Glucose homeostasis in viral hepatitis

Severe hypoglycemia in patients with liver cirrhosis and type 2 diabetes

Introduction

Advanced liver disease with massive liver damage may affect the metabolism of hypoglycemic agents and increase the risk of hypoglycemia. We conduct this research to compare the risk of severe hypoglycemia between patients with type 2 diabetes, with and without compensated liver cirrhosis.

Methods

From Taiwan's National Health Insurance Research Database, we identified persons with type 2 diabetes with cirrhosis (n = 18,209) and without cirrhosis (n = 538,510) from January 1, 2000, to December 31, 2010. Cox proportional hazards models were adopted to assess risks of all-cause mortality and severe hypoglycemia.

Results

The mean follow-up period of this study was 3.7 years. The incidence rates of death during follow-up were 26.54 and 2.75 per 1,000 patient-years [aHR 7.63 (6.70-8.70)] for patients with cirrhosis and without cirrhosis, respectively. The incidence rates of severe hypoglycemia during follow-up were 0.53 and 0.14 per 1,000 patient-years [aHR 2.74 (1.52-4.92)] for patients with and without cirrhosis, respectively. The subgroup analysis of hypoglycemia risks in patients with and without cirrhosis disclosed no significant interaction for variables such as age, sex, chronic kidney disease, sulfonylurea use, number of oral antidiabetic drugs, insulin, b-blocker, and fibrate.

Conclusion

This cohort study demonstrated that patients with type 2 diabetes and compensated cirrhosis showed a higher risk of mortality and severe hypoglycemia than those without liver cirrhosis.

The Risk of Severe Hypoglycemia and Mortality in Patients With Type 2 Diabetes and Discharged With Acute Liver Injury

OBJECTIVE

To compare the risks of severe hypoglycemia and mortality between patients with type 2 diabetes (T2D) and discharged with and without acute liver injury.

RESEARCH DESIGN AND METHODS

From 1 January 2000 to 31 December 2010, we identified patients with T2D and hospitalization for acute liver injury and hospitalization for other causes from the National Health Insurance Research Database of Taiwan. Multivariable-adjusted Cox proportional hazards models were used to compare the risks of severe hypoglycemia and mortality between the study and control groups.

RESULTS

The incidence rates and adjusted hazard ratios (aHRs) for severe hypoglycemia within 90 days and 365 days after discharge were 12.28 and 5.59/1,000 person-years (aHR 1.92 [1.30-2.85]) and 7.35 and 2.9/1,000 person-years (aHR 1.98 [1.52-2.58]) for patients discharged with and without acute liver injury, respectively. The incidence rates and aHRs for mortality within 90 days and 365 days after discharge were 82.4 and 27.54/1,000 person-years (aHR 1.73 [1.46-2.05]) and 36.8 and 9.3/1,000 person-years (aHR 1.94 [1.69-2.24]) for patients discharged with and without acute liver injury, respectively. The subgroup analysis of hypoglycemia risk in patients discharged with acute liver injury revealed no significant interaction in risk factors of age, chronic kidney disease, and medications, except for sex difference, which has significant interaction.

CONCLUSIONS

This cohort study demonstrated that patients with T2D and discharged with acute liver injury showed significantly higher risks of severe hypoglycemia and mortality within 90 days and 365 days after discharge than patients discharged with other causes.

Hypoglycemia, Malnutrition and Body Composition

Hypoglycemia is one of the most significant factors to affect prognosis, and is detrimental to patients regardless of diabetes mellitus (DM) status. The classical paradigms dictate that hypoglycemia is a result of overtreatment with glucose lowering agents (iatrogenic hypoglycemia), or, as among patients without DM, this condition is attributed to disease severity. New information shows that hypoglycemia occurs among patients that have a tendency for it. Incident hypoglycemia is very prevalent in the hospital setting, occurring in 1:6 patients with DM and in 1:17 patients without DM (Leibovitz E, Khanimov I, Wainstein J, Boaz M; Diabetes Metab Syndr Clin Res Rev. 13:222-226, 2019).One of the major factors associated with incidence of hypoglycemia is the nutritional status on hospital admission and during the hospitalization. Assessment of nutritional status using questionnaires and biomarkers might be helpful in determining risk of hypoglycemia. Moreover, administration of oral nutritional supplements was shown to decrease this risk.It is also well known that a high burden of comorbidities is associated with an increased risk of hypoglycemia. For example, kidney disease, whether acute or chronic, was shown to increase the risk for hypoglycemia, as well as some endocrine disorders.In this review we elaborate on specific findings that are characteristic of patients at risk for developing hypoglycemia, as well as treatment aimed at preventing its occurrence.

