Is insulin sensitivity a causal intermediate in the relationship between alcohol consumption and carotid atherosclerosis?: the insulin resistance and atherosclerosis study

Spontaneous Retroperitoneal Hematoma: A Deadly Complication for Patients Awaiting Liver Transplant

BACKGROUND

Patients with end-stage liver disease (ESLD) are at increased risk for hemorrhage and spontaneous retroperitoneal hematoma (sRPH) and also carry a high mortality rate. We sought to review the natural history of sRPH in patients with ESLD at a single center.

METHODS

All patients admitted to a single transplantation intensive care unit (TICU) at Froedtert and the Medical College of Wisconsin Transplant Center between June 2016 and August 2018 were retrospectively reviewed. Six ESLD patients with sRPH were studied. Clinical outcome measures were liver disease severity, sRPH treatment, and patient survival.

RESULTS

Six patients were included, four male and two female patients, with a median age of 56.5 years (range 30-67 years). All had alcohol-induced liver cirrhosis. The median Model for End-Stage Liver Disease (MELD) score at the time of sRPH diagnosis was 40 (range 30-43). The most commonly identified source of bleeding was from lumbar arteries. One patient had recurrent bleeding after embolization and underwent repeat embolization. Five patients died. The median time to death from the diagnosis of sRPH was 7.2 days (range 2-12 days). The patient who survived following embolization had the lowest MELD score.

CONCLUSION

Critically ill cirrhotic patients with sRPH have a significant mortality rate. Embolization is successful, albeit seldom. This is the largest retrospective series of sRPH in cirrhotic patients in the literature.

Simultaneous muscular hemorrhages in two regions three years after successfully controlling refractory ascites using transjugular intrahepatic portosystemic shunt treatment: a case report

INTRODUCTION

Various therapies and drugs have been developed to extend the life expectancy of patients with liver cirrhosis. The prolonged prognosis of cirrhotic patients may change the final cause of death in the future. Deep bleeding into the muscle is an uncommon but potentially life-threatening complication of liver cirrhosis.

CASE REPORT

A 53-year-old man had undergone transjugular intrahepatic portosystemic shunt treatment for refractory ascites, which successfully controlled it for three years. However, he had started drinking again and experienced acute-on-chronic liver failure. He also had severe back pain. Abdominal computed tomography showed hyperdensities in the retroperitoneum and right pleural cavity. Despite blood infusion, he died from acute-on-chronic liver failure. A pathological autopsy revealed bleeding from the iliopsoas and right diaphragmatic muscle simultaneously, evident from the presence of red blood cells located between the muscle sheaths. Disruption of the small vessels in the skeletal muscle fibers was inferred.

CONCLUSION

This is a critical case that underscores the significance of improving available knowledge based on the cause of final death of the patients with cirrhosis, who now have a good long-term prognosis owing to the latest medical developments.

Obesity and accumulation of subcutaneous adipose tissue are poor prognostic factors in patients with alcoholic liver cirrhosis

In alcoholic liver cirrhosis (LC) patients, obesity has become a problem that progresses into liver dysfunction. Herein, we investigated the relationship between the prognosis of steatohepatitis and body weight, along with fat accumulation in patients with alcoholic LC. We conducted a single-center retrospective study, enrolled 104 alcoholic LC patients without hepatocellular carcinoma (HCC) based on histological and clinical evidence, and investigated factors related to poor prognosis using multivariate Cox regression and cluster analyses. Cox regression analysis revealed three independent relevant factors: subcutaneous adipose tissue (SAT) index (median 34.8 cm2/m2, P = 0.009, hazard ratio [HR] 1.017, 95% confidence interval [CI] 1.004-1.030), total bilirubin level (median 1.7 mg/dL, P = 0.003, HR 1.129, 95% CI 1.042-1.223), and prothrombin time value (median 64%, P = 0.007, HR 0.967, 95% CI 0.943-0.991). In the cluster analysis, we categorized the patients into three groups: no adipose tissue accumulation (NAT group), SAT prior accumulation (SAT group), and visceral adipose tissue prior accumulation (VAT group). The results of the three groups revealed that the SAT group displayed a significantly poor prognosis of the Kaplan-Meier curve (67.1 vs 21.2 vs 65.3, P<0.001) of a 5-year survival rate. Propensity score matching analysis of the SAT and VAT groups was performed to adjust the patient's background, but no significant differences were found between them; however, the prognosis was poorer (21.2 vs 66.3, P<0.001), and hemostatic factors were still at a lower level in the SAT group. These findings suggest that SAT accumulation type of obesity is a poor prognostic factor in alcoholic LC patients without HCC, and the hemorrhagic tendency might worsen the poor prognosis in such cases.

