flourescein fundus angiography. The distribution of ACE I/D polymorphism and allele frequencies in diabetic patients were not significantly different from controls, DD genotype 32.2 versus 37.2%; ID genotype 50.6 versus 47.1%; and II 17.2 versus 15.2%; D allele 57.5 versus 61.2%; I allele 42.5 versus 38.8%. Genotype distribution between normo-, micro- and macroalbuminuric patients did not differ significantly (DD:ID:II (%), normoalbuminuria, 35:46:19; microalbuminuria, 28:55:17; macroalbuminuria, 31:55:14). There was also no difference in genotype distribution between patients with and without retinopathy (DD:ID:II (%), retinopathy positive, 32:51:17; retinopathy negative, 33:49:18). In conclusion, the ACE I/D polymorphism does not seem to be associated with diabetic nephropathy and retinopathy in Turkish type 2 diabetic patients.     

Neutrophil aldose reductase activity and its association with established diabetic microvascular complications.

Direct investigation of the polyol pathway is rarely possible in studies of human diabetes. A spectrophotometric assay has been developed for the measurement of aldose reductase and sorbitol dehydrogenase activity in the neutrophil. Neutrophil aldose reductase activity was increased in patients with Type 1 diabetes with complications (median 40 (interquartile range 28-48) u, where 1 unit of enzyme activity = nmol NADPH min-1 10(8)-cells-1) compared with those without complications (20 (16-36) u, p less than 0.01) and normal control subjects (20 (8-36) u, p less than 0.01). In Type 2 diabetes, patients with complications also had higher aldose reductase activity (40 (28-52) u) than those without complications (24 (16-36) u, p less than 0.01). There were no differences between patients without complications and normal control subjects. Sorbitol dehydrogenase activity was decreased in diabetic patients (p less than 0.02) but not significantly different between diabetic patients with and without complications.     

Association between (AC)n dinucleotide repeat polymorphism at the 5'-end of the aldose reductase gene and diabetic nephropathy: a meta-analysis

Association between the (AC)(n) dinucleotide repeat polymorphism at the 5'-end of the aldose reductase gene and the occurrence of diabetic nephropathy was conducted. We examined eight studies consisting of ten Caucasian type 1 diabetes mellitus case-control comparisons and eight studies consisting of nine type 2 diabetes mellitus case-control comparisons, which were based on our inclusion criterion and available in the literature. The meta-analysis demonstrated a large heterogeneity among the studies on the type 1 diabetic subjects and a significant association was observed between the (AC)(n) dinucleotide repeat polymorphism at the 5'-end of the aldose reductase gene and diabetic nephropathy. The Z-2 allele appeared to be a genetic risk factor for susceptibility to diabetic nephropathy with a random effects odds ratio (OR) of 1.40 (95% confidence interval, CI (1.07, 1.84)). The Z+2 allele showed a protective effect on diabetic nephropathy with a random effects OR of 0.77 (95% CI (0.65, 0.91)). The meta-analysis, however, showed no association between the genetic polymorphism and diabetic nephropathy in type 2 diabetic subjects. Neither the risk Z-2 allele nor the protective Z+2 allele in type 1 diabetic subjects appeared to have an effect on nephropathy in type 2 diabetic subjects, while their fixed effects OR was 1.09 (95% CI (0.96, 1.22)) and 0.88 (95% CI (0.67, 1.15)) respectively. The current meta-analysis demonstrated a correlation between the (AC)(n) dinucleotide repeat polymorphism and the occurrence of diabetic nephropathy in Caucasian type 1 diabetic subjects in contrast to type 2 diabetic subject population in which such an association could not be demonstrated.     

