Variations of serum levels of adiponectin and resistin in chronic viral hepatitis

BACKGROUND AND AIMS

Several studies investigated the possible role of adipokines during chronic viral hepatitis, not producing defined results neither clearly establishing their behavior in course of anti-viral treatment. Our study evaluated blood concentrations of adiponectin and resistin in patients with chronic hepatitis C (CHC), B (CHB), and D (CHD) receiving anti-viral treatment, at baseline and after therapy.

METHODS

We examined 122 subjects, divided into two groups: 64 patients with chronic hepatitis C virus (HCV) infection (38 males and 26 females, mean age 47.25 yr) and 58 patients including 39 ones with chronic hepatitis B virus (HBV) infection (26 males and 13 females, mean age 48.46 yr) and 19 ones with chronic HBV-hepatitis D virus (HDV) infection (15 males and 4 females, mean age 45.79 yr). Serum levels of adiponectin and resistin were assayed by enzyme-linked immunosorbent assay.

RESULTS

In the group of CHC patients we observed a significant decrease in resistin after therapy (p=0.006), while not a significant increase in adiponectin after treatment (p=0.32). Evaluation of changes in adiponectin and resistin levels after anti-viral treatment, both in responders and non-responders, revealed no significant variations. In the group of HBV+ and HBV-HDV+ patients, we found a decrease in resistin after therapy (p=0.0016) and a not significant reduction in adiponectin after treatment (p=0.13). Furthermore, we noticed a significant reduction of resistin (p=0.006) in the sub-group of responders.

CONCLUSIONS

Our data suggested the possible marker role of adiponectin and resistin in the inflammatory process in course of chronic viral hepatitis.

Is left ventricular hypertrophy a low-level inflammatory state? A population-based cohort study

BACKGROUND AND AIMS

Cross-sectional studies have shown that chronic sub-clinical inflammation is associated with left ventricular hypertrophy (LVH), but results are conflicting. We investigated the association between baseline LVH and high-sensitivity C-reactive protein (CRP) values, both cross-sectionally and after a six-year-follow-up, in a population-based cohort (n = 1564) and a subgroup from this cohort (n = 515), without obesity, diabetes, metabolic syndrome or any drugs.

METHODS AND RESULTS

ECG tracings at baseline were interpreted according to the Cornell voltage-duration product criteria: 166/1564 subjects (10.6%) showed LVH. Patients with baseline LVH showed increased BMI, waist circumference, blood pressure, and a worse metabolic pattern. Their CRP values both at baseline and at follow-up were almost two-fold higher than in patients without LVH. Similar results were found in the healthier sub-sample. In a multiple regression model, CRP at follow-up was directly associated with baseline LVH (expressed as Cornell voltage-duration product) in the whole cohort (β = 0.0003; 95%CI 0.0002-0.0006; p < 0.001) and in the sub-sample (β = 0.0003; 0.0002-0.0004; p < 0.001), after adjusting for age, sex, BMI, waist circumference, smoking, exercise levels, blood pressure and baseline CRP values.

CONCLUSION

Baseline LVH, which is associated with systemic inflammation, predicts increased CRP values at follow-up, independently of cardiovascular and metabolic risk factors, both in a population-based cohort and a healthier sub-sample. The inflammatory consequences of LVH might be an intriguing subject for further researches.

C-peptide and the risk for incident complications and mortality in type 2 diabetic patients: a retrospective cohort study after a 14-year follow-up

OBJECTIVE

C-peptide, a cleavage product of insulin, exerts biological effects in patients with type 1 diabetes mellitus, but its role in type 2 diabetes mellitus is controversial. Our aim was to examine the associations between fasting C-peptide levels and all-cause mortality, specific-cause mortality and the incidence of chronic complications in patients with type 2 diabetes.

DESIGN

Retrospective cohort study with a median follow-up of 14 years.

METHODS

A representative cohort of 2113 patients with type 2 diabetes mellitus and a subgroup of 931 individuals from this cohort without chronic complications at baseline from a diabetic clinic were studied.