The impact of diabetes on the association between alcohol intake and the risk of end-stage kidney disease in the Singapore Chinese Health Study

BACKGROUND

The relationship between alcohol intake and end-stage kidney disease (ESKD) risk is controversial. Moreover, while evidence has shown that the relationship between alcohol and atherosclerosis may be modified by diabetes, whether this applies to ESKD is unknown.

METHODS

We examined these associations in the Singapore Chinese Health Study, a prospective cohort of 63 257 adults aged 45 to 74 years. Information on alcohol intake, diet, lifestyle factors, and medical history was collected at recruitment. We identified 1217 ESKD cases via linkage with the Singapore Renal Registry after a mean follow-up of 17.5 years. Cox regression models were used to estimate hazard ratios (HRs) and 95% CI of ESKD.

RESULTS

Among the participants without diabetes at baseline, monthly to weekly drinking was associated with a decreased risk of ESKD (HR 0.69; 95% CI, 0.54-0.87) compared to nondrinkers. In contrast, this association was attenuated and not significant among those with diabetes (HR 0.82; 95% CI, 0.58-1.16; P_interaction = .19). Comparatively, alcohol intake of ≥2 drinks per day was significantly associated with an increased risk of ESKD compared to nondrinkers among those with diabetes (HR 2.00; 95% CI, 1.14-3.53) but not among those without diabetes (HR 0.91; 95% CI, 0.53-1.56; P_interaction = .01). The risk of ESKD among those with diabetes and who also consumed ≥2 drinks per day was increased by nearly 12-fold compared to nondrinkers without diabetes (HR 11.6; 95% CI, 6.73-19.9).

CONCLUSION

Low-dose drinking is associated with a reduced risk of ESKD among individuals without diabetes. However, joint exposure to heavy drinking and diabetes is associated with a substantially higher risk of ESKD.

Predictive formula for acute liver failure is useful for predicting the prognosis of patients with acute-on-chronic liver failure

AIM

The prognosis of acute-on-chronic liver failure (ACLF) is extremely poor in comparison to acute liver failure (ALF). We aimed to establish methods for the early diagnosis of ACLF and its severity to identify the patients with a poor prognosis.

METHODS

The laboratory data at admission of 30 ACLF and 46 ALF patients were compared. Three established prognosis prediction models (Model for End-Stage Liver Disease [MELD]; MELD modified by serum sodium concentration, [MELD-Na]; and the Japan hepatic encephalopathy prediction model [J-HEPM]) were assessed using area under the receiver-operator curve (AUROC) values.

RESULTS

No significant difference was found in the laboratory data of the two patient groups. J-HEPM was able to predict the outcome of the ACLF subjects (AUROC = 0.93).

CONCLUSION

Although ACLF could not be differentially diagnosed from ALF at admission from the laboratory data alone, the J-HEPM effectively predicted the prognosis of liver failure in patients with ACLF. These findings indicate that ACLF patients with high J-HEPM scores require earlier and more intensive care than ALF patients.

Adipose tissue hypoxia and low-grade inflammation: a possible mechanism for ethanol-related glucose intolerance?

The exact mechanism of ethanol's effects on glucose tolerance has not been well determined. The present study focuses for the first time on hypoxia and low-grade inflammation in adipose tissue (AT). In the in vivo experiments, twenty-four male Wistar rats were randomly allocated into control and ethanol feeding groups. Ethanol-treated rats received edible ethanol once a day at a total dosage of 5 g/kg per d, and the controls received distilled water. Ethanol volumes were adjusted every week. At the end of 8 weeks, we carried out an oral glucose tolerance test. Blood and AT were collected for measuring hypoxia-inducible factor-1α (HIF-1α), GLUT1, TNF-α, IL-6, leptin and vascular endothelial growth factor (VEGF). In the in vitro experiments, differentiated OP9 adipocytes were incubated with 100 mm of ethanol for 48 h; the media and cells were then collected for measuring HIF-1α, GLUT1, TNF-α and IL-6. The results showed that long-term ethanol consumption impaired glucose tolerance in rats. Ethanol consumption had little influence on body weight, but both epididymal and perirenal AT were markedly enlarged in the ethanol-treated rats as compared to the controls. Visceral adipose tissue (VAT) had accumulated, and the protein levels of HIF-1α and GLUT1, the indicators of hypoxia in rat epididymal AT and OP9 adipocytes, were elevated. Secondary to the AT hypoxia, the levels of inflammation-related adipokines, such as TNF-α, IL-6, leptin and VEGF, were increased. Based on these findings, we conclude that VAT hypoxia and low-grade inflammation might be a new mechanism in the treatment of ethanol-related diabetes.

