Heritability of arterial stiffness and carotid intima-media thickness: an Italian twin study

BACKGROUND AND AIMS

Carotid intima-media thickness (IMT) and arterial stiffness parameters, including aortic augmentation index (AIx) and pulse wave velocity (PWV), are independent predictors of stroke and cardiovascular disease. Genetic effects on these traits were never explored in a Mediterranean country. The present study aims to quantify the contribution of genes, environment and age to carotid IMT and aortic Aix and PWV.

METHODS AND RESULTS

The twin design was used. A total of 348 adult twins from the Italian Twin Register underwent measurements of carotid IMT and aortic PWV and AIx in three university hospitals located in Rome, Padua and Perugia. Carotid IMT was measured by B-mode ultrasound, aortic PWV and AIx by Arteriograph. Genetic modelling was performed to decompose total variance of traits into genetic, shared and unshared environmental and age components. For each phenotype, the best-fitting model included additive genetic, unshared environmental and age effects. For IMT, heritability was 0.32 (95% confidence interval (CI): 0.25-0.38), unshared environmental component was 0.25 (0.18-0.32) and age contribution was 0.44 (0.39-0.49). For AIx and PWV, heritabilities were 0.42 (0.29-0.55) and 0.49 (0.35-0.62), unshared environmental components were 0.31 (0.22-0.44) and 0.37 (0.26-0.51) and age contributions were 0.27 (0.16-0.39) and 0.14 (0.06-0.24), respectively.

CONCLUSION

This study shows substantial genetic and unshared environmental influences on carotid intima-media thickness and arterial stiffness and confirms the relevant role of age in the aetiology of these traits. Further support is provided for prevention and health promotion strategies based on modifiable factors.

Health status and 6 years survival of 552 90+ Italian sib-ships recruited within the EU Project GEHA (GEnetics of Healthy Ageing)

In a scenario of increasing life expectancy worldwide, it is mandatory to identify the characteristics of a healthy aging phenotype, including survival predictors, and to disentangle those related to environment/lifestyle versus those related to familiarity/genetics. To this aim we comprehensively characterised a cohort of 1,160 Italian subjects of 90 years and over (90+, mean age 93 years; age range 90-106 years) followed for 6 years survival, belonging to 552 sib-ships (familiar longevity) recruited (2005-2008) within the EU-funded GEHA project in three Italian geographic areas (Northern, Central and Southern Italy) different for urban/rural and socio-economical characteristics. On the whole, the following factors emerged as significant predictors of survival after 90 years of age: absence of cognitive impairment and physical disability, high hand grip strength scores and body mass index (BMI) values, "excellent/good" self-reported health, high haemoglobin and total cholesterol levels and low creatinine levels. These parameters, excluding BMI values, were also significantly associated within sib-ships, suggesting a strong familial/genetic component. Geographical micro-heterogeneity of survival predictors emerged, such as functional and physical status being more important in Southern than in Central and Northern Italy. In conclusion, we identified modifiable survival predictors related to specific domains, whose role and importance vary according to the geographic area considered and which can help in interpreting the genetic results obtained by the GEHA project, whose major aim is the comprehensive evaluation of phenotypic and genetic data.

Serum elements and oxidative status in clinically isolated syndromes: imbalance and predictivity

BACKGROUND

Metals are suspected of being involved in the pathogenesis of various neurologic diseases. We previously found a complex imbalance in serum chemical elements and oxidative status in patients with clinically definite multiple sclerosis (CDMS).

OBJECTIVE

To understand whether this imbalance affects people with clinically isolated syndrome (CIS) and, if so, whether it predicts conversion to CDMS.

METHODS

We studied 22 chemical elements and the oxidative status in 49 patients with CIS, 49 patients with CDMS, and 49 healthy donors (HD). Univariate and multivariate approaches were used to identify profiles for each group. A logistic regression analysis was used to identify the predictive potential of baseline data (elements, oxidative status, and MRI findings) for conversion to CDMS over 36 months.

RESULTS

Several elements and oxidative status values differed significantly among the 3 groups. Discriminant analysis revealed a major contribution of Ca, Fe, Sn, Zn, serum antioxidant capacity, and serum oxidative status, which resulted in distinct profiles (the prediction of group membership was 96% [cross-validated 92%] for HD, 92% [cross-validated 92%] for CDMS, and 90% [cross-validated 86%] for CIS). A weighted combination of element concentrations and oxidative status values, adjusting for all other predictors, would predict a reduction in the risk of conversion to CDMS within 3 years (odds ratio 0.37; 95% confidence interval 0.18-0.76; p = 0.007), thereby proving more effective than MRI at baseline.

