Resting energy expenditure in diabetic and nondiabetic patients with liver cirrhosis: relation with insulin sensitivity and effect of liver transplantation and immunosuppressive therapy

Insulin Resistance across the Spectrum of Nonalcoholic Fatty Liver Disease

Insulin resistance (IR) is defined as a lower-than-expected response to insulin action from target tissues, leading to the development of type 2 diabetes through the impairment of both glucose and lipid metabolism. IR is a common condition in subjects with nonalcoholic fatty liver disease (NAFLD) and is considered one of the main factors involved in the pathogenesis of nonalcoholic steatohepatitis (NASH) and in the progression of liver disease. The liver, the adipose tissue and the skeletal muscle are major contributors for the development and worsening of IR. In this review, we discuss the sites and mechanisms of insulin action and the IR-related impairment along the spectrum of NAFLD, from simple steatosis to progressive NASH and cirrhosis.

Cirrhosis and insulin resistance: current knowledge, pathophysiological mechanisms, complications and potential treatments

End-stage chronic liver diseases are often associated with insulin resistance (IR) and diabetes mellitus (DM). Indeed, to quantify insulin sensitivity the euglycemic clamp technique was utilized, allowing the following to be stated: in small groups of patients, an IR in almost all cirrhotic patients can be observed, compared with a control group. Additionally, it has been demonstrated that IR in cirrhosis is linked to a decreased peripheral (muscle) glucose uptake rather than an increased liver glucose production. The homoeostasis model of IR (HOMA-IR) technique, devised only later, was then exploited to assess this same phenomenon in a larger sample population. The research established that even in patients with preserved liver function, cirrhosis is associated with significant alterations in glucose homoeostasis levels. The purpose of the present paper is to present the current research around the affiliation of cirrhosis and IR, discuss potential mechanisms explaining the association between cirrhosis and IR (i.e. endocrine perturbation, liver inflammation, altered muscle mass and composition, altered gut microbiota and permeability), complications that can arise as well as treatment options, through a critical review of the literature surrounding this subject. This research will also be investigating the beneficial impact, if there is any, of identifying and curing IR in patients with cirrhosis.

Influence of diabetes mellitus on energy metabolism in patients with alcoholic liver cirrhosis

OBJECTIVE

The objective was to explore the characteristics of energy metabolism in patients with alcoholic liver cirrhosis (ALC) and diabetes mellitus (DM).

METHODS

Thirty-four male patients with ALC and DM, 30 male patients with ALC without DM and 10 male healthy controls (HC) were enrolled in this study. Resting energy expenditure (REE), respiratory quotient (RQ) were measured by indirect calorimetry. Data were analyzed using the Student's t-test, Mann-Whitney U-test and χ2 tests between two groups. Logistic regression analysis was used to analyze the risk factors for hypermetabolism.

RESULTS

Measured REE was significantly higher in patients with ALC and DM (1740 ± 338 kcal/d) than in patients with ALC (1400 ± 304 kcal/d, P < 0.01). Fasting blood glucose was an independent factor predicting hypermetabolism in all of the patients with ALC (P = 0.005). RQ was lower in patients with ALC and DM (0.80 ± 0.06) than in patients with ALC (0.83 ± 0.05, P = 0.027) and the HC (0.86 ± 0.03, P = 0.001). In the ALC and DM group, measured REE as percentage of predicted REE by Harris-Benedict formula was higher in patients with HbA1c ≥ 7.5% than in those with HbA1c < 7.5% (126.36 ± 15.19% vs. 109.48 ± 23.89%, P = 0.040).

CONCLUSION

REE was increased and RQ was significantly decreased in patients with ALC and DM. These changes were associated with poor glucose control. HbA1c less than 7.5% may reduce the risk of hypermetabolism.

