The threshold value for identifying insulin resistance (HOMA-IR) in an admixed adolescent population: A hyperglycemic clamp validated study

Objective

To validate the homeostasis model assessment (HOMA) of insulin resistance (IR) as a surrogate to the hyperglycemic clamp to measure IR in both pubertal and postpubertal adolescents, and determine the HOMA-IR cutoff values for detecting IR in both pubertal stages.

Subjects and methods

The study sample comprised 80 adolescents of both sexes (aged 10-18 years; 37 pubertal), in which IR was assessed with the HOMA-IR and the hyperglycemic clamp.

Results

In the multivariable linear regression analysis, adjusted for sex, age, and waist circumference, the HOMA-IR was independently and negatively associated with the clamp-derived insulin sensitivity index in both pubertal (unstandardized coefficient - B = -0.087, 95% confidence interval [CI] = -0.135 to -0.040) and postpubertal (B = -0.101, 95% CI, -0.145 to -0.058) adolescents. Bland-Altman plots showed agreement between the predicted insulin sensitivity index and measured clamp-derived insulin sensitivity index in both pubertal stages (mean =-0.00 for pubertal and postpubertal); all P > 0.05. The HOMA-IR showed a good discriminatory power for detecting IR with an area under the receiver operator characteristic curve of 0.870 (95% CI, 0.718-0.957) in pubertal and 0.861 (95% CI, 0.721-0.947) in postpubertal adolescents; all P < 0.001. The optimal cutoff values of the HOMA-IR for detecting IR were > 3.22 (sensitivity, 85.7; 95% CI, 57.2-98.2; specificity, 82.6; 95% CI, 61.2-95.0) for pubertal and > 2.91 (sensitivity, 63.6; 95% CI, 30.8-89.1, specificity, 93.7; 95%CI, 79.2-99.2) for postpubertal adolescents.

Conclusion

The threshold value of the HOMA-IR for identifying insulin resistance was > 3.22 for pubertal and > 2.91 for postpubertal adolescents.

Evaluation of the Relationship between Insulin Resistance and HBV DNA Level in Patients with HBeAg-negative Chronic HBV Infection (Natural Course Phase 3)

Background and aims

Chronic hepatitis B (CHB) infection is an important cause of morbidity and mortality worldwide with an increased risk of liver failure, cirrhosis, and hepatocellular carcinoma. Hepatitis B virus (HBV) DNA level, the marker of viral load in the host, is a parameter affected by host factors. In this study, we investigated the relationship between HBV DNA level and insulin resistance as a host factor.

Methods

In this study, 146 patients diagnosed with “HBeAg-negative chronic HBV infection” (natural course phase 3, inactive carrier) according to the European Association for the Study of the Liver (EASL) 2017 guidelines were retrospectively analyzed and demographic, anthropometric, histopathological, radiological and laboratory data of the patients were recorded. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) levels of the patients were calculated, and according to the value, the patients were divided into two groups as insulin resistant and non-insulin resistant. All parameters, including HBV DNA, were evaluated and compared between the two groups.

Results

77 patients (52.7%) were insulin resistant with a HOMA-IR value of 2.5 or more. The remaining 69 patients (47.3%) whose HOMA-IR value less than 2.5 were non-insulin resistant. The median HBV DNA was 410 IU in the insulin-resistant group and 350 IU in the other group, and there was no statistical significance between the two groups (p: 0.537). HBV DNA level was only positive correlated with HBsAg level and negatively correlated with anti-Hbs level and age (p < 0.005). Compared to the non-insulin resistant group, body mass index (BMI), presence of hepatosteatosis on ultrasonography (USG), fasting blood sugar, fasting insulin, total protein, gamma glutamyl transferase (GGT), triglyceride (TG), very-low-density lipoprotein (VLDL), uric acid level, triglyceride/high-density lipoprotein (HDL) ratio were significantly higher and HDL levels were significantly lower in the insulin-resistant group (p < 0.005). GGT levels and TG/HDL ratio were found to be higher in patients with hepatosteatosis on ultrasonography than in patients without hepatosteatosis (p < 0.005). TG/HDL ratio was found to be an independent factor in predicting insulin resistance and every 1 unit increase of this ratio increases the risk of developing insulin resistance 2.1 times.