CONCLUSIONS

The peculiar imbalance in serum elements and oxidative status that characterizes patients with CIS and may predict conversion to CDMS warrants studies on larger sample sizes.

Serum transforming growth factor β1 during diabetes development in non-obese diabetic mice and humans

Recent data show that regulatory cells with transforming growth factor (TGF)-β1-dependent activity are able to restore self-tolerance in overtly diabetic non-obese diabetic (NOD) mice. Thus, TGF-β1 seems to have a relevant role in protection from autoimmune diabetes. Our aim was to investigate the possible significance of serum TGF-β1 measurement in the natural history of diabetes in NOD mice, as well as in children positive for at least one islet-related antibody. Serum TGF-β1 (both total and active) was measured by enzyme-linked immunosorbent assay at monthly intervals in 26 NOD mice during the spontaneous development of diabetes and, on a yearly basis, in nine siblings of patients with type 1 diabetes (T1D) with a follow-up of 4 years. Diabetes appeared between the 12th week of age and the end of the study period (36 weeks) in 17 mice. TGF-β1 serum level variations occurred in the prediabetic period in both NOD mice and humans and diabetes diagnosis followed a continuing reduction of active TGF-β1 (aTGF-β1) serum levels. In mice, aTGF-β1 serum levels measured at 4 weeks of age correlated positively with severity of insulitis, and negatively with percentage of insulin-positive cells. Our findings suggest that in NOD mice serum TGF-β1 levels during the natural history of the diabetes reflect the course of islet inflammation. The measurement of aTGF-β1 in islet-related antibody-positive subjects may provide insights into the natural history of prediabetic phase of T1D.

Increasing hepatitis B vaccination coverage among healthcare workers in Italy 10 years apart

BACKGROUND

In Italy, vaccination against hepatitis B virus infection was strongly recommended for healthcare workers since 1985. Update findings on vaccination coverage are lacking.

AIM

To assess current vaccination coverage against hepatitis B in this job category.

METHODS

In 2006, 1,632 healthcare workers randomly selected in 15 Italian public hospitals completed a self-administered precoded questionnaire.

RESULTS

The overall vaccination coverage was 85.3%, a figure higher than the 64.5% observed in 1996. Vaccine coverage showed a significant downtrend (p<0.01) from the Northern (93.1%) to the Southern (77.7%) areas. Logistic regression analysis showed that residence in the North (Odds ratio 4.2; 95% confidence interval 2.6-6.7) and youngest age (Odds ratio 4.5; 95% confidence interval 2.6-7.8), both were independent predictors of vaccine acceptance.

CONCLUSIONS

Ten years apart, vaccine coverage has markedly increased, closely paralleling the downtrend in the incidence of acute B hepatitis among healthcare workers in Italy.

Concordance, disease progression, and heritability of coeliac disease in Italian twins

BACKGROUND AND AIMS

We adopted the twin method to disentangle the genetic and environmental components of susceptibility to coeliac disease (CD). We estimated disease concordance rate by zygosity and HLA genotypes, discordance times, progression rates to disease, and heritability.

METHODS

We crosslinked the Italian Twin Registry with the membership lists of the Italian Coeliac Disease Association and recruited 23 monozygotic (MZ) and 50 dizygotic (DZ) twin pairs with at least one affected member. Zygosity was assigned by DNA fingerprinting, and HLA-DQ and DR alleles were genotyped. Disease status was ascertained by antiendomysial, anti-human tissue transglutaminase antibodies, and bowel biopsy.

RESULTS

Concordance was significantly higher in MZ (83.3% probandwise, 71.4% pairwise) than in DZ (16.7% probandwise, 9.1% pairwise) pairs. Concordance was not affected by sex or HLA genotype of the co-twin and being MZ was significantly associated with the occurrence of CD (Cox adjusted hazard ratio 14.3 (95% confidence interval 4.0-50.3)). In 90% of concordant pairs the discordance time was <or=2 years. MZ and DZ co-twins had 70% and 9% cumulative probability of having symptomatic or silent forms of CD, respectively, within five years. Under ACE (additive genetic, common, and unshared environmental factors) models, with CD population prevalences of 1/91 and 1/1000, heritability estimates were 87% and 57%, respectively.

CONCLUSION

MZ pairs have a high probability of being concordant, regardless of sex or HLA genotype. Most of the affected co-twins receive a diagnosis within two years. A remarkable proportion of phenotypic variance is due to genetic factors.