Prevalence and predictors of low muscle mass in HIV/viral hepatitis coinfection

OBJECTIVE

Low muscle mass is associated with reduced survival in HIV, possibly mediated by systemic inflammation. Viral hepatitis coinfection can induce additional inflammation and hepatic dysfunction that may exacerbate low muscle mass. We determined the prevalence of and risk factors for low muscle mass in HIV/viral hepatitis coinfection.

DESIGN AND METHODS

A cross-sectional study of participants in the Multicenter AIDS Cohort Study and Women's Interagency HIV Study with anthropometry performed after 1 January 2000. Viral hepatitis defined by positive hepatitis B virus surface antigen and/or hepatitis C virus RNA. Low muscle mass defined as less than 10th percentile of age-matched and sex-matched reference values for mid-upper arm circumference. Using multivariable logistic regression, we determined adjusted odds ratios with 95% confidence intervals (CIs) of the association of HIV/viral hepatitis coinfection with low muscle mass and factors associated with low muscle mass in coinfected persons. Analyses adjusted for age, race, BMI, alcohol use, and IDU (also, nadir CD4 cell count and HIV RNA where appropriate).

RESULTS

Among 3518 participants (164 HIV/viral hepatitis, 223 viral hepatitis alone, 1070 HIV alone, and 2061 uninfected), HIV/viral hepatitis-coinfected persons had a 3.50-fold (95% CI, 1.51-8.09), 1.93-fold (1.17-3.20), and 2.65-fold (1.62-4.35) higher odds of low muscle mass than viral hepatitis-monoinfected, HIV-monoinfected, and uninfected persons, respectively. Lack of HIV RNA suppression [odds ratio, 2.26 (95% CI, 1.10-4.63)] was the only factor associated with low muscle mass in coinfected persons.

CONCLUSION

HIV/viral hepatitis-coinfected persons have a higher likelihood of low muscle mass than those with viral hepatitis monoinfection, HIV monoinfection, or neither infection. HIV viremia is an important risk factor for low muscle mass among coinfected persons.

Hypoglycemia in the Critically Ill Patient

Hypoglycemia is diagnosed convincingly when typical symptoms are associated with a low plasma glucose concentration and are relieved by glucose administration. It requires urgent treatment (usually with intravenous glucose in the hospital setting), diagnostic explanation, and long-term prevention. The latter is based upon an understanding of the pathogenesis of hypoglycemia in the affected patient. Postabsorptive (fasting) hypoglycemia is often caused by drugs (especially insulin, a sulfonylurea, or alcohol); it can also result from endogenous hyperinsulinism (insulinoma, autoimmune hypoglycemia), a non-β-cell tumor, hormonal deficiencies, or a variety of clinical syndromes including sepsis, cardiac, renal, and hepatic failure, and even inanition per se. Hypoglycemia is a treatable cause of acute morbidity. It is sometimes a cause of chronic morbidity and even mortality that could have been prevented.

Infection-related hypoglycemia in institutionalized demented patients: a comparative study of diabetic and nondiabetic patients

Hypoglycemia is common in elderly community dwelling patients and may accompany episodes of acute infection. We analyzed the interrelations of clinical variables with infection-related hypoglycemia (IRH) and its outcome in institutionalized demented elderly patients, with and without diabetes mellitus (DM). This is a retrospective cohort study involving residents of a large long term-care facility. We measured demographic, clinical, functional, nutritional and cognitive data as well as blood counts and chemistry analysis. We identified 65 elderly patients with IRH and compared data of 33 diabetic patients with 32 nondiabetic patients. Mean age of patients was 77.7 years and mean Mini-Mental score of 1.8. Diabetic patients were younger, more cognitively impaired, had a lower functional score (nonsignificant differences), but presented with more comorbidities, compared with nondiabetics (p=0.004). Mean blood glucose levels in diabetics and nondiabetics were 53.2 and 54.3 mg/dl, respectively. Only 22% of the patients showed clinical signs indicating hypoglycemia. Multivariate analysis showed that, in groups, comorbidity and functional status, creatinine, albumin, C-reactive protein (CRP) and total cholesterol were all associated with IRH. During a 6 months period, 58% (38/65) of the patients died, out of whom 47% (18/38) died within one month following the documentation of IRH. There were no statistically significant differences in short and late mortality rates between patients with and without DM. we conclude that asymptomatic IRH in institutionalized demented elderly is frequently associated with common respiratory and urinary infections, in both diabetic and nondiabetic patients. IRH seems to indicate a poor general health status rather than being the cause of death. Blood glucose needs to be screened in this population during common infections, also in nondiabetics, to identify patients at high risk.