Conclusion

In this study, no significant relationship was found between insulin resistance and HBV DNA levels in chronic inactive HBV carriers. In addition, insulin resistance was observed more frequently in these patients compared to the general population, and insulin resistance was found to be associated with high BMI, hepatosteatosis rate, VLDL, TG, GGT, total protein, uric acid, TG/HDL ratio, and low HDL. TG/HDL ratio was found to be successful in predicting insulin resistance.

How to cite this article

Senoymak MC, Ozkan H. Evaluation of the Relationship between Insulin Resistance and HBV DNA Level in Patients with HBeAg-negative Chronic HBV Infection (Natural Course Phase 3). Euroasian J Hepatogastroenterol 2020;10(2):85–91.

Exploring cellular markers of metabolic syndrome in peripheral blood mononuclear cells across the neuropsychiatric spectrum

Recent evidence suggests that comorbidities between neuropsychiatric conditions and metabolic syndrome may precede and even exacerbate long-term side-effects of psychiatric medication, such as a higher risk of type 2 diabetes and cardiovascular disease, which result in increased mortality. In the present study we compare the expression of key metabolic proteins, including the insulin receptor (CD220), glucose transporter 1 (GLUT1) and fatty acid translocase (CD36), on peripheral blood mononuclear cell subtypes from patients across the neuropsychiatric spectrum, including schizophrenia, bipolar disorder, major depression and autism spectrum conditions (n = 25/condition), relative to typical controls (n = 100). This revealed alterations in the expression of these proteins that were specific to schizophrenia. Further characterization of metabolic alterations in an extended cohort of first-onset antipsychotic drug-naïve schizophrenia patients (n = 58) and controls (n = 63) revealed that the relationship between insulin receptor expression in monocytes and physiological insulin sensitivity was disrupted in schizophrenia and that altered expression of the insulin receptor was associated with whole genome polygenic risk scores for schizophrenia. Finally, longitudinal follow-up of the schizophrenia patients over the course of antipsychotic drug treatment revealed that peripheral metabolic markers predicted changes in psychopathology and the principal side effect of weight gain at clinically relevant time points. These findings suggest that peripheral blood cells can provide an accessible surrogate model for metabolic alterations in schizophrenia and have the potential to stratify subgroups of patients with different clinical outcomes or a greater risk of developing metabolic complications following antipsychotic therapy.

The Insulin-like Growth Factor-1 (G>A) and 5,10-methylenetetrahydrofolate Reductase (C677T) Gene Variants and the Serum Levels of Insulin-like Growth Factor-1, Insulin, and Homeostasis Model Assessment in Patients with Acne Vulgaris

Background & Objective

To find an association between gene variants of insulin-like growth factor-1 (IGF-1) and 5,10-methylenetetrahydrofolate reductase (MTHFR) with the risk of acne vulgaris (AV).

Methods

In a case-control study, we investigated 150 AV patients and 148 healthy individuals (aged 18-25 years) for the IGF-1 G>A and MTHFR C677T polymorphisms, as well as the serum levels of IGF-1, insulin, and the homeostasis model assessment of insulin resistance (HOMA-IR). The serum biochemical parameters and the genotypes of IGF-1 G>A and MTHFR C677T were detected by using appropriate kits and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods, respectively.