RESULTS

Patients with higher C-peptide levels had higher baseline BMI and triglyceride and lower HDL-cholesterol values. During the follow-up, 46.1% of the patients died. In a Cox proportional hazard model, after multiple adjustments, no significant association was found between the C-peptide tertiles and all-cause mortality or mortality due to cancer, diabetes or cardiovascular diseases. In the subgroup of 931 patients without chronic complications at baseline, the incidence of microvascular complications decreased from the first to the third C-peptide level tertile, while the incidence of cardiovascular disease did not differ. The risks for incident retinopathy (hazard ratio (HR)=0.33; 95% confidence interval (CI) 0.23-0.47), nephropathy (HR=0.27; 95% CI 0.18-0.38) and neuropathy (HR=0.39; 95% CI 0.25-0.61) were negatively associated with the highest C-peptide tertile, after adjusting for multiple confounders.

CONCLUSIONS

Higher baseline C-peptide levels were associated with a reduced risk of incident microvascular complications but imparted no survival benefit to patients with type 2 diabetes mellitus.

The rs553668 polymorphism of the ADRA2A gene predicts the worsening of fasting glucose values in a cohort of subjects without diabetes. A population-based study

AIMS

Single-nucleotide polymorphisms in the human ADRA2A gene have been associated with increased risk of Type 2 diabetes. The associations between the rs553668 polymorphism and fasting glucose concentrations both cross-sectionally and longitudinally after 6-year follow-up were evaluated in an adult Caucasian population-based cohort.

METHODS

From a cohort of 1658 individuals, after excluding patients with diabetes, those who died and those whose blood samples were not available for genotyping, data of 1345 individuals were analysed.

RESULTS

Subjects homozygous for the A allele showed significantly increased baseline fasting glucose values and a significant worsening of fasting glucose (β = 0.48; 95% CI 0.10-0.86) and insulin secretion (β =-20.75; -32.67 to -8.82 for homeostasis model assessment for β-cell function) at follow-up by using generalized estimating equations. Incidence of impaired fasting glucose and diabetes was almost twofold higher in subjects homozygous for the A allele (respectively: incident impaired fasting glucose 7.6-8.2, 16.1%, incident diabetes 1.7-2.3, 3.2% in GG, AG, AA carriers).

CONCLUSIONS

Our results suggested that the rs553668 polymorphism is associated with glucose worsening in subjects without diabetes at baseline.

Does use of metformin protect against cancer in Type 2 diabetes mellitus?

BACKGROUND

Type 2 diabetes mellitus has been associated with an increased cancer risk, which can be modified by specific hypoglycemic drugs. In particular, metformin, the most frequently prescribed biguanide, is now considered a protective agent against cancer incidence and mortality in Type 2 diabetic patients.

AIMS

To review the potential associations between metformin use and cancer incidence and mortality and the possible biological links implicated in these associations.

MATERIALS AND METHODS

We searched English-language original investigations published through September 2011.

RESULTS

Metformin could block the mitogenic effects of insulin, but this effect does not entirely explain the reduction in cancer incidence. Metformin also plays a direct inhibition of cancer cell growth via the inhibitory effects of AMP-activated protein kinase on the mTOR pathway, which regulates cell growth and proliferation. Accordingly, many epidemiological studies have shown that metformin use is associated with a lower cancer incidence and mortality through a dose-response relationship, with greater exposure being associated with stronger risk reduction. Randomized clinical trials testing the effects of metformin on both recurrence and survival in early-stage breast cancer are on-going; these trials are based on pilot studies demonstrating an adjuvant effect of this drug in breast cancer.

CONCLUSIONS

Metformin is an inexpensive and safe drug, that may modify the increased cancer risk of Type 2 diabetic patients. On-going clinical trials will show whether this drug can enhance the effect of chemotherapy in the treatment of cancer.