Hypoglycemia

Under physiologic conditions, glucose plays a critical role in providing energy to the central nervous system. A precipitous drop in the availability of this substrate results in dramatic symptoms that signal a medical emergency and warrant immediate therapy aimed at restoring plasma glucose to normal levels. A systemic approach to the differential diagnosis is useful in identifying the cause of hypoglycemia. Once established, a specific and/or definitive intervention that addresses that underlying problem can be implemented. In most cases, this systemic approach to diagnosis and therapy is rewarded with a good outcome for the patient.

Mechanisms of the protective effect of L-alanine to D-galactosamine-induced hepatocellular injury: comparative studies of L-alanine and pyruvate

The addition of L-alanine reduced lactate dehydrogenase leakage from primary cultured rat hepatocytes treated with galactosamine (D-gal), while D-alanine and other amino acids did not. However, the mechanisms have not yet been entirely clarified. In this study, we used various inhibitors of metabolism, i.e., aminooxyacetate, oligomycin, and quinolinic acid, to examine the relation between this protective effect and the metabolism of L-alanine. Quinolinic acid (10 mM) did not affect the hepatoprotective effect of L-alanine, while oligomycin (0.1 mug/ml) and aminooxyacetate (1 mM) eliminated the hepatoprotective effect of L-alanine. L-Alanine also increased the albumin secretion by cultured hepatocytes treated with D-gal, while pyruvate had little effect. It was revealed that the intracellular content of pyruvate did not increase as a result of addition of L-alanine. These results are consistent with the hypothesis that L-alanine metabolism is important for hepatoprotection, but pyruvate cannot be used as a substitute for L-alanine.

Splanchnic metabolism of fuel substrates in acute liver failure

BACKGROUND/AIMS

This study aimed to characterize the exchange of fuel substrates in the splanchnic circulation in acute liver failure.

METHODS

Liver vein catheterization was used in 22 patients with acute liver failure after development of hepatic encephalopathy grade III-IV Healthy controls, patients with cirrhosis and patients with acute on chronic liver disease were also studied.

RESULTS

In acute liver failure there was splanchnic removal of glucose (0.21+/-0.44 mmol/min), release of lactate (0.34+/-0.37 mmol/min), pyruvate (0.08+/-0.06 mmol/min) and ketone bodies (0.04+/-0.02 mmol/min), while extraction of amino acids and free fatty acids was insignificant. In the acute liver failure group, a normal hepatic venous oxygen saturation (0.69+/-0.12) and normal pyruvate/lactate ratio suggested absence of hypoxia even though the acetoacetate/beta-hydroxybutyrate ratio was decreased. Only in the acute liver failure group did the measured splanchnic oxygen content difference exceed what could be accounted for even by hypothesizing complete oxidation of all extracted blood-borne fuel substrates; oxidation of endogenous substrates may be quantitatively important in this condition.

CONCLUSION

Acute liver failure was associated with a state of accelerated glycolysis in the splanchnic region, leading to release of lactate in the absence of splanchnic hypoxia.

Classification of hypoglycemic disorders

The classification of symptoms of hypoglycemia, namely, reactive versus fasting, based on segregation by timing in relation to meals is no longer useful from a clinical point of view. Every patient with neuroglycopenic symptoms, regardless of relation to food ingestion, requires comprehensive evaluation. Identification of the possible cause of hypoglycemia and selection of diagnostic modalities are facilitated by considering whether the patient appears to be healthy (with or without compensated coexistent disease) or ill (with a disease known to have a proclivity to develop hypoglycemia, or is hospitalized). Medications may mediate hypoglycemia in anybody, whether they appear healthy or ill.