Iliopsoas muscle hematoma secondary to alcoholic liver cirrhosis

Iliopsoas muscle hematoma in a patient with alcoholic liver cirrhosis is rarely seen, however it has a high mortality. Thus we should cautiously make a diagnosis and treatment. This is the case of a 60-year-old male. He had a 15-year history of alcoholic liver disease and emphysema. He presented with low back pain after a fall that had happened 2 months before. Due to persistent back pain, he went to see a local physician who, after detailed examination, suspected rupture of bilateral common iliac artery aneurysms and transferred the patient to our hospital. The same presumptive diagnosis was made, and on this basis, an aortic bifemoral Y-graft was implanted. He developed aspiration pneumonia and hepatic and renal dysfunction postoperatively, which led to multiple organ failure and subsequent in-hospital death on postoperative day 62. This was believed to be a case of iliopsoas muscle hematoma developed in a patient with liver cirrhosis, and considering it was a case with poor surgical risk, a conservative treatment option such as transcatheter arterial embolization should also have been considered. Although iliopsoas muscle hematoma with alcoholic liver cirrhosis is rare, an appropriate treatment plan should be determined on a case-by-case basis despite its poor prognosis.

The frequency of daily ethanol consumption influences the effect of ethanol on insulin sensitivity in rats fed a high-fat diet

The different effects of ethanol on insulin sensitivity may be due to complex reasons. Here, we focus on the various daily ethanol consumption frequencies in rats fed a high-fat (HF) diet and explore the possible mechanism mediated by adiponectin and AMP-activated protein kinase (AMPK). A total of thirty-six male Wistar rats were fed a HF diet and were randomly divided into three groups: those that received tap water (C); those that received ethanol via a gastric tube twice per d (E1); those that received free access to ethanol for drinking (E2). The total daily ethanol dosage in groups E1 and E2 were the same (5 g/kg per d). At the end of 18 weeks, insulin sensitivity was evaluated. Adiponectin AMPK and GLUT4 levels were determined. We found that the different administration frequencies led to markedly different plasma ethanol concentrations and there were intimate relationships between plasma ethanol concentration and insulin sensitivity. Insulin resistance was markedly improved in group E1, whereas only a slight improvement was observed in group E2. Accordingly, adiponectin, phosphorylated AMPK and GLUT4 levels were significantly increased in group E1. Based on these findings, we propose that ethanol concentration might be the major influencing factor mediating the effect of ethanol on insulin sensitivity. At a total daily dosage of 5 g/kg per d, twice daily administration of ethanol was more beneficial than continuous drinking. The protective effect of ethanol might be mediated by increased adiponectin levels, which subsequently improve the activation of AMPKα and GLUT4 expression in adipose tissue.

The relationship between psychosocial stress, age, BMI, CRP, lifestyle, and the metabolic syndrome in apparently healthy subjects

The aim of this cross-sectional study was to examine the factors which may be associated with the metabolic syndrome by exploring the relationship between psychosocial stress, age, body mass index (BMI), C-reactive protein (CRP), lifestyle factors, and the components of the metabolic syndrome, such as glycated hemoglobin (HbA1c), fasting blood sugar (FBS), body fat percentage, and triglyceride concentration, among apparently healthy subjects. Psychosocial stress was measured by the use of the inventory to measure psychosocial stress (IMPS). One thousand four hundred and ninety-nine people out of 1,941 public school workers admitted to a hospital for a medical check-up responded to the IMPS, yielding a response rate of 77.2%. A total of 1,201 workers excluding 298 who were taking medication for various diseases were analyzed with the use of hierarchical multiple regression models. It was found that IMPS-measured stress score, age, BMI, and smoking habit were associated with an increase in glycated hemoglobin among men, while alcohol consumption was associated with a decrease in glycated hemoglobin. Stress score, age, BMI, and alcohol consumption were found to be associated with an increase in FBS among men, while smoking and exercise habits were associated with a decrease in FBS. CRP was found to be associated with an increase in body fat percentage among men, though stress score was not associated with an increase in body fat percentage. Stress score, age, and BMI were associated with an increase in triglyceride concentration among women. The findings of the present study seem to be in line with the hypothesis that psychosocial stress plays an important role in developing the metabolic syndrome, which may be associated with inflammatory processes in the vascular wall, resulting in atherosclerosis and cardiovascular disease.