Cancer mortality reduction and metformin: a retrospective cohort study in type 2 diabetic patients

AIMS

Few studies suggest that metformin decreases cancer mortality in type-2 diabetic patients (T2DP). We explored the association between the type and duration of antidiabetic therapies and cancer and other-than-cancer mortality in a T2DP cohort, taking into account the competing risks between different causes of death and multiple potential confounding effects. The mortality rates were compared with the general population from the same area.

METHODS

In 1995, all T2DP (n = 3685) at our diabetes clinic in Turin (∼12% of all T2DP in the city), without cancer at baseline, were identified. Vital status was assessed after a mean 4.5-year follow-up.

RESULTS

Metformin users had greater adiposity, while insulin users had more co-morbidities. All-cause- and cancer-related deaths occurred in: 9.2 and 1.6% of metformin users, 13.1 and 3.0% of sulfonylureas users and 26.8 and 4.8% of insulin users, respectively. In a Cox regression model for competing risks, adjusted for propensity score, metformin users showed a lower cancer mortality risk [hazard ratio (HR) = 0.56; 95% confidence interval (CI) 0.34-0.94], while insulin was positively associated with other-than-cancer mortality (HR = 1.56; 95%CI 1.22-1.99). Each 5-year metformin exposure was associated with a reduction in cancer death by 0.73, whereas every 5-year insulin exposure was associated with 1.25-fold increase in other-than-cancer death. Standardized mortality ratios for cancer and other-than-cancer mortality in metformin users were 43.6 (95%CI 25.8-69.0) and 99.1 (95%CI 79.3-122.5), respectively, in comparison with the general population.

CONCLUSIONS

Metformin users showed a lower risk of cancer-related mortality than not users or patients on diet only; this may represent another reason to choose metformin as a first-line therapy in T2DP.

Issues of internal medicine in psychiatric patients

In opposition to opinions of a sectorialization of psychiatric illness, phenomena of comorbidity due to susceptibility of psychiatric patients to contract other diseases--whose co-presence is difficult to translate and treat--are more and more evident. In this review we have marked main issues of internal medicine in psychiatric patients. This review will discuss particularly main cardiovascular diseases (CAD, VTE), lung diseases (COPD,asthma, restrictive lung disease) gastroenterologic disease (IBS, coeliac disease, ulcerous rectocolitis), diabetes and metabolic syndrome, more likely infections verified in these patients (HIV, viral hepatitis), cancers considerably underlined (breast cancer, colon-rectal cancer and lung cancer), internistic issues in alcohol abuse which is a frequent state in these subjects. A special chapter is dedicated to antipsychotics. These drugs are characterized by a complex action modality and by frequent interactions with a large number of other drugs.

Male sexual disturbances in liver diseases: what do we know?

The alterations of sexual function known as the erectile dysfunction are quite frequent among patients affected by liver diseases and they tend to increase in advanced liver failure. This process is directly linked to cirrhosis or its treatments, such as liver transplantation, or to certain drugs (e.g. beta-blockers). Independent of cirrhosis, other factors may cause sexual problems in these patients. Alcohol itself seems to worsen sexual function in the absence of cirrhosis. Viral hepatitis has an uncertain influence on male gonadic function and even antiviral therapy itself can worsen some seminal and hormonal parameters, although it is reversible. Quality of life may be greatly decreased in cases of cirrhosis where these alterations are present, so it is important to value and care for them, if possible. This review investigates the major male sexual disturbances in liver diseases of various origins.

Plasma visfatin concentrations after a lifestyle intervention were directly associated with inflammatory markers

BACKGROUND AND AIMS

The biological activity and regulation of the novel adipokine visfatin are still largely unknown. Our aim was to evaluate if visfatin plasma concentrations may be influenced by a lifestyle intervention.

