Glucose intolerance and hyperinsulinemia of cirrhosis are not results of spontaneous or surgical portosystemic shunting

Occlusion of portosystemic shunts improves hyperinsulinemia due to insulin resistance in cirrhotic patients with portal hypertension

BACKGROUND

Liver cirrhosis (LC) is often complicated by hyperinsulinemia due to insulin resistance (IR), which is considered to be closely related to shunt formation and impaired liver function. This study evaluates whether balloon-occluded retrograde transvenous obliteration (B-RTO) can affect glucose and insulin metabolism in patients with LC.

METHODS

Twenty-five cirrhotic patients (mean age = 69.6 years; female/male = 12/13; hepatitis C virus/alcohol/nonalcoholic steatohepatitis = 14/6/5; Child-Pugh's class A/B = 10/15) with gastric varices and/or hepatic encephalopathy caused by portosystemic shunts (PSS) due to portal hypertension (PH) underwent B-RTO at our hospital. Testing was performed before and at 1 month after the procedure.

RESULTS

Shunt occlusion resulted in a decrease in extrahepatic collateral blood flow and an increase in portal venous flow, as well as a dramatic improvement in hepatic function markers. In addition, B-RTO significantly decreased homeostasis model assessment (HOMA) of IR without a statistical decline of HOMA of β-cell function. The 75-g oral glucose tolerance test (75-OGTT) revealed that occlusion of PSS reduced both fasting immunoreactive insulin (IRI) levels and the area under the curve for IRI. However, no significant change in preprandial or postprandial plasma glucose levels was observed. Furthermore, according to the criteria of the American Diabetes Association, B-RTO led to an improved 75-OGTT profile in 58.3 % of patients who had impaired glucose tolerance or diabetes mellitus before the procedure.

CONCLUSIONS

Shunt occlusion improves IR-related hyperinsulinemia through increased portal venous flow, ameliorated liver function, and consequent augmented hepatic insulin clearance in cirrhotic patients with PH.

Altered basal and postprandial plasma melatonin, gastrin, ghrelin, leptin and insulin in patients with liver cirrhosis and portal hypertension without and with oral administration of melatonin or tryptophan

This investigation was designed to assess the effects of oral administration of melatonin (10 mg) and tryptophan (Trp) (500 mg) on fasting and postprandial plasma levels of melatonin, gastrin, ghrelin, leptin and insulin in 10 healthy controls and in age-matched patients with liver cirrhosis (LC) and portal hypertension. Fasting plasma melatonin levels in LC patients were about five times higher (102 +/- 15 pg/mL) than in healthy controls (22 +/- 3 pg/mL). These levels significantly increased postprandially in LC patients, but significantly less so in controls. Treatment with melatonin or L-Trp resulted in a further significant rise in plasma melatonin, both under fasting and postprandial conditions, particularly in LC patients. Moreover, plasma gastrin, ghrelin, leptin and insulin levels under fasting and postprandial conditions were significantly higher in LC subjects than in healthy controls and they further rose significantly after oral application of melatonin or Trp. This study shows that: (a) patients with LC and portal hypertension exhibit significantly higher fasting and postprandial plasma melatonin levels than healthy subjects; (b) plasma ghrelin, both in LC and healthy controls reach the highest values under fasting conditions, but decline postprandially, especially after oral application of melatonin or Trp; and (c) plasma melatonin, gastrin, ghrelin and insulin levels are altered significantly in LC patients with portal hypertension compared with that in healthy controls possibly due to their portal systemic shunting and decreased liver degradation.

Some metabolic and endocrine consequences in portacaval-shunted rats

Some metabolic and endocrine consequences of portacaval shunt were examined in rats eight weeks after the operation. Plasma levels of insulin, glucagon somatostatin, such as pancreatic content of insulin, glucagon, and somatostatin were determined by radioimmunoassay. Numerous biochemical parameters, such as the concentration of serum ammonia, transaminase (AST and ALT), urea bilirubin, total plasma protein and plasma albumin levels were determined by standard biochemical tests. Normal plasma levels of insulin and somatostatin hyperglucagonaemia were observed in rats with portacaval shunt. After portacaval shunt there was a highly significant increase (p<0.01) in levels of blood ammonia, AST and ALT. Serum fasting glucose levels were significantly lower in portacaval shunt rats (p<0.01) in comparison to controls and sham operated rats. We conclude that the metabolic and endocrine consequences of portacaval shunt in rats are probably related to the functional deterioration of the liver due to diversion of the portal blood in systemic circulation.

Insulin resistance in non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis is a chronic liver disease that is capable of progressing to end-stage liver disease, but generally has a benign course. Obesity, non-insulin-dependent diabetes mellitus and hyperlipidaemia are the most common associations of the disease.

AIMS

To investigate the insulin resistance in patients with non-alcoholic steatohepatitis who have no other causes of insulin resistance such as obesity, diabetes mellitus, and hyperlipidaemia.

PATIENTS

Thirteen patients (7 male, 6 female) with non-alcoholic steatohepatitis and 12 (6 male, 6 female) healthy volunteers.

METHODS

All patients and healthy volunteers were submitted to biochemical tests and hyperinsulinaemic euglycaemic insulin clamp technique.

