The interleukin-6--174 single nucleotide polymorphism: cervical protein production and the risk of preterm delivery

OBJECTIVE

The purpose of this study was to determine the associations between preterm delivery (PTD), cervical fluid interleukin-6 (IL-6) concentration, and the single nucleotide polymorphism at position -174 in the IL-6 gene.

STUDY DESIGN

Cervical fluid samples were obtained from women 23 to 32 weeks' gestation with symptoms of preterm labor. Concentrations of IL-6 were determined by enzyme-linked immunosorbent assay (ELISA). IL-6 genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique.

RESULTS

One hundred thirty-seven women were enrolled, and complete information was available for 126. Cervical fluid IL-6 concentrations were not elevated in women destined to have a spontaneous PTD ( P = .86). IL-6 -174 genotype was not associated with PTD ( P = .62) or cervical fluid IL-6 concentration ( P = .36). Neonatal IL-6-174 genotype was not associated with PTD or IL-6 concentration.

CONCLUSION

Cervical fluid concentrations of IL-6 were not elevated in symptomatic women destined to have a spontaneous PTD. The presence of maternal IL-6 -174C was not associated with cervical fluid concentration of IL-6 or risk of PTD.

The K469E polymorphism of the intercellular adhesion molecule-1 gene is associated with plasma fibrinogen level in type 2 diabetes

Intercellular adhesion molecule-1 (ICAM-1) is involved in inflammation and development of atherosclerotic change of vascular endothelium. The aim of the present study is to investigate whether K469E polymorphism of the ICAM-1 gene is associated with various clinical factors including plasma fibrinogen in patients with type 2 diabetes. ICAM-1 gene polymorphism was examined using polymerase chain reaction and restriction enzyme analysis in 360 type 2 diabetic patients. Plasma fibrinogen levels and other clinical variables were measured as well as circulating soluble ICAM-1 (sICAM-1) levels by enzyme-linked immunosorbent assay. The distribution of ICAM-1 genotypes, EE, EK, and KK, was not significantly different between type 2 diabetes and 152 healthy control subjects. Among 3 groups according to ICAM-1 genotypes in type 2 diabetes, no difference was found in adiposity, glycemic control, lipid profile, insulin sensitivity evaluated by homeostasis model assessment, or sICAM-1. Regarding fibrinogen, the patients with E allele showed significantly lower plasma fibrinogen levels in a dose-dependent manner (P = .033). Spearman rank correlation analyses revealed that ICAM-1 genotype showed significant correlation with plasma fibrinogen level (P < .001). In multiple regression analysis, ICAM-1 genotype was independent contribution factor of plasma fibrinogen level as well as high-density lipoprotein-cholesterol and urinary albumin excretion (R2 = 0.148, P < .001). In conclusion, K469E polymorphism of the ICAM-1 gene had impact on plasma fibrinogen level independently of other clinical factors in 360 type 2 diabetic patients, suggesting that fibrinogen is a candidate which links the ICAM-1 gene polymorphism to atherosclerosis.

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&gt;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-1β, IL-6, and tumor necrosis factor-α (TNF-α) 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 &lt;0.005). There were no differences between the two genotypes regarding serum concentrations of IL-1β and TNF-α before or after vaccination.

Conclusions: The −174 G&gt;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.

Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis

BACKGROUND CONTEXT

Most surgeons have thought that posterior decompression is necessary to treat isthmic spondylolisthesis with leg pain. However, the surgical procedure not only requires wide muscle dissection but can also lead to spinal instability. The authors' treatment concept for isthmic spondylolisthesis is one-stage anterior reduction and posterior stabilization with minimally invasive surgical procedure without touching the spinal thecal sac and nerve.

PURPOSE

To investigate a new surgical concept of minimally invasive anterior-posterior fusion without posterior decompression for the treatment of isthmic spondylolisthesis with leg pain.

STUDY DESIGN

This is a retrospective study of 73 patients with isthmic spondylolisthesis who underwent minimally invasive anterior lumbar interbody fusion (mini-ALIF) followed by percutaneous pedicle screw fixation (PF) between October 2000 and February 2002.