METHODS AND RESULTS

Out of 335 dysmetabolic patients from a population-based cohort, randomized to receive a lifestyle intervention program (intervention group) or family physician usual care (controls), 20 patients per group were randomly selected for plasma visfatin determination. The before-after variation (Delta) in visfatin concentration at 1-year from randomization, and the correlations between (Delta)visfatin and intervention-induced changes in waist circumference, fasting glucose, markers of inflammation, and oxidative stress were evaluated. The intervention group showed a significant improvement in waist circumference, and many metabolic/inflammatory variables, while the controls worsened. Visfatin concentrations slightly decreased in the former and significantly increased in the controls ((Delta)visfatin=-2.4 vs 66.0 ng/ml, p<0.001). In robust regression models, the following variables resulted associated with (Delta)visfatin: (Delta)waist circumference, (Delta)fasting glucose, (Delta)hs-CRP (high-sensitivity C-reactive protein) and (Delta)TNFalpha (tumor necrosis factor-alpha). Significant effects on (Delta)visfatin of (Delta)TNFalpha (beta=16.8; 6.1-25.6; p=0.003) and, modified by group, of (Delta)hs-CRP (beta=29.8; 95% CI 15.4-44.2; p<0.001 and beta=4.2; 2.9-5.5; p<0.001 in the control and intervention group, respectively) were detected. By controlling for (Delta)waist, the effects of (Delta)TNFalpha and of (Delta)hs-CRP on (Delta)visfatin by group did not change, while (Delta)waist was no longer associated. The association between (Delta)visfatin and (Delta)glucose was no longer significant, after adjusting for (Delta)hs-CRP.

CONCLUSION

Visfatin values increased with waist circumference and were associated with variations of inflammatory markers, suggesting participation in inflammatory mechanisms.

Molecular characterisation of outbreak-related strains of vancomycin-resistant Enterococcus faecium from an intensive care unit in Beijing, China

We investigated an outbreak of vancomycin-resistant Enterococcus faecium affecting 14 patients in a 20-bed intensive care unit (ICU) between September 2006 and August 2007 (incidence: 3.56 cases per 1000 ICU patient days). Eighteen isolates of vanA type E. faecium were analysed by pulsed field gel electrophoresis, which showed 14 types overall. Multilocus sequence typing (MLST) identified eight different sequence types (STs) (ST78, ST117, ST203, ST316, ST362, ST363, ST364 and ST365), including four new types (ST362, ST363, ST364 and ST365) and 17 strains belonged to clonal complexes CC17. Sixteen of these carried the esp gene. Eighteen Tn1546-like elements encoding vanA-type VRE were classified into three types (types I to III) and all of them contained both IS1216V and IS1542 insertions. Vancomycin resistance of 14 vanA type E. faecium isolates was transferred at a frequency of 1.3 x 10(-6) to 6.4 x 10(-5) between E. faecium strains during filter mating. Our findings indicate that conjugative dissemination of Tn1546-like elements among CC17 E. faecium occurred during the outbreak in this ICU.

Characteristics of liver diseases in the elderly: a review

Chronic liver diseases are becoming more commonly diagnosed in the elderly, although they are not age-related. Most liver functions in advanced age appear to be well preserved, but some changes in liver morphology and physiology with aging may lead to several differences in clinical course and management of liver diseases in older patients compared to younger. A cautious individual evaluation is therefore required in aged patients, especially concerning reduced hepatic drug clearance and comorbidity. Many chronic liver diseases are characterized by a slow and indolent course with non-specific clinical presentation and this may lead a later diagnosis in the elderly. The presence of an advanced liver disease or cirrhosis is more frequent in old patients as the first clinical presentation. No significant differences in diagnostic investigations or treatment options occur between the elderly and the young. Hepatocellular carcinoma is an affliction of the old patients (mean age 65 age) and follow up with ultrasonography and alpha-fetoprotein is mandatory. Advanced age is not considered a contraindication to liver transplantation, but recipients older than 60 years with poor hepatic synthetic function and comorbidity show a worse prognosis with lower survival rates. This review focuses on new emerging conditions, clinical features and updated therapeutic approaches of the most common chronic liver diseases among the elderly.

