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Nicola Bartolomeo
Ruolo
Ricercatore
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI SCIENZE BIOMEDICHE ED ONCOLOGIA UMANA
Area Scientifica
AREA 06 - Scienze mediche
Settore Scientifico Disciplinare
MED/01 - Statistica Medica
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
Abstract: Aim of this study is to assess the effect of smoothing, based on the assumption that hospitalization rates may be influenced by the neighboring municipalities, the health service organization (HSO) and environmental risk factors. To smooth rates two different Multilevel Multimembership Models are fitted: in the first the random effects where the municipality heterogeneity, the spatial dependence of the municipalities and the local HSO; in the second we replaced the local HSO effect with the environmental risk effect. The models were applied to spatially represent the rates of hospitalization for lung cancer in Apulia in the year 2006. Maps shaded with the rates obtained at the end of the smoothing procedure seem to express a geographical distribution pattern in specific areas of the region. The effect of smoothing was greater in municipalities with a more unstable Risk Adjusted Rate.
Context: Pediatric obesity is associated with endothelial dysfunction and hypoadiponectinemia, but the relationship between these two conditions remains to be fully clarified. Whether enhanced release of endothelin-1 (ET-1) may directly impair adiponectin (Ad) production in obese children is not known. Objective: The aim of the study was to explore whether and how high circulating levels of ET-1 may contribute to impair Ad production, release, and vascular activity. Design and Participants: Sixty children were included into obese (Ob; n = 30), overweight (OW; n = 11), and lean (n = 19) groups. Total and high-molecular-weight Ad, ET-1, vascular cell adhesion molecule-1, and von Willebrand factor levels were measured in serum samples. Adipocytes were stimulated with exogenous ET-1 or with sera from lean, OW, and Ob, and Ad production and release measured in the absence or in the presence of ET A (BQ-123) and ETB (BQ-788) receptor blockers, p42/44 MAPK inhibitor PD-98059, or c-Jun NH2-terminal protein kinase inhibitor SP-600125. Vasodilation to Ad was evaluated in rat isolated arteries in the absence or in the presence of BQ-123/788. Results: Total and high-molecular-weight Ad was significantly decreased and ET-1 levels significantly increased in OW (P < .01) and Ob (P < .001) children. A statistically significant linear regression (P < .01) was found between Ad and ET-1. Exposure of adipocytes to exogenous ET-1 or serum from OW and Ob significantly decreased Ad mRNA and protein levels (P < 0.001). The inhibitory effect of ET-1 on Ad was reverted by BQ-123/788 or PD-98059 but not SP-600125. Admediated vasodilation was further increased in arteries pretreated with BQ-123/788. Conclusions: ET-1-mediated inhibition of Ad synthesis via p42/44 MAPK signaling may provide a possible explanation for hypoadiponectinemia in pediatric obesity and contribute to the development of cardiovascular complications.
Low vitamin D levels have been associated with autoimmune disorders and, then, with the Hashimoto's autoimmune thyroiditis (AT), the most common autoimmune disease. Obesity is characterized by lower vitamin D levels and higher risk to develop autoimmune diseases. The aim of the study was to examine the possibility of an association between AT and decreased 25(OH) vitamin D (25(OH)D) levels in a cohort of otherwise healthy overweight and obese subjects.
A group of 608 apparently healthy patients, 136 men and 472 women, either overweight or obese, aged 18-69 years, were examined. BMI, waist circumference, fasting blood glucose (FBG), insulin, and complement 3 (C3) serum levels were measured; the homeostasis model assessment (HOMAIR) was used to evaluate insulin resistance; and physical activity was quantified by a questionnaire. Results: HOMAIR showed a positive correlation with BMI (r: 0.478, p < 0.001), waist circumference (r: 0.487, p < 0.001), and C3 (r: 0.445, p < 0.001). Moreover, it was significantly associated with gender (F Fisher = 22.12, p < 0.001), and the mean HOMAIR levels were significantly different among the three groups of physical activity, with the lowest level of insulin resistance at the highest level of physical activity (F=7,31, p < 0.001). A multiple regression analysis was carried out with HOMAIR as the dependent variable and gender, age, BMI, waist circumference, C3 and the level of physical activity as independent variables (fitted model: F = 41.24, P<0.001, R2 = 0.328). HOMAIR maintained an independent association with C3 (β = 0.678, P<0.001), sex (β = 0.189, P<0.001), BMI (β = 0.637, P<0.01), and age (β = -0.004, P<0.05). Conclusions: This study of a cohort of overweight and obese subjects has shown that insulin resistance (dependent variable) is positively associated with C3 serum levels, independently of age, gender, anthropometric parameters and physical activity, suggesting that higher C3 serum levels may directly increase insulin resistance in obesity.
