Metabolic responses to lipid infusions in patients with liver cirrhosis

Glucose turnover at whole-body and skeletal muscle level in response to parenteral nutrition in male patients with alcoholic liver cirrhosis

BACKGROUND & AIMS

Cirrhosis is associated with insulin resistance and impaired glucose tolerance, which may be caused by impairments at different tissue levels (liver, skeletal muscle, and/or beta cell).

METHODS

Here, glucose kinetics at whole-body and skeletal muscle level in patients with cirrhosis (Child-Pugh A and B) were studied during parenteral nutrition using the isotope dilution technique and arteriovenous balance approach across the leg. As opposed to the euglycemic hyperinsulinemic clamp or glucose tolerance tests applied in previous studies, this approach provides a nutrient composition more similar to a normal meal while circumventing any possible portal-systemic shunting, impaired hepatic uptake and incretin effect.

RESULTS

We confirmed the presence of hepatic and peripheral insulin resistance in our patient population. Endogenous glucose production was less suppressed in response to parenteral nutrition. However, glucose uptake in skeletal muscle was increased.

CONCLUSION

Our results suggests that in our study participants with cirrhosis, the hepatic and peripheral insulin resistance is compensated for by increased insulin secretion and thus, increased glucose uptake in muscle. Hereby, glucose homeostasis is maintained.

Hepatic FATP5 expression is associated with histological progression and loss of hepatic fat in NAFLD patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are characterized by the accumulation of excess hepatic fat. However, in the progression from NASH to cirrhosis, hepatic fat is often lost. Our aim was to elucidate the mechanism underlying hepatic fat loss during NASH progression.

METHODS

Liver biopsies were performed at The University of Tokyo Hospital between November 2011 and March 2016 on 146 patients with NAFLD and 14 patients with cryptogenic cirrhosis who were not being treated with any diabetes or dyslipidemia drugs. Among them, 70 patients underwent liver biopsy after an overnight fast, and 90 patients were biopsied 5 h after an oral glucose tolerance test. Expression differences in genes encoding several fatty acid metabolism-related factors were examined and correlated with hepatic histological changes based on NAFLD activity scores. Prospective patient follow-up continued until June 2018.

RESULTS

The level of fatty acid transport protein 5 (FATP5), which is associated with free fatty acid intake, was significantly and inversely correlated with features of histological progression, including ballooning and fibrosis. This was confirmed by immunohistochemical analysis. Transcript levels of genes encoding fatty acid metabolism-related proteins were comparable between NASH with severe fibrosis and cryptogenic cirrhosis. Furthermore, a prospective cohort study demonstrated that low FATP5 expression was the most significant risk factor for hepatic fat loss.

CONCLUSIONS

Decreased hepatic FATP5 expression in NAFLD is linked to histological progression, and may be associated with hepatic fat loss during NASH progression to cirrhosis.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Three targets of branched-chain amino acid supplementation in the treatment of liver disease

The article explains the pathogenesis of disturbances in branched-chain amino acid (BCAA; valine, leucine, and isoleucine) and protein metabolism in various forms of hepatic injury and it is suggested that the main cause of decrease in plasma BCAA concentration in liver cirrhosis is hyperammonemia. Three possible targets of BCAA supplementation in hepatic disease are suggested: (1) hepatic encephalopathy, (2) liver regeneration, and (3) hepatic cachexia. The BCAA may ameliorate hepatic encephalopathy by promoting ammonia detoxification, correction of the plasma amino acid imbalance, and by reduced brain influx of aromatic amino acids. The influence of BCAA supplementation on hepatic encephalopathy could be more effective in chronic hepatic injury with hyperammonemia and low concentrations of BCAA in blood than in acute hepatic illness, where hyperaminoacidemia frequently develops. The favorable effect of BCAA on liver regeneration and nutritional state of the body is related to their stimulatory effect on protein synthesis, secretion of hepatocyte growth factor, glutamine production and inhibitory effect on proteolysis. Presumably the beneficial effect of BCAA on hepatic cachexia is significant in compensated liver disease with decreased plasma BCAA concentrations, whereas it is less pronounced in hepatic diseases with inflammatory complications and enhanced protein turnover. It is concluded that specific benefits associated with BCAA supplementation depend significantly on the type of liver disease and on the presence of inflammatory reaction. An important task for clinical research is to identify groups of patients for whom BCAA treatment can significantly improve the health-related quality of life and the prognosis of hepatic disease.

