Acquired hepatocerebral degeneration: full recovery after liver transplantation.
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Biomedical subjects
Publications and source records attributed to G Marchesini.
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Insulin sensitivity (euglycemic clamp, insulin infusion rate: 40 mU. m(-2). min(-1)) was studied in 30 subjects with biopsy-proven nonalcoholic fatty liver disease (NAFLD), normal glucose tolerance, and a BMI <30 kg/m(2). Of those 30 subjects, 9 had pure fatty liver and 21 had evidence of steatohepatitis. In addition, 10 patients with type 2 diabetes under good metabolic control and 10 healthy subjects were studied. Most NAFLD patients had central fat accumulation, increased triglycerides and uric acid, and low HDL cholesterol, irrespective of BMI. Glucose disposal during the clamp was reduced by nearly 50% in NAFLD patients, as well as in patients with normal body weight, to an extent similar to that of the type 2 diabetic patients. Basal free fatty acids were increased, whereas insulin-mediated suppression of lipolysis was less effective (-69% in NAFLD vs. -84% in control subjects; P = 0.003). Postabsorptive hepatic glucose production (HGP), measured by [6,6-(2)H(2)]glucose, was normal. In response to insulin infusion, HGP decreased by only 63% of basal in NAFLD vs. 84% in control subjects (P = 0.002). Compared with type 2 diabetic patients, NAFLD patients were characterized by lower basal HGP, but with similarly reduced insulin-mediated suppression of HGP. There was laboratory evidence of iron overload in many NAFLD patients, but clinical, histological, and biochemical data (including insulin sensitivity) were not correlated with iron status. Four subjects were heterozygous for mutation His63Asp of the HFE gene of familiar hemochromatosis. We concluded that NAFLD, in the presence of normoglycemia and normal or moderately increased body weight, is characterized by clinical and laboratory data similar to those found in diabetes and obesity. NAFLD may be considered an additional feature of the metabolic syndrome, with specific hepatic insulin resistance.
OBJECTIVE: To investigate the effects of hyperglycaemia and hyperinsulinaemia on amino acid disposal in human obesity. DESIGN: Four sequential experimental conditions: (1) overnight fasting; (2) hyperglycaemia with hyperinsulinaemia (2 h hyperglycaemic clamp at 11 mmol/l); (3) hyperglycaemia with basal insulin (1 h hyperglycaemic clamp during somatostatin infusion), (4) hyperglycaemia with resuming hyperinsulinaemia (1 h hyperglycaemic clamp after somatostatin discontinuation). SUBJECTS: Seven non-obese and seven obese non-diabetic, normo-insulinaemic subjects. MEASUREMENTS: Glucose infused to maintain steady-state hyperglycaemia. Plasma insulin, glucagon, free fatty acid and amino acid concentrations in the last 20 min of the four experimental conditions. Net rates of plasma amino acid disappearance and appearance (micromol/l per hour), calculated as the slopes of the regression of amino acid concentration on time. RESULTS: The amount of glucose infused to maintain hyperglycaemia was reduced by nearly 50% in obese subjects. During hyperinsulinaemia, FFA suppression was lower in obese subjects. In all experimental conditions plasma amino acid levels were slightly, non-significantly higher in obese than in non-obese subjects. In both groups plasma amino acids decreased slightly with ongoing fasting, decreased remarkably during hyperglycaemia-hyperinsulinaemia, rose promptly when insulin concentration was suppressed by somatostatin infusion, and declined again after somatostatin discontinuation. Also the time-course of plasma branched-chain amino acids, which paralleled that of total amino acids, was similar in the two groups. The net rates of amino acid disappearance from plasma did not differ in obese and non-obese subjects both at fasting and during hyperglycaemia-hyperinsulinaemia. Also plasma amino acid appearance during hyperglycaemia with basal insulin was not different in the two groups. CONCLUSION: The net traffic of amino acids to and from plasma in relation to insulin drive and prevailing glucose is not impaired in obese subjects with normal glucose tolerance, in spite of a decreased insulin sensitivity of glucose and lipid metabolism.