Results

The frequencies of IGF-1 and the MTHFR polymorphisms were not significantly different comparing patients and controls. The serum level of IGF-1 was 179.8±72.8 µg/L in AV patients compared to 164.6±63.7 µg/L in controls (P=0.056). The serum level of insulin in female patients was significantly higher than controls. The HOMA was 3.54±5.6 in patients compared to 1.16±1.4 (P<0.001) in controls. Significantly higher levels of fasting blood sugar (FBS), total cholesterol, and low-density lipoprotein-cholesterol (LDL-C) were detected in female patients than controls. However, the level of estradiol was significantly lower in female patients than in controls. In females, the presence of the MTHFR T allele was associated with significantly higher levels of FBS and LDL-C, as well as a significantly lower level of estradiol compared to those carriers of the C allele.

Conclusion

We found the absence of an association between IGF-1 and MTHFR polymorphisms with the risk of AV. However, increased insulin, IGF-1, and HOMA levels in AV patients indicated the effect of insulin and insulin resistance in the risk of AV and its severity.

Distinction of cardiometabolic profiles among people ≥75 years with type 2 diabetes: a latent profile analysis

BACKGROUND

Older patients with type 2 diabetes mellitus represent a heterogeneous group in terms of metabolic profile. It makes glucose-lowering-therapy (GLT) complex to manage, as it needs to be individualised according to the patient profile. This study aimed to identify and characterize subgroups existing among older patients with diabetes.

METHODS

Retrospective observational cohort study of outpatients followed in a Belgian diabetes clinic. Included participants were all aged ≥75 years, diagnosed with type 2 diabetes, Caucasian, and had a Homeostasis Model Assessment (HOMA2). A latent profile analysis was conducted to classify patients using the age at diabetes diagnosis and HOMA2 variables, i.e. insulin sensitivity (HOMA2%-S), beta-cell-function (HOMA2%-β), and the product between both (HOMA2%-βxS; as a measure of residual beta-cell function). GLT was expressed in defined daily dose (DDD).

RESULTS

In total, 147 patients were included (median age: 80 years; 37.4% women; median age at diabetes diagnostic: 62 years). The resulting model classified patients into 6 distinct cardiometabolic profiles. Patients in profiles 1 and 2 had an older age at diabetes diagnosis (median: 68 years) and a lesser decrease in HOMA2%-S, as compared to other profiles. They also presented with the highest HOMA2%-βxS values. Patients in profiles 3, 4 and 5 had a moderate decrease in HOMA2%-βxS. Patients in profile 6 had the largest decrease in HOMA2%-β and HOMA2%-βxS. This classification was associated with significant differences in terms of HbA1c values and GLT total DDD between profiles. Thus, patients in profiles 1 and 2 presented with the lowest HbA1c values (median: 6.5%) though they received the lightest GLT (median GLT DDD: 0.75). Patients in profiles 3 to 5 presented with intermediate values of HbA1c (median: 7.3% and GLT DDD (median: 1.31). Finally, patients in profile 6 had the highest HbA1c values (median: 8.4%) despite receiving the highest GLT DDD (median: 2.28). Other metabolic differences were found between profiles.

CONCLUSIONS

This study identified 6 groups among patients ≥75 years with type 2 diabetes by latent profile analysis, based on age at diabetes diagnosis, insulin sensitivity, absolute and residual β-cell function. Intensity and choice of GLT should be adapted on this basis in addition to other existing recommendations for treatment individualisation.

The Effects of Berberis Vulgaris Juice on Insulin Indices in Women with Benign Breast Disease: A Randomized Controlled Clinical Trial