Hepatology - Guidelines on Parenteral Nutrition, Chapter 16

Parenteral nutrition (PN) is indicated in alcoholic steatohepatitis (ASH) and in cirrhotic patients with moderate or severe malnutrition. PN should be started immediately when sufficientl oral or enteral feeding is not possible. ASH and cirrhosis patients who can be sufficiently fed either orally or enterally, but who have to abstain from food over a period of more than 12 hours (including nocturnal fasting) should receive basal glucose infusion (2–3 g/kg/d). Total PN is required if such fasting periods last longer than 72 h. PN in patients with higher-grade hepatic encephalopathy (HE); particularly in HE IV° with malfunction of swallowing and cough reflexes, and unprotected airways. Cirrhotic patients or patients after liver transplantation should receive early postoperative PN after surgery if they cannot be sufficiently rally or enterally nourished. No recommendation can be made on donor or organ conditioning by parenteral administration of glutamine and arginine, aiming at minimising ischemia/reperfusion damage. In acute liver failure artificial nutrition should be considered irrespective of the nutritional state and should be commenced when oral nutrition cannot be restarted within 5 to 7 days. Whenever feasible, enteral nutrition should be administered via a nasoduodenal feeding tube.

Short-term effects of parenteral nutrition of cholestatic infants with lipid emulsions based on medium-chain and long-chain triacylglycerols

OBJECTIVE

Infants with chronic cholestasis may require parenteral nutrition with lipid emulsions to provide energy and essential fatty acids but the optimal strategy is controversial.

METHODS

We studied the effects of parenteral lipid emulsions with long-chain triacylglycerols (LCTs) or a mixture of LCTs and medium-chain triacylglycerols (MCTs/LCTs) on serum bilirubin and lipid metabolism in cholestatic infants who received these 20% emulsions in alternating order for 3 d each, together with a glucose and amino acid infusion.

RESULTS

Of 11 recruited infants, two dropped out because enteral feeding could be established. In nine infants (2-8 mo of age, mean age 4.2 mo) who completed the study, serum bilirubin decreased from baseline to 6 h after the end of LCT infusion (from 8.5 +/- 2.0 to 7.8 +/- 1.8 mg/dL, mean +/- SEM, P < 0.05) and MCT/LCT infusion (7.9 +/- 6.5 to 7.1 +/- 6.5 mg/dL, P < 0.05). Cholesterol, triacylglycerol, and phospholipid concentrations in plasma and in chylomicrons, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein were not changed by either emulsion. Total polyunsaturated fatty acid contents in high-density lipoprotein phospholipids increased during LCT infusion (from 29.8 +/- 0.9 to 35.9 +/- 1.4% wt/wt, P < 0.05) and MCT/LCT infusion (from 30.4 +/- 1.0 to 33.0 +/- 0.7%, P < 0.05). The long-chain polyunsaturated fatty acid docosahexaenoic acid increased only with the LCT infusion. Because docosahexaenoic acid availability during infancy is important for early visual and cognitive development, the use of soybean oil-based lipid emulsions may be preferable for infants with severe progressive cholestasis.

CONCLUSION

The MCT/LCT and LCT emulsions showed a good metabolic tolerance in infants with chronic cholestasis but had a differential effect on high-density lipoprotein phospholipid contents of arachidonic and docosahexaenoic acids.

Nutritional modulation of liver regeneration by carbohydrates, lipids, and amino acids: a review

The survival of patients after a life-threatening hepatic injury of varying etiology depends on the ability of the remaining hepatocytes to regenerate. Thus, the stimulation of hepatic regeneration can have tremendous therapeutic relevance. Experimental studies--performed mostly on a model of regenerating rat liver after partial hepatectomy--indicate that glucose administration inhibits, whereas infusion of a lipid emulsion can enhance, the rate of liver regeneration. However, the inhibitory effect of glucose on liver regeneration is not observed when glucose is administered together with other nutrients. The results further indicate that administration of a standard amino acid mixture without energy substrate has an inhibitory effect and that development of liver regeneration can be favorably influenced by branched-chain amino acids (valine, leucine, and isoleucine) and glutamine.