PATIENT SAMPLE

A total of 73 patients with low-grade isthmic spondylolisthesis (46 with Grade 1 and 27 with Grade 2) who underwent mini-ALIF followed by percutaneous PF were retrospectively analyzed. There were 20 men and 53 women, with a mean age of 50.6 (range, 19 to 77) years. All patients had low back pain and referred or radicular leg pain or neurogenic intermittent claudication in walking or standing. Average duration of symptoms was 26 (range, 3 to 120) months.

OUTCOME MEASURES

The clinical outcome was graded according to the modified Macnab criteria.

METHODS

The authors retrospectively reviewed clinical and radiological data of 73 patients who had isthmic spondylolisthesis. All patients underwent mini-ALIF and percutaneous PF on the same day between October 2000 and February 2002. The mean follow-up period was 16 months (range, 12 to 26).

RESULTS

The mean operating time, blood loss and hospital stay were 210 minutes, 135 ml and 4.1 days, respectively. No blood transfusion was necessary. Clinical outcome was excellent in 26 patients (35.6%), good in 43 (58.9%), fair in 3 (4.1%) and poor in 1 (1.4%). The fusion rate was 97.3% (71 of 73). There were 6 cases (8.2%) of mini-ALIF complications and 6 (8.2%) of percutaneous PF complications. There were no postoperative neurologic deficits.

CONCLUSIONS

Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge.

No association of interleukin-6 gene polymorphism (−174 G/C) with myocardial infarction or traditional cardiovascular risk factors

BACKGROUND

Recently, a polymorphism at position -174 (G>C) of the interleukin-6 (IL-6) promoter was found to be associated with an increased prevalence of myocardial infarction (MI). The aim of the present study was to further investigate the association of the IL-6 -174 G/C allele status with specific end organ damage, i.e. myocardial infarction in large population-based samples.

METHODS

Individuals from two Bavarian samples of MI patients (total n=1322) and the population-based Augsburg MONICA survey (1023 unselected controls) were studied by questionnaire, physical examination, echocardiographical assessment and biochemical analyses. The -174 G/C polymorphism was genotyped using a newly established PCR-RFLP. IL-6 levels were measured in a subset of 574 MI patients.

RESULTS

In the population-based sample, the IL-6 genotype was neither associated with traditional cardiovascular risk factors (systolic and diastolic blood pressure, total cholesterol, HDL and LDL cholesterol, body mass index, diabetes mellitus) nor with cardiac structural or functional parameters (left ventricular mass index, ejection fraction, diastolic inflow pattern). Moreover, the genotype distribution of the -174 G/C polymorphism was not different in MI patients (GG: 34.1%; GC: 47.4%; CC: 18.5%) and population-based controls (GG: 32.4%; GC: 48.8%; CC: 18.9%) (p=0.67). IL-6 levels were neither related to the -174 G/C polymorphism (p=0.29) nor to ACE-inhibitor treatment (2.16 with vs. 2.09 pg/ml without ACE-inhibitor, p=0.27). However, patients receiving statins displayed significantly lower IL-6 levels (1.83 vs. 2.32 pg/ml in the group without statins, p<0.0001).

CONCLUSIONS

This extensive investigation failed to obtain evidence that the IL-6 -174 G/C promoter polymorphism affects traditional cardiovascular risk factors or the prevalence of myocardial infarction in a Caucasian sample.

Prognostic value of plasma interleukin-6 concentrations and the -174 G > C and -572 G > C promoter polymorphisms of the interleukin-6 gene in patients with acute myocardial infarction treated with thrombolysis