The aim of this study was to investigate the effect of Berberis vulgaris (BV) juice consumption on insulin homeostasis, glycemic profiles of patients with benign breast disease (BBD). This parallel design, triple-blind, randomized and placebo controlled clinical trial was conducted on 85 eligible women diagnosed with BBD who recruited from Nour-Nejat hospital, Tabriz, Iran. Participants were randomly allocated into either intervention group who received BV juice (480 mL/day, n = 44) or BV juice placebo at the same time (480 mL/day, n = 41). After a 7 day run-in period, treatments were administered for the duration of 8 weeks. Participants, care givers and those who assessed laboratory analyses were blinded to the assignments (IRCT registry no: IRCT2012110511335N2). The relative treatment effects of BV supplementation showed decreased serum levels of insulin for 19%, C-peptide for 8%, homeostasis model assessment of insulin resistance index (HOMA-IR) for 16% and glucose to insulin ratio for 22% but HOMA-B increased 44% relative to placebo group over 8 weeks BV supplementation. Although these changes were not statistical significant, the mean changes for C-peptide and HOMA-B were significant just after adjusting for baseline data and covariates. Administration of BV juice showed controlling effects on HOMA related indices, consequently might have beneficial effects on insulin signaling-related functions in women with benign breast tumor.

Assessment of Insulin Sensitivity and its Convalescence with Dietary Rehabilitation in Undernourished Rural West Bengal Population

INTRODUCTION

Metabolic syndrome involving diabetes is acquiring the eminence of prospective epidemic in India with dramatic rise in rural population prevalence where majority are undernourished and creates significant healthcare burden.

AIM

To investigate the prevalence of the insulin resistance amongst the undernourished rural population, involving children, adolescents and adult volunteers of the West Bengal and the effect of nutritional supplementation in the parameters echoing insulin sensitivity.

MATERIALS AND METHODS

A prospective interventional study was carried out on 120 volunteers in three age groups; Group 1 (5-12 years), Group 2 (13-18 years) and Group 3 (19-40 years), each with 40 subjects who fulfilled the inclusion criteria, under informed consent over six months. Baseline data regarding demography, family history including parental history of diabetes, medical history, physical, activity, anthropometrical status and blood parameters echoing insulin sensitivity were obtained from volunteers. Intervention included daily nutritional supplementation with eggs and banana. After six months of food supplementation, parameters reflecting insulin sensitivity were assessed.

RESULTS

Initial low figures of fasting insulin and blood sugar levels improvised with the nutritional supplementation alongside the absence of wasting in Group 1. HOMA-IR and IRI values of the Group 2 improved from the initial figures (3.19, 2.87) to (2.204, 1.99) and that of Group 3 from (5.0, 4.52) to (4.08, 3.67) respectively over six months (p<.05). Average Fasting Blood Sugar (FBS) enhanced from 85.5±9.6 mg/dl to 78.4±7.3 mg/dl and from 90.1±10.2 mg/dl to 84.8±8.4 mg/dl in Group 2 and 3 respectively by the end of the supplementation study (p<.05).

CONCLUSION

Six months study revealed the existence of insulin resistance and malnourishment in the selected rural population in three groups. Decrement in HOMA-IR, IRI, FBS and serum insulin alongside the improvement in the body mass, in comparison to that of initial values is evocative of restoration of insulin sensitivity with nutrition supplementation.

Premature birth and insulin resistance in infancy: A prospective cohort study

OBJECTIVE

This study was done to determine the role of prematurity and other variables to predict insulin sensitivity in infancy.

SUBJECTS AND METHODS

In this prospective study, 36 preterm appropriate for gestational age (AGA), 11 preterm small for gestational age (SGA), and 17 term SGA included as study cohort and 36 term AGA as control cohort. Detailed anthropometry assessment was performed at birth, 3, 6, and 9 months and at 9 months, fasting plasma glucose and serum insulin was done. Insulin resistance was determined by using homeostasis model assessment version 2.

RESULTS

It is found that preterm AGA (mean difference 0.617, 95% confidence interval [CI]; 0.43-0.80, P = 0.0001), preterm SGA (mean difference 0.764, 95% CI; 0.44-1.09, P = 0.0001), and term AGA (mean difference 0.725, 95% CI; 0.49-0.96, P = 0.0001) group had significantly higher insulin resistance than control. There was no significant difference in between preterm SGA and preterm AGA (mean difference 0.147 95% CI; -0.13-0.42, P = 0.927). In multiple regression models, SGA status (β =0.505) was more significant predictor of insulin resistance index than gestational age (β = -0.481), weight-for-length (β =0.315), and ponderal index (β = -0.194).

