Cristina Gutiérrez

The TNF-alpha gene Nco I polymorphism influences the relationship among insulin resistance, percent body fat, and increased serum leptin levels.

Tumor necrosis factor-α (TNF-α), acting as a modulator of gene expression in adipocytes, is implicated in the development of insulin resistance and obesity. The aim of this study was to investigate whether the Nco I polymorphism of the TNF-a gene influences the relationship among insulin resistance, percent body fat, and serum leptin levels. A sample of 38 subjects (19 men, mean age 36.2 ± 1.9 years, BMI 28.8 ± 1.2 kg/m2, range 22.2–35.7; and 19 women, age 34.9 ± 1.4 years, BMI 28.1 ± 0.8 kg/m2, range 19–37.9) was divided into two groups on the basis of the Nco I genotype. Twenty-three subjects were (+/+) homozygotes for the presence of the Nco I restriction site that is associated with a guanine at position −308 of the TNF-a promoter. Of the other subjects, 12 were (+/−) heterozygotes and 3 (−/−) homozygotes for the absence of the restriction site, resulting from a guanine-to-adenine substitution at position −308 of the TNF-a promoter. This substitution (termed TNF-2) leads to higher rate of transcription of TNF-a than the wild-type allele TNF-1 in vitro. TNF-1 (+/+) and TNF-2 (+/− and −/−) groups of subjects were comparable in sex, age, BMI, waist-to-hip ratio, and several skinfold measurements. Basal serum insulin was greater (14.2 ± 2 vs. 9.2 ± 0.9 mlM, P = 0.041) in the TNF-2 group in the presence of comparable serum glucose concentration. The integrated area under the curve of serum insulin concentrations, measured in response to a 75-g oral glucose challenge, and the percent body fat, measured by bioelectric impedance, were significantly increased in TNF-2 subjects (226.8 ± 33 vs. 139.4 ± 17.8 mU/l, P = 0.032; 33.6 ± 2.8 vs. 24.9 ± 2%, P = 0.01). TNF-2 subjects also showed a decreased insulin sensitivity index, as determined by the frequently sampled intravenous glucose tolerance test with minimal model analysis (1.9 ± 0.4 vs. 3.05 ± 0.3 min−1 · mU−1 · 1−1 P = 0.03). These differences were more marked among women. Paralleling the known relationship between insulin and leptin levels, serum leptin concentration was clearly increased in the TNF-2 group (19.6 ± 3.4 vs. 11.1 ± 1.5 ng/ml, P = 0.03). Therefore, (+/−) heterozygotes and (−/−) homozygotes may be more susceptible to developing insulin resistance and increased percent body fat. Results of the present study suggest that TNF-αNco I polymorphism may exacerbate the alterations in leptin levels normally found among insulin-resistant subjects.

A polymorphism in the promoter of the tumor necrosis factor-α gene (-308) is associated with coronary heart disease in type 2 diabetic patients

BACKGROUND Tumor necrosis factor-alpha (TNF-alpha) is a key cytokine in the inflammation process of atherosclerosis. Through its effects on lipid metabolism, insulin resistance and endothelial function, it might be involved in coronary heart disease (CHD). A biallelic polymorphism within the promoter of TNF-alpha locus at the position -308 has been reported to be associated with TNF production. We have studied the association of this polymorphism with CHD in a Mediterranean non-diabetic and type 2 diabetic population. METHODS Three hundred and forty one CHD patients (106 with type 2 diabetes), 207 healthy matched control subjects and 135 type 2 diabetic patients without CHD were evaluated. A single nucleotide polymorphism at the promoter TNF-alpha (-308) was analyzed by RFLP-PCR. RESULTS TNF-alpha (-308) genotype and allele frequencies for A carriers were higher in CHD patients than those observed in the control group (32.3 vs. 23.2%, P=0.03; and 18.8 vs. 12.1%, P=0.0047; respectively) independently of other risk factors. Genotypic analysis revealed that CHD patients with type 2 DM displayed a greater prevalence of the -308 TNF-alpha A allele (40.6%) than controls (23.2%) or CHD patients without type 2 DM (28.5%) (P=0.0056). The odds ratio for CHD in type 2 diabetic patients in presence of -308 TNF-alpha A allele was 2.86 (CI 95%: 1.55-5.32). This difference was observed mainly in diabetic women for the A allele carriers (OR: 4.29; CI 95%: 1.6-11.76). CONCLUSIONS These results suggest that -308 TNF-alpha gene polymorphism may contribute to CHD risk in patients with type 2 diabetes and it could constitute an useful predictive marker for CHD in type 2 diabetic women.