结合珠蛋白基因多态性与糖尿病视网膜病变（一）

目的探讨结合珠蛋白（Hp）基因多态性与2型糖尿病（T2DM）患者糖尿病视网膜病变（DR）发病的关系。方法将317例T2DM患者分为糖尿病无视网膜病变（NDR）组和DR组,并选取100名正常人作为对照（NC）组。采用PCR技术扩增Hp1和Hp2特异的目的片段,分析Hp基因型及糖尿病（DM）病程、尿白蛋白（UAlb）等生化指标与DR的关系。结果NDR组、DR组和NC组间Hp等位基因和基因型频率比较,均无统计学差异（P〉0．05）。经Logistic回归分析显示,DM病程和24hUAlb是DR的独立危险因素,Hp可能与DR无相关性。结论Hp基因多态性可能与DR无相关性,而DM病程和24hUAlb是DR的独立危险因素。     

结合珠蛋白基因多态性与糖尿病视网膜病变（二）

目的探讨结合珠蛋白（Hp）多态性与2型糖尿病（T2DM）患者糖尿病视网膜病变（DR）发病的关系。方法418例T2DM患者分为3组：糖尿病无视网膜病变（NDR）组、非增生型糖尿病视网膜病变（NPDR）组、增生型糖尿病视网膜病变（PDR）组,另选取100名性别构成、年龄与之相匹配的健康者作为对照（NC）组。采用PCR技术扩增Hp1和Hp2特异目的片段,利用聚丙烯酰胺凝胶电泳技术对Hp分型,分析Hp多态性及各项临床指标与DR的关系。结果NDR组、NPDR组与PDR组两两组间,T2DM组与NC组间,Hp基因型及等位基因频率均无统计学差异（P〉0．05）。经Logistic回归分析显示：DM病程、SBP、TC、24h尿白蛋白（24h UAlb）是DR的独立危险因素（P〈0．05）,Hp与DR发病无关。结论Hp多态性与天津地区DR发病可能无相关性。     

(AC)23 [Z-2] polymorphism of the aldose reductase gene and fast progression of retinopathy in Chilean type 2 diabetics

Mutations in the glucokinase (GCK) gene are considered to be a possible cause of maturity-onset diabetes of the young. The purpose of this study was to evaluate the contribution of this gene to the development of post-renal transplantation diabetes mellitus (PTDM). Identification of the GCK mutation was attempted in 58 selected renal allograft recipients with PTDM and 45 normal controls. The exons in the GCK gene were examined using polymerase chain reaction (PCR), followed by an analysis of single-stranded DNA conformational polymorphism (SSCP). The abnormal bands were then confirmed by DNA sequencing analysis. The family members of the patients affected with GCK mutation were also examined. Two of the 58 PTDM patients (3.4%) were found to have GCK mutations. One had the mutation on exon 5 and the other on intron 7. One control subject had the mutation on intron 9. The mutation on exon 5 was identified as a substitution of CCT (proline) for CTT (leucine) at codon 164, which has never been reported before. The family members of the PTDM patient with a mutation on exon 5 were analyzed by PCR, followed by SSCP, and two of them had the same mutation. The abnormal band seen on SSCP analysis of exon 7 was identified as the C→T substitution at the 39th nucleotide in intron 7. Two of the family members also displayed the same bands on the SSCP. One of the 45 normal controls had a known polymorphism located at the 8th nucleotide in intron 9. We found a GCK mutation on the exon in subjects with PTDM and we speculate that this mutation may be one of the possible contributing factors of PTDM, although variations of the GCK gene are not common causes of PTDM.     

醛糖还原酶基因内含子多态性与2型糖尿病肾病的相关性研究

209例2型糖尿病人和84名健康对照者的醛糖还原酶基因第8内含子第95位点AC多态性研究发现基因型AA的频度,糖尿病肾病患者是7%,明显高于非肾病组(1%)和健康对照组(1%)。这提示,该酶第8内含子基因型AA可能是糖尿病肾病的危险因子。     

Aldose reductase gene polymorphisms and susceptibility to microvascular complications in Type 2 diabetes.