Hypoglycemia

The diagnosis of a hypoglycemic disorder requires a high level of suspicion, careful assessment of the patient for the presence of mediating drugs or predisposing illness, and, when indicated, methodic evaluation of the basis of well-defined diagnostic criteria. The diagnostic burden is heaviest for healthy-appearing persons with episodes of confirmed neuroglycopenia. The author's criteria for insulin mediation of hypoglycemia are plasma insulin of 6 microU/mL or higher (radioimmunoassay), C-peptide of 200 pmol/L or higher (ICMA), proinsulin of 5 pmol/L or higher (ICMA), beta OH butyrate of 2.7 mmol/L or lower, and generous (> or = 25 mg/dL) response of plasma glucose to intravenous glucagon administered when the patient is hypoglycemic. Sulfonylurea should be sought in the plasma of any hypoglycemic patient, especially by an assay which can detect the second generation of these drugs.

Gastrointestinal endocrine tumours. Insulinoma

Fundamental to establishing a diagnosis of insulinoma is first to consider the diagnosis when presented with the constellation of symptoms and signs that indicate hypoglycaemia. Prominent and most convincing are manifestations of neuroglycopenia. Although hypoglycaemia can be caused by a number of disorders, the combination of hypoglycaemia and endogenous hyperinsulinaemia is diagnostic of insulinoma. Our criteria now include a glucose level of 40 mg/dl with a concomitant insulin level of 6 microU/ml, a C-peptide level exceeding 200 pmol/l, and negative screen for sulphonlyurea. Ancillary diagnostic tests or the use of insulin surrogates may offer helpful confirmation. Localization is still evolving, but in our hands pre-operative ultrasound is the best and only pre-operative test that we obtain in the usual situation. Expertise and experience with other modalities at other institutions offer reasonable but more costly alternatives. Intraoperative ultrasonography provides significant benefit in both tumour localization and delineating important related anatomy. Insulinomas are virtually all located in the pancreas; 90% are benign, single, and are generally firmer than surrounding normal pancreas. Extensive exposure may be required to identify and remove safely the tumour. Enucleation is our preferred technique, but distal pancreatectomy for tumours in the body or tail is an excellent method as well. Pancreatoduodenectomy is rarely necessary. Complications most commonly relate to leak of pancreatic secretions, causing pseudocyst, abscess, or fistula. except in MEN 1 syndrome, excision of a benign insulinoma equates with disease cure, and patients are often extraordinarily grateful as the change in their lives may be profound.

Insulin and glucagon levels in fulminant hepatic failure in man

The behavior of insulin and glucagon and related metabolic substrates was assayed in plasma of patients with fulminant hepatic failure. All 12 subjects were provided the same nutritional support. High levels of insulin and glucagon were present at all times and no difference was observed between surviving patients (four) and those who died (8). Elevated values for branched-chain and aromatic amino acids as well as alanine were present. Statistically significant lower levels of aromatic amino acids and consequently a greater branched chain-aromatic amino acid ratio was found in surviving vs nonsurviving patients. A significantly greater level of alpha-fetoprotein was found in patients who survived as compared to those who died.

Energy metabolism in patients with acute and chronic liver disease

Energy expenditure and substrate oxidation rate for fat, glucose and protein were evaluated by indirect calorimetry in 20 normal individuals, 35 patients with acute hepatitis and 22 patients with biopsy-proven alcoholic cirrhosis in the postabsorptive state. Measurements were done in the resting state after an overnight fast (10 to 12 hr). Oxygen consumption (ml/min/1.73 m2) in normal subjects, in patients with acute hepatitis and in patients with cirrhosis was 206.5 +/- 4.0 (mean +/- S.E.M.), 216.4 +/- 4.7 and 228.8 +/- 7.1 (p less than 0.05 vs. controls), respectively. When related to body surface area (kcal/min/1.73 m2), resting energy expenditure did not differ between normal subjects (0.98 +/- 0.02), patients with acute hepatitis (1.03 +/- 0.02) and cirrhotic patients (1.06 +/- 0.03). However, when related to 24-hr urinary creatinine excretion as an estimate of lean body mass, energy expenditure was increased in cirrhosis (p less than 0.0001). In cirrhosis an inverse association between the severity of liver disease according to Pugh and oxygen consumption and resting energy expenditure was found. In cirrhotic patients the percentages of total calories derived from fat (86% +/- 5%), carbohydrate (2% +/- 4%) and protein (12% +/- 1%) were different from those of normal controls who metabolized 45% +/- 4%, 38% +/- 4%, 17% +/- 1%, respectively. In acute hepatitis no alterations in metabolism could be found apart from a decreased protein oxidation rate. In conclusion no appreciable changes in energy metabolism exist in acute hepatitis. The pattern of fuel use in cirrhosis resembles that in starvation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute viral hepatitis: morphologic and functional correlations in human livers