Prevalence of diabetes in liver cirrhosis: A systematic review and meta-analysis

An association between diabetes mellitus (DM) and liver cirrhosis is well-known, but estimates of the prevalence of DM in patients with liver cirrhosis vary widely. A systematic review was undertaken to determine the prevalence of DM in adult patients with liver cirrhosis. The Medline, EMBASE, and Cochrane Library databases were searched for peer-reviewed studies published in English (1979-2017) that investigated the prevalence of diabetes in adult patients with cirrhosis. Pooled estimates of prevalence of DM were determined for all eligible patients and according to aetiology and severity of liver disease. Fifty-eight studies satisfied criteria for inclusion, with 9705 patients included in the pooled prevalence analysis. The overall prevalence of DM was 31%. The prevalence of DM was highest in patients with nonalcoholic fatty liver disease (56%), cryptogenic (51%), hepatitis C (32%), or alcoholic (27%) cirrhosis. For assessing prevalence of DM as a function of severity of liver disease, evaluable data were available only for hepatitis C and hepatitis B cirrhosis. DM may be more prevalent in cirrhosis than previously thought. This has implications for prognosis and treatment in these patients.

Fasting Whole-Body Energy Homeostasis and Hepatic Energy Metabolism in Nondiabetic Humans with Fatty Liver

Background

Fatty liver is believed to be sustained by a higher than normal adipose-derived NEFA flux to the liver. Also, hepatic energy metabolism may be a rate-limiting step of intrahepatic fat (IHF) accumulation.

Aims

To assess whole-body energy metabolism and hepatic high-energy phosphates (HEPs) in individuals with fatty liver.

Methods

We studied 22 individuals with fatty liver and 22 control individuals matched for anthropometric features by means of (1) hepatic ¹H-magnetic resonance spectroscopy (MRS) to measure the IHF content, (2) hepatic ³¹P-MRS to assess the relative content of HEPs (phosphomonoesters, phosphodiesters, inorganic phosphorus, and ATP), and (3) indirect calorimetry to assess whole-body resting energy expenditure and substrate oxidation.

Results

Patients with newly diagnosed fatty liver and controls were not different for anthropometric parameters. Based on HOMA2%-S, individuals with fatty liver were more insulin resistant than controls. Resting energy expenditure and the pattern of substrate oxidation were not different between groups. Relative content of HEPs was not different between groups; in particular, the Pi/γ-ATP ratio, the most important signals in terms of monitoring energy homeostasis, was not different even if it was associated with indirect calorimetry-derived parameters of oxidative substrate disposal.

Conclusions

These data demonstrate that fasting whole-body energy metabolism and the relative content of HEPs in nondiabetic patients with fatty liver are not different than those in controls when they are matched for anthropometric features.

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.

Resting and Exercise Energy Metabolism After Liver Transplantation for Nonalcoholic Steatohepatitis

Background

Nonalcoholic steatohepatitis (NASH) is a leading indication for liver transplantation (LT). We hypothesized that weight gain after LT may be exacerbated by reduced metabolic rates due to the LT procedure, particularly during exercise. We aimed to compare resting and exercise energy expenditure between patients transplanted for NASH and nontransplant nonalcoholic fatty liver disease (NAFLD) subjects.

Methods

NASH LT recipients (>1-year post, n = 14) and NAFLD controls (n = 13) underwent analysis of body composition, resting energy expenditure (REE), and exercise energy expenditure (VO_2max), the latter using a ramped-Bruce protocol assessed by expired gas analysis and peak heart rate.

Results

Participants were mean 61.5 ± 7.9 years, 48.1% men, and 66.7% white. Baseline comorbidities were similar between groups. Among men, mean REE adjusted for total (17.7 vs 18.8, P = 0.87) and lean body mass (23.5 vs 26.9, P = 0.26), as well as VO₂ (20.1 vs 23.9, P = 0.29), was lower in NASH LT recipients compared with NAFLD controls, respectively, although not statistically significant. However, female NASH LT recipients had significantly lower mean REE than NAFLD controls when adjusted for total (14.2 vs 18.9, P = 0.01) and lean body mass (19.3 vs 26.5, P = 0.002), as well as significantly lower VO_2max (14.4 vs 20.6, P = 0.017).