Long-term ethanol exposure inhibits glucose transporter 4 expression via an AMPK-dependent pathway in adipocytes

AIM

The roles of AMP-activated protein kinase (AMPK) and myocyte enhancer factor 2 isoforms (MEF2A, D) as mediators of the effects of ethanol on glucose transporter 4 (GLUT4) expression are unclear. We studied the effects of ethanol in adipocytes in vivo and in vitro.

METHODS

Thirty-six male Wistar rats were divided into three groups and given ethanol in a single daily dose of 0, 0.5, or 5 g/kg for 22 weeks. The expression of AMPK, MEF2 isoforms A and D, and GLUT4 was measured and compared in the three groups. The existence of the AMPK/MEF2/GLUT4 pathway in adipocytes and the effects of ethanol on this pathway were studied in (a) epididymal adipose tissue from six male Wistar rats subcutaneously injected with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR, an AMPK activator) or with 0.9% NaCl (control); and (b) isolated rat and human adipocytes treated with or without ethanol, AICAR, and compound C (a selective AMPK inhibitor). Expression of AMPK, MEF2, and GLUT4 was measured by RT-PCR and Western blotting.

RESULTS

(1) Long-term ethanol exposure decreased activated AMPK, MEF2A, MEF2D, and GLUT4 expression in rat adipose tissue. (2) In rat and human adipocytes, AICAR-induced AMPK activation, with subsequent elevation of MEF2 and GLUT4 expression, was inhibited by compound C. (3) In vitro ethanol-treatment suppressed the AMPK/MEF2/GLUT4 pathway.

CONCLUSION

The AMPK/MEF2/GLUT4 pathway exists in both rat and human adipocytes, and activated AMPK may positively regulate MEF2 and GLUT4 expression. Ethanol inhibition of this pathway leads to decreased GLUT4 expression, thus reducing insulin sensitivity and glucose tolerance.

Muscle hematoma: A critically important complication of alcoholic liver cirrhosis

An iliopsoas hematoma can occur either spontaneously or secondary to trauma or bleeding tendency due to hemophilia and anticoagulant therapy. Although liver cirrhosis is commonly associated with coagulopathy, iliopsoas hematoma is very rare. We herein, present a case of bilateral iliopsoas hematoma in a patient with alcoholic cirrhosis, and review the literature on muscle hematoma associated with cirrhosis. A 56-year-old man with alcoholic cirrhosis was admitted in a state of shock with anemia. The cause of anemia could not be detected, and the patient was treated conservatively. The site of bleeding was not detected with either gastroduodenal endoscopy or upper abdominal computed tomography, the latter of which did not include the iliopsoas muscle. He died on the 10th day of admission and bilateral iliopsoas hematomas were found on autopsy. An iron stain was positive in the iliopsoas muscle. Eight cases of muscle hematoma associated with cirrhosis, including the present case, were found in a review of the literature. Four of these cases involved the rectus abdominis muscle, 3 involved the iliopsoas muscle and 1 involved combined muscles. Alcoholic cirrhosis accounted for 75% of the cases. One case (12.5%) was associated with virus-related cirrhosis, and another with combined virus- and alcohol-related cirrhosis. The mortality rate was 75% despite early diagnosis and low risk scores for cirrhosis. Muscle hematoma in patients with cirrhosis is closely related to alcoholism, and the mortality rate of the condition is extremely high. In conclusion, muscle hematoma should be recognized as an important complication of cirrhosis.

Alcohol consumption and diabetes risk in the Diabetes Prevention Program

BACKGROUND

Moderate alcohol consumption is associated with a decreased risk of type 2 diabetes in the general population, but little is known about the effects in individuals at high risk of diabetes.

OBJECTIVES

The objectives were to determine associations between alcohol consumption and diabetes risk factors and whether alcohol consumption was a predictor of incident diabetes in individuals enrolled in the Diabetes Prevention Program (DPP).

