Israel Roisenberg

Prevalência de complicações micro e macrovasculares e de seus fatores de risco em pacientes com diabetes melito do tipo 2 em atendimento ambulatorial

BACKGROUND: Type 2 diabetes (DM2) has been related to the development of macroangiopatic [coronary heart disease (CHD), peripheral vascular disease (PVD) and stroke] and microangiopatic [retinopathy, nephropathy, and distal sensory neuropathy (DSN)] complications. The aims of this study were to analyze prevalence of complications in DM2 patients and to estimate their associated risk factors. METHODS: Cross-sectional study, including 927 out patients with DM2 from three medical centers in Rio Grande do Sul: Hospital de Clinicas de Porto Alegre (n = 475), Grupo Hospitalar Conceicao (n = 229) and Hospital Sao Vicente de Paula (n = 223). Of the patients 42% were male, mean age was 59 ± 10 years and the median known duration of DM2 was 11 (5 - 43) years. Retinopathy was identified by direct fundoscopy; CHD by WHO questionnaire and/or abnormal ECG and/or perfusion abnormalities on myocardial scintigraphy; DSN by compatible symptoms and absent sensation on 10 g monofilament and/or tune fork; PVD by the presence of claudication and absent foot pulses; stroke by presence of sequels and history; and nephropathy by the urinary albumin excretion rate (>20 µg/min). Hypertension was defined by blood pressure (>140/90 mmHg) and/or use of antihypertensive drugs. Body mass index (BMI, kg/m2) and waist-to-hip ratio (WHR) were calculated. RESULTS: CHD was present in 36% and PVD in 33% of the patients. Among the microvascular, 37% had nephropathy (12% with macroalbuminuria); 48% retinopathy (15% proliferative retinopathy). DSN was present in 36%. Seventy three percent of the patients presented arterial hypertension. Cholesterol levels were >200 mg/dl in 64% and BMI > 30 kg/m2 in 36%. Twenty two percent of patients were smokers and 21% ex-smokers. CONCLUSION: Diabetic complications are frequent among out patients referring to general hospitals. Almost all patients presented at least one risk factor for cardiovascular disease, justifying the efforts for identification and adequate control.

Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects

Abnormal folate/homocysteine metabolism due to polymorphisms in genes involved in this pathway has been implicated as an etiologic factor in Down syndrome (DS). This case–control study aimed to evaluate the effect of maternal C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) as risk factors for the development of DS and congenital heart defects (CHD). The distribution of these genotypic variants was similar between mothers of children with DS (n = 239) and control mothers of normal children (n = 197), but the combined genotypes 677CT or TT and 1298AA increased the risk of having offspring with DS (OR = 1.99; 95% CI 1.11–3.55). The presence of the 677T allele in case mothers resulted in a 2.07‐fold higher odds of CHD in the offspring (P < 0.01). Among the 57 mothers of CHD‐affected children with DS who carried the MTHFR 677CT or TT genotypes and did not have periconceptional folic acid intake, we observed a 2.26‐fold increased odds (95% CI 1.25–4.09) of having any CHD‐affected child with DS. Our results show that MTHFR genetic polymorphisms may be involved in the etiology of DS in our population when controlling for age. We noted a borderline significant association for the C677T polymorphism (P = 0.05). Maternal 677T allele may be associated with an increased occurrence of CHD in children with DS and we anticipate that women who carry this polymorphism would benefit from periconceptional folic acid supplementation.

The European-Specific Mitochondrial Cluster J/T Could Confer an Increased Risk of Insulin-Resistance and Type 2 Diabetes: An Analysis of the m.4216T > C and m.4917A > G Variants

The aims of this study were to investigate the contributions of the mitochondrial DNA m.4216T > C and m.4917A > G variants, and also of the European‐specific mitochondrial cluster J/T, to the development of type 2 diabetes mellitus in Caucasian‐Brazilian patients from Southern Brazil. We analyzed 347 type 2 diabetes patients and 350 control subjects. Variant frequencies in patients and control subjects were compared using χ2 tests or odds ratio. We also compared clinical and laboratory characteristics among patients with and without the variants. We found that the frequencies of the m.4216T > C and m.4917A > G variants are higher in diabetic patients than in control subjects. Moreover, haplogroups J (partially defined by the presence of the m.4216T > C variant only) and T (partially defined by the presence of both m.4216T > C and m.4917A > G variants) are more frequent in the type 2 diabetic group than in the control group. Patients belonging to the cluster J/T are more insulin resistant than patients of other haplogroups. In conclusion, our results indicate the association of the cluster J/T (as suggested by analyses of the m.4216T > C and m.4917A > G variants) with insulin resistance and type 2 diabetes.