The usual histologic pattern in acute viral hepatitis (AVH) includes cellular abnormalities predominantly in the perivenular (zone 3) hepatocytes and changes interpreted as representing regenerative activity in the periportal (zone 1) hepatocytes. Enzyme histochemical and ultrastructural studies of livers of 12 patients with AVH were undertaken to see whether these features support the concept of regeneration of hepatocytes in zone 1. The swollen hepatocytes in the perivenular areas were hydropic, with dilated or eccentric rough endoplasmic reticulum and decreased or vesicular smooth endoplasmic reticulum; correspondingly, the glucose-6-phosphatase activity (reflecting, when present, intact and functional endoplasmic reticulum) was markedly decreased. Succinic dehydrogenase and diphosphopyridine nucleotide diaphorase activities, representing mitochondrial enzymes, were limited to the perinuclear or pericanalicular cytoplasm of swollen hepatocytes. gamma-Glutamyl transpeptidase activity was increased. The periportal hydropic hepatocytes were small and arranged in clusters displacing sinusoids. Ultrastructurally, these hepatocytes had nearly normal organelles but scanty smooth endoplasmic reticulum. Activities of the enzymes glucose-6-phosphatase, succinic dehydrogenase, and diphosphopyridine nucleotide diaphorase were weak, although glycogen was abundant. gamma-Glutamyl transpeptidase activity was scanty in these hepatocytes. These findings from enzyme histochemical and electron microscopic studies could be interpreted as evidence of functional deterioration of perivenular swollen hepatocytes and relative functional immaturity of periportal hydropic clustered hepatocytes, suggesting regeneration of zone 1 hepatocytes.

Glomerular hyperfiltration after protein ingestion, during glucagon infusion, and in insulin-dependent diabetes is induced by a liver hormone: deficient production of this hormone in hepatic failure causes hepatorenal syndrome

Glomerular hyperfiltration induced by various stimuli (protein ingestion, amino-acid infusion, glucagon infusion, diabetes mellitus) is postulated to be associated with increased secretion by the liver of a hormone that increases glomerular filtration rate. In severe liver failure deficient secretion of this hormone is presumed to cause or contribute to the development of the hepatorenal syndrome. There is evidence that increased hepatic uptake of aminoacids is a factor triggering secretion of this hormone. The hypothesis, which is based on earlier published studies in laboratory animals and in man, accords well with clinical observations. This hypothesis may explain how glomeruli respond to metabolic stimuli and raises the possibility of therapeutic intervention in the glomerular hyperfiltration of diabetes and chronic renal failure.

Amino acids and lipoproteins in plasma of duodenopancreatectomized patients: effects of glucagon in physiological amounts

Duodenopancreatectomy induces a severe glucagon deficiency and elevated plasma concentrations of alanine, aspartate, glycine, proline, serine, arginine, citrulline, ornithine, phenylalanine and tyrosine. Restoring high physiological plasma glucagon in six such patients by infusing 0.3 mg/24 h of exogenous glucagon reduced significantly (P less than 0.01 or 0.001) the mentioned amino acids (except phenylalanine) and further asparagine, glutamine, methionine and threonine. In six normal subjects the same infusion reduced significantly (P less than 0.05 to 0.001) plasma alanine, asparagine, glutamate, glutamine, glycine, proline, serine, threonine, arginine, ornithine, lysine and tyrosine. However, the effect was significantly (P less than 0.01 or 0.001) less marked for alanine, glutamine, glycine, methionine, serine, threonine and arginine. This particular glucagon sensitivity of duodenopancreatectomized patients suggests that glucagon deficiency is the cause of their hyperaminacidaemia. By contrast, lipoprotein concentrations were virtually unaffected by either glucagon deficiency or its replacement. In the light of the marked hypoaminacidaemia in glucagonoma patients these results attribute to glucagon a major role as a regulator of protein metabolism.