DESIGN

DPP participants (n = 3175) had impaired glucose tolerance (2-h glucose: 7.8-11.1 mmol/L), elevated fasting glucose (5.3-7.0 mmol/L), and a body mass index (in kg/m(2)) > or =24. Participants were randomly assigned to placebo, metformin, or lifestyle modification and were followed for a mean of 3.2 y. Alcohol intake was assessed at baseline and year 1 by using a semiquantitative food-frequency questionnaire. Diabetes was diagnosed by annual oral-glucose-tolerance testing and semiannual fasting plasma glucose measurement.

RESULTS

Participants who reported higher alcohol consumption tended to be male, older, white, and less obese and to have a higher calorie intake and a higher HDL-cholesterol concentration. Higher alcohol consumption was associated with lower insulin secretion at any level of insulin sensitivity. We found lower incidence rates of diabetes with higher alcohol consumption in the metformin (P < 0.01 for trend) and lifestyle modification (P = 0.02 for trend) groups, which remained significant after adjustment for multiple baseline covariates. No similar association was observed in the placebo group.

CONCLUSIONS

Despite overall low rates of alcohol consumption, there was a reduced risk of incident diabetes in those who reported modest daily alcohol intake and were assigned to metformin or lifestyle modification. Moderate daily alcohol intake is associated with lower insulin secretion-an effect that warrants further investigation. This trial was registered at clinicaltrials.gov as NCT00038727.

Greater habitual soyfood consumption is associated with decreased carotid intima-media thickness and better plasma lipids in Chinese middle-aged adults

Many clinical studies have shown high-dose supplemental soy protein has beneficial effects on cardiovascular risk factors. We examined the association between habitual soyfood intake and carotid intima-media thickness (IMT) and plasma lipids in a cross-sectional study including 406 (M 134, F 272) middle-aged Chinese adults (40-65 years) without confirmed relevant diseases. We found significantly dose-respondent decreases in bifurcation IMT, total and LDL cholesterol associated with increased usual soyfood intake after adjusting for potential confounders (p for trend, all p<0.05). Covariate-adjusted mean bifurcation IMT, total and LDL cholesterol decreased by 9.4%, 6.2% and 10.4% in women (p=0.020, 0.035, 0.110), 16.0%, 12.3% and 19.6% in men (p=0.036, 0.005, 0.002), and 9.9%, 9.3% and 15.4% in total men and women combined (p=0.010, <0.001, <0.001) when the mean intake of soy protein increased from 0.87 (F) or 0.64 (M) g/day (1st tertile) to 8.35 (F) or 7.48 (M) g/day (3rd tertile), respectively. Significant interaction between sex and soy consumption on bifurcation IMT was observed (p=0.008). In conclusion, higher habitual soyfood consumption is associated with decreased bifurcation IMT, plasma TC and LDL-c in middle-aged Chinese adults. The association is more apparent in men than in women.

Glycemic effects of moderate alcohol intake among patients with type 2 diabetes: a multicenter, randomized, clinical intervention trial

OBJECTIVE

In a randomized controlled trial, we assessed the effect of daily moderate alcohol intake on glycemic control in the fasting and postprandial states in patients with type 2 diabetes who previously had abstained from alcohol.

RESEARCH DESIGN AND METHODS

We randomly assigned 109 patients (41-74 years old) with established type 2 diabetes who abstained from alcohol to receive 150 ml wine (13 g alcohol) or nonalcoholic diet beer (control) each day during a 3-month multicenter trial. The beverages were consumed during dinner. Diet and alcohol consumption were monitored.

RESULTS

During the intervention, 17% of participants (12% from the alcohol group) dropped out, leaving 91 who completed the trial. Within the alcohol group, fasting plasma glucose (FPG) decreased from 139.6 +/- 41 to 118.0 +/- 32.5 mg/dl after 3 months compared with 136.7 +/- 15.4 to 138.6 +/- 27.8 mg/dl in the control subjects (P(v) = 0.015). However, alcohol consumption had no effect on 2-h postprandial glucose levels (difference of 18.5 mg/dl in the control group vs. 17.7 mg/dl in the alcohol group, P(v) = 0.97). Patients in the alcohol group with higher baseline A1C levels had greater reductions in FPG (age-adjusted correlation -0.57, P(v) < 0.001). No significant changes were observed in the levels of bilirubin, alkaline phosphatase, alanine aminotransferase, or aspartate aminotransferase, and no notable adverse effects were reported. Participants in the alcohol group reported an improvement in the ability to fall asleep (P(v) < 0.001).