Diabetic retinopathy in Euro-Brazilian type 2 diabetic patients: relationship with polymorphisms in the aldose reductase, the plasminogen activator inhibitor-1 and the methylenetetrahydrofolate reductase genes

We investigated the relationship between diabetic retinopathy (DR) and three polymorphisms, C(-106)T in the aldose reductase (ALR2) gene, 4G/5G in the plasminogen activator inhibitor-1 (PAI-1) gene and C677T in the methylenetetrahydrofolate reductase (MTHFR) gene, in 210 Euro-Brazilian type 2 diabetic patients. Retinopathy was evaluated by funduscopic examination and genotype analysis was performed using the polymerase chain reaction and allele-specific restriction. Retinopathy was detected in 47% of the patients. There were no significant differences in allele or genotype distributions between patients with or without retinopathy for all polymorphisms. Thus, the three polymorphisms are not related to the presence of DR in Euro-Brazilian type 2 diabetic patients.

Polymorphisms in genes MTHFR, MTR and MTRR are not risk factors for cleft lip/palate in South Brazil

Non-syndromic cleft lip and palate (CL/P) occurs due to interaction between genetic and environmental factors. Abnormalities in homocysteine metabolism may play a role in its etiology due to polymorphisms in genes involved in this pathway. Because of the involvement of MTHFR, MTR and MTRR genes with folate metabolism and the evidence that maternal use of folic acid in early pregnancy reduces the risk for CL/P, we evaluated the influence of their polymorphisms on the etiology of CL/P through a case-control study. The analyses involved 114 non-syndromic phenotypically white children with clefts (case) and 110 mothers, and 100 non-affected (control) children and their mothers. The polymorphisms 677C>T of MTHFR, 2756A>G of MTR, and 66A>G of MTRR genes were analyzed by PCR-RFLP. Allelic frequencies did not differ from other studies conducted on white populations for MTHFR 677T allele (0.35) and for MTR 2756G allele (0.17), but MTRR 66G allele frequency (0.35) was lower than observed elsewhere. The genotypic distribution of the 677C>T polymorphisms under study did not show significant differences between CL/P patients, their mothers and controls. These results suggest that the alterations of folate metabolism related to these polymorphisms are not involved in clefting in the population under study.

Functional Vascular Endothelial Growth Factor −634G>C SNP Is Associated With Proliferative Diabetic Retinopathy A case-control study in a Brazilian population of European ancestry

OBJECTIVE—The purpose of this study was to evaluate the effect of the single nucleotide polymorphism (SNP) −634G>C at the 5′ regulatory region of the vascular endothelial growth factor (VEGF) in the risk of proliferative diabetic retinopathy (PDR) in the Brazilian population of European ancestry with type 2 diabetes. RESEARCH DESIGN AND METHODS—A case-control study was conducted in 501 type 2 diabetic patients of European ancestry. Patients underwent a standardized clinical, ophthalmological, and laboratory evaluation. Of these, 167 patients had PDR (case patients), and 334 were considered as control subjects (patients without PDR) for PDR. A reference population (110 individuals of European ancestry) was also evaluated. RESULTS—No evidence of association between −634G>C/VEGF and the presence of diabetic retinopathy or type 2 diabetes was observed (P > 0.05). However, CC homozygous for the SNP −634G>C was significantly more frequent in patients with PDR (37 of 167; 22.2%) than in the corresponding control group (40 of 334; 12%) in accordance with a recessive model (P = 0.003). This effect was further observed when creatinine, BMI, sex, duration of type 2 diabetes, HDL cholesterol, and systolic blood pressure were taken into account (odds ratio 1.9 [95% CI 1.01–3.79], P = 0.04). CONCLUSIONS—The presence of the allele −634C/VEGF in homozygosity is an independent risk factor for the development of PDR in type 2 diabetic patients of European ancestry.