The glucagon test in obstructive and hepatocellular jaundice

The plasma glucose response to an intravenous bolus of glucagon was examined in patients with obstructive jaundice, hepatocellular jaundice and in healthy volunteers. Plasma glucose levels were determined before and at 15, 30 and 45 min after glucagon. The glucose response to glucagon differed markedly in the two patient groups with significantly higher plasma glucose values in the obstructive jaundice group.

Measurement of blood glucose after intravenous glucagon provides a simple test to assist in the differential diagnosis of obstructive and hepatocellular jaundice.

Infection and diabetes: the case for glucose control

This review summarizes data concerning the host resistance to infection in diabetes and the influence of an acute infection upon the endocrinologic-metabolite status of the diabetic patient. While it is well known that acute infections lead to difficulty in controlling blood sugar levels and the infection is the most frequently documented cause of ketoacidosis, controversy persists as to whether or not patients with diabetes mellitus are more susceptible to infection than age- and sex-matched nondiabetic control subjects. Our data obtained from the charts of 241 diabetic patients who were being followed as outpatients show a striking direct correlation between the overall prevalence of infection (p less than 0.001) and the mean plasma glucose levels (representing three or more fasting glucose determinations taken at times when no evidence of infection existed). There is a significant diminution in intracellular bactericidal activity of leukocytes with Staphylococcus aureus and Escherichia coli in subjects with poorly controlled diabetes in comparison with the control group. Serum opsonic activity for both Staph. Aureus and E. coli were significantly lower than in the control subjects. Taken together, the results from published reports as well as our data suggest to us that good control of blood sugar in diabetic patients is a desirable goal in the prevention of certain infections (Candida vaginitis, for example) and to ensure maintenance of normal host defense mechanisms that determine resistance and response to infection.

Effects of pharmacologic hyperglucagonemia on plasma amino acid concentrations in normal and diabetic man

Four normal and five insulin dependent diabetic men received a 2 h pharmacologic glucagon infusion (50 ng/kg/min) resulting in plasma glucagon levels (4400 pg/ml) similar to those seen in glucagonoma patients. In normal subjects in whom plasma insulin concentrations rose significantly (239 uU/ml) and the blood level of 15 of the 18 amino acids measured fell significantly. In contrast, in the diabetic men who secreted no insulin in response to glucagon (no rise in C-peptide levels), only 10 of 18 amino acid levels fell significantly. The branched chain amino acids valine, leucine and isoleucine, as well as tyrosine and phenylalanine were among the 8 amino acids which showed no change in response to glucagon in the diabetics. Thus, glucagon appears to have no acute affect on branched chain amino acid levels in man.

Plasma levels of insulin, C-peptide and glucagon in liver cirrhosis

Plasma levels of immunoreactive insulin (IRI), C-peptide and glucagon were assayed in 16 patients with liver cirrhosis and 9 control subjects after an oral glucose load (OGTT). Nine of the cirrhotics showed glucose intolerance, the remaining 7 cases showed normal OGTT. Both groups of cirrhotics showed high IRI and C-peptide values in basal conditions; peaks of these parameters, higher than those observed in the control subjects, were found during the OGTT. The C-peptide/IRI ratio, which was lower than normal both during fasting and after glucose load, presented the lowest values in patients with normal OGTT. In the conditions adopted for this study, glucagon showed higher plasma levels in all the cirrhotics studied than those found in the controls, but the highest levels were found in patients with normal OGTT. It can be concluded that the high levels of insulin found in liver cirrhosis are due to a beta-pancreatic hypersecretion (high C-peptide levels) but are also maintained by a decreased hepatic degradation of the hormone (C-peptide/IRI ratio below normal). Hyperglucagonemia is not the chief factor in determining the insulin-resistance observed in liver cirrhosis.

Disopyramide (Norpace)-induced hypoglycemia

Disopyramide (Norpace) is a recently released antiarrhythmic agent with quinidine-like actions, but structurally unique. We describe a patient in whom impressive hypoglycemia developed following treatment with this agent. Blood glucose levels returned to normal after cessation of therapy, but dropped again following rechallenge with the drug. The pathogenesis of the hypoglycemia was investigated by assessment of serum insulin, plasma glucagon and serum alanine levels during disopyramide rechallenge. Clinicians should be aware of fasting hypoglycemia as an unusual but potentially serious complication of disopyramide therapy.