What predicts the occurrence of the metabolic syndrome in a population-based cohort of adult healthy subjects?

BACKGROUND

Metabolic syndrome (MS), the concurrence of hyperglycaemia, dyslipidaemia, hypertension and visceral obesity, increases cardiovascular risk and mortality. Predictors of MS were previously evaluated in patients without the full syndrome, but with some of its traits. This might confound the resulting associations.

METHODS

The relationship between baseline variables and MS development was evaluated in healthy middle-aged subjects without any MS component at baseline, over a 4.5-year follow-up.

RESULTS

From a population-based cohort of 1658 subjects, 241 individuals showed no MS components and 201 (83.4%) of them participated in a follow-up screening. At baseline, patients who developed the MS (n = 28/201; 13.9%) showed significantly higher Homeostasis Model Assessment-Insulin Resistance score (HOMA-IR) and C-reactive protein (CRP) values, and lower exercise level than subjects who did not. In a multiple logistic regression analysis, after multiple adjustments, the only baseline variable significantly (p < 0.01) associated with the MS was CRP (OR = 4.05; 95% CI 2.23-7.38; p < 0.001). Results did not change after adjusting for weight gain. The area under the receiver-operating curve was 0.83 for CRP after multiple adjustments. The optimal cut-off point of baseline CRP values was 2.1 mg/L, with 86% (95% CI 81-90) sensitivity and 75% (69-81) specificity in predicting the MS. Baseline CRP resulted associated with after-study glucose values in a multiple regression model (beta = 0.14; 0.08-0.20; p < 0.001).

CONCLUSIONS

Higher baseline CRP values confer a significant increased risk of developing the MS in healthy subjects, independently of weight gain.

Plasma adiponectin levels in primary biliary cirrhosis: a novel perspective for link between hypercholesterolemia and protection against atherosclerosis

INTRODUCTION

Hypercholesterolemia is a common finding in primary biliary cirrhosis (PBC), but the risk of cardiovascular events in PBC patients is not increased in respect to the general population. High serum adiponectin levels appear to play a protective role in the development of either metabolic syndrome or cardiovascular disease.

AIM

To investigate factors potentially preventing atherosclerosis in PBC patients.

METHODS

Circulating levels of adiponectin, resistin, leptin, and tumor necrosis factor-alpha (TNF-alpha) were measured in 137 consecutive PBC patients (125 women, 12 men; mean age 61.6 +/- 12.3 yr), 137 sex- and age-matched healthy controls, and 30 female patients with nonalcoholic steatohepatitis (NASH) and associated metabolic syndrome.

RESULTS

The body mass index (BMI) was comparable in the three groups, whereas total cholesterol was significantly higher in both PBC and NASH cases than in controls (221.6 +/- 50.5 mg/dL in PBC vs 221.7 +/- 39.7 mg/dL in NASH vs 209.8 +/- 39.2 mg/dL in controls, P < 0.05). Serum concentrations of adiponectin, resistin, and leptin were significantly higher in PBC patients than in either NASH cases or controls (P < 0.05). Among the PBC patients, only adiponectin correlated positively with histological progression of the disease (P= 0.001) and negatively with BMI (P= 0.01). Logistic regression analysis revealed that adiponectin correlated independently with age, BMI, Mayo score, and gamma-glutamyl transpeptidase.

CONCLUSIONS

The high adiponectin concentrations observed in PBC patients should be regarded as a possible protective factor against atherogenesis. The search for further protective factors should be encouraged.

Associations between serum uric acid and adipokines, markers of inflammation, and endothelial dysfunction

AIM

Serum uric acid is associated with the metabolic syndrome and its components, while its relationship with cardiovascular disease is controversial. The aim of the study was to evaluate the association between uric acid and adipokines, markers of inflammation, oxidative stress, and endothelial dysfunction, which are all linked to cardiovascular disease.