Primary breast lymphoma: Patient profile, outcome and prognostic factors. A multicentre Rare Cancer Network study

BackgroundTo asses the clinical profile, treatment outcome and prognostic factors in primary breast lymphoma (PBL).MethodsBetween 1970 and 2000, 84 consecutive patients with PBL were treated in 20 institutions of the Rare Cancer Network. Forty-six patients had Ann Arbor stage IE, 33 stage IIE, 1 stage IIIE, 2 stage IVE and 2 an unknown stage. Twenty-one underwent a mastectomy, 39 conservative surgery and 23 biopsy; 51 received radiotherapy (RT) with (n = 37) or without (n = 14) chemotherapy. Median RT dose was 40 Gy (range 12–55 Gy).ResultsTen (12%) patients progressed locally and 43 (55%) had a systemic relapse. Central nervous system (CNS) was the site of relapse in 12 (14%) cases. The 5-yr overall survival, lymphoma-specific survival, disease-free survival and local control rates were 53%, 59%, 41% and 87% respectively. In the univariate analyses, favorable prognostic factors were early stage, conservative surgery, RT administration and combined modality treatment. Multivariate analysis showed that early stage and the use of RT were favorable prognostic factors.ConclusionThe outcome of PBL is fair. Local control is excellent with RT or combined modality treatment but systemic relapses, including that in the CNS, occurs frequently.

Left ventricular mass and diastolic function in normotensive young adults with autosomal dominant polycystic kidney disease.

Left ventricular hypertrophy is often found very early in the course of autosomal dominant polycystic kidney disease (ADPKD). Diastolic dysfunction has been shown in hypertensive adult patients with ADPKD with increased left ventricular mass (LVM), but there are no data about diastolic function in the young ADPKD population without hypertension and with normal renal function. To evaluate very early alterations in cardiac structure and diastolic function in young normotensive patients with ADPKD, color Doppler echocardiography was performed in 46 young normotensive patients with ADPKD and 35 healthy subjects. LVM, transmitral pulsed Doppler flow (diastolic function), and valvular abnormalities were studied. Patients with ADPKD showed higher LVM indices (LVMIs) than controls (89.7+/-17.3 v 68.5+/-17.2 g/m2; P < 0.0001). Peak early diastolic velocity (E wave) deceleration time and isovolumic relaxation time were significantly prolonged in patients with ADPKD compared with controls (E wave deceleration time, 182.5+/-51.3 v 149.4+/-34 msec; P=0.002; isovolumic relaxation time, 97.7+/-17.5 v 79+/-15 msec; P=0.0001). No differences were found in valvular abnormalities in the two groups. In conclusion, young normotensive patients with ADPKD showed increased LVMIs and Doppler abnormalities consistent with early diastolic dysfunction.

Circulating and Adipose Tissue Gene Expression of Zinc-α2-Glycoprotein in Obesity: Its Relationship with Adipokine and Lipolytic Gene Markers in Subcutaneous and Visceral Fat

CONTEXT Zinc-alpha2-glycoprotein (ZAG) is a soluble protein similar to the class I major histocompatibility complex heavy chain, which has been implicated in lipid catabolism. We hypothesized that ZAG mRNA expression in adipose tissue may be linked with lipolytic and adipokine gene expression and have a close relationship with clinical phenotype. OBJECTIVES The objective of the study was to analyze ZAG gene expression in human adipose tissue from lean and obese subjects. ZAG circulating plasma levels and its relationship with cardiometabolic risk factors were also studied. DESIGN Seventy-three Caucasian (43 male and 30 female) subjects were included. Plasma and adipose tissue [sc (SAT) and visceral (VAT)] from the same patient were studied. mRNA of PPARgamma, hormone-sensitive lipase (HSL), adipose triglyceride lipase, adiponectin, omentin, visfatin, and ZAG were quantified. Plasma concentrations of ZAG were determined with ELISA. RESULTS ZAG plasma levels showed a negative correlation with insulin (r = -0.39; P = 0.008) and the homeostasis model assessment for insulin resistance index (r = -0.36; P = 0.016). No differences in ZAG circulating levels according to body mass index classification were observed. ZAG expression in SAT was significantly reduced in overweight and obese individuals compared with lean subjects (P < 0.001 and P = 0.007, respectively). ZAG mRNA expression in both SAT and VAT depots were negatively correlated with many clinical and metabolic cardiovascular risk factors. After multiple linear regression analysis, SAT ZAG was mainly predicted by adiponectin mRNA expression (B = 0.993; P < 0.0001) and plasma triglyceride levels (B = -0.565; P = 0.006). VAT ZAG expression was predicted by adiponectin expression (B = 0.449; P < 0.0001), and HSL VAT expression (B = 0.180; P = 0.023). CONCLUSIONS The present study provides evidence of a role of ZAG gene in adipose tissue metabolism, with a close association with adiponectin gene expression in sc and visceral fat.