CONCLUSION

Preterm birth is a risk factor for the future development of insulin resistance which may develop as early as infancy.

Association of birthweight with diabetes and insulin sensitivity or secretion in the Japanese general population

Aims/Introduction

Low birthweight (birthweight <2,500 g) has been considered to be a risk factor for diabetes in data from Western countries, and its percentage is increasing in Japan. The aim of the present study was to assess the association between birth weight and diabetes, as well as both insulin resistance and secretion.

Materials and Methods

The participants were 847 adults who underwent health check-ups. The participants were divided by birthweight into four groups (low birthweight and tertiles 1–3 above it). We assessed the effect of birthweight on diabetes using a logistic regression model. Multivariable liner regression analyses were carried out to examine whether birthweight is independently associated with homeostasis model assessment of insulin resistance and β-cell function.

Results

The prevalence of diabetes tended to increase with decreasing birthweight. The adjusted odds ratio for diabetes with low birthweight was 3.52 (1.04–11.96) as compared with the reference category, tertile 2. Univariable linear regression analyses showed that homeostasis model assessment of insulin resistance was negatively associated with birthweight, and this association remained after adjusting for age, sex, current body mass index and family history of diabetes. There was no significant association between homeostasis model assessment of β-cell function and birthweight.

Conclusions

Low birthweight was inversely associated with diabetes and insulin resistance in the Japanese general population. Longitudinal data analyses are required to examine the causal relationship between bodyweight and diabetes or insulin resistance in adulthood.

Assessment of insulin sensitivity/resistance

Insulin resistance is one pretty troublesome entity which very commonly aggravates metabolic syndrome. Many methods and indices are available for the estimation of insulin resistance. It is essential to test and validate their reliability before they can be used as an investigation in patients. At present, hyperinsulinemic euglycemic clamp and intravenous glucose tolerance test are the most reliable methods available for estimating insulin resistance and are being used as a reference standard. Some simple methods, from which indices can be derived, have been validated e.g. homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI). For the clinical uses HOMA-insulin resistance, QUIKI, and Matsuda are suitable, while HES, McAuley, Belfiore, Cederholm, Avignon and Stumvoll index are suitable for epidemiological/research purposes. With increasing number of these available indices of IR, it may be difficult for clinicians to select the most appropriate index for their studies. This review provides guidelines that must be considered before performing such studies.

Relationship between serum concentrations of persistent organic pollutants and markers of insulin resistance in a cohort of women with a history of gestational diabetes mellitus

The aim of the present study was to assess the relationship between serum concentrations of several persistent organic pollutants and insulin resistance markers in a cohort of women with a history of gestational diabetes mellitus. ∑POPs was computed as the sum of individual serum POP concentrations. No statistically significant associations were found between levels of any POP and fasting glucose. However, polychlorinated biphenyl (PCB) congeners 138 and 180 were positively associated with 2-h glucose levels and PCB 180 also with fasting immunoreactive insulin (IRI). We also found a positive association of p,p'- dichlorodiphenyldichloroethylene (p,p'- DDE), PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs with 2-h IRI. Serum concentrations of PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs were also positively associated with homeostasis model assessment (HOMA2-IR) levels. Moreover, p,p'- DDE, PCBs (138, 153 and 180), hexachlorobenzene, and ∑POPs were negatively associated with Insulin Sensitivity Index (ISI-gly) levels. No significant association was found between glycated hemoglobin and the concentrations of any POP. The removal of women under blood glucose lowering treatment from the models strengthened most of the associations previously found for the whole population. Our findings suggest that exposure to certain POPs is a modifiable risk factor contributing to insulin resistance.