METHODS

The associations between uric acid and adiponectin, resistin, leptin, high-sensitivity-C-reactive protein (hs-CRP), interleukin-6, tumor necrosis factor-alpha, nitrotyrosine, Total Antioxidant Status (TAS), E-selectin, vascular adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were cross-sectionally evaluated in a randomly collected sample of 100 men from a population-based cohort.

RESULTS

Subjects within the highest uric acid quartile showed a worse metabolic pattern and a higher prevalence of the metabolic syndrome [odds ratio (OR)=3.6; 95% confidence interval (CI) 1.6-8.2; p<0.001 for each 50 micromol/l uric acid increment in a logistic regression model after multiple adjustments]. Nitrotyrosine and adiponectin were significantly lower, while TAS, hs-CRP, E-selectin, ICAM-1, and VCAM-1 were higher in the groups with increased uric acid levels. In a multiple regression model, after adjustments for multiple confounders, uric acid levels were inversely associated with nitrotyrosine (p<0.001) and adiponectin (p=0.02), and directly with TAS (p<0.001), and E-selectin (p=0.006).

CONCLUSION

Serum uric acid showed opposite relationships, being associated with both beneficial (inverse association with nitrotyrosine, direct association with TAS) and detrimental (inverse association with adiponectin, direct association with E-selectin) markers, thus providing a possible explanation for the previously reported controversial and not linear association between uric acid and cardiovascular disease.

Should we consider gestational diabetes a vascular risk factor?

Few and contrasting data have reported vascular endothelial dysfunction and increased serum levels of endothelial dysfunction and inflammatory markers in women with previous gestational diabetes mellitus (pGDM). We aimed at evaluating 6.5 years after delivery: intimal medial thickness (IMT), and C-reactive protein (CRP), interleukin-6 (IL-6), E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1) levels in 82 non-pregnant pGDM and 113 control women without pGDM. A subgroup of 21 women, taken from the pGDM group, showing current normal BMI, and no metabolic abnormalities, was separately analysed. All the subjects were free of medication and non-smokers. Women with pGDM, independently by their current BMI and presence of metabolic abnormalities, showed significantly higher E-selectin, ICAM-1 and IMT values than controls. IMT proved to be significantly associated with pGDM in a regression model, after adjustments for BMI, waist circumference, blood pressure, and glucose values (beta=0.046; 95% CI 0.028-0.064). In all pGDM women, E-selectin, ICAM-1, IL-6 and hs-CRP values were significantly associated with IMT in the same model. Post-GDM women, despite being currently free from metabolic abnormalities, showed higher values of markers of endothelial dysfunction and IMT than controls, consistent with an increased future cardiovascular risk.

Gastrointestinal problems in the elderly

Gastrointestinal (GI) disorders represent the third cause of consultations by general practitioners among subjects older than 65 years in Western countries. Although GI diseases in the elderly do not show peculiar characteristics, they often may present a more severe course, due to comorbidities and intake of many drugs. Moreover, several illnesses, such as neoplasias, are more frequent in the elderly. This review focuses on the epidemiological, physiopathological, and clinical aspects of GI diseases in advanced age. Some relevant issues are considered. It is advisable to avoid empirical approaches in the elderly and to choose endoscopic examinations because of the possibility to detect conditions such as already complicated gastroesophageal reflux disease or peptic ulcers as well as to diagnose precociously neoplastic formations in esophagus, stomach or colon. The monitoring of chronic liver disease is very important, mainly to prevent or detect hepatocellular carcinoma early. Idiopathic (or autoimmune) chronic pancreatitis in the elderly is more frequent than other forms of pancreatic diseases, like alcoholic pancreatitis.