The fasting plasma level of reduced glutathione (GSH), a methionine-derived tripeptide, is reduced in cirrhosis. There is evidence that a reduced activity of S-adenosyl-L-methionine synthetase limiting the flux of methionine along the transmethylation/transsulfuration pathway may contribute to decrease GSH levels. No studies have analyzed plasma GSH in response to a methionine load. In 6 control subjects and in 10 patients with cirrhosis, plasma sulfur amino acid and plasma and erythrocyte GSH levels were measured in response to a L-methionine load (0.1 g/kg). Blood samples were obtained throughout the day after the oral load. Urine was collected for measurement of sulfur excretion. During the study period, all subjects consumed a standard diet of 1,683 kcal containing 2% protein and virtually no methionine. Plasma methionine increased in both groups to a peak level exceeding 20 times the basal value 90 minutes after the load, and declined thereafter. Methionine clearance, calculated on the descending part of the methionine-time curve, was reduced by 50% in cirrhosis (P = .0001). Fasting GSH was higher in controls (mean +/- SD, 3.9 +/- 1.3 v 1.6 +/- 0.7 micromol/L, P = .0004). In response to a methionine load, it peaked at 10.2 +/- 7.2 and 3.2 +/- 1.3 micromol/L, respectively (P = .009). Thereafter, plasma GSH progressively declined, and after 24 hours, it returned to the fasting preinfusion values in both groups. Plasma cysteine and taurine concentrations, as well as the erythrocyte GSH time course, paralleled plasma GSH levels, with less significant differences between groups. Sulfate excretion was delayed. GSH synthesis is stimulated by a methionine load. The reduced flux of methionine along the transmethylation/transsulfuration pathway reduces GSH synthesis in cirrhosis. Defective methionine metabolism also may be responsible for reduced fasting GSH.
During the last 20 years there has been much interest in nutritional treatment for patients with advanced cirrhosis. Most studies have measured the potential benefit of nutritional supplements of dietary proteins, generic protein hydrolysates, or specific branched-chain amino acid (BCAA)-enriched formulas in regard to nutritional parameters and hepatic encephalopathy. The issue is not definitively settled; data are conflicting and meta-analyses have failed to produce unequivocal results. A consensus review, recently produced under the auspices of the European Society for Parenteral and Enteral Nutrition, concluded that: (1) patients with cirrhosis tend to be hypermetabolic, and a higher-than-normal supply of dietary proteins is needed to achieve nitrogen balance; (2) most patients tolerate a normal or even increased dietary protein intake, without risk of hepatic encephalopathy; (3) a modified eating pattern, based on several meals and a late evening snack, is useful; (4) in severely malnourished patients, amino acid supplements may be considered to provide the necessary amount of proteins to meet protein requirements; (5) in a few patients intolerant to the required protein intake, BCAA supplements may be considered to provide the necessary nitrogen intake without detrimental effects on the mental state, perhaps even improving it. Future studies are needed to quantify the advantage of nutritional support with amino acids or BCAA supplements on overall well-being, complications, and ultimately survival with a long-lasting disease where self-perceived health-related quality of life is a major outcome.