A cohort of 66 healthy overweight and obese patients, 53 women and 13 men were examined. Waist circumference and fasting 25(OH)D, insulin, glucose, lipid (cholesterol, HDL cholesterol, and triglyceride), C-reactive protein (CRP), and complement 3 (C, and 4 (C serum concentrations were measured. Insulin resistance was assessed by the homeostasis model assessment (HOMA. Results. 25(OH)D levels showed a significant negative correlation with BMI (P < 0.01), waist circumference (P < 0.05), fasting insulin (P < 0.01), HOMA(P < 0.01), triglycerides (P < 0.01), CRP (P < 0.01), C(P < 0.05), and C(P < 0.05). Multiple regression analyses were performed with 25(OH)D as the dependent variable and BMI (or waist circumferences), fasting insulin (or HOMA, triglycerides, and CRP (or Cor C as independent variables. Only insulin or HOMAmaintained a significant independent association with 25(OH)D levels, whereas vitamin D did not maintain a significant independent association with CRP or Cor Cconcentrations. Conclusions. The present study, performed in overweight and obese subjects, shows that 25(OH)D levels are negatively associated with inflammatory parameters such as CRP and Cand Clevels, but not independently of BMI, body fat distribution, insulin levels, or insulin resistance. Our results suggest that hyperinsulinemia and/or insulin resistance are directly responsible for decrease of 25(OH)D levels in obesity.
Background: Health service databases of administrative type can be a useful tool for the study of progression of a disease, but the data reported in such sources could be affected by misclassifications of some patients’ real disease states at the time. Aim of this work was to estimate the transition probabilities through the different degenerative phases of liver cirrhosis using health service databases. Methods: We employed a hidden Markov model to determine the transition probabilities between two states, and of misclassification. The covariates inserted in the model were sex, age, the presence of comorbidities correlated with alcohol abuse, the presence of diagnosis codes indicating hepatitis C virus infection, and the Charlson Index. The analysis was conducted in patients presumed to have suffered the onset of cirrhosis in 2000, observing the disease evolution and, if applicable, death up to the end of the year 2006. Results: The incidence of hepatocellular carcinoma (HCC) in cirrhotic patients was 1.5% per year. The probability of developing HCC is higher in males (OR = 2.217) and patients over 65 (OR = 1.547); over 65-year-olds have a greater probability of death both while still suffering from cirrhosis (OR = 2.379) and if they have developed HCC (OR = 1.410). A more severe casemix affects the transition from HCC to death (OR = 1.714). The probability of misclassifying subjects with HCC as exclusively affected by liver cirrhosis is 14.08%. Conclusions: The hidden Markov model allowing for misclassification is well suited to analyses of health service databases, since it is able to capture bias due to the fact that the quality and accuracy of the available information are not always optimal. The probability of evolution of a cirrhotic subject to HCC depends on sex and age class, while hepatitis C virus infection and comorbidities correlated with alcohol abuse do not seem to have an influence.
Single nucleotide polymorphisms (SNPs) rs12979860 and rs8099917 near the interleukin 28B gene are predictors of virological response (SVR) to IFN-based therapy for monoinfected chronic hepatitis C patients. We retrospectively evaluated the impact of IL28B SNPs and other factors on SVR in a cohort of 102 HIV-1/HCV-coinfected patients treated with pegylated interferon-? (peg-INF?) and ribavirin. Data on baseline features and virological response at different time-points were collected. Overall, 89/102 patients (87%) were males, 44 (43%) of whom infected with HCV genotype 1; SVR was achieved by 50 patients (49%). A univariate logistic regression analysis demonstrated that rs129679860 SNP genotype CC (p<0.034), rs8099917 SNP genotype TT (p<0.01), HCV genotype 2 or 3 (p<0.0001), low HCV viral load (p<0.028) and RVR (rapid virological response) (p<0.0001) were associated with a higher likelihood of SVR. Multivariate analysis confirmed only RVR and HCV genotype as independent predictors of SVR. In a real life setting, the importance of RVR and IL28B SNPs was confirmed as predictive of SVR to identify patients with a higher likelihood of SVR to Peg-INF?+RBV, and also to designate a deferred therapy for patients with a low likelihood of SVR for whom it is preferable to wait for more successful options.
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