Insulin sensitivity and resistin levels in gestational diabetes mellitus and after parturition

CONTEXT Resistin is expressed and secreted by the placenta during pregnancy. Increased serum resistin levels have been found in the second half of normal pregnancy, but its role in the pathogenesis of the insulin resistance of pregnancy is undetermined. OBJECTIVE The objective of the study was to assess the relationship between circulating resistin levels and insulin sensitivity in gestational diabetes mellitus (GDM). DESIGN AND SETTING A case (n=23)-control (n=35) study was performed at the obstetrics and endocrinology clinic of a university hospital. PATIENTS In total, 58 Caucasian women with a singleton pregnancy who had been referred for a 100 g oral glucose tolerance test were enrolled between the weeks 26 and 30, and 22 women with GDM were also evaluated after pregnancy. MAIN OUTCOME MEASURES Serum resistin and insulin sensitivity in GDM during and after pregnancy. The relationship of resistin to metabolic abnormalities was evaluated. RESULTS Resistin levels were lower in GDM women than in pregnant women with normal glucose tolerance (NGT) (4.32+/-1.56 vs 9.30+/-1.32 ng/ml, P<0.001), and experienced a further decrease after parturition (4.24+/-1.56 vs 3.11+/-1.63 ng/ml, P=0.003). The association between low serum resistin levels and the diagnosis of GDM was independent of the degree of insulin sensitivity. CONCLUSION Lower resistin levels were observed in GDM than in NGT women and decreased after parturition, suggesting a role for resistin in the development of this disease. But we have failed to find an independent relationship between resistin levels and insulin sensitivity during pregnancy.

Insulin Resistance, Leptin and TNF-α System in Morbidly Obese Women after Gastric Bypass

Obesity is a complex disease associated with insulin resistance. Leptin and the TNF-α system could be involved in the pathogenesis of obesity and insulin resistance. Gastric bypass (GBP) is a surgical treatment for morbidly obese patients. We conducted a study after GBP to analyze the pattern of variation of anthropometric and body composition variables, leptin and sTNFR1 and 2. Methods: 29 morbidly obese women were studied, at baseline and throughout 6 months after gastric bypass. Results: At baseline, the BMI was 49 ± 6 kg/m2 and patients showed a higher fasting insulin resistance index (FIRI), leptin, leptin/fat mass and sTNFR1 and 2 than did controls. 6 months after GBP, BMI was 35±4, and FIRI, leptin and leptin/fat mass decreased significantly in the first months and throughout the follow-up. sTNFR1 and 2 showed an initial increase, but at 6 months their concentrations were similar to baseline (2.6±0.8 vs 3.1±0.95 ng/ml, P < 0.05; 4.6±1.4 vs 7±2.5 ng/ml, P < 0.05). At baseline, there was no correlation between leptin and BMI and body composition variables but there was a correlation with fat mass (r=0.42, P=0.004) and sTNFR1 (r=0.58, P=0.001). At 6 months, there was a correlation between leptin and BMI (r=0.53, P=0.004) and sTNFR1 (r=0.46, P=0.013). Conclusions: Morbidly obese women after GBP became less insulin resistant with lower leptin concentrations, but showed an initial increase of sTNFR1 and 2. This pattern of variation of the leptin TNF-α axis suggests a disregulation of the system after dramatic weight loss and also that insulin and leptin up-regulate TNF-α production irrespective of insulin resistance status.

Plasma levels of the soluble fraction of tumor necrosis factor receptors 1 and 2 are independent determinants of plasma cholesterol and LDL-cholesterol concentrations in healthy subjects

In the last few years, it has been demonstrated that tumor necrosis alpha (TNF-alpha) has important effects on whole-body lipid metabolism. TNF-alpha administration has been found to produce an increase in serum cholesterol levels and increased hepatic hydro-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase activity in mice. The purpose of this study was to test whether plasma levels of the soluble forms of the TNF-alpha receptors 1 and 2 (sTNFR1, sTNFR2) are associated with lipid abnormalities. A total of 36 healthy subjects (19 males, mean age 36.2 +/- 1.9, and 17 females, mean age 34.9 +/- 1.4) were studied. Plasma sTNFR1 levels correlated with total (r = 0.43, P = 0.01) and LDL-cholesterol (r = 0.52, P = 0.002) levels, but not with total or HDL2-HDL3 subfractions of HDL-cholesterol, total plasma triglycerides, VLDL-cholesterol or VLDL-triglycerides (all r < 0.11, P = NS). Plasma sTNFR2 levels also correlated with total (r = 0.44, P = 0.009) and LDL-cholesterol (r = 0.57, P < 0.0001) levels, and negatively with HDL2-cholesterol (r = -0.37, P = 0.029). A stepwise multiple linear regression was constructed to predict total cholesterol levels, with BMI, sex, age, sTNFR1 or sTNFR2 as independent variables. Both sTNFR1 and sTNFR2 were significantly associated with total cholesterol (P = 0.031 and 0.009), contributing to 26 and 19%, respectively, of its variance. In another model in which LDL-cholesterol was substituted for total cholesterol, sTNFR1 or sTNFR2 (P = 0.0084 and 0.0005) were significantly associated with LDL-cholesterol, contributing to 39 and 32% of its variance. In summary, plasma levels of sTNFR1 and sTNFR2 circulate in proportion to total and LDL-cholesterol in healthy subjects.