CONCLUSIONS

Among patients with type 2 diabetes who had previously abstained from alcohol, initiation of moderate daily alcohol consumption reduced FPG but not postprandial glucose. Patients with higher A1C may benefit more from the favorable glycemic effect of alcohol. Further intervention studies are needed to confirm the long-term effect of moderate alcohol intake.

Beer ethanol consumption and plasma homocysteine among patients with type 2 diabetes

We analyzed the association between beer and other type of ethanol consumption and tHcy levels among type 2 diabetic patients. Male type 2 diabetic patients without overt nephropathy were studied (n=242). Ethanol consumptions of the patients were 35.1+/-37.8mL/day for total ethanol, 13.9+/-15.2mL/day for beer ethanol and 21.2+/-32.1mL/day for non-beer ethanol. Both, total and non-beer ethanol consumption correlated with tHcy, whereas beer ethanol consumption showed a trend to inverse association with tHcy (standard regression coefficient, 0.184, 0.283 and -0.110, respectively). Each intake of 30mL/day ethanol consumption was associated with an increase of tHcy of 0.6micromol/L for total ethanol and 1.1micromol/L for non-beer ethanol and a decrease of tHcy of 0.7micromol/L for beer ethanol. Similar trend was observed in the analysis model which included only drinkers, and also in an adjusted analysis model. Plasma tHcy of beer only drinkers was lower than that of non-beer alcohol only drinkers (8.9+/-1.9micromol/L versus 11.5+/-5.5micromol/L, P=0.003). Non-beer ethanol consumption might be less healthy compared with beer ethanol consumption among type 2 diabetic patients in terms of the effects on tHcy.

INFLUENCE OF DRINKING ALCOHOL ON ATHEROSCLEROTIC RISK IN ALCOHOL FLUSHERS AND NON-FLUSHERS OF ORIENTAL PATIENTS WITH TYPE 2 DIABETES MELLITUS

AIMS

Facial flushing caused by alcohol drinking is a typical symptom of high sensitivity to alcohol in orientals. We investigated whether drinking alcohol influences atherosclerotic risk factors in alcohol flushers and non-flushers in patients with diabetes mellitus.

METHODS

A cross-sectional study was performed using 225 subjects with type 2 diabetes. Sensitivity to alcohol was surveyed by a questionnaire on facial flushing. Subjects were divided into three groups by average amount of alcohol drinking (non-drinkers; light drinkers: <140 g/week; heavy drinkers: 140 g/week or more).

RESULTS

Systolic blood pressure and blood HDL cholesterol were significantly higher in heavy drinkers than in non-drinkers. There were no significant differences in body mass index, blood pressure, blood total cholesterol, HDL cholesterol, uric acid, fibrinogen and sialic acid levels in flushers and non-flushers. In alcohol flushers, diastolic blood pressure and HDL cholesterol in heavy drinkers were significantly higher than those in non-drinkers, and systolic blood pressure was significantly higher in heavy drinkers than in non-drinkers and light drinkers. On the other hand, blood pressure and HDL cholesterol in non-flushers were not significantly different among non-, light and heavy drinkers. Serum total cholesterol was not significantly different among the three drinking groups both in flushers and non-flushers.

CONCLUSIONS

Blood pressure and HDL cholesterol are more prone to be affected by drinking in flushers than in non-flushers, suggesting that alcohol sensitivity evaluated by flushing response due to drinking alcohol should be taken into account when the effects of alcohol drinking on atherosclerotic risk factors are considered in oriental patients with type 2 diabetes mellitus.

Meta-analysis of the relationship between alcohol consumption and coronary heart disease and mortality in type 2 diabetic patients

AIMS/HYPOTHESIS

This systematic review examines the relationship between alcohol consumption and long-term complications of type 2 diabetes. Meta-analyses could only be performed for total mortality, mortality from CHD, and CHD incidence, because the availability of articles on other complications was too limited.

MATERIALS AND METHODS

A PubMed search through to September 2005 was performed and the reference lists of relevant articles examined. Among the relevant articles there were six cohort studies reporting on the risk of total mortality and/or fatal and/or incident CHD in alcohol non-consumers and in at least two groups of alcohol consumers.

RESULTS

Statistical pooling showed lower risks in alcohol consumers than in non-consumers (the reference category). The relative risk (RR) of total mortality was 0.64 (95% CI 0.49-0.82) in the <6 g/day category. In the higher alcohol consumption categories (6 to <18, and > or =18 g/day), the RRs of total mortality were not significant. Risks of fatal and total CHD were significantly lower in all three categories of alcohol consumers (<6, 6 to <18 and > or =18 g/day) than in non-consumers, with RRs ranging from 0.34 to 0.75.