A poor health-related quality of life (HRQL) has been repeatedly documented in obesity. Overweight per se and associated diseases affect physical fitness, whereas mental well-being depends on social, cultural and behavioural components. Very few studies are available on HRQL in obese persons in relation to eating behaviour. We measured HRQL by means of Short-Form-36 questionnaire in 183 obese subjects, seeking specific treatment at a University-based weight management center. Only half had a Body Mass Index exceeding 35 kg/m2. Data were compared to age- and gender-adjusted normative values of the Italian population (2031 subjects). The Binge Eating Scale (BES) and the Three-Factor Eating Questionnaire (TFEQ) were used to assess eating behaviour. Most domains of HRQL were impaired in obese subjects, more severely in younger subjects and in females. The severity of overweight progressively affected physical fitness, but had a minor effect on mental status. In over 50% of subjects, BES and TFEQ identified a binge eating pattern, more frequently in females. A positive BES, as well as lower restriction, higher disinhibition and hunger values at TFEQ, identified subjects with poorer HRQL. Logistic regression analysis identified in a positive BES the variable more closely associated with low scores in mental domains of perceived HRQL. Waist-to-hip ratio, degree of obesity, osteoarticular and respiratory diseases, but also positive BES, were selected as variables more closely associated with poor physical fitness. HRQL is variably impaired in obese persons seeking treatment for their disease, mainly in patients with binge eating. Treatment of binge eating may be as important as any weight-reducing intervention for the overall well-being of the majority of obese persons.
BACKGROUND AND PURPOSE: Nonalcoholic fatty liver disease is frequently associated with type 2 diabetes mellitus, obesity, and dyslipidemia, but some patients have normal glucose tolerance or normal weight. We tested the hypothesis that there is an association between nonalcoholic fatty liver disease and insulin resistance that is independent of diabetes and obesity. SUBJECTS AND METHODS: We measured anthropometric and metabolic variables in 46 patients with chronically elevated serum aminotransferase levels, "bright liver" on ultrasound scan, and normal glucose tolerance. Indexes of insulin resistance and secretion were determined using the homeostasis model assessment method. They were compared with 92 normal subjects who were matched for age and sex. RESULTS: Patients with nonalcoholic fatty liver disease were characterized by fasting and glucose-induced hyperinsulinemia, insulin resistance, postload hypoglycemia, and hypertriglyceridemia. Insulin resistance [odds ratio (OR) = 15 per percent increase, 95% confidence interval (CI): 3.0 to 70], fasting triglyceride level (OR = 3.1 per mmol/liter increase, 95% CI: 1.1 to 8.9), 180-minute blood glucose level (OR = 4.3 per mmol/ liter decrease, 95% CI: 1.6 to 12), and average insulin concentration in response to oral glucose (OR = 3.0 per 100 pmol/liter increase, 95% CI: 1.5 to 6.2) were independently associated with nonalcoholic fatty liver disease. The exclusion of overweight and obese subjects did not change the results. CONCLUSION: Nonalcoholic fatty liver disease is associated with insulin resistance and hyperinsulinemia even in lean subjects with normal glucose tolerance. Genetic factors that reduce insulin sensitivity and increase serum triglyceride levels may be responsible for its development.
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Metabolic effects of prostaglandin E1 have been previously demonstrated in cirrhosis, apparently independent of changes in large splanchnic vessel hemodynamics. The effects of prostaglandin E1 on functional liver blood flow were tested by measuring the extrarenal clearance of D-sorbitol in six controls and eight patients with cirrhosis during systemic superinfusion of saline or prostaglandin E1 (30 microg/hr), in random order. Doppler ultrasonography of systemic and splanchnic circulation was also performed before the test and at the end of the two study periods. Prostaglandin E1 infusion increased femoral blood flow by nearly 60% in controls and over 30% in cirrhosis, without any effect on mean arterial pressure and heart rate. Mesenteric artery and portal blood flow were unchanged, as were Doppler-measured resistance indices in the liver, spleen and kidney. Sorbitol-assessed functional hepatic flow was 30% lower in cirrhosis, and did not change systematically during prostaglandin E1 infusion. We conclude that prostaglandin E1, at doses able to elicit metabolic effects and changes in systemic hemodynamics, does not affect splanchnic blood flow and/or hepatic microcirculation in normal subjects and in portal-hypertensive patients with cirrhosis.