Macronutrient preference, dietary intake, and substrate oxidation among stable cirrhotic patients

Anorexia in liver disease is common; however, its association with aberrant metabolism and the type of cirrhosis has not been considered. Dietary intake, nutritional status, fasting substrate oxidation, and macronutrient preference were examined in controls (n = 18) and 65 patients with hepatocellular (n = 31) or biliary cirrhosis (n = 34). Energy intakes were lowest in hepatocellular patients (controls: 9.0 +/- 0.48 megajoules/day compared with biliary: 7.0 +/- 0.40 MJ/day, P <.05; controls compared with hepatocellular 6.5 +/- 0.39 megajoules/day, P <.01). Triceps skinfold was lower only in hepatocellular patients (controls: 109 +/- 9.2% compared with hepatocellular 79 +/- 5.6%, P <.05). The fasting rate of lipid oxidation was elevated in hepatocellular patients when compared with controls and biliary patients (controls: 40.9 +/- 15.1 mg/min compared with hepatocellular 62.8 +/- 16.8 mg/min, P <.001, and biliary : 45.5 +/- 17.0 mg/min compared with hepatocellular, P <.001). Control subjects exhibited a greater preference for the high fat, moderate carbohydrate food (controls: median 7.0 IQR 2.0 compared with biliary: median 5.0 interquartile range [IQR] 4.7, P <.01) (controls compared with hepatocellular: median 6.0 IQR 4.0, P <.01). Cirrhotic patients' spontaneous dietary intake is lower than that of controls and recommended intakes. Although macronutrient preference ratings were different within cirrhotic patient groups it remains unclear whether associated nutrient deficits are metabolically driven and dictated by primary cause.

Hepatic energy and substrate metabolism: a possible metabolic basis for early nutritional support in cirrhotic patients

In the liver, the in vivo assessment of metabolic functions is limited by methodologic problems. The present evidence suggests that the liver contributes to 20-30% of whole body energy expenditure. Hepatic fuel selection can change considerably under different circumstances. During tissue catabolism (i.e., depletion of glycogen stores, increased lipid oxidation), the "hepatic respiratory quotient (RQ)" is lower than whole body RQ, suggesting that hepatic catabolism exceeds whole body catabolism. By contrast, the hepatic RQ may exceed whole body RQ during tissue anabolism (i.e., after full repletion of hepatic glycogen stores and significant lipogenesis). In cirrhosis, both the hepatic RQ and the whole body RQ are markedly reduced. When compared with the whole body level, the cirrhosis-induced decrease in the hepatic RQ is more pronounced. Given that liver catabolism exceeds (or possibly precedes) whole body catabolism, early nutritional support is mandatory in cirrhotic patients. The assessment of hepatic, in addition to whole body, energy metabolism may provide a basis for future recommendations of more specific nutritional support in patients with liver diseases.

Steatosis and collagen content in experimental liver cirrhosis are affected by dietary monounsaturated and polyunsaturated fatty acids

BACKGROUND AND METHODS

We used thioacetamide administered orally to induce cirrhosis in rats, and after these had recovered for 1 and 2 weeks we examined the effects of dietary supplementation with monounsaturated and n-3 polyunsaturated fatty acids, or with a combination of n-3 and n-6 polyunsaturated fatty acids, on the extent of steatosis and collagen content in the liver.

RESULTS

Nodular cirrhosis, increased collagen content, and lipid accumulation were established after 4 months of treatment with thioacetamide. When the animals were fed a diet rich in oleic acid for 2 weeks, the steatosis and fibrosis decreased. Supplementation with n-3 polyunsaturated fatty acids favored reductions in collagen content but did not reduce the fat accumulation. With a diet supplemented with a mixture of n-3 and n-6 fatty acids we found no reduction in either lipid accumulation or collagen content.

CONCLUSIONS

Fibrosis and steatosis may be influenced by dietary fat, and monounsaturated fat appears to influence favorably the histologic recovery of the damaged liver.

Metabolic, endocrine, haemodynamic and pulmonary responses to different types of exercise in individuals with normal or reduced liver function

The liver is central to the metabolic response to exercise but measurements of effects of reduced liver function on the physiological adaptation to exercise are scarce. We investigated metabolic, endocrine, pulmonary and haemodynamic responses to exercise in 15 healthy untrained controls (Co) and in 30 subjects with reduced liver function (i.e. liver cirrhosis, Ci). The following protocols were used: protocol 1 maximal oxygen uptake (VO2max) and anaerobic threshold (AT), protocol 2 stepwise increases in exercise intensity from 0 to 40% VO2max giving steady-stage conditions, protocol 3 1 h exercise at 20% VO2max. Muscle glycogen content was determined in 15 Ci. Spirometry was essentially normal in Ci.