AIMS: The gene encoding the human aldose reductase, the first and rate-limiting enzyme of the polyol pathway of glucose metabolism, is a promising candidate gene which may contribute to diabetic microvascular complications. We investigated the association of two previously reported DNA sequence variants of this gene, the C-106T polymorphism and the (CA)(n) dinucleotide repeat marker, with the risk of albuminuria and retinopathy in Finnish Type 2 diabetic patients and non-diabetic control subjects. METHODS: The study population included 85 Finnish, middle-aged, newly diagnosed Type 2 diabetic patients and 126 non-diabetic control subjects. Genetic analyses were performed using the polymerase chain reaction, restriction fragment length polymorphism, and automated laser fluorescence scanning analyses. Microvascular complications were determined using 10-year follow-up data of urinary albumin excretion measurements and ophthalmological examinations. RESULTS: The C and Z-2 alleles of the C-106T polymorphism and the (CA)(n) repeat marker, respectively, were found to be more frequent in Type 2 diabetic subjects than in non-diabetic subjects. The C and Z-2 alleles were in 60% linkage disequilibrium in diabetic subjects. At the time of diagnosis, diabetic subjects with the T allele of the C-106T polymorphism had significantly higher urinary albumin excretion rate and prevalence of albuminuria than subjects with the C-106C genotype (prevalence of albuminuria: 33.3 vs. 13.8%, P = 0.036, odds ratio = 3.9, 95% confidence interval 1.1, 14.7). The Z-2 allele of the (CA)(n) repeat marker was not consistently associated with the prevalence of albuminuria. No associations were observed between the polymorphisms examined and the prevalence of retinopathy at any point of the follow-up. CONCLUSIONS: The present study suggests that the C-106T polymorphism of the aldose reductase gene could be involved in the early development of microalbuminuria in Finnish Type 2 diabetic patients.     

Common polymorphism in the cannabinoid type 1 receptor gene (CNR1) is associated with microvascular complications in type 2 diabetes

Endocannabinoids exert their biological effects via interaction with G-protein coupled cannabinoid receptors CB1 and CB2. Polymorphisms in the CNR1 gene (encoding CB1 receptor) were previously found to be associated with dyslipidemia and cardiovascular diseases. We investigated a role of the polymorphism in CNR1 gene in type 2 diabetes and its complications. The study involved 667 T2DM patients and 450 healthy individuals. All subjects were genotyped for G1359A polymorphism by PCR-RFLP procedure. Genotype frequencies did not differ significantly between patients and controls. The statistically significant differences were seen between T2DM patients with diabetic nephropathy (DN) and those without it (OR for risk allele 2.84, 95% CI 2.04–3.94, p < 0.0001). There were also differences between patients with diabetic retinopathy (DR) and those without DR (OR for risk allele 1.81, 95% CI 1.30–2.53, p = 0.0005). No differences were observed in diabetic neuropathy. The A allele was more frequent in patients with coexisting cardiovascular disease (CVD) compared to patients without CVD (p = 0.0044). The novel finding of our study is the association of the G1359A polymorphism with diabetic nephropathy and diabetic retinopathy in patients with T2DM. This polymorphism was also associated with cardiovascular disease in the patient group.     

2型糖尿病患者内皮型一氧化氮合酶基因(CA)n多态性分析

目的　探讨内皮型一氧化氮合酶 (eNOS)基因 (CA)n多态性与 2型糖尿病及 2型糖尿病患者血清中一氧化氮 (NO)含量的相关关系。　方法　采用聚合酶链反应 (PCR)技术结合聚丙烯酰胺凝胶电泳和硝酸银染色 ,检测不同个体基因型 ;硝酸还原酶法测定空腹血清NO含量 ;分光光度法测定空腹血清NOS含量。　结果　eNOS基因 (CA)n多态性存在 2 2种等位基因 ,所含CA重复次数分别为 19～ 4 0 ,其中 (CA) 3 0 (16 6bp)等位基因最常见。该位点杂合度为 0 85 ,多态信息量为 0 83。糖尿病组和对照组中 (CA) 3 4 等位基因频率分别为 7 5 %和 2 9% ,差异有显著性 (χ2 =5 8,P <0 0 5 ,OR =1 31,95 %CI =1 2 7～ 3 96 ) ;基因型为 (CA)n1(CA)n2 的 2型糖尿病个体 ,当n1≥ 34或n2 ≥ 34时 ,血清中NO的含量显著低于对照组 (P <0 0 5 )。　结论　eNOS基因 (CA) 3 4 可能与 2型糖尿病相关 ,该基因多态性与血清NO水平有一定关系。     