Higher plasma lipopolysaccharide concentrations are associated with less favorable phenotype in overweight/obese men

PURPOSE

Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria might be an inflammation trigger in adipose tissue. It has recently been proposed that there is a link between adipose tissue distribution and blood LPS. However, the number of studies on this topic is scarce, and further investigation in humans is required. In this study, we explored the association between plasma LPS concentrations and body fat distribution, as well as the biochemical parameters that may indicate the presence of metabolic disorders.

METHODS

Sixty-seven young adult men with body mass index of 26-35 kg/m(2) were evaluated. Anthropometry, body composition and body fat distribution, blood pressure, energy expenditure, physical activity level, dietary intake, and biochemical parameters were assessed.

RESULTS

Men with median plasma LPS ≥ 0.9 EU/mL presented higher sagittal abdominal diameter, trunk fat percentage, and android fat percentage, and mass, insulin and alanine aminotransferase concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), and beta cell dysfunction (HOMA-B) than those with lower plasma LPS. LPS correlated positively with the trunk fat percentage, and android fat percentage, and mass, insulin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase concentrations, as well as HOMA-IR and HOMA-B.

CONCLUSION

Our results suggest that a higher plasma LPS concentration is associated with a less favorable phenotype as characterized by higher central adiposity, higher values of HOMA-IR, and beta cell function impairment in overweight/obese men.

HOMA-IR and the risk of hyperuricemia: a prospective study in non-diabetic Japanese men

AIMS

To examine the relation of insulin resistant status determined by homeostasis model assessment of insulin resistance (HOMA-IR) with the risk of incident hyperuricemia.

METHODS

The study participants included 2071 Japanese men without hyperuricemia and diabetes, aged 35-54 years. The participants had undergone annual heath examinations for 6 years to compare incident hyperuricemia (serum uric acid >416.4μmol/L (7.0mg/dL) and/or taking medication for hyperuricemia) in four groups based on quartiles of baseline HOMA-IR.

RESULTS

During follow-up there were 331 incident cases of hyperuricemia. The hazard ratios for hyperuricemia, compared with HOMA-IR ≤0.66, were 1.42 (95% confidence interval 1.02-1.98) for HOMA-IR 0.67-0.98, 1.20 (0.86-1.68) for HOMA-IR 0.99-1.49 and 1.44 (1.04-1.98) for HOMA-IR ≥1.50 after adjustment for baseline serum uric acid, creatinine, hypercholesterolemia and hypertension status, age, alcohol intake, and smoking and exercise habits. The hazard ratio associated with an increase of one standard deviation in lnHOMA-IR (1.85 as one geometric standard deviation of HOMA-IR) was 1.14 (1.03-1.28) (p for trend=0.02).

CONCLUSIONS

Increased HOMA-IR independently predicted the subsequent development of hyperuricemia. Insulin resistance itself or compensatory hyperinsulinemia may contribute to the development of hyperuricemia.

High dietary salt decreases antioxidant defenses in the liver of fructose-fed insulin-resistant rats

In this study we investigated the hypothesis that a high-salt diet to hyperinsulinemic rats might impair antioxidant defense owing to its involvement in the activation of sodium reabsorption to lead to higher oxidative stress. Rats were fed a standard (CON), a high-salt (HS), or a high-fructose (HF) diet for 10 weeks after which, 50% of the animals belonging to the HF group were switched to a regimen of high-fructose and high-salt diet (HFS) for 10 more weeks, while the other groups were fed with their respective diets. Animals were then euthanized and their blood and liver were examined. Fasting plasma glucose was found to be significantly higher (approximately 50%) in fructose-fed rats than in the control and HS rats, whereas fat liver also differed in these animals, producing steatosis. Feeding fructose-fed rats with the high-salt diet triggered hyperinsulinemia and lowered insulin sensitivity, which led to increased levels of serum sodium compared to the HS group. This resulted in membrane perturbation, which in the presence of steatosis potentially enhanced hepatic lipid peroxidation, thereby decreasing the level of antioxidant defenses, as shown by GSH/GSSG ratio (HFS rats, 7.098±2.1 versus CON rats, 13.2±6.1) and superoxide dismutase (HFS rats, 2.1±0.05 versus CON rats, 2.3±0.1%), and catalase (HFS rats, 526.6±88.6 versus CON rats, 745.8±228.7 U/mg ptn) activities. Our results indicate that consumption of a salt-rich diet by insulin-resistant rats may lead to regulation of sodium reabsorption, worsening hepatic lipid peroxidation associated with impaired antioxidant defenses.