Influence of chronic alcohol abuse and liver disease on hepatic aldehyde dehydrogenase activity

Alcohol metabolism results in the production of acetaldehyde, a compound that is much more toxic than ethanol itself. Hepatic aldehyde dehydrogenase (ALDH) is the main enzymatic system responsible for acetaldehyde clearance from the hepatocyte. The objective of this study was to determine the modifications in ALDH activity due to chronic alcohol abuse and liver disease. ALDH activity was determined in samples of liver tissue from 69 alcoholic and 82 nonalcoholic subjects, with and without liver disease. According to the results of liver pathology examination, alcoholic patients were classified into the following groups: controls, with no liver disease (group 1), noncirrhotic liver disease patients (group 2), and cirrhotics (group 3). Nonalcoholic subjects were categorized, using the same criteria, into groups 4, 5, and 6, respectively. ALDH activity was determined spectrophotometrically at two substrate concentrations: 18 mM for total activity and 180 microM for low Km activity. High Km activity was calculated by subtracting the low Km activity value from that of total ALDH activity. Results obtained in each group were expressed as the mean +/- SD of mU of g of wet weight. There were no significant differences when the total ALDH activity from the alcoholic and the nonalcoholic patients with a similar degree of liver pathology were compared: group 1, 1257 +/- 587 vs. group 4, 1328.1 +/- 546.2 (p: NS); group 2, 919.1 +/- 452.4 vs. group 5, 753.5 +/- 412 (p: NS); and group 3, 430.2 +/- 162.4 vs. group 6, 473.2 +/- 225.3 (p: NS). On the other hand, total ALDH activity was significantly lower in cirrhotics than in controls, both among alcoholics (p < 0.01) and among nondrinkers (p < 0.05). The low Km activity was severely reduced in cirrhotics, both alcoholics and nonalcoholics (p < 0.01). High Km activities in cirrhotic patients were low, compared to controls, both in alcoholics and nonalcoholics, although the difference was nonsignificant. The results of the present study suggests that chronic alcohol abuse does not depress ALDH activity. A reduction in the ALDH activity detected in patients with severe liver disease (cirrhotics) was clearly a consequence of liver damage. This reduction was due mainly to a decrease of the low Km ALDH activity, but a trend to a decrease in the high Km ALDH activity was also detected.

Spanish HIV-1-infected long-term nonprogressors of more than 15 years have an increased frequency of the CX3CR1 249I variant allele

Background and Objectives:The influence of the polymorphisms of the CX3CR1 chemokine receptor gene on the natural history of HIV-1 infection is controversial. This study aimed to determine whether functionally active CX3CR1 genetic variants are associated with long-term nonprogressive infection of >15 years in HIV-1-infected Spanish patients. Patients and Methods:Two single-nucleotide polymorphisms, V249I (G > A) and T280M (C > T), of the CX3CR1 gene were assessed in 271 Spaniards. These included 60 HIV-1-infected patients who were long-term nonprogressors (LTNPs) of >15 years, 109 HIV-1-infected patients who were usual progressors (UPs), and 102 control subjects. The CCR5Δ32 was also assessed. Genotyping was performed using polymerase chain reaction and automatic sequencing analysis methods on white cell DNA. Genotype and allele frequencies were compared by the χ2 test and the Fisher exact test. Results:The frequencies of the 249I variant allele were 42% for LTNPs, 24.5% for UPs, and 35% for healthy controls; the differences between LTNPs and UPs were significant (odds ratio 0.46; 95% CI: 0.27 to 0.75; P = 0.0017). For 280M the distribution was 16% for LTNPs, 14% for UPs, and 17% for healthy controls (P = NS). The haplotype 249I280T was significantly more common in LTNPs than in UPs (P = 0.0007). These results persisted after excluding from the analysis the individuals carrying the CCR5Δ32. Conclusions:CX3CR1 249I variant allele is more frequent in Spanish HIV-1-infected LTNPs of >15 years. This effect is independent of the presence of the CCR5Δ32 allele.