The role of aldose reductase gene in the susceptibility to diabetic nephropathy in Type II (non-insulin-dependent) diabetes mellitus (Short Communication)

Summary The dinucleotide repeat polymorphism (5 ′-ALR2) in the promoter region of the aldose reductase gene on chromosome 7q35 has been implicated in the development of diabetic nephropathy in Type I (insulin-dependent) diabetes mellitus, and markers flanking the aldose reductase locus have given evidence suggestive of a linkage between diabetic nephropathy and Type II (non-insulin-dependent) diabetes mellitus in Pima Indians. To examine whether the 5 ′-ALR2 polymorphism in the aldose reductase gene is involved in the development of diabetic nephropathy in Caucasians with Type II diabetes, we carried out a large association study. Patients with Type II diabetes from one outpatient clinic were screened for diabetic nephropathy and divided into three groups according to the degree of this disease: 179 patients with normoalbuminuria, 225 patients with microalbuminuria and 70 patients with proteinuria. Patients with normoalbuminuria were included in the study only if they had had Type II diabetes for 10 or more years. DNA from all patients was genotyped for the 5 ′-ALR2 polymorphism using a previously established polymerase chain reaction protocol. The frequency of the putative risk allele Z-2 was 34.6 %, 34.2 % and 33.6 % in the normoalbuminuria, microalbuminuria and proteinuria groups, respectively. Similarly no difference among groups was found for the frequency of the putative protective allele Z + 2. In conclusion, the results of our association study in Caucasian patients with Type II diabetes do not support the hypothesis that the 5 ′-ALR2 polymorphism in the aldose reductase gene contributes to susceptibility to diabetic nephropathy. Diabetologia (1999) 42: 94–97 Received: 4 May 1998 and in revised form: 20 July 1998     

Lipoprotein(a) levels and apolipoprotein(a) polymorphism in type 1 diabetes mellitus: relationships to microvascular and neurological complications

To investigate plasma concentrations of lipoprotein(a) [Lp(a)] and apolipoprotein(a) [apo(a)] polymorphism in relation to the presence of microvascular and neurological complications in type 1 diabetes mellitus, 118 young diabetic patients and 127 age-matched controls were recruited. Lp(a) levels were higher in patients than in controls, but the apo(a) isoforms distribution did not differ between the two groups [higher prevalence of isoforms of high relative molecular mass (RMM) in both groups]. Microalbuminuric patients had Lp(a) levels significantly greater than normoalbuminuric patients, and normoalbuminuric patients showed higher Lp(a) levels than controls. Patients with retinopathy or neuropathy showed similar Lp(a) levels to those without retinopathy or neuropathy. No differences in apo(a) isoforms frequencies were observed between subgroups with and without complications (higher prevalence of isoforms of high RMM in every subgroup). However, among patients with retinopathy, those with proliferative retinopathy had higher Lp(a) levels and a different apo(a) isoforms distribution (higher prevalence of isoforms of low RMM) than those with non-proliferative and background retinopathy (higher prevalence of isoforms of high RMM). Our data suggest that young type 1 diabetic patients without microalbuminuria have Lp(a) levels higher than healthy subjects of the same age. Lp(a) levels are further increased in microalbuminuric patients. High Lp(a) levels and apo(a) isoforms of low RMM seem to be associated with the presence of proliferative retinopathy, but have no relation to neuropathy. Received: 23 June 1997 / Accepted in revised form: 27 November 1997     

Analysis of the association between diabetic nephropathy and polymorphisms in the aldose reductase gene in Type 1 and Type 2 diabetes mellitus.