Insulin resistance in Nigerians with essential hypertension

BACKGROUND

Reports on the association between hypertension and insulin resistance have been inconsistent even though most studies show a definite association. It is also not certain if the association between insulin resistance and hypertension applies to all populations.

OBJECTIVE

To determine the prevalence of insulin resistance in hypertensive Nigerians and to examine the association of insulin resistance with hypertension and some anthropometric indices.

METHODS

Thirty five adults with essential hypertension and thirty five normotensives were studied. Anthropometric parameters, blood pressure, fasting glucose and insulin were measured. Homeostasis model assessment (HOMA) was used to determine insulin resistance (IR).

RESULTS

The hypertensive subjects had significantly higher fasting insulin and HOMA-IR compared with normotensives (p = 0.02 and 0.04) respectively. There were significant correlations between HOMA-IR, BMI, waist and hip circumference in subjects with hypertension. At multiple linear regression, hypertension and body mass index were found to be the only significant predictors of insulin resistance.

CONCLUSION

The hypertensives we studied had a higher occurrence of insulin resistance compared to the normotensives. This makes it necessary for persons with hypertensive to have regular screening for diabetes and other categories of glucose intolerance as the increased insulin increases their risk of developing type 2 diabetes mellitus.

Prolonged QT dispersion in inflammatory bowel disease

AIM: To investigate the frequency and factors of prolonged QT dispersion that may lead to severe ventricular arrhythmias in patients with inflammatory bowel disease (IBD).

METHODS: This study included 63 ulcerative colitis (UC) and 41 Crohn’s disease (CD) patients. Forty-seven healthy patients were included as the control group. Heart rate was calculated using electrocardiography, corrected QT dispersion (QTcd) and the Bazett’s formula. Homeostasis model assessment (HOMA) was used to determine insulin resistance (IR). HOMA values < 1 were considered normal and values > 2.5 indicated a high probability of IR.

RESULTS: Prolonged QTcd was found in 12.2% of UC patients, and in 14.5% of CD patients compared with the control group (P < 0.05). A significant difference was found between the insulin values (CD: 10.95 ± 6.10 vs 6.44 ± 3.28, P < 0.05; UC: 10.88 ± 7.19 vs 7.20 ± 4.54, P < 0.05) and HOMA (CD: 2.56 ± 1.43 vs 1.42 ± 0.75, P < 0.05; UC: 2.94 ± 1.88 vs 1.90 ± 1.09, P < 0.05) in UC and CD patients with and without prolonged QTcd. Disease behavior types were determined in CD patients with prolonged QTcd. Increased systolic arterial pressure (125 ± 13.81 vs 114.09 ± 8.73, P < 0.01) and age (48.67 ± 13.93 vs 39.57 ± 11.58, P < 0.05) in UC patients were significantly associated with prolonged QTcd.

CONCLUSION: Our data show that IBD patients have prolonged QTcd in relation to controls. The routine follow-up of IBD patients should include determination of HOMA, insulin values and electrocardiogram examination.