The present study was performed to investigate the prognostic value of plasma interleukin-6 (IL-6) concentrations and promoter polymorphisms of the IL-6 gene in patients with acute myocardial infarction treated with thrombolysis. Two hundred and eight patients with myocardial infarction treated with thrombolysis were included and followed for 2-5 years. Plasma concentrations of IL-6 were measured at admission and 48 h after admission. Genotyping for the -174 G > C and -572 G > C IL-6 polymorphisms was performed. Patients who died of cardiovascular causes or suffered a new myocardial infarction during follow-up had increased plasma concentrations of IL-6 at admission (P < 0.002) and at 48 h after admission (P < 0.05) compared with patients who had an uneventful course. IL-6 levels above the median at admission were independently associated with a worse prognosis. No associations were found between IL-6 levels and the promoter polymorphisms. The -174 G > C polymorphism was not associated with cardiovascular death or a new myocardial infarction, whereas the -572 G > C polymorphism showed a borderline significant increase in risk (P = 0.05) in univariate analysis. In conclusion, the early IL-6 response during myocardial infarction is associated with prognosis in patients with Q-wave myocardial infarction, whereas no associations were found between IL-6 genotype and phenotype.

Proinflammatory Genetic Profiles in Subjects With History of Ischemic Stroke

BACKGROUND AND PURPOSE

Proinflammatory genetic profiles, resulting from the combination of single nucleotide polymorphisms in genes encoding inflammatory molecules, may contribute to the development and progression of cardiovascular diseases. We evaluated the association between history of ischemic stroke and genetic profiles determined by the synergistic effects of polymorphisms in genes encoding prototypical inflammatory proteins.

METHODS

The study included 237 individuals with history of ischemic stroke and 223 age-matched and gender-matched controls. The polymorphisms of the C-reactive protein (CRP), interleukin-6 (IL-6), macrophage migration inhibitory factor (MIF), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), E-selectin (E-sel), and matrix metalloproteinase-3 (MMP-3) genes were studied.

RESULTS

IL-6 GG, IL-6 GC, MCP-1 GG, ICAM-1 EE, E-sel AA, and MMP-3 5A5A genotypes were significantly and independently associated with stroke history. The odds of stroke increased with the number of high-risk genotypes: carrying 1 proinflammatory gene variant conferred a risk of 3.3 (1.6 to 6.9), whereas individuals concomitantly carrying 2 and 3 proinflammatory gene variants had adjusted odds ratios of 21.0 (7.6 to 57.5) and 50.3 (10.2 to 248.1), respectively.

CONCLUSIONS

Proinflammatory genetic profiles are significantly more common in subjects with stroke history. Synergistic effects between proinflammatory genotypes might be potential markers for cerebrovascular diseases.

Polymorphisms in genes involved in inflammatory and angiogenic pathways and the risk of hemorrhagic presentation of brain arteriovenous malformations

BACKGROUND AND PURPOSE

Accurate estimates of intracranial hemorrhage (ICH) risk in patients harboring brain arteriovenous malformation (BAVM) are needed to evaluate interventional strategies and to help guide clinical management. Identification of genetic polymorphisms associated with ICH would facilitate risk stratification in BAVM patients.

METHODS

We identified patients with BAVM and documented clinical presentation, demographic data, venous drainage pattern, and BAVM size. Patients were genotyped for 5 polymorphisms in 3 inflammatory cytokine genes, and 9 polymorphisms in 5 angiogenesis-related genes. Association of genotype with risk of hemorrhagic BAVM presentation was evaluated using logistic regression analysis.

RESULTS

We genotyped 180 patients with BAVM (53% female, 57% white, mean age at diagnosis 35+/-17 years, 41% presenting with ICH). BAVM patients homozygous for the interleukin 6 (IL6)-174G allele had a greater risk of ICH presentation (OR, 2.62, P=0.003) than IL6-174C carriers. In a multivariate logistic regression model, IL6-174G>C genotype, small BAVM size, and exclusively deep venous drainage were independent predictors of ICH presentation. A similar univariate trend was noted for the TNFalpha-308 GG genotype (P=0.055). The other polymorphisms genotyped were not associated with ICH.

CONCLUSIONS

A polymorphism in the inflammatory cytokine IL6, but not polymorphisms in angiogenesis-related genes, was associated with ICH presentation of BAVM. Further studies are needed to define the role of inflammatory cytokines in the pathogenesis of BAVM hemorrhage.