AIMS: To investigate the association between polymorphisms of the aldose reductase gene and diabetic nephropathy in both Type 1 and Type 2 diabetes mellitus, and to carry out a meta-analysis of published results. METHODS: We have investigated the role of two aldose reductase polymorphisms in four independent cohorts of cases and controls (two each with Type 1 and Type 2 diabetes) drawn from two ethnic populations, including 471 patients with nephropathy and 494 control diabetic patients without nephropathy. A C/T transition at position -106, and a (CA)n microsatellite marker 2.1 kb from the start site of the aldose reductase gene were genotyped in nephropathic patients and non-nephropathic controls from each cohort. RESULTS: Carriage of the -106 T allele was significantly associated with diabetic nephropathy in three of the four study groups. The Mantel-Haenszel combined odds ratio was 2.22 (95% CI 1.69, 2.94), P = 1.05 x 10(-8). We found no evidence for association of the microsatellite marker with nephropathy, despite moderate levels of disequilibrium between the two markers. Meta-analysis of published data yielded no evidence for association of the microsatellite marker with diabetic nephropathy in Type 2 diabetes, but varying degrees of association with diabetic nephropathy in Type 1 diabetes. CONCLUSIONS: Meta-analyses provide more convincing evidence of a role for the ALR2-106 marker than for the microsatellite marker in diabetic nephropathy (DN). More studies are now required to confirm these results and to establish whether the ALR2-106 polymorphism has a functional role in DN.     

亚甲基四氢叶酸还原酶基因多态性与糖尿病肾病相关性研究

目的：研究亚甲基四氢叶酸还原酶（MTHFR）基因多态性与2型糖尿病肾病的关系。方法：运用聚合酶链反应－限制性片段长度多态性技术（PCR－RFLP）检测85例2型糖尿病患者（其中39例伴糖尿病肾病）及57例正常对照组MTHFR C677T基因型,采用高效液相色谱法测定血浆同型半胱酸水平。结果：糖尿病肾病组MTHFR基因TT纯合基因型,CT杂合基因型及T等位基因频率（分别为38．21％,51．28％,53．85％）均明显高于糖尿病不伴肾病组（分别为19．57％,28．26％,33．70％）及正常对照组（分别为17．54％,28．07％,31．58）,基因型和等位基因频率分布差异均有统计学意义（P＜0．05）,而MTHFR基因该多态性在不伴肾病组与正常对照组之间差异无显著性（P＞0．05）,T等位基因与糖尿病肾病的发生密切相关（OR＝2．30,95％可信区间;1．24－4．26）。糖尿病肾病组,糖尿病不伴肾病组及正常对照组中,MTHFR基因有C677T突变者血浆同型半胱氨酸水平均显著高于无基因突变者。结论：MTHFR基因C677T位碱基突变致血浆同型半胱氨酸水平高是糖尿病肾病发病的重要遗传因素。     

Methylenetetrahydrofolate reductase gene polymorphism in patients with type 2 diabetes

Hyperhomocysteinemia is recognised as a risk factor of ischaemic heart disease and vascular complications of arterial hypertension. Methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism is associated with hyperhomocysteinaemia. The aim of the study was the assessment of an association of the above polymorphism with type 2 diabetes with special attention to myocardial infarction and arterial hypertension accompanying diabetes. The study group consisted of 172 type 2 diabetics. 172 control subjects with normal glucose tolerance were age and sex matched to patients with diabetes. C677T polymorphism in MTHFR gene locus was detected using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. CT and TT genotypes were found more often among diabetics (OR 1.83, 95% CI 1.16-2.89; p < 0.01). This finding may be secondary to the excess of T allele bearers among diabetics with myocardial infarction when compared to diabetics without infarction and to control group. Upon obtained results the potential role of genotypes CT and TT as risk factors of myocardial infarction among patients with type 2 diabetes could not be excluded (OR 2.33, 95% CI 0.93-5.8; p = 0.07). Genotypes containing T allele are not associated with diabetes type 2 and concomitant arterial hypertension (OR 1.45, 95% CI 0.89-2.57; p = 0.14). A confirmation in further studies is needed for the presented findings.