RESULT

protocol 1 Ci had impaired VO2max and reduced AT (P < 0.05). Basal plasma concentrations of insulin, glucagon, growth hormone and adrenaline were increased in Ci (P < 0.05); cortisol was normal. During exercise, only glucagon remained different between groups. In protocol 2 Ci had decreased resting respiratory exchange ratio (RQ: p < 0.05) associated with increased plasma concentrations of free fatty acids and glycerol. They had disproportionately enhanced lipolysis and RQ. heart rate (+24%), ventilation (+28%), thermal effects of exercise (+31%) and intrapulmonary shunt volume (+76%), which accounted for 11.7 (SD 3.0) or 7.4 (SD 0.9%) of cardiac output during exercise in Ci and Co, respectively (P < 0.05 for all the differences reported). The metabolic effects of Ci were independent of the clinical and nutritional state of the patients. In protocol 3 muscle glycogen content was highly variable in Ci, but mean values were normal [16.9 (SD 8.9) mumol.g-1 wet mass]. Glycogen content positively correlated with resting and exercise-induced RQ, but negatively correlated with the exercise-induced alterations in plasma glucose concentration. From these results we concluded that with reduced liver function VO2max and AT are reduced, but metabolic, pulmonary and haemodynamic responses per unit power output are enhanced. Muscle glycogen content would seem to contribute to the metabolic response, but its mobilization to be limited in individuals with reduced liver function.

Parenteral use of medium-chain triglycerides: a reappraisal

Over the last two decades, the clinical use of intravenous fat emulsions for the nutritional support of hospitalized patients has become routine. During this time long-chain triglycerides (LCT) derived from soybean and/or safflower oils were the exclusive lipid source for these emulsions, providing both a safe calorically dense alternative to dextrose and essential fatty acids needed for biologic membranes and the maintenance of immune function. During the past decade, the availability of novel experimental triglycerides for parenteral use has generated interest in the use of these substrates for nutritional and metabolic support. Medium-chain triglycerides (MCT), long advocated as a superior substrate for parenteral use, possess many unique physiochemical and metabolic properties that make them theoretically advantageous over their LCT counterparts. Although not yet approved in the United States, preparations containing MCT have been widely available in Europe. Intravenous MCT preparations, either as physical mixtures or structured lipids, have been used clinically in patients with immunosuppresion, critical illness, liver and pulmonary disease and in premature infants. Despite great promise, the clinical data comparing the efficacy of MCT-based lipid emulsions to their LCT counterparts has been equivocal. This may be due in part to the limited nature of the published clinical trials. Measures of efficacy for parenteral or enteral nutritional products has taken on new meaning, in light of the reported experience using immunomodulatory nutrients. Current concerns about cost of medical care and resource use warrant careful deliberation about the utility of any new and expensive therapy. Until clinical data can fulfill expectations derived from animal studies, it is difficult to advocate the general use of MCT-based lipid emulsions. Future clinical studies with MCT-based emulsions should have clear outcome objectives sufficient to prove their theorized metabolic superiority.

Influence of dietary nucleotides on liver structural recovery and hepatocyte binuclearity in cirrhosis induced by thioacetamide

Intake of thioacetamide in drinking water causes liver cirrhosis in rats, which exhibit many changes similar to human disease. Nucleotides play an important part in major cellular functions, and recent studies suggest that dietary nucleotides may be considered 'semi-essential' nutrients in situations when an inadequate dietary supply may affect the growth of tissues with a rapid turnover rate. The aim of this study was to assess the effect of dietary nucleotides on lesions in thioacetamide-cirrhotic rats, and to calculate the proportion of mono and binucleated hepatocytes in different experimental groups. Rats were given cirrhosis by oral intake of thioacetamide in the drinking water (300 mg/l) for four months. One group was treated with a standard nucleotide free diet, and another group was treated with the same diet supplemented with 250 mg of nucleotides per 100 g of diet for one and two weeks. A striking reduction (mean (SEM)) in the proportion of binucleated cells was seen in thioacetamide-cirrhotic rats (4.8 (1.3) v 21.4 (1.0)), showing a change in the mitotic mechanism in focal lesions. Cirrhotic rats that consumed a semipurified diet supplemented with nucleotides during two weeks showed considerable histological regeneration of the injured liver. These animals had significantly higher proportion of binucleated cells than did animals at the beginning of the recovery period (8.2 (1.2) v 4.8 (1.3)). In the second week of recovery, both types of diet (F = 5.54, p < 0.05) and the previous administration of thioacetamide (F = 142.82, p < 0.001) had significant effects on the percentage of binucleated hepatocytes.