CONCLUSIONS/INTERPRETATION

This meta-analysis shows that, as with findings in the general population, moderate alcohol consumption is associated with a lower risk of mortality and CHD in type 2 diabetic populations.

Adult rats prenatally exposed to ethanol have increased gluconeogenesis and impaired insulin response of hepatic gluconeogenic genes

Rat offspring exposed to ethanol (EtOH rats) during pregnancy are insulin resistant, but it is unknown whether they have increased gluconeogenesis. To address this issue, we determined blood glucose and liver gluconeogenic genes, proteins, and enzyme activities before and after insulin administration in juvenile and adult EtOH rats and submitted adult EtOH rats to a pyruvate challenge. In juvenile rats, basal glucose; peroxisome proliferator-activated receptor-coactivator-1alpha protein and mRNA; and phosphoenolpyruvate carboxykinase enzyme activity, protein, and mRNA were similar between groups. After insulin injection, these parameters failed to decrease in EtOH rats, but glucose decreased by 30% and gluconeogenic enzymes, proteins, and mRNAs decreased by 50-70% in control rats. In adult offspring, basal peroxisome proliferator-activated receptor-coactivator-1alpha protein and mRNA levels were 40-80% higher in EtOH rats than in controls. Similarly, basal phosphoenolpyruvate carboxykinase activity, protein, and mRNA were approximately 1.8-fold greater in EtOH rats than in controls. These parameters decreased by approximately 50% after insulin injection in control rats, but they remained unchanged in EtOH rats. After insulin injection in the adult rats, glucose decreased by 60% in controls but did not decrease significantly in EtOH rats. A subset of adult EtOH rats had fasting hyperglycemia and an exaggerated glycemic response to pyruvate compared with controls. The data indicate that, after prenatal EtOH exposure, the expression of gluconeogenic genes is exaggerated in adult rat offspring and is insulin resistant in both juvenile and adult rats, explaining increased gluconeogenesis. These alterations persist through adulthood and may contribute to the pathogenesis of Type 2 diabetes after exposure to EtOH in utero.

Heavy alcohol intake, homocysteine and Type 2 diabetes

Although moderate alcohol intake is associated with reduced risk of atherosclerotic disease in both the general population and in diabetic patients, a recent report suggests that heavy alcohol intake facilitates the development of atherosclerosis exclusively in diabetic individuals. We studied cross-sectionally the effects of the interaction between ethanol consumption category and the prevalence of diabetes on plasma total homocysteine (tHcy), a risk factor for atherosclerotic disease, in middle-aged men. Heavy drinking was associated with elevated tHcy levels only in diabetic subjects but not in non-diabetic subjects. Plasma tHcy of heavy drinkers (average ethanol consumption > 30 ml/day) was higher than that of abstainers in the diabetic subgroup (10.25 +/- 3.39 vs. 8.88 +/- 1.94 micromol/l, P < 0.05), whereas tHcy levels in heavy drinkers were comparable with that of abstainers in the non-diabetic subgroup (9.36 +/- 2.52 vs. 9.12 +/- 2.10 micromol/l, NS). In a two-factor anova, significant interaction was observed on the effects of ethanol consumption category and diabetes prevalence on tHcy levels (P < 0.01). Confounding factors including folate, vitamin B(12), creatinine, age or cigarette smoking did not contribute to the interaction. These findings may partly explain the reported association between heavy drinking and atherosclerosis in diabetic subjects.

In vivo insulin signaling through PI3-kinase is impaired in skeletal muscle of adult rat offspring exposed to ethanol in utero

It is now known that prenatal ethanol (EtOH) exposure is associated with impaired glucose tolerance and insulin resistance in rat offspring, but the underlying mechanism(s) is not known. To test the hypothesis that in vivo insulin signaling through phosphatidylinositol 3 (PI3)-kinase is reduced in skeletal muscle of adult rat offspring exposed to EtOH in utero, we gave insulin intravenously to these rats and probed steps in the PI3-kinase insulin signaling pathway. After insulin treatment, EtOH-exposed rats had decreased tyrosine phosphorylation of the insulin receptor β-subunit and of insulin receptor substrate-1 (IRS-1), as well as reduced IRS-1-associated PI3-kinase in the gastrocnemius muscle compared with control rats. There was no significant difference in basal or insulin-stimulated Akt activity between EtOH-exposed rats and controls. Insulin-stimulated PKC isoform ζ phosphorylation and membrane association were reduced in EtOH-exposed rats compared with controls. Muscle insulin binding and peptide contents of insulin receptor, IRS-1, p85 subunit of PI3-kinase, Akt/PKB, and atypical PKC isoform ζ were not different between EtOH-exposed rats and controls. Thus insulin resistance in rat offspring exposed to EtOH in utero may be explained, at least in part, by impaired insulin signaling through the PI3-kinase pathway in skeletal muscle.