Conclusions

NASH LT recipients, particularly women, have lower REE and exercise energy expenditure compared with nontransplant NAFLD patients. More aggressive diet and exercise programs for post-LT NASH recipients to account for reduced resting and exercise metabolic rates may attenuate weight gain in this vulnerable population.

Factors related to increased resting energy expenditure in men with liver cirrhosis

OBJECTIVE

Hypermetabolism in cirrhosis is associated with a high risk of complications and mortality. However, studies about underlying mechanisms are usually focussed on isolated potential determinants and specific etiologies, with contradictory results. We aimed at investigating differences in nutrition, metabolic hormones, and hepatic function between hypermetabolic and nonhypermetabolic men with cirrhosis of the liver.

PATIENTS AND METHODS

We prospectively enrolled 48 male cirrhotic inpatients. We evaluated their resting energy expenditure (REE) and substrate utilization by indirect calorimetry, body composition by dual-energy X-ray absorptiometry, liver function, and levels of major hormones involved in energy metabolism by serum sample tests. Patients with ascites, specific metabolic disturbances, and hepatocellular carcinoma were excluded.

RESULTS

REE and REE adjusted per fat-free mass (FFM) were significantly increased in cirrhotic patients. Overall, 58.3% of cirrhotic patients were classified as hypermetabolic. Groups did not differ significantly in age, etiology of cirrhosis, liver function, presence of ascites, use of diuretics, β-blockers, or presence of transjugular intrahepatic portosystemic shunts. Hypermetabolic cirrhotic patients had lower weight, BMI (P<0.05), nonprotein respiratory quotient (P<0.01), leptin (P<0.05), and leptin adjusted per fat mass (FM) (P<0.05), but higher FFM% (P<0.05) and insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR)] (P<0.05). Only HOMA-IR, leptin/FM, and FFM% were independently related to the presence of hypermetabolism.

CONCLUSION

Hypermetabolic cirrhotic men are characterized by lower weight, higher FFM%, insulin resistance, and lower leptin/FM when compared with nonhypermetabolic men. HOMA-IR, FFM%, and leptin/FM were independently associated with hypermetabolism, and may serve as easily detectable markers of this condition in daily clinical practice.

Resting energy expenditure, body composition, and dietary intake: a longitudinal study before and after liver transplantation

BACKGROUND

The loss of hepatic innervations after liver transplantation (LTx) might affect the energy metabolism of the patients. The aim of this study was to assess the resting energy expenditure (REE), body composition, and dietary intake before and during the first year after the LTx.

METHODS

The REE was measured by indirect calorimetry. Nutritional status was assessed by anthropometric assessment, bioimpedance, handgrip strength, and dietary intake (before and 30, 90, 180, 270, and 370 days after LTx). Social, clinical, and nutritional variables were assessed as being potentially associated with REE or hypermetabolism and hypometabolism after LTx.

RESULTS

Seventeen patients were included. REE was elevated at 30 days and reduced at the end of the study (P<0.05). Hypermetabolism/hypometabolism were low but present at the end of the study (11.8% of each). Increases in body weight and fat mass were observed (P<0.05). Handgrip strength and phase angle improved after LTx (P<0.05). Energy balance was positive at all times after LTx, and an increase in fat intake occurred (P<0.05). After multivariate analyses (P<0.05), the REE before transplantation and triceps skinfold thickness were positively associated and the cumulative dose of prednisone was negatively associated with REE after LTx. The presence of hypermetabolism was significantly associated with the presence of hypermetabolism before LTx and the cumulative dose of prednisone. Percentage of fat intake and fat mass before LTx was associated with hypometabolism.

CONCLUSION

Some potential modifiable factors are related to resting energy metabolism in patients undergoing LTx. Adequate and individualized nutritional guidance should be started before LTx.