OBJECTIVE: Oxygen free radicals (OFR) play a role in the pathogenesis of tissue damage in many pathological conditions via the peroxidation of membrane phospholipids. Experimental studies showed an elevated oxidative stress during hyperthyroidism, which is reduced by treatment. Therapy per se might decrease oxidative stress. DESIGN: Fasting plasma levels of thiobarbituric acid reacting substances (TBARS), vitamin E and coenzyme Q10 were measured in 22 hyperthyroid patients, before treatment for their thyroid disease, after 13.9 [SD 9.2] weeks, when they achieved an euthyroid state on thyrostatic drugs, and again after 47.7 [21.0] weeks, off therapy. No patient presented additional risk factors for increased lipoperoxidation and/or increased OFR levels. Smokers were asked to abstain from smoking overnight. METHODS: All analytes were measured by HPLC. RESULTS: In hyperthyroidism, plasma levels of TBARS were increased, whereas vitamin E and coenzyme Q10 were reduced. Average levels of TBARS and antioxidant agents returned to normal in euthyroid patients, without differences in relation to stop of thyrostatic therapy. CONCLUSIONS: Our data confirm the presence of oxidative stress and decreased anti-oxidant metabolites in hyperthyroid patients, which are corrected in euthyroidism, without any influence of thyrostatic drugs per se. Nutritional support with antioxidant agents, which are defective during hyperthyroidism, is warranted.
OBJECTIVES: To study changes in hepatic blood flow with age. DESIGN: Functional hepatic flow (FHF) and total hepatic flow (THF) were determined by non-invasive methods in 40 normal subjects in four age groups (<45, 45-60, 61-75 and >75 years). All subjects had normal routine liver function tests and no history of liver disease. RESULTS: THF was measured by pulsed echo-Doppler, as the sum of portal and hepatic artery blood flow; FHF was measured by the hepatic clearance of D-sorbitol. THF significantly decreased with age, particularly in subjects over 75 (from 1445+/-220 ml/min to 1020+/-148; P<0.001), and a similar reduction was observed in FHF (from 1514+/-250 ml/min to 1015+/-163; P<0.001). THF and FHF were strictly correlated in the whole population (r = 0.871; P<0.001) and both correlated with age (r = -0.510 and r = -0.596; P<0.005). CONCLUSION: With ageing there is a reduction of hepatic blood flow without any additional intrahepatic shunting.
OBJECTIVE: Impaired glucose tolerance or diabetes are frequently observed in cirrhosis. Overt diabetes was reported to affect long term survival of cirrhotic patients by increasing the risk of hepatocellular failure, without increasing the risk of diabetes-associated cardiovascular events. METHODS: We evaluated the prevalence of cardiovascular disease in 122 patients with cirrhosis, subdivided according to their glucose tolerance. The following parameters were considered: arterial pressure, peripheral vascular disease (ankle to brachial pressure ratio), ischemic heart disease, microalbuminuria, retinopathy. The prevalence of abnormal findings was compared with that observed in 60 randomly selected patients with noninsulin-dependent diabetes and in 40 controls. RESULTS: Noninsulin-dependent diabetic patients and patients with cirrhosis and diabetes were comparable for age, metabolic control, and smoking habits; the duration of diabetes was 5 yr longer for noninsulin-dependent diabetes. In cirrhosis, the prevalence of micro- and peripheral macroangiopathy, as well as coronary heart disease, was not different in relation to glucose tolerance, it was comparable to that of controls, and significantly lower than that observed in non-insulin-dependent diabetes. CONCLUSIONS: Cirrhotic patients, even in the presence of overt diabetes, are at low risk of cardiovascular disease. The low prevalence may be related to shorter duration of diabetic disease, also in relation to reduced life expectancy, as well as to liver disease-induced abnormalities protecting the cardiovascular system from atherosclerosis.