Postpartum thyroiditis is associated with fluctuations in transforming growth factor-beta1 serum levels

Postpartum thyroiditis (PPT) is characterized by a rapid evolution and recovery of euthyroidism. Therefore, it can represent a good model to study early cytokine fluctuations in autoimmune thyroid diseases. TGFbeta1 is an immunosuppressive cytokine, as it inhibits T and B cell proliferation, natural killer cell cytotoxic activity, and the generation of T cell cytotoxicity. The aim of this study was to assess serum concentrations of TGFbeta1 during pregnancy and to study possible serum fluctuations of this cytokine during the different phases of PPT. Thyroid biochemical pattern, antithyroid autoantibodies (ATA), and total and active TGFbeta1 (aTGFbeta1) serum concentrations were evaluated in 63 pregnant women. Thirty-four of them were ATA(+), and 29 were ATA(-). Twenty of the 34 ATA(+) women were followed in the postpartum year. Nine of these 20 women developed PPT; 11 remained euthyroid. All of the PPT women became euthyroid during the follow-up. Our results showed 1) detectable serum levels of aTGFbeta1 in 50% of ATA(+) pregnant women, suggesting that the presence of autoantibodies may characterize a favorable condition for TGFbeta1 activation; and 2) decreased total TGFbeta1 and increased aTGFbeta1 serum levels during the active phase of PPT in ATA(+) women. This seems to suggest that inflammation may be responsible for TGFbeta1 activation and autoantibody increase because of antigen release. Although further studies of women with persistent hypothyroidism after the postpartum year are needed, the possibility that the enhanced activation of TGFbeta1 may contribute to resolution of thyroid inflammation postpartum cannot be excluded.

Permanent diabetes mellitus in the first year of life

AIMS/HYPOTHESIS

The pathogenesis of permanent diabetes mellitus diagnosed early in life is heterogeneous and, in most cases, not known. We aimed at identifying markers differentiating between non-autoimmune and autoimmune diabetes.

METHODS

The clinical, genetic and epidemiological features of 111 diabetic patients (62 males) who received insulin within 12 months of life were studied.

RESULTS

The epidemic curve by age of diabetes onset revealed two subsets of patients at a cutoff of 180 days. In the group with diabetes onset before 180 days ("early onset" permanent diabetes) the analysis of HLA susceptibility heterodimers (available for 21 individuals) showed that 76% had a "protective" HLA genotype for Type I (insulin-dependent) diabetes mellitus as compared to 11.9% (5/42) of the later onset group. Accordingly, "early onset" children were less likely to have autoimmunity markers (4 out of 26 tested) than children with onset after 180 days (13 out 20 tested) (15.4% vs. 65.0%, p<0.01). Of note, 19 out of 20 (or the 95%) patients who were born on the island of Sardinia, an Italian region where the incidence of Type I diabetes is six times higher than continental Italy (33/100,000/year vs 5/100,000/year), were included in the later onset group (>180 days). Small-for-date birthweight, a possible sign of reduced foetal insulin secretion, was more common in the "early onset" group (OR=9.9, 95%-CI 2.6-38.6).

CONCLUSION/INTERPRETATION

These results, obtained in the largest population-based cohort of diabetic infants hitherto reported, suggest that "early onset" permanent diabetes cases differ from later onset cases and that most of them do not have an autoimmune pathogenesis.

The first large population based twin study of coeliac disease

BACKGROUND AND AIMS

The genetic load in coeliac disease has hitherto been inferred from case series or anecdotally referred twin pairs. We have evaluated the genetic component in coeliac disease by estimating the concordance rate for the disease among twin pairs in a large population based study.

METHODS

The Italian Twin Registry was matched with the membership lists of a patient support group. Forty seven twin pairs were recruited and screened for antiendomysial (EMA) and antihuman-tissue transglutaminase (anti-tTG) antibodies; zygosity was verified by DNA fingerprinting and twins were typed for HLA class II DRB1 and DQB1 molecules.

RESULTS

Concordance rates for coeliac disease differ significantly between monozygotic (MZ) (0.86 probandwise and 0.75 pairwise) and dizygotic (DZ) (0.20 probandwise and 0.11 pairwise) twins. This is the highest concordance so far reported for a multifactorial disease. A logistic regression model, adjusted for age, sex, number of shared HLA haplotypes, and zygosity, showed that genotypes DQA1*0501/DQB1*0201 and DQA1*0301/DQB1*0302 (encoding for heterodimers DQ2 and DQ8, respectively) conferred to the non-index twin a risk of contracting the disease of 3.3 and 1.4, respectively. The risk of being concordant for coeliac disease estimated for the non-index twin of MZ pairs was 17 (95% confidence interval 2.1-134), independent of the DQ at risk genotype.