Interleukin 6 −174 G/C promoter gene polymorphism in centenarians: no evidence of association with human longevity or interaction with apolipoprotein E alleles

The C allele at position -174 in the promoter of the interleukin 6 (IL-6) gene has been associated with reduced gene expression and reduced plasma levels of IL-6. Given that IL-6 tracks with functional disability and age-related diseases, there may be attrition or reduction in the frequency of the homozygous subjects, who produce higher IL-6 serum levels, in older survivors in a population. In fact, a marked reduction of the IL-6*G/*G genotype was recently demonstrated in male though not female Italian centenarians compared with younger age groups. First aim of the present study was to investigate whether there was evidence of an association among IL-6 -174 G/C promoter polymorphism and extreme longevity in a population of 81 centenarians compared with a control group of 122 middle-aged healthy subjects (mean age: 51+/-18 SD; range: 19-73 years), from Apulia (Southern Italy). Secondly, we also tested possible interaction of apolipoprotein E (APOE) alleles with the IL-6 -174 G/C promoter polymorphism in view of our recent findings for reduced APOE epsilon4 allele in centenarians. No differences have been found in the IL-6 -174 G/C promoter allele and genotype frequencies between centenarians and controls nor was there any observed interaction with APOE alleles that are also reputed to be linked to longevity. Regional genetic differences in conjunction with differing environmental factors may explain in part previous results suggesting a role of this polymorphism in longevity.

Interleukin-6 Promoter Genotype and Restenosis after Femoropopliteal Balloon Angioplasty: Initial Observations

PURPOSE

To investigate whether there is an association between a functional polymorphism in the interleukin (IL)-6 gene promoter (-174)G/C and restenosis after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery.

MATERIALS AND METHODS

A total of 281 patients underwent PTA of the femoropopliteal artery during the study period; 23 (8%) patients had to be excluded due to missing genetic data. We studied 258 patients with intermittent claudication (n = 174) or critical limb ischemia (n = 84). The IL-6 promoter genotype was determined from venous blood samples before intervention by using a mutagenically separated polymerase chain reaction, and patients were followed up for 6 months with duplex ultrasonography for the occurrence of restenosis (> or =50%) after angioplasty. Multivariate Cox proportional hazards analysis was performed to assess the association between the IL-6 promoter genotype and restenosis, with adjustment for possible confounders such as atherosclerotic risk factors and angiographic covariates.

RESULTS

The 6-month restenosis rate was 26% (23 of 90) in patients with the (-174)GG genotype, 28% (33 of 117) with the (-174)GC genotype, and 43% (22 of 51) with the (-174)CC genotype (P =.044). Homozygous carriers of the (-174)C allele ([-174]CC) exhibited a 2.42-fold increased adjusted risk for restenosis (95% CI: 1.28, 4.58; P =.007) compared with homozygous (-174)G allele carriers ([-174]GG). Heterozygous carriers ([-174]GC) had no significantly increased restenosis risk (hazard ratio, 1.37; 95% CI: 0.84, 2.22; P =.21).

CONCLUSION

The IL-6 promoter polymorphism (-174)G/C seems to influence the occurrence of restenosis after PTA. Homozygous carriers of the (-174)C allele have an increased rate of intermediate-term restenosis.

CYTOCHROMES P450 ARE DIFFERENTLY EXPRESSED IN NORMAL AND VARICOSE HUMAN SAPHENOUS VEINS: LINKAGE WITH VARICOSIS

The expression of cytochrome P450 (CYP) enzymes and cyclo-oxygenases (COX) was investigated in human saphenous veins by reverse transcription-polymerase chain reaction analysis. Non-varicose veins were obtained from patients undergoing aortocoronary bypass grafting, whereas varicose veins were obtained from patients undergoing stripping removal of varicose saphenous veins. In non-varicose veins, CYP1B1, CYP2C, CYP2E1 and CYP4A11 were detected, whereas CYP2J2, CYP3A5, COX-1 and COX-2 were detected almost exclusively in varicose veins. CYP4F2 was not detectable. Except for CYP4A11, the levels of individual CYP mRNA were higher in varicose veins than in control veins. Smooth muscle cell volume, determined by a colour image-analysis system, was increased approximately 1.5-fold in varicose veins. Because CYPs and COXs produce various vasoactive compounds, increased expression of these enzymes could be involved in the impairment of vascular tone and may contribute to varicose pathology. Then, CYP or COX modulators may be potentially active in the treatment of chronic venous insufficiency.