Acute alcohol consumption improves insulin action without affecting insulin secretion in type 2 diabetic subjects

OBJECTIVE

Long-term exposure to alcohol is associated with an improvement in insulin sensitivity. At this time, however, there is no definitive proof that alcohol per se has an effect on the insulin sensitivity index (S(i)) in type 2 diabetes patients. The aim of the present study was to assess the role of acute moderate alcohol intake on insulin sensitivity and insulin secretion in comparable subjects with and without type 2 diabetes.

RESEARCH DESIGN AND METHODS

Frequently sampled intravenous glucose tolerance tests (FSIGTs) were performed twice on eight healthy and eight type 2 diabetic volunteers. Forty grams of alcohol (vodka 40% wt/vol) or tap water were sipped from time -60 min to the end of the FSIGT.

RESULTS

Lactate area under the curve (AUC) was higher in both groups during the alcohol study than in the control study. Free fatty acid (FFA) AUC was higher in type 2 diabetic subjects than in control subjects; alcohol slightly reduced FFA by 17% in control subjects (34 +/- 4 mmol. min(-1). l(-1); P = 0.1) but significantly decreased FFA by 23% in type 2 diabetic subjects (54 +/- 10; P = 0.007). Beta-cell response was markedly reduced in type 2 diabetic subjects regardless of the type of study. Alcohol significantly increased S(i) in both groups.

CONCLUSIONS

Acute alcohol consumption improves insulin action without affecting beta-cell secretion. This effect may be partly due to the inhibitory effect of alcohol on lipolysis. Alcohol intake increases insulin sensitivity and may partly explain both the J-shaped relationship between the prevalence of diabetes and the amount of alcohol consumption and the decreased mortality for myocardial infarction.

Moderate alcohol consumption, estrogen replacement therapy, and physical activity are associated with increased insulin sensitivity: is abdominal adiposity the mediator?

OBJECTIVE

To investigate 1). associations between environmental factors (alcohol consumption, hormone replacement therapy [HRT], and physical activity) and insulin resistance and secretion, independent of genetic influences; 2). the contribution of abdominal adiposity to these relationships; and 3). whether gene-environment interactions mediate these associations.

RESEARCH DESIGN AND METHODS

Reported effects of lifestyle factors on insulin resistance and secretion are inconsistent, possibly due to difficulty in dissecting environmental from genetic influences and to confounding by adiposity. We examined these relationships in 798 nondiabetic female twins. Insulin resistance and secretion were estimated by modified homeostasis model assessment (HOMA-R' and HOMA-beta', respectively). Percent total body fat and percent central abdominal fat (CAF) were measured by dual-energy X-ray absorptiometry.

RESULTS

All categories of alcohol consumption were associated with lower insulin levels and HOMA-beta' than abstinence. Only moderate alcohol consumers (11-20 units/week) had lower HOMA-R' than abstainers (-0.16 +/- 0.09 vs. 0.14 +/- 0.13 SD, P = 0.048). This difference was attenuated after controlling for percent CAF (P = 0.57), which was lower in moderate drinkers. Controlling for genetic and smoking effects in cotwin case-control analysis, monozygotic pairs discordant for alcohol consumption had greater within-pair differences in HOMA-R' than concordant pairs (P = 0.02). Postmenopausal women using estrogen-only HRT had lower HOMA-R' than non-HRT users (-0.33 +/- 0.16 vs. 0.17 +/- 0.08 SD, P = 0.003), even after controlling for percent CAF. Lower fasting glucose levels and insulin resistance and secretion indexes in physically active subjects were partly explained by lower abdominal adiposity.

CONCLUSIONS

Moderate alcohol consumption, estrogen replacement, and physical activity are associated with increased insulin sensitivity in female twins. The favorable effects of moderate alcohol consumption and physical activity on insulin sensitivity are partly mediated by lower abdominal adiposity.