CONCLUSION

This study provides substantial evidence for a very strong genetic component in coeliac disease, which is only partially due to the HLA region.

Prevalence of and risk factors for Helicobacter pylori infection among healthcare workers at a teaching hospital in Rome: the Catholic University Epidemiological Study

OBJECTIVES

To evaluate the prevalence of and the risk factors for Helicobacter pylori in a population of medical and non-medical workers at a teaching hospital in Rome, Italy.

DESIGN

A cross-sectional study.

METHODS

From January to October 1998, 655 subjects (65% of the total population) underwent a 13C-urea breath test to assess H. pylori infection. Subjects completed a questionnaire concerning sociodemographic characteristics, work departments and history of some gastrointestinal symptoms. Differences in means and proportions were evaluated and independent predictors of H. pylori infection status were assessed by multiple logistic regression analysis.

RESULTS

Forty percent of the subjects were found to be H. pylori infected. The mean age of positive subjects was significantly higher than that of negative ones (38 +/- 14 versus 34 +/- 12 years; P < 0.01). No significant difference was found between males and females concerning the infection status (40.2% males versus 39.9% females). Lower years of father's education [odds ratio (OR), 3.1; 95% confidence interval (CI), 1.9-5.1] and age older than 35 years (OR, 2.0; 95% CI, 1.3-3.1) were the only independent predictors of the likelihood of H. pylori positivity. Prevalence of gastrointestinal symptoms was similar in infected and uninfected subjects. Physicians were significantly less infected than nurses and auxiliary personnel (26% versus 47% versus 55%, respectively); however, a loss of association was observed after adjustment by multiple logistic regression (OR, 1.8; 95% CI, 0.9-3.7). In all groups, some specific departments appear to be associated with a higher infection status.

CONCLUSIONS

Among healthcare workers, H. pylori infection was associated with specific sociodemographic characteristics, such as age and level of father's education. The prevalence of H. pylori infection was not associated with different professional categories. However, some specific departments seem to increase infection risk.

Tuberculin skin reactivity in Italian military recruits tested in 1996-1997

In 1996-1997 data was collected and a Mantoux tuberculin test performed in 2882 Italian military recruits aged 18-23 years in order to establish the prevalence of tuberculin reactivity. In addition, the annual risk of infection, defined as the probability that a non-infected individual would be infected during the following year, was calculated. Of the 2882 recruits, 513 had received a BCG vaccination, the remaining 2369 had not. The overall prevalence of subjects with a tuberculin skin reaction size >5 mm (the cut-off point for positivity corresponding to the antimode in the reaction size frequency curve) was 6.1% (144/2369). The prevalence of skin reactivity increased with age but remained similar when related to area of residence, duration of father's school education and family size. The same general trend was observed if the standard pre-established cut-off point of 10 mm was used. In this case the overall prevalence of a positive skin reaction was 4% (95/2369). The annual risk of infection was 0.3% for a prevalence of tuberculin skin reactivity of 6.1% (cut-off point 5 mm) and 0.19% for a prevalence of 4% (cut-off point 10 mm). Analysis of the population sample vaccinated with BCG showed a lack of correlation between the positive reaction after vaccination reported retrospectively by the subject and the current skin reaction observed by the physician in this study (K = 0.254). Moreover, a significant difference was observed between the skin reaction in subjects vaccinated with BCG in 1993-1994 (average size 12.5 mm) and that of subjects vaccinated in 1995-1996 (average size 10.1 mm, P<0.01), probably as a consequence of mycobacteria circulating in the general population which act as a natural booster in people already vaccinated with BCG. A booster effect of tuberculin in Mantoux assays also cannot be excluded.

Lack of evidence for increased risk of hepatitis A infection in homosexual men

In 1997, prevalence of and risk factors for hepatitis A virus (HAV) infection were evaluated in 146 homosexual and 286 heterosexual men attending a Sexually Transmitted Disease (STD) Clinic in Rome, Italy. Total HAV antibody (anti-HAV) was detected in 60.3% of homosexuals and 62.2% of heterosexuals. After adjustment for the confounding effects of age, years of schooling, number of sexual partners, use of condoms, and history of STD, homosexuals were not found to be at increased risk of previous HAV exposure than heterosexuals (OR 1.1; 95% CI 0.7-1.9). Independent predictors of the likelihood of anti-HAV seropositivity among homosexuals and heterosexuals were: age older than 35 years and positive syphilis serology which is likely a proxy of lifestyles that increase the risk of faecal-oral infections. These findings do not support a higher risk in homosexual men but could suggest a role for the vaccination of susceptible patients attending STD clinics.