BACKGROUND: A laboratory-based model able to describe muscle energy status during physical exercise and changes in myofibrillar composition in response to training would be desirable. Lactate and ammonia concentrations are not sufficient for a comprehensive knowledge of these systems. All muscle fibres, irrespective of the type, show ATP depletion and IMP accumulation following exhausting muscular exercise with quantitative differences due to the different concentrations of deaminase. We studied the plasma concentration of metabolites of oxypurine cascade to test their reliability to classify different exercises. METHODS: We studied 52 athletes, measuring plasma metabolites at the beginning and at the end of their specific field exercise (cycle pursuers, 8 cases; soccer players, 19; marathon runners, 25). K3EDTA-blood samples were assayed for plasma hypoxanthine, xanthine, and inosine, using an HPLC technique, as well as ammonia and lactate by means of enzymatic methods. RESULTS AND CONCLUSIONS: Basal oxypurines levels were not different in relation to any specific physical exercise. Post-exercise oxypurines, namely hypoxanthine, were more precise predictors of muscle energy exhaustion than strain intensity or duration. Plasma levels of hypoxanthine may be elevated also in the presence of normal xanthine and uric acid concentrations, due to an exhaustion of the enzymatic pathway, to a reduced activity of xanthine-oxidase or finally to a substrate-dependent inhibition of the process.
Prostaglandins of the E (PGE) series have long been considered "catabolic" hormones, but recent data suggest that they may be secreted in critically ill patients to counteract stress hormones, stimulating protein synthesis. Their use is under scrutiny to improve hepatic microcirculation and as cytoprotective agents. We tested the effects of PGE1 on hepatic and whole-body nitrogen metabolism in eight patients with cirrhosis. Urea-nitrogen synthesis rate, alpha-amino-nitrogen levels, and nitrogen exchange were measured in the basal, postabsorptive state and in response to continuous alanine infusion, in paired experiments, during superinfusion of PGE1 or saline. Splanchnic and systemic hemodynamics were assessed by echo-Doppler at the beginning and at the end of each experiment. PGE1 produced a rapid fall in plasma amino acids and in urea-nitrogen synthesis rate, as well as a positive nitrogen exchange. The slope of the regression of alpha-amino-nitrogen levels on urea-nitrogen synthesis rate, a measure of liver cell metabolic activity, was not affected, but the regression line was shifted rightward, suggesting a nitrogen-sparing effect of PGE1. Mesenteric artery and portal flow were unchanged, whereas femoral artery flow increased by 30%. Insulin and glucagon levels were not systematically different. We conclude that PGE1 reduces hepatic urea synthesis rate, independent of hormones and/or hepatic flow, possibly acting at the peripheral level on amino acid transport, thus reducing amino acid supply to the liver. The resulting net nitrogen sparing might be the basis for the beneficial effect of PGE1 in clinical hepatology.
BACKGROUND & AIMS: Accelerated starvation and early recruitment of alternate fuels in cirrhosis have been attributed to reduced availability of hepatic glycogen. The aim of this study was to measure gluconeogenesis (as a marker of protein oxidation) in relation to total glucose production and glucagon-stimulated glycogenolysis. METHODS: Glucose and urea production, gluconeogenesis, and glycogenolysis were calculated using stable isotope methods before and during glucagon infusion (3 ng. kg-1. min-1) in 5 cirrhotic patients and 5 matched controls before and after glycogen repletion. RESULTS: In the basal state, cirrhotic patients had a normal rate of glucose production, but the contribution of gluconeogenesis was increased (74.3% +/- 4.1% vs. 55. 6% +/- 12.1%; P < 0.005). Glycogen repletion normalized the rate of gluconeogenesis. The glycemic response to glucagon (3 ng. kg-1. min-1) was blunted in cirrhotic patients because of a lower rate of glycogenolysis (0.63 +/- 0.23 vs. 1.22 +/- 0.23 mg. kg-1. min-1; P < 0.01) and was not affected by glycogen repletion. Despite increased gluconeogenesis, the simultaneously measured rate of urea synthesis was lower in cirrhotic patients (3.11 +/- 1.02 vs. 5.0 +/- 1.0 mg/kg; P < 0.05). CONCLUSIONS: These data show that in cirrhosis, glucose production is sustained by an increased rate of gluconeogenesis. The hepatic resistance to glucagon action is not caused by reduced glycogen stores.