Hepatitis C virus induced insulin resistance impairs response to anti viral therapy

Hepatitis C virus (HCV) infection is an important risk factor for insulin resistance (IR). The latter is the pathogenic foundation underlying metabolic syndrome, steatosis and cirrhosis, and possibly hepatocellular carcinoma (HCC). The interplay between genetic and environmental risk factors ultimately leads to the development of IR. Obesity is considered a major risk factor, with dysregulation of levels of secreted adipokines from distended adipose tissue playing a major role in IR. HCV-induced IR may be due to the HCV core protein inducing proteasomal degradation of insulin receptor substrates 1 and 2, blocking intracellular insulin signaling. The latter is mediated by increased levels of both tumour necrosis factor-α (TNF-α) and suppressor of cytokine signaling 3 (SOC-3). IR, through different mechanisms, plays a role in the development of steatosis and its progression to steatohepatitis, cirrhosis and even HCC. In addition, IR has a role in impairing TNF signaling cascade, which in turn blocks STAT-1 translocation and interferon stimulated genes production avoiding the antiviral effect of interferon.

Association between Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Components of Metabolic Syndrome in Young Chinese Men

BACKGROUND

To investigate the prevalence of metabolic syndrome (MetS) in young Chinese population and assess the association between HOMA-IR and different components of MetS in young Chinese men.

METHODS

Overall 5576 young Chinese subjects (age range [19-44 yr], 3636 men) were enrolled in, who visited our Health Care Center for a related health checkup from March to December 2008. The international diabetes federation (IDF) definition for MetS was used. The SPSS statistical package, version 11.5 was used for the statistical analysis.

RESULTS

The prevalence of MetS was 21.81% in young men and 5.62% in young women. According to suffering from different numbers of MetS components, the male subjects were divided into four groups. Numbers of MetS components were more and HOMA-IR values were significantly higher. In this male population, the quartile of HOMA-IR was higher, values of triglyceride (TG), fasting plasma glucose (FBG), systolic blood pressure(SBP), diastolic blood pressure(DBP) and waist circumference (WC) were all significantly higher, as well as high density lipoprotein cholesterol (HDL-C) value was significantly lower (P= 0.000). In Spearman's correlation analysis, HOMA-IR was positively correlated with TG, FBG, SBP, DBP and WC, and negatively correlated with HDL-C (r= 0.460, 0.464, 0.362, 0.346, 0.586, -0.357, respectively, all P value= 0.000).

CONCLUSION

The prevalence of MetS in these young Chinese men was obviously high. Insulin resistance played an important role in occurrence and development of MetS. Waist circumference was the best correlation with HOMA-IR among all components of MetS.

Clearance of HCV by Combination Therapy of Pegylated Interferon alpha-2a and Ribavirin Improves Insulin Resistance

Background/Aims

Chronic hepatitis C virus (HCV) infection is associated with a higher risk of the development of insulin resistance. If HCV is a causal factor for insulin resistance, then clearance of HCV might decrease insulin resistance. The aim of this study was to elucidate the effects of clearance of HCV on insulin resistance.

Methods

We analyzed 28 patients with HCV infection who received combination treatment of 180 µg of pegylated interferon α-2a and ribavirin at our institution from May 2004 to November 2006. Insulin resistance was calculated according to the homeostasis model assessment of insulin resistance (HOMA-IR) method.

Results

Twenty-two patients (78.6%) achieved sustained virologic response (SVR), where the fasting plasma glucose level significantly decreased after antiviral treatment. Fasting serum insulin and HOMA-IR also significantly decreased after antiviral treatment, whereas the BMI value was not significantly affected. For the nonresponders (n=6), no significant changes were evident in BMI, fasting plasma glucose, fasting serum insulin, and HOMA-IR at 6 months after the end of antiviral treatment. Logistic regression analysis indicated that the only independent factor contributing to the reduction of insulin resistance was the complete disappearance of HCV RNA at 6 months after the end of antiviral treatment (SVR).

Conclusions

The clearance of HCV by the combination therapy of pegylated interferon α-2a and ribavirin improves insulin resistance by reducing fasting serum insulin and glucose levels.