Acute promyelocytic leukaemia: epidemiology and risk factors. A report of the GIMEMA Italian archive of adult acute leukaemia. GIMEMA Cooperative Group

Acute promyelocytic leukaemia (APL) exhibits peculiar epidemiological, clinical, cytogenetic and molecular features, compared to the other acute myeloid leukaemias (AML). Data on epidemiology and occupational risk factors for APL desumed from the GIMEMA archive are reported and compared with those of the other AML. An exploratory case-case study was designed on AML patients from 56 haematology centres in Italy. Overall, 4296 patients older than 15 yr with a new diagnosis of acute leukaemia were recorded between July 1992 and July 1997. Of these, 335 were classified as APL, and 2894 as other AML. The median age of APL patients was 43 compared to 59 yr for the other AML (p < 0.00001). In order to identify peculiar risk factors for APL development, different parameters were compared in the 2 groups. After adjusting by age no significant differences were observed with regard to education, lifetime prevalence of cancer among siblings and previous diseases in the patient's history. Occupational exposure as a possible risk factor for APL showed no increased risk compared to other AML among farmers, builders and leather workers. A significant association was found in electricians (OR=4.4, 95% CI=2.0-9.7) and a weak association was found in wood workers (OR=3.2, 95% CI=0.8-10.8). The proportion of APL with respect to other AML was significantly higher in the north east of Italy compared to the rest of the country (OR=1.7, 95% CI=1.3-2.2). These data confirm the younger age of APL patients compared to the other AML. A possible role of electromagnetic fields is suggested by the higher risk of APL in electrical workers and in the more industrialized areas of the country.

The relationships of chronic hepatitis and cirrhosis to alcohol intake, hepatitis B and C, and delta virus infection: a case-control study in Albania

The present study examined the effect of hepatitis B virus (HBV) and alcohol intake, and the role of hepatitis delta virus (HDV) and hepatitis C virus (HCV) in the aetiology of chronic liver disease in Albania. A total of 106 cases of liver cirrhosis or chronic hepatitis were compared to 195 control patients without these or other liver diseases. Adjusted odds ratios were 52.7 (95% CI 22.7-122) for HBV surface antigen, 26.9 (95% CI 4.9-147) for anti-HCV, 26.2 (95% CI 3-1-221) for anti-HDV, 2.4 (95% CI 1.3-4.4) for lifetime alcohol intake and 2.3 (95% CI 1-5.5) for duration of alcohol intake. Although not significant, an interaction was suggested between HBsAg and anti-HCV and between HBsAg and alcohol intake. Our study underlines the role of hepatitis viruses in the development of chronic liver diseases. Additionally, it suggests that heavy alcohol intake may magnify the effect of HBV on these diseases. HBV vaccination and alcohol abstention appear to be important strategies to reduce the risk of liver cirrhosis and chronic hepatitis in Albania.

Influence of type and severity of pure forms of age-related cataract on visual acuity and contrast sensitivity. Italian American Cataract Study Group

PURPOSE

To compare the relationship between logMAR visual acuity (VA) and cataract severity and between contrast sensitivity (CS) and cataract severity in pure types of age-related lens opacities.

METHODS

Analysis included patients followed in the ongoing Italian-American Study of the Natural History of Age-Related Cataract. Lens opacities were classified and graded according to the Lens Opacities Classification System II (LOCS II). Visual acuity was measured with the Early Treatment Diabetic Retinopathy Study Chart. Contrast sensitivity was measured with the Pelli-Robson chart.

RESULTS

Data from 1,076 eyes were used for the analysis (366 clear lenses; 550, 124, and 36 eyes with cortical, nuclear and posterior subcapsular cataract, respectively). In age-adjusted analyses, increasing severity of all three cataract types was associated with progressively higher logMAR VA, which translates into poorer acuity, and lower CS scores. For both VA and CS, the effect of increasing severity was greatest for nuclear and least for cortical opacities. After adjusting for age and VA, CS scores were no longer associated with cataract type and severity, with the exception of advanced cortical opacities.

CONCLUSIONS

Increased cataract severity, as determined by LOCS II grading, is strongly associated with both VA and CS scores. Contrast sensitivity scores obtained from testing at low spatial frequency do not seem to offer additional information over standard VA testing in early cortical and posterior subcapsular opacities nor in nuclear cataracts.