Hyper- and hypometabolism are not related to nutritional status of patients on the waiting list for liver transplantation

BACKGROUND & AIMS

Metabolic disorders and malnutrition are well known conditions reported in patients with liver disease (LD), but the relationship between them are underexplored. So, the aim of this study was to assess the resting energy expenditure (REE) of these patients, identifying the prevalence of hyper- and hypometabolism. In addition, to evaluate whether malnutrition and clinical variables were associated with REE and metabolic disorders.

METHODS

The REE was measured by indirect calorimetry and predicted by the Harris and Benedict formula (REEHB). Nutritional status was assessed by different methods. The etiology, severity and complications of LD were also evaluated.

RESULTS

A total of 81 patients were assessed. The measured REE was 1587.5 ± 426.6 kcal. The REE was overestimated by the REEHB (REE:REEHB <0.8) in 7.4% and underestimated (REE:REEHB >1.2) in 24.7% of the patients. The REE was lower in malnourished patients (p < 0.05). However, hyper- and hypometabolism were not associated with nutritional status (p > 0.05). The REE and hypermetabolism were not associated with LD, but hypometabolic patients had a higher prevalence of Child C, and had higher values for MELD, INR and total bilirubin (p < 0.05). After multiple regression analyses, the REE was significantly associated (p < 0.05) with intracellular body water, arm muscle area and serum glucose. Serum glucose was only significantly associated (p < 0.05) with hypermetabolism, and INR with hypometabolism.

CONCLUSION

Changes in resting metabolism are present but not universal. The hypermetabolism was associated with extrahepatic factors, and hypometabolism with the severity of LD. Under these conditions in the clinical setting, calculated energy requirements using the HB formula should be adjusted.

No effect of adjunctive, repeated dose intranasal insulin treatment on body metabolism in patients with schizophrenia

OBJECTIVE

This study examined the effect of adjunctive intranasal insulin therapy on body metabolism in patients with schizophrenia.

METHOD

Each subject had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder and had been on stable dose of antipsychotic agent for at least one month. In an 8-week randomized, double-blind, placebo-controlled study, subjects received either intranasal insulin (40 IU 4 times per day) or placebo. The whole body dual-energy X-ray absorptiometry (DXA) was used to assess body composition. Lipid particles were assessed using nuclear magnetic resonance (NMR) spectroscopy. All assessments were conducted at baseline, and repeated at week 8.

RESULTS

A total number of 39 subjects completed the study (18 in the insulin group, 21 in the placebo group). There were no significant differences between the two groups in week 8 changes for body weight, body mass index, waist circumference, as well as various measures of lipid particles (p's>0.100). The DXA assessment showed no significant differences between the two groups in week 8 changes for fat mass, lean mass or total mass (p's>0.100).

CONCLUSION

In the present study, adjunctive therapy of intranasal insulin did not seem to improve body metabolism in patients with schizophrenia. The implications for future studies were discussed.

Study of adiponectin in chronic liver disease and cholestasis

PURPOSE

Adiponectin is an adipocytokine suggested to have a hepatoprotective effect. To date, little information is available in the literature regarding changes in serum adiponectin levels in cirrhosis and cholestasis and the associated metabolic disturbances. In order to elucidate the role of adiponectin in chronic liver disease our aim was to determine serum adiponectin in patients with different grades of cirrhosis and cholestasis and to correlate it with markers of liver injury, inflammation and cholestasis. We also aimed to correlate adiponectin with markers of metabolic syndrome such as body mass index and insulin resistance.

METHODS

Forty patients with cirrhosis; 30 patients with cirrhosis and cholestasis; and 20 matched controls were studied. They were subjected to clinical assessment, laboratory investigations: serum bilirubin, ALT, AST, alkaline phosphatase, GGT, albumin, C-reactive protein, prothrombin activity, fasting blood sugar, insulin. HOMA index was calculated. Abdominal ultrasonography and upper GI endoscopy were performed.