Insulin secretion and carbohydrate metabolism in experimental protein malnutrition

In order to study the evolution of endocrine and metabolic changes in protein malnutrition, we created a replica of this human syndrome in a primate model. This model was free from stress factors like infestations, and infections and provided an opportunity to study the details more closely. Our results showed that definite endocrine and metabolic changes are established by six weeks of protein deprivation. The study demonstrated that protein deprivation results in decreased fasting blood glucose levels associated with diminution in fasting, and total insulin output when presented with a glucose load. There is also deterioration of carbohydrate tolerance. It is suggested that decreased fasting blood glucose is a consequence of impaired breakdown and/or depletion of glycogen stores, and hepatic dysfunction secondary to fatty infiltration. The exact cause of decrease in insulin output remains to be clearly elucidated. The carbohydrate intolerance is attributed to insulin lack, hepatic dysfunction and decreased glucose disposal consequent to protein deprivation.

Hypoglycemia as a manifestation of sepsis

Hypoglycemia has rarely been described as a clinical sign of severe bacterial sepsis. We recently encountered nine patients in whom hypoglycemia (mean serum glucose of 22 mg/dl) was associated with overwhelming sepsis. Clinical disease in these patients included pneumonia and cellulitis; in three patients, no focus of infection was apparent. Altered mental status, metabolic acidosis, leukopenia, abnormal clotting studies and bacteremia were common features in these cases. In four patients, no cause for hypoglycemia other than sepsis was present. In five patients, another possible metabolic cause for hypoglycemia was present (alcoholism in four and chronic renal insufficiency in one) although none had been observed to be hypoglycemic on previous hospitalizations. Streptococcus pneumoniae (three cases) and Hemophilus influenzae, type b, (two cases) were the most common pathogens, and the over-all mortality was 67 per cent. The mechanism(s) for hypoglycemia with sepsis is not well defined. Depleted glycogen stores, impaired gluconeogenesis and increased peripheral glucose utilization may all be contributing factors. Incubation of bacteria in fresh blood at room temperature does not increase the normal rate of breakdown of glucose suggesting that the hypoglycemia occurs in vivo. Hypoglycemia is an important sign of overwhelming sepsis that may be more common than has previously been recognized.

Perspective in liver disease: An Irish experience

CONCLUSIONS

Graves travelled extensively and on one trip to Italy in 1819 he was joined by a man he describes as of rough exterior and being more "like a ship's mate" (Widdess, 1963). This man sketched extensively and was in fact the famous English painter - J. M. W. Turner. Graves, who was also sketching, was under no illusion as to who was the master and remarked later to Stokes - "When we compared drawings, the effect was strange. Not a single stroke in Turner's drawing was like nature … and yet my work was worthless in comparison to his. The whole glory of the scene was there". Graves acknowledged Turner's mastery in the field of sketching. No one can deny that this extra-ordinary man, with his clinical observations, deserves his eminent place in Irish medicine. Indeed continued studies of his writings can still prove beneficial to the present day scholar.

Combined deficiency of glucose-6-phosphatase and fructose-1, 6-diphosphatase. Studies of glucagon secretion and fuel utilization

An adult woman with hypoglycemia, hyperlactatemia, hyperuricemia, hypertriglyceridemia, hyperketonemia and inability to make new glucose from galactose, fructose, glycerol and alanine was found to have no hepatic glucose-6-phosphatase and deficient fructose-1,6-diphosphatase. Nonautonomous hyperglucagonemia was demonstrated and shown to contribute to the hyperlactatemia and hyperketonemia. A paradoxic hyperlactatemic response to glucose and galactose was observed. Studies of substrate utilization showed prompt adaptation to changes in dietary supply of energy which probably accounted for her never having experienced symptoms of hypoglycemia.