The influence of patient- and facility-specific factors on nutritional status and survival in hemodialysis

BACKGROUND

Parameters of nutritional status, including serum albumin, serum creatinine, and body mass index (BMI), are powerful predictors of mortality and hospitalization in patients with end stage renal disease (ESRD). Patient-specific characteristics and facility-related practice patterns modify certain parameters of nutritional status. We aimed to determine whether patient and facility characteristics modify the risk profiles associated with malnutrition in hemodialysis patients.

METHODS

We analyzed data on 5,234 prevalent hemodialysis patients from the Dialysis Morbidity and Mortality Study (DMMS) Wave 1 for whom information on demographic, clinical, nutritional, and facility-related characteristics were available. We evaluated the associations among facility characteristics and serum albumin, serum creatinine, and BMI, adjusting for the effects of age, sex, race/ethnicity, diabetes, and dialysis vintage. We determined correlates of mortality and hospitalization, focusing on nutritional parameters, facility effects, and the interactions among patient-specific and facility-specific characteristics, albumin, creatinine, and BMI.

RESULTS

Serum albumin was lower with older age, diabetes, nonblack race, and hemodialysis using a catheter. Serum albumin was higher with annual vascular access surveillance, higher BMI among women, higher urea reduction ratio, among patients in whom dialyzers were reprocessed (particularly with bleach), among dialysis units in which water purification was used, and when vascular access blood flow rates were > or =350 mL/min. Overall survival was decreased with lower albumin, creatinine, and BMI. There were interactions among albumin, age, and vintage. Whereas lower serum albumin concentrations consistently were associated with an increased risk of death, the differences were attenuated among older patients and accentuated among patients of longer vintage.

CONCLUSION

Some facility-specific factors are associated with nutritional parameters including serum albumin, serum creatinine, and BMI. The associations of nutritional parameters with mortality and hospitalization vary by age, sex, and vintage but not by facility-specific factors, including those associated with the nutritional parameters themselves.

Adhesion molecules and atherosclerosis

One early phase of atherosclerosis involves the recruitment of inflammatory cells from the circulation and their transendothelial migration. This process is predominantly mediated by cellular adhesion molecules, which are expressed on the vascular endothelium and on circulating leukocytes in response to several inflammatory stimuli. Selectins (P, E and L) and their ligands (mainly P-selectin ligand) are involved in the rolling and tethering of leukocytes on the vascular wall. Intercellular adhesion molecules (ICAMs) and vascular cell adhesion molecules (VCAM-1), as well as some of the integrins, induce firm adhesion of inflammatory cells at the vascular surface, whereas platelet endothelial cellular adhesion molecules (PECAM-1) are involved in extravasation of cells from the blood compartment into the vessel and underlying tissue. For most of the cellular adhesion molecules, except integrins, soluble forms have been identified in the circulation although their origins are not fully understood. Several lines of evidence support a crucial role of adhesion molecules in the development of atherosclerosis and plaque instability. Expression of VCAM-1, ICAM-1 and L-selectin has been consistently observed in atherosclerotic plaques. There is accumulating evidence from prospective studies for a predictive role of elevated circulating levels of sICAM-1 in initially healthy people, and of sVCAM-1 in patients at high risk or with overt CAD. A large number of common polymorphisms has been identified in the genes encoding the different adhesion molecules, but studies investigating their relationship either with soluble forms or with CAD are still sparse and often based on small samples. Further research is needed to firmly establish the potential clinical and therapeutic utilities of (soluble) adhesion molecules, but results in both fields hold the promise that in future, adhesion molecules might add information for clinical risk prediction and serve as therapeutic targets.