Influence of administration of long-chain polyunsaturated fatty acids on process of histological recovery in liver cirrhosis produced by oral intake of thioacetamide

Patients with liver cirrhosis frequently show some degree of protein-energy malnutrition and obviously require nutritional support. In this study, the treatment of rats consisted of the ad libitum oral intake of a 300 mg/liter thioacetamide solution, used as drinking water for four months. Thioacetamide treatment produced a severe alteration in the plasma fatty acid profile with significant decreases of these, which mimicked changes described in human cirrhosis. This hepatotoxic agent causes nodular cirrhosis, with loss of the normal architecture of the liver and disruption of the vascular pattern. The goal of the study was to evaluate the influence of n-3 and n-6 series long-chain polyunsaturated fatty acid dietary supplementation in experimental animals and to assess the effects of those dietary components on structural recovery in the liver. Significant increases of saturated and monounsaturated fatty acids as well as n-6 polyunsaturated fatty acids were seen only in the animals given the n-6 polyunsaturated fatty acid supplemented diet. However, only rats given the standard diet exhibited some degree of histological regeneration.

Glucose intolerance in liver cirrhosis: role of hepatic and non-hepatic influences

Oral glucose tolerance was tested in a heterogeneous group of 108 patients with liver cirrhosis. Data were compared with those from 181 subjects without liver disease (44% normal, 35% impaired glucose tolerance and 21% type 2 diabetes mellitus). In cirrhosis, 27% of the patients had normal, 36% had impaired glucose tolerance, and 37% were diabetic. There was no association between glucose intolerance or diabetes and the aetiology of cirrhosis, the duration of the disease, the biochemical indicators of hepatocyte damage, cholestasis and/or liver function. Only weak associations were found between the results of quantitative liver functions tests (caffeine, xylocaine, indocyanine green) and basal and post load glucose and insulin concentrations. Cirrhotics with 1st degree relatives with type 2 diabetes mellitus (n = 16) did not show an increased prevalence of diabetes. Older and/or malnourished patients were more frequently glucose intolerant. Using the plasma glucose concentration 120 minutes after glucose load as the dependent variable, multivariate regression analysis showed that 54% of its variance is associated with the following variables: basal plasma glucose (36%) and free fatty acid concentration (5%), age (3%), basal glucose oxidation rate (3%), muscle mass (3%) and plasma free glycerol at 120 minutes after glucose load (3%). By contrast, the clinical state of the patients (i.e. the CHILD-Pugh score) accounted for only 2% of the variance. We conclude that glucose tolerance is variable in cirrhosis. After manifestation of liver disease, glucose intolerance or diabetes cannot be explained by the clinical, histological or biochemical signs of liver disease.

Reduced metabolic efficiency in patients with Crohn's disease

Malnutrition is frequently seen in patients with inflammatory bowel disease, and parenteral or enteral nutrition is considered essential in this patient group. However, many patients with Crohn's disease have difficulties in gaining weight in response to overfeeding, suggesting reduced energy retention. Substrate utilization and nutrient balances as well as changes in body composition were followed in 10 patients with Crohn's disease immediately in the course of remission on low-dose steroid treatment, during an eight-day period of continuous enteral nutrition at constant (protocol 1:1.5-fold basal energy expenditure) and increasing (protocol 2:0.5- to 2.0-fold basal energy expenditure) nutrient supply. Energy, substrate, and nitrogen balances all became positive in response to overfeeding. However, fat was predominantly oxidized at an infusion rate of 1.2 g/kg body wt/day, whereas carbohydrates and proteins were effectively stored. A positive energy balance was reached at an energy infusion rate exceeding 31 kcal/kg body wt/day and corresponding substrate supplies of 1.6, 1.7, and 1.1 g/kg body wt/day for carbohydrates, fat, and protein, respectively. Nitrogen balance normalized at a supply of 0.14 g/kg body wt/day, which also reduced myofibrillar protein breakdown. Considering the relative contributions made by these nutrients in the diets, an accumulation of carbohydrates and protein but a depletion in fat became evident from nutrient balances. In fact, body weight increased by 0.12 kg/day, which was explained by an increased extracellular (+0.18 kg/day) and body cell mass (+0.04 kg/day) at reduced fat mass (-0.10 kg/day). Concomitantly, plasma T3 and insulin secretion both increased, whereas sympathetic nervous system activity decreased with overfeeding. This is contrary to data observed in healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)