Role of glucagon in mediating metabolic effects of epinephrine

In order to separate direct effects of epinephrine on fuel metabolism from those mediated by glucagon, epinephrine (0.1 microng/kg-min) was infused for 120 min in 18- and 65-h fasted, nonanesthetized baboons with and without a concomitant somatostatin infusion. At both stages of fasting, epinephrine stimulated glucagon, secretion, and this was blocked by somatostatin. At 18 h, with epinephrine alone, glucose rose early and remained elevated throughout the infusion. In the glycogen-depleted 65-h fasted animals, there was attenuation of the early glucose rise, with glucose reaching a maximum level at 100-120 min. With somatostatin blockade of glucagon release in the 18-h fasted animals, a pattern of attenuated early glucose rise similar to that of the 65-h fasted animals occurred. Somatostatin also inhibited this early glycogenolytic response when the epinephrine dose was increased fivefold. The behavior of FFA, glycerol, and beta-hydroxybutyrate was unchanged by the addition of somatostatin to epinephrine at either stage of fasting. Thus, glucagon mediates the early glycogenolytic response to epinephrine, but not the delayed hyperglycemia and probably not the lipolysis.

The probable significance of hypertriglyceridaemia in viral hepatitis

It is proposed that the raised serum glutamic pyruvic transaminase activity (SGPT) in viral hepatitis reflects an adaptive increase in glutamic pyruvic transminase in muscle for the increased transamination of alanine for post-absorptive glucose homeostasis. However, in a disease where the SGPT is elevated for four to six weeks, muscle cannot be an indefinite source of alanine unless it could, concurrently, resynthesize alanine. Since the two substrates of muscle are glucose and fat, fasting blood sugars, serum triglycerides and SGPT were estimated weekly, for one month, in 12 children with viral hepatitis. This was done to see if there was evidence of increased substrate availability for alanine synthesis, and whether any relationship existed between increased substrate availability and SGPT. The results show that there is a relationship between triglycerides and SGPT. This suggests that the hypertriglyceridaemia, by providing substrate to meet the energy requirements of muscle, spares glucose for alanine synthesis to maintain the alanine content of muscle. The paper suggests the existence of a glucose-alanine-pyruvate-glucose cycle in viral hepatitis and also reviews evidence for increased ammonia uptake by muscle, in liver diseases associated with raised SGPT, to support the concept of amino acid synthesis.

Carbohydrate metabolism in liver disease

Most forms of liver disease are probably associated with impaired gluconeogenesis, although hypoglycaemia is rarely an important clinical feature. Blood concentrations of the gluconeogenic precursors, lactate, glycerol and alanine are elevated although, in certain situations, alanine levels may be decreased. Abnormal glucose tolerance is present in both acute and chronic liver disease, but is usually not of clinical importance. The mechanism of glucose intolerance remains uncertain, with diminished hepatocyte mass, portal diversion and insulin resistance the major postulates. Indeed, the importance of the liver in disposing of an oral glucose load, is still questioned. Both hyperinsulinism and hypoinsulinism are found in liver disease, with hyperinsulinism common in cirrhosis and acute viral hepatitis. This is accompanied by insulin resistance. The hyperinsulinism is probably due to defective hepatic clearance of insulin rather that to over-production. The cause of the insulin resistance remains to be established. Glucagon levels are raised and may contribute to this resistance. Growth hormone levels are also increased but are associated with low somatomedin levels and the role of growth hormone in insulin resistance is therefore questionable. Future developments include use of new animal models, studies of biopsy specimens and studies of hepatic hormone receptors.

Effects of exogenous hormones and glucose on plasma levels and hepatic metabolism of amino acids in the fetus and in the newborn rat

The present study examines the role of insulin, glucagon and cortisol in the regulation of gluconeogenesis from lactate and amino acids in fetal and newborn rats. Injection of glucagon in the full-term fetal rat caused a rise in glucose (and insulin) and a fall in blood levels of most individual amino acids, stimulated hepatic accumulation of 14C-amino isobutyric acid and 14C-cycloleucine and increased the conversion of 14C lactate, alanine and serine to glucose in vivo and in vitro (liver slices). Such changes were equivalent to the changes seen in 4 h old newborn rats. When glucagon was administered at birth, little difference was observed between control and treated animals in plasma amino acids and a smaller increment in conversion of 14C substrate to glucose occurred. By contrast, insulin injection at birth caused hypoglycemia, suppression of levels of certain amino acids and inhibition of conversion of 14C substrates into glucose. Glucose injection at birth caused elevated glycemia and plasma insulin and suppression of most amino acid levels and of conversion of 14C substrate into glucose. Cortisol injection at birth caused a marked, generalized by hyperaminoacidemia, a stimulation of glucagon secretion and of conversion of 14C substrates into glucose. These observations support the thesis that glucagon plays a major role in the induction of hepatic gluconeogenesis and that insulin acts as an antagonist hormone.