The −174G/C polymorphism of IL-6 is useful to screen old subjects at risk for atherosclerosis or to reach successful ageing

High levels of IL-6 are coupled with impaired immune efficiency, morbidity and mortality in ageing. Elderly men with GG (C-) genotype in -174 locus of IL-6 promoter are disadvantaged for longevity due to higher IL-6 than CG or CC (C+) carriers. As IL-6 increases in atherosclerosis, the study of the polymorphism of IL-6 may be a useful tool in identifying old subjects at risk for atherosclerosis. Thus, we divided old men into C+ and C- genotypes. Natural killer (NK) cell cytotoxicity, IL-6, IL-10, TNF-alpha, MTmRNA and zinc ion bioavailability were also evaluated and compared with nonagenarians and old patients affected by carotid stenosis. Old C- patients display, other than elevated IL-6, higher IL-10, TNF-alpha and MTmRNA coupled with impaired NK cell cytotoxicity and lower zinc ion bioavailability than C+ patients. The same trend is observed in old subjects with C- phenotype. Nonagenarians with C+ genotype show less inflammation, low MTmRNA, satisfactory NK cell cytotoxicity and good zinc bioavailability than long-living individuals with C- genotype. A higher degree of bilateral carotid stenosis is observed in C- patients than in C+ patients (88 vs 52%). Therefore, C- genotype is coupled with chronic inflammation, impaired immune efficiency, low zinc ion bioavailability and high MTmRNA. As such, C- genotype is a risk factor for the appearance of severe atherosclerosis. Thus, the polymorphism of IL-6, together with the analysis of zinc turnover and immune parameters, is of a great clinical relevance in order to genetically identify old subjects at risk in developing severe atherosclerosis and, at the same time, to predict subjects predestined to successful ageing. As a consequence, more convenient therapies may be prepared for a complete recovery.

Distribution of HIV-1 in the genomes of AIDS patients

The localization of HIV-1 proviruses in compositional DNA fractions from 27 AIDS patients during the chronic phase of the disease with depletion of CD4+ and different levels of viremia showed the following. (1) At low viremia, proviruses are predominantly localized in the GC-richest isochores, which are characterized by an open chromatin structure; this result mimics findings on HIV-1 integration in early infected cells in culture. (2) At higher viremia, an increased distribution of proviruses in GC-poor isochores (which match the GC poorness of HIV-1) was found; this suggests a selection of cells in which the 'isopycnic' localization leads to a higher expression of proviruses and, in turn, to higher viremia. (3) At the highest viremia, integrations in GC-rich isochores are often predominant again, but generally not at the same level as in (1); this may be the consequence of new integrations from the extremely abundant RNA copies.

Current limitations of SNP data from the public domain for studies of complex disorders: a test for ten candidate genes for obesity and osteoporosis

BACKGROUND

Public SNP databases are frequently used to choose SNPs for candidate genes in the association and linkage studies of complex disorders. However, their utility for such studies of diseases with ethnic-dependent background has never been evaluated.

RESULTS

To estimate the accuracy and completeness of SNP public databases, we analyzed the allele frequencies of 41 SNPs in 10 candidate genes for obesity and/or osteoporosis in a large American-Caucasian sample (1,873 individuals from 405 nuclear families) by PCR-invader assay. We compared our results with those from the databases and other published studies. Of the 41 SNPs, 8 were monomorphic in our sample. Twelve were reported for the first time for Caucasians and the other 29 SNPs in our sample essentially confirmed the respective allele frequencies for Caucasians in the databases and previous studies. The comparison of our data with other ethnic groups showed significant differentiation between the three major world ethnic groups at some SNPs (Caucasians and Africans differed at 3 of the 18 shared SNPs, and Caucasians and Asians differed at 13 of the 22 shared SNPs). This genetic differentiation may have an important implication for studying the well-known ethnic differences in the prevalence of obesity and osteoporosis, and complex disorders in general.

CONCLUSION

A comparative analysis of the SNP data of the candidate genes obtained in the present study, as well as those retrieved from the public domain, suggests that the databases may currently have serious limitations for studying complex disorders with an ethnic-dependent background due to the incomplete and uneven representation of the candidate SNPs in the databases for the major ethnic groups. This conclusion attests to the imperative necessity of large-scale and accurate characterization of these SNPs in different ethnic groups.