RESULTS

Basal insulin levels and C-peptide levels were significantly higher in non-alcoholic steatohepatitis group than in controls (p<0.001 and p<0.001, respectively). Hyperinsulinaemic euglycaemic insulin clamp technique revealed lower glucose utilization in the non-alcoholic steatohepatitis group and the difference was statistically significant (p<0.001).

CONCLUSIONS

Our study revealed marked hyperinsulinaemia and insulin resistance in patients with non-alcoholic steatohepatitis. Hyperinsulinaemia and insulin resistance may contribute to pathogenesis of nonalcoholic steatohepatitis.

Effect of mesocaval interposition shunting and repeated sclerotherapy on blood levels of gastrointestinal regulatory peptides, amino acids, and lysosomal enzymes--a prospective randomised trial

AIMS/BACKGROUND

Patients with liver cirrhosis and portal hypertension frequently exhibit a multitude of alterations of hormones and metabolism, but the relation of these alterations to liver function, degree of blood shunting, and hepatic encephalopathy remains unclear.

METHODS

Twenty-four patients were randomised to mesocaval interposition shunt (MIS) and 21 patients to repeated sclerotherapy (ST). Several peptide hormones, amino acids and lysosomal enzymes were monitored during a 4 year follow-up period.

RESULTS

Insulin and glucagon levels were elevated in the MIS group compared to pre-therapy levels, whereas the gastrin level was significantly higher in the ST group. Pancreatic polypeptide, somatostatin and vasoactive intestinal peptide levels were not affected by either treatment. The branched chain amino acids valine, leucine and isoleucine serum levels were all elevated after ST, and the arginine, proline and tyrosine levels were higher in the MIS group at follow-up. Other amino acids were not changed, neither were the lysosomal enzymes beta-hexosaminidase nor beta-glucoronidase during this longterm follow-up.

CONCLUSION

MIS or repeated ST treatment only affected serum levels of hormones, amino acids and lysosomal enzymes to a limited extent. In this trial, the type of treatment had only a small influence on these parameters during long term follow-up.

Insulin autoimmune syndrome as a cause of spontaneous hypoglycemia in alcoholic cirrhosis

Hypoglycemia in fulminant hepatic failure and hyperinsulinemia in cirrhosis are well-described phenomena. A patient with alcoholic cirrhosis who developed fasting hypoglycemia with an extremely high immunoreactive insulin level and a mildly elevated C-peptide level is reported. An insulinoma was excluded by detailed radiological imaging of the pancreas and by endoscopic ultrasonography. Detection of very high levels of insulin autoantibodies with no prior exposure to exogenous insulin confirmed the diagnosis of insulin autoimmune syndrome. During his hospital course, the patient developed another rare syndrome, acquired inhibitors to factor V, which led to the fatal coagulopathy that resulted in his death. Insulin autoimmune syndrome is the third leading cause of spontaneous hypoglycemia in Japan, where it has been associated with a variety of diseases and drugs. Outside of Japan, only approximately 20 cases have been reported and usually have been found in the context of an underlying autoimmune disorder or prior exposure to sulfhydryl drugs. It is believed that this is the first case reported outside Japan occurring in association with alcoholic liver disease, and the first in the world with coexisting acquired inhibitors to factor V.

Insulin secretion in pancreatic islets from rats with cirrhosis

Cirrhosis was induced in rats by subcutaneous injections of CCl4 for 13 or 17 weeks. The morphology of the pancreatic islets from the CCl4-treated rats was found to be normal. The CCl4-treated rats had lower fasting serum glucose levels and higher serum insulin levels than the controls. After an oral glucose load (3 g/kg body weight), glucose levels in CCl4-treated rats stayed within the normal range, whereas the serum insulin levels remained higher with a delayed decline of insulin with time. In vitro perifusion of islets from the CCl4-treated rats showed that the response to 16.7 mmol/l glucose was reduced with both lower total insulin output and stimulated insulin output, whereas the patterns of first and second phase of insulin release did not differ. The insulin content of the perifused islets was not affected by 13 weeks of CCl4 treatment. Islets from rats treated with CCl4 for 17 weeks showed normal secretory response to 20 mmol/l L-arginine. Taken together, the results, showing normal or reduced capacity for insulin secretion, suggest that the hyperinsulinemia accompanying CCl4-induced cirrhosis is not due to increased secretion of the pancreatic islets. It may rather be associated with decreased insulin degradation by the liver with cirrhosis.

Liver regeneration in rats after complete and partial occlusion of the portal blood influx

The role of portal blood influx in liver regeneration was studied in rats. Partial hepatectomy with removal of 45% of the liver mass was performed after end-to-side portacaval shunt (PCS) leading to complete diversion of portal blood from the liver, or after side-to-side PCS causing partial portal blood deprivation. Liver resection was limited to 45% to avoid the high mortality rate in rats with vascular anastomoses and 70% hepatectomy, but it did not change the pattern of liver regeneration. The total RNA and DNA content, the rate of DNA synthesis and the number of hepatocyte mitoses in regenerating liver were measured in comparison to sham-operated controls. Complete occlusion of the portal blood influx did not block hepatoproliferative response, but caused a significant decrease and delay of regeneration. Partial preservation of portal flow in rats with side-to-side PCS markedly improved liver regeneration in comparison to end-to-side PCS, but the process was slower than in the control group.