The catalase -262C/T promoter polymorphism and diabetic complications in Caucasians with type 2 diabetes

Catalase is a central antioxidant enzyme constituting the primary defense against oxidative stress. In this study, we investigated whether the functional –262C/T polymorphism in the promoter of catalase gene is associated with the presence of diabetic retinopathy (DR), diabetic nephropathy (DN) and ischemic heart disease (IHD) in 520 Caucasian-Brazilians with type 2 diabetes. The –262C/T polymorphism was also examined in 100 Caucasian blood donors. Patients underwent a clinical and laboratory evaluation consisting of a questionnaire, physical examination, assessment of diabetic complications and laboratory tests. Genotype analysis was performed using the polymerase chain reaction followed by digestion with restriction enzyme. The genotype and allele frequencies of the –262C/T polymorphism in patients with type 2 diabetes were very similar to those of blood donors (T allele frequency = 0.20 and 0.18, respectively). Likewise, there were no differences in either genotype or allele frequencies between type 2 diabetic patients with or without DR, DN or IHD. Thus, our results do not support the hypothesis that the –262C/T polymorphism is related to the development of DR, DN or IHD in patients with type 2 diabetes. Further studies are necessary to elucidate the role of catalase gene polymorphisms in the pathogenesis of diabetic complications.

Familial history of type 2 diabetes in patients from Southern Brazil and its influence on the clinical characteristics of this disease

OBJECTIVE To investigate the presence of maternal and paternal history of type 2 diabetes mellitus (DM) in relatives of 644 type 2 diabetic patients from Southern Brazil, and also to evaluate its influence on the clinical characteristics of this disease. PATIENTS AND METHODS Familial history of type 2 DM was investigated by a questionnaire. The maternal and paternal history was investigated over two generations. Complete data sets on familial history were obtained from 396 patients. RESULTS In general, 76.6% of the patients reported at least one first-degree affected relative. Besides, 31.6% of the patients reported a maternal history of type 2 DM and 12.6% reported a paternal history. Patients with maternal and/or paternal history presented a lower age at type 2 DM diagnosis when compared to patients without familial history. In addition, patients with only paternal history presented a higher frequency of hypertension than patients with no familial history. CONCLUSIONS This study suggests that there is a significant maternal effect in the transmission of type 2 DM in Southern Brazil, and that most of the clinical characteristics of this disease do not differ between patients with or without familial history of type 2 DM.

von Willebrand factor antigen levels in plasma of patients with malignant breast disease

von Willebrand factor (vWF) is a protein that mediates platelet adherence to the subendothelium during primary hemostasis. High plasma vWF concentrations have been reported in patients with various types of cancer, such as head and neck, laryngeal and prostatic cancer, probably representing an acute phase reactant. In the present study we determined the plasma levels of vWF antigen (vWF:Ag) by quantitative immunoelectrophoresis in 128 female patients with breast cancer as well as in 47 women with benign breast disease and in 27 healthy female controls. The levels of vWF:Ag were 170.7 +/- 78 U/dl in patients with cancer, 148.4 +/- 59 U/dl in patients with benign disease and 130.6 +/- 45 U/dl in controls (P<0.005). We also detected a significant increase in the levels of vWF:Ag (P<0.0001) in patients with advanced stages of the disease (stage IV = 263.3 +/- 113 U/dl, stage IIIB = 194.0 +/- 44 U/dl) as compared to those with earlier stages of the disease (stage I = 155.3 +/- 65 U/dl, stage IIA = 146.9 +/- 75 U/dl). In conclusion, vWF levels were increased in plasma of patients with malignant breast disease, and these levels correlated with tumor progression.

Relationship of endothelial nitric oxide synthase (eNOS) gene polymorphisms with diabetic retinopathy in Caucasians with type 2 diabetes.

Background: Nitric oxide synthesized by endothelial nitric oxide synthase (eNOS) plays a key role in the regulation of endothelial function, and controversial results regarding the association of eNOS gene polymorphisms with diabetic complications have been reported. Materials and Methods: In this case-control study, the relationship of the −786T/C, the VNTR intron 4 a/b and the 894G/T (Glu298Asp) polymorphisms in the eNOS gene with the presence or severity of diabetic retinopathy was analyzed in 630 Caucasian-Brazilians with type 2 diabetes (434 with and 196 without diabetic retinopathy). Genotyping of eNOS polymorphisms was carried out using the PCR or PCR-RFLP method, and haplotype frequencies were estimated using a Bayesian method. Results: Genotype and allele frequencies in patients with any degree of diabetic retinopathy or proliferative diabetic retinopathy were not significantly different from those of patients without this complication for all eNOS polymorphisms. Likewise, there were no differences in haplotype frequencies among diabetic patients with or without diabetic retinopathy (p values > 0.05 for all comparisons). Conclusion: Our findings do not support the hypothesis that the −786T/C, the VNTR intron 4 a/b and the 894G/T (Glu298Asp) polymorphisms in the eNOS gene play a role in the pathogenesis of diabetic retinopathy in type 2 diabetes.