The IL-6 −174G>C polymorphism is associated with cardiovascular diseases and mortality in 80-year-old humans

Chronic low-grade elevations in circulating levels of interleukin (IL)-6 act as a marker of subclinical cardiovascular diseases (CVD) and provide an independent predictor of increased mortality in elderly populations. The purpose of the present study was to test the hypothesis that the IL-6 -174G>C promoter polymorphism was associated with a high prevalence of CVD and acted as an independent predictor of mortality in a longitudinal study of 324 relatively healthy 80-year-old people with a history of CVD in 18% of the cases. The C allele was associated with elevated serum levels of IL-6 at baseline and the CC genotype had a high prevalence of CVD. A Cox regression model was used to explore the effect of the polymorphism on survival in the following six years. A significant interaction was found between smoking status and the polymorphism. Thus, C allele carrier status was associated with increased all-cause mortality risk in non-smokers independently of sex, body mass index, co-morbidity, and low-grade elevations in serum levels of IL-6. This effect was not detected among smokers. We conclude that the IL-6 -174G>C polymorphism was an independent predictor of all-cause mortality in octogenarians but the effect was complex and interacted with the smoking status.

Evaluation and medical treatment of peripheral arterial disease

PURPOSE OF REVIEW

This review reports various advances in the evaluation and medical management of patients with peripheral arterial disease (PAD) in the last 1 to 2 years.

RECENT FINDINGS

Several community surveys have clearly highlighted the fact that despite being a very highly prevalent disease, physicians underdiagnose and undertreat PAD. This led to the Executive Committee of the Prevention of Atherothrombotic Disease Network to issue a "call to action," citing critical issues in PAD detection and management.

SUMMARY

PAD affects more than 27 million people in North America and Europe, and the prevalence of this disease continues to increase as the population ages. This disease has significant adverse effects on the quality of life and survival, with mortality as high as 30% in 5 years and 50% in 10 years. Although surgical, endovascular, and medical therapies for atherosclerosis in general, and PAD specifically, continue to be developed, there appears to be considerable room for improvement in physician adoption of proven effective therapies, such as cholesterol-lowering therapies and blood pressure management. Additionally, new therapies, such as gene transfer and cell therapy, are under development for this population.

Children and adolescents with low back pain: a descriptive study of physical examination and outcome measurement

STUDY DESIGN

A retrospective, cohort study of children and adolescents with low back pain (LBP) referred to physical therapy.

OBJECTIVES

To describe the clinical presentation, examination findings, and classification of children and adolescent patients with LBP, and to explore the concurrent validity of the Oswestry questionnaire as a disability measure in this group.

BACKGROUND

Little information is available regarding the clinical presentation, physical examination findings, and outcome assessment in children and adolescents with LOP.

METHODS AND MEASURES

Charts were reviewed for historical, diagnostic, physical examination,and outcome information. Diagnoses given by the referring physicians were recorded. A treatment-based classification was made for each subject. Descriptive statistics were calculated for all variables. The validity of the Oswestry questionnaire was examined.

RESULTS

The children and adolescents included in this study represented 5% (n = 25) of all cases of LOP referred to physical therapy. A greater percentage of patients had difficulty with extension than with flexion range of motion (ROM). Initial pain scores were lower if a specific pathology was present (P = .001). Initial pain and Oswestry scores were poorly correlated (r = 0.16). Forty-four percent (n = 11) of patients scored under the floor value of 12% on the Oswestry.

CONCLUSION

The referral rate of children and adolescents with LBP seems to be low. Compared to adults, children and adolescents appear more likely to have a specific diagnosis given to them by their physician. The physical examination findings appear to indicate that spinal stabilization approaches may be beneficial for many patients. The Oswestry questionnaire may not be a valid tool for documenting changes in disability in these patients. Further research is needed on the conservative management of children and adolescents with LBP.