RESULTS

Adiponectin was elevated in patients with cirrhosis and cirrhosis/cholestasis and was significantly higher in Child A and B. Adiponectin showed correlation with liver cell injury, marker of inflammation, synthetic liver function and markers of cholestasis. Adiponectin did not correlate with complications of cirrhosis as ascites and esophageal varices nor did it correlate with BMI or HOMA.

CONCLUSIONS

Adiponectin is elevated in cirrhosis and shows correlation with degree of hepatocellular injury and cholestasis. Finally, adiponectin levels in cirrhosis do not correlate with parameters of body composition or metabolism but exclusively with reduced liver function.

Plasma bile acids are not associated with energy metabolism in humans

Bile acids (BA) have recently been shown to increase energy expenditure in mice, but this concept has not been tested in humans. Therefore, we investigated the relationship between plasma BA levels and energy expenditure in humans. Type 2 diabetic (T2DM) patients (n = 12) and gender, age and BMI-matched healthy controls (n = 12) were studied before and after 8 weeks of treatment with a BA sequestrant. In addition, patients with liver cirrhosis (n = 46) were investigated, since these display elevated plasma BA together with increased energy expenditure. This group was compared to gender-, age- and BMI-matched healthy controls (n = 20). Fasting plasma levels of total BA and individual BA species as well as resting energy expenditure were determined. In response to treatment with the BA sequestrant, plasma deoxycholic acid (DCA) levels decreased in controls (-60%, p < 0.05) and T2DM (-32%, p < 0.05), while chenodeoxycholic acid (CDCA) decreased in controls only (-33%, p < 0.05). Energy expenditure did not differ between T2DM and controls at baseline and, in contrast to plasma BA levels, was unaffected by treatment with the BA sequestrant. Total BA as well as individual BA species did not correlate with energy expenditure at any time throughout the study. Patients with cirrhosis displayed on average an increase in energy expenditure of 18% compared to values predicted by the Harris-Benedict equation, and plasma levels of total BA (up to 12-fold) and individual BA (up to 20-fold) were increased over a wide range. However, neither total nor individual plasma BA levels correlated with energy expenditure. In addition, energy expenditure was identical in patients with a cholestatic versus a non-cholestatic origin of liver disease while plasma total BA levels differed four-fold between the groups. In conclusion, in the various (patho)physiological conditions studied, plasma BA levels were not associated with changes in energy expenditure. Therefore, our data do not support an important role of circulating BA in the control of human energy metabolism.

Posttransplant metabolic syndrome: an epidemic waiting to happen

With increasing survival after orthotopic liver transplantation (OLT), metabolic syndrome and its individual components, including diabetes mellitus, hypertension, dyslipidemia, and obesity, are increasingly being identified and contributing to cardiovascular complications and late morbidity and mortality. The prevalence of posttransplant metabolic syndrome (PTMS) and its individual components has been found to be higher post-OLT versus a comparable population without OLT. The development of nonalcoholic fatty liver disease (NAFLD) after liver transplantation for non-NAFLD cirrhosis is also being increasingly recognized. A number of predictors have been identified as potential risk factors related to these complications. The pretransplant risk factors include immunosuppression, a higher age at transplant, male gender, a history of smoking, the pretransplant body mass index, pre-OLT diabetes, the etiology of the underlying liver disease that resulted in OLT (hepatitis C, cryptogenic cirrhosis, or alcohol), an increased donor body mass index, and marital status. Although there is an increased risk of cardiovascular events, rejection, and infection among patients with PTMS, the overall impact on long-term survival and mortality remains inconclusive. Strategies to reduce the development of metabolic syndrome after transplantation should include lifestyle modifications involving alterations in diet and increased physical activity. Additional measures that may be potentially beneficial include the use of lipid-lowering agents, the optimal control of blood glucose, and the use of tacrolimus instead of cyclosporine.

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.