Molecular and biochemical detection of fengycin- and bacillomycin D-producing Bacillus spp., antagonistic to fungal pathogens of canola and wheat

Bacillus species are well known for their ability to control plant diseases through various mechanisms, including the production of secondary metabolites. Bacillus subtilis DFH08, an antagonist of Fusarium graminearum , and other Bacillus spp. that are antagonists of common fungal pathogens of canola were screened for peptide synthetase biosynthetic genes of fengycin and bacillomycin D. Specific polymerase chain reaction (PCR) primers identified B. subtilis strains DFH08 and 49 for the presence of the fenD gene of the fengycin operon. Bacillus cereus DFE4, Bacillus amyloliquefaciens strains DFE16 and BS6, and B. subtilis 49 were identified for the presence of the bamC gene of the bacillomycin D synthetase biosynthetic operon. Both fengycin and bacillomycin D were detected in the culture extract of strain Bs49, characterized through MALDI–TOF–MS (matrix-assisted laser desorption ionization – time of flight – mass spectrometry), and their antifungal activities demonstrated against F. graminearum and Sclerotinia sclerotiorum . This study designed and used specific PCR primers for the detection of potential fengycin- and bacillomycin D-producing bacterial antagonists and confirmed the molecular detection with the biochemical detection of the corresponding antibiotic produced. This is also the first report of a B. cereus strain (DFE4) to have bacillomycin D biosynthetic genes. Bacteria that synthesize these lipopeptides could act as natural genetic sources for genetic engineering of the peptide synthetases for production of novel peptides.

[Identification of a new Puumala hantavirus subtype in rodents from China]

In order to detect the nucleic acid of Puumala hantavirus, RNA was extracted from lungs of bank voles captured in Northeast China, and partial S and M genome segments of Puumala virus were amplified by RT-PCR and sequenced. Phylogenetic analysis suggested that Chinese Puumala virus had diverged from the common node of PUUV, with accumulating nucleotide substitutions and formed a distinct lineage from other Puumala viruses. Newly found Puumala virus was most closely related to the Kamiiso-8Cr-95 and Tobetsu-60Cr-93 strains which came from Japan and the muju strains which came from South Korea. By analysis of S and M genome segments of Puumala virus, we deduced a new Puumala virus subtype did exist in Northeast China.

Evaluating cardiovascular mortality in type 2 diabetes patients: an analysis based on competing risks Markov chains and additive regression models

RATIONALE, AIMS AND OBJECTIVES

Type 2 diabetes represents a condition significantly associated with increased cardiovascular mortality. The aims of the study are: (i) to estimate the cumulative incidence function for cause-specific mortality using Cox and Aalen model; (ii) to describe how the prediction of cardiovascular or other causes mortality changes for patients with different pattern of covariates; (iii) to show if different statistical methods may give different results.

METHODS

Cox and Aalen additive regression model through the Markov chain approach, are used to estimate the cause-specific hazard for cardiovascular or other causes mortality in a cohort of 2865 type 2 diabetic patients without insulin treatment. The models are compared in the estimation of the risk of death for patients of different severity.

RESULTS

For younger patients with a better covariates profile, the Cumulative Incidence Function estimated by Cox and Aalen model was almost the same; for patients with the worst covariates profile, models gave different results: at the end of follow-up cardiovascular mortality rate estimated by Cox and Aalen model was 0.26 [95% confidence interval (CI) = 0.21-0.31] and 0.14 (95% CI = 0.09-0.18).

CONCLUSIONS

Standard Cox and Aalen model capture the risk process for patients equally well with average profiles of co-morbidities. The Aalen model, in addition, is shown to be better at identifying cause-specific risk of death for patients with more severe clinical profiles. This result is relevant in the development of analytic tools for research and resource management within diabetes care.