Insulin resistance and chronic cardiovascular inflammatory syndrome

Insulin resistance is increasingly recognized as a chronic, low-level, inflammatory state. Hyperinsulinemia and insulin action were initially proposed as the common preceding factors of hypertension, low high-density lipoprotein cholesterol, hypertriglyceridemia, abdominal obesity, and altered glucose tolerance, linking all these abnormalities to the development of coronary heart disease. The similarities of insulin resistance with another inflammatory state, atherosclerosis, have been described only in the last few decades. Atherosclerosis and insulin resistance share similar pathophysiological mechanisms, mainly due to the actions of the two major proinflammatory cytokines, TNF-alpha and IL-6. Genetic predisposition to increased transcription rates of these cytokines is associated with metabolic derangement and simultaneously with coronary heart disease. Dysregulation of the inflammatory axis predicts the development of insulin resistance and type 2 diabetes mellitus. The knowledge of how interactions between metabolic and inflammatory pathways occur will be useful in future therapeutic strategies. The effective administration of antiinflammatory agents in the treatment of insulin resistance and atherosclerosis is only the beginning of a promising approach in the management of these syndromes.

Synergistic effect of -174 G/C polymorphism of the interleukin-6 gene promoter and 469 E/K polymorphism of the intercellular adhesion molecule-1 gene in Italian patients with history of ischemic stroke

BACKGROUND AND PURPOSE

Interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) are involved in the pathogenetic mechanisms responsible for several ischemic cardiovascular disorders, including cerebral ischemia. IL-6 and ICAM-1 plasma levels and/or function may be genetically influenced. We sought to evaluate distribution and reciprocal interaction of IL-6 G/C gene promoter polymorphism and ICAM-1 E/K gene polymorphism in Italian patients with history of ischemic stroke.

METHODS

One hundred nineteen patients with history of ischemic stroke and 133 age- and sex-matched controls were studied. IL-6 and ICAM-1 genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis.

RESULTS

The GG genotype of -174 IL-6 G/C gene polymorphism was significantly associated with history of ischemic stroke at both univariate (P<0.0001) and multivariate analysis (odds ratio [OR], 8.6; P<0.0001). Additionally, the EE genotype of ICAM-1 E/K gene polymorphism was significantly more common in the group of patients with history of ischemic stroke (P=0.003) and was an independent variable associated with stroke history (OR, 4.0; P=0.002). Interestingly, a further increased risk of stroke was found in subjects who concomitantly carry the IL-6 GG and ICAM-1 EE genotypes (IL-6 GG/ICAM-1 EE double-homozygous subjects) (OR, 10.1; P=0.004).

CONCLUSIONS

There is a synergistic effect of IL-6 G/C and ICAM-1 E/K gene polymorphisms in patients with stroke history. Reciprocal interactions between genotypes may contribute in determining the risk profile for cardiovascular diseases and may merit further investigation as potential therapeutic targets.

Interleukins in atherosclerosis: molecular pathways and therapeutic potential

Interleukins are considered to be key players in the chronic vascular inflammatory response that is typical of atherosclerosis. Thus, the expression of proinflammatory interleukins and their receptors has been demonstrated in atheromatous tissue, and the serum levels of several of these cytokines have been found to be positively correlated with (coronary) arterial disease and its sequelae. In vitro studies have confirmed the involvement of various interleukins in pro-atherogenic processes, such as the up-regulation of adhesion molecules on endothelial cells, the activation of macrophages, and smooth muscle cell proliferation. Furthermore, studies in mice deficient or transgenic for specific interleukins have demonstrated that, whereas some interleukins are indeed intrinsically pro-atherogenic, others may have anti-atherogenic qualities. As the roles of individual interleukins in atherosclerosis are being uncovered, novel anti-atherogenic therapies, aimed at the modulation of interleukin function, are being explored. Several approaches have produced promising results in this respect, including the transfer of anti-inflammatory interleukins and the administration of decoys and antibodies directed against proinflammatory interleukins. The chronic nature of the disease and the generally pleiotropic effects of interleukins, however, will demand high specificity of action and/or effective targeting to prevent the emergence of adverse side effects with such treatments. This may prove to be the real challenge for the development of interleukin-based anti-atherosclerotic therapies, once the mediators and their targets have been delineated.