BACKGROUND & AIMS: Leptin is a peptide that decreases food intake and increases energy expenditure. It is produced in fat cells, is stimulated by cytokines, and its levels in serum are higher in females. Because anorexia, hypermetabolism, and elevated cytokine levels are frequently observed in cirrhosis, we hypothesized that the serum leptin level would be elevated in cirrhosis. The aim of this study was to investigate the relationship of serum leptin to gender, body composition, and tumor necrosis factor (TNF). METHODS: Male (n = 18) and female (n = 10) abstinent alcoholic cirrhotic patients were studied and compared with control subjects (15 male and 8 female). Fat mass, fat-free body mass, and body cell mass were calculated by using H2[18O] and bromide dilution methodology. Serum leptin and TNF concentrations were measured by immunoassays. RESULTS: Fat mass was decreased only in male cirrhotics (P < 0.05), whereas body cell mass was decreased in both male and female cirrhotics (P < 0.01). Leptin levels were elevated in female (P < 0. 001) but not male cirrhotics compared with controls. When expressed per kilogram of fat mass, leptin was elevated in both male (P < 0. 01) and female (P < 0.01) cirrhotics. Women in both cirrhotic and control groups had higher leptin levels than men. TNF was elevated in both male and female cirrhotics and did not correlate with leptin levels. CONCLUSIONS: Cirrhotics have elevated serum leptin levels, which are related to both gender- and gender-dependent alterations in body composition.
Zinc deficiency is common in cirrhosis, and was proved to affect nitrogen metabolism. In experimental animals, zinc status may also affect glucose disposal, and acute zinc supplementation improves glucose tolerance in healthy subjects. This study was aimed at measuring the effects of long-term oral zinc supplements on glucose tolerance in cirrhosis. The time courses of glucose, insulin, and C-peptide in response to an intravenous (i.v.) glucose load were analyzed by the minimal-model technique before and after long-term oral zinc supplements (200 mg three times per day for 60 days) in 10 subjects with advanced cirrhosis and impaired glucose tolerance or diabetes. The test was performed using a simplified procedure, based on 20 blood samples collected within 4 hours from the glucose load. Normal values were obtained in 25 age-matched healthy subjects. Zinc levels were low to normal or reduced before treatment, and were normalized by oral zinc. Glucose disappearance improved by greater than 30% in response to treatment. There were no changes in pancreatic insulin secretion and systemic delivery, or in the hepatic extraction of insulin. Insulin sensitivity (SI), which was reduced by 80% before treatment, did not change. Glucose effectiveness (SG) was nearly halved in cirrhosis before treatment (0.013 [SD 0.007] min(-1) v. 0.028 [SD 0.009] in controls; P < .001), and increased to 0.017 (SD 0.009) after zinc (P < .05 v. baseline). The return to normal of plasma zinc levels after long-term zinc treatment in advanced cirrhosis improves glucose tolerance via an increase of the effects of glucose per se on glucose metabolism. Poor zinc status may contribute to the impaired glucose tolerance and diabetes of cirrhosis.
Prostaglandins of the E series showed metabolic and clinical effects in patients with liver disease; changes in splanchnic haemodynamics might be involved. Blood flow in femoral and mesenteric artery and in the portal vein was measured by echo-Doppler in 10 controls and 14 cirrhotic patients, in response to the systemic infusion of a PGE1 analogue (30 micrograms/h for 2-6 h) or saline, performed in random order. Intraparenchymal resistive and pulsatility indices in the liver, spleen and kidney were also measured. In both groups PGE1 increased femoral artery flow by 40%, irrespective of infusion time. Heart rate increased slightly, whereas mean arterial pressure decreased. There were no changes in mesenteric artery and portal vein flow, as well as in resistance indices. Saline infusion increased femoral artery flow by 4%. PGE1 infusion does not produces significant effects on Doppler-assessed splanchnic hemodynamics in controls and in cirrhotic patients, in spite of significant effects on peripheral circulation.