Diagnostic and therapeutic questions in overlap syndromes of autoimmune hepatitis

The term ''overlap syndromes of liver diseases'' includes coexistence of autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), primary biliary cirrhosis (PBC). Due to their unknown etiology, as well as their variable presentation with mixed clinical and biochemical features, these overlap syndromes are often a diagnostic and therapeutic challenge for hepatologists. The most frequent association reported occurs between AIH and PBC. More rare is the overlap between AIH and PSC, typical in young age and often concomitant with an inflammatory bowel disease as ulcerative colitis. The treatment of choice is based on ursodeoxycholic acid and immunosoppressive drugs, used at the same time or consecutively, according to the course of disease. Histological examination seems an important tool, but often does not help for a correct diagnosis due to lack of specificity. Two particular forms of variant syndrome are the so called outlier syndromes, without clear characteristics of overlap: the autoimmune cholangitis, probably a form of PBC anti-mitochondrial antibodies negative, and the hepatitis C virus related with stigmata of autoimmunity, such as nonspecific autoantibodies at low titer. The diagnostic score system elaborated in 1999 by the International AIH Group can help for diagnosis, even if its definite validity is lacking.

Evaluating hospital costs in type 2 diabetes care: does the choice of the model matter?

BACKGROUND

Awareness of the economic burden of diabetes has led to a number of studies on economic issues. However, comparison among cost-of-illness studies is problematic because different methods are used to arrive at a final cost estimate.

OBJECTIVE

The aim of the study is to show how estimates of hospitalisation costs for diabetic patients can vary significantly in relation to the statistical method adopted in the analysis.

RESEARCH DESIGN AND METHODS

The study analyses diabetic patients' costs as a function of demographic and clinical covariates, by applying the following statistical survival models: the parametric survival model assuming Weibull distribution, the Cox proportional hazard (PH) model and the Aalen additive regression for modelling costs. The Aalen approach is robust both for the non proportionality in hazard and for departures from normality. In addition it is able to easily model the effect of covariates on the extreme costs. This cost analysis is based on data collected for a retrospective observational study analysing repeated hospitalisations (N = 4816) in a cohort of 3892 diabetic patients.

RESULTS

There is agreement in all models with the effects of the considered covariates (age, sex, duration of disease and presence of other pathologies). An effect of over- or under-estimation, according to the chosen model due to arguably inappropriate model fitting, was observed, being more evident for some specific profiles of the patients, and overall accounting for as much as 20% of the estimated effect. The Aalen model was able to cope with all the other models in furnishing unbiased estimates with the advantage of a greater flexibility in representing the covariates' effect on the cost process.

CONCLUSIONS

An appropriate choice of the model is crucial in avoiding misinterpretation of cost determinants of type 2 diabetes care. For our data set the Aalen model proved itself to be a realistic and informative way to characterise the effect of covariates on costs.

Insulin resistance in pre-school very-low-birth weight pre-term children

AIMS

To evaluate the metabolic pattern of a group of pre-school small- (SGA) and appropriate-for-gestational age (AGA) pre-term very-low-birthweight (VLBW) (<1500 gr) Italian children and retrospectively verify if the growth rate in the first years of life is associated to the laboratory and anthropometric characteristics of these children.

METHODS

58 (16 SGA, 42 AGA) VLBW children, without major congenital malformations/conditions were enrolled; their anthropometric, clinical and (in 34 of them) laboratory characteristics were evaluated at pre-school age (> 2<6 years of corrected age).

RESULTS

Clinical, anthropometric and laboratory characteristics at pre-school age were similar in SGA and AGA. Sixty-nine percent of SGA and 51% of AGA children showed a significant weight centile crossing (CC) at 24 months. Fasting serum glucose, insulin and insulin resistance (evaluated by the Homeostasis Model Assessment -HOMA-IR-) were higher in AGA and SGA with CC. The increment in weight standard deviation scores from birth-to-24 months was significantly associated with pre-school BMI SDS, waist, fasting insulin, and HOMA-IR values, both in unadjusted and adjusted models. In a multiple regression model, after multiple adjustments, this increment is the only significant predictor of pre-school insulin (B = 0.19; 95%CI 0.07-0.31; P = 0.006) and HOMA-IR levels (B = 0.20; 95%CI 0.08-0.32; P = 0.004) both in SGA and AGA children.

CONCLUSIONS

The adverse metabolic pattern of pre-school VLBW children seems related to post-natal events (rapid weight growth) independently by their being small- or appropriate-for gestational age.