ESPEN Guidelines on Parenteral Nutrition: hepatology

Parenteral nutrition (PN) offers the possibility to increase or to ensure nutrient intake in patients, in whom sufficient nutrition by oral or enteral alone is insufficient or impossible. Complementary to the ESPEN guideline on enteral nutrition of liver disease (LD) patients the present guideline is intended to give evidence-based recommendations for the use of PN in LD. For this purpose three paradigm conditions of LD were chosen: alcoholic steatohepatitis (ASH), liver cirrhosis and acute liver failure. The guideline was developed by an interdisciplinary expert group in accordance with officially accepted standards and is based on all relevant publications since 1985. The guideline was presented on the ESPEN website and visitors' criticism and suggestions were welcome and included in the final revision. PN improves nutritional state and liver function in malnourished patients with ASH. PN is safe and improves mental state in patients with cirrhosis and severe HE. Perioperative (including liver transplantation) PN is safe and reduces the rate of complications. In acute liver failure PN is a safe second-line option to adequately feed patients in whom enteral nutrition is insufficient or impossible.

Familial influences and obesity-associated metabolic risk factors contribute to the variation in resting energy expenditure: the Kiel Obesity Prevention Study

BACKGROUND

A low metabolic rate may be inherited and predispose to obesity, whereas a higher metabolic rate in obesity may be acquired by obesity-associated cardiometabolic risk.

OBJECTIVE

We aimed to explain the interindividual variation in resting energy expenditure (REE) by assessing 1) the association between REE and body composition, thyroid hormones, and obesity-related cardiometabolic risk factors, and 2) the familial (genetic and environmental) contribution to REE.

DESIGN

REE and metabolic risk factors (ie, blood pressure and plasma insulin, glucose, and C-reactive protein concentrations) were assessed in 149 two- or three-generation families, including at least one overweight or obese member. Heritability of REE, respiratory quotient (RQ), thyroid hormones [thyrotropin (TSH), free triiodothyronine (FT3) and free thyroxine (FT4)], and body composition (fat-free mass and fat mass) were estimated by using variance components-based quantitative genetic models.

RESULTS

REE adjusted for body composition, sex, and age (REEadj) significantly correlated with systolic and diastolic blood pressure, plasma insulin and glucose concentrations, and the homeostasis model assessment (HOMA) (r = 0.14-0.31, P < 0.05). Thyroid hormones had a modest influence on REE variance only. Heritability was 0.30 +/- 0.07 for REEadj and 0.29 +/- 0.08 for REE after additional adjustment for thyroid hormones and metabolic risk. Furthermore, heritability was estimated to be 0.22 +/- 0.08 for RQ, 0.37 +/- 0.08 for TSH, 0.68 +/- 0.06 for FT4, and 0.69 +/- 0.05 for FT3 (all significantly larger than zero).

CONCLUSIONS

Obesity-related cardiometabolic risk factors contribute to interindividual variation in REE, with hypertension and insulin resistance being associated with a higher REE. REE was moderately heritable, independent of body composition, sex, age, thyroid function, and cardiometabolic risk.

Higher total ghrelin levels are associated with higher insulin-mediated glucose disposal in non-diabetic maintenance hemodialysis patients

BACKGROUND & AIMS

Insulin resistance is common in maintenance hemodialysis (MHD) and it can contribute to exceedingly high mortality in MHD patients. Ghrelin is a gastric hormone whose total plasma concentration is increased in MHD. Emerging data suggest a potential role of ghrelin to modulate intermediate metabolism but the metabolic impact of ghrelin in chronic kidney disease is unknown. The current study aimed at assessing the potential relationships between ghrelin and insulin sensitivity in MHD.

METHODS

Total (T-Ghr) and acylated (A-Ghr) ghrelin as well as insulin-mediated glucose disposal [(M): hyperinsulinemic-euglycemic clamp] were measured in non-diabetic non-obese ambulatory MHD patients (n=19, 16 Males). C-reactive protein (CRP) was also measured since systemic inflammation is associated with insulin resistance in non-renal patients and inflammation is negatively modulated by ghrelin in experimental models.

RESULTS

Compared to control subjects (C: n=9, 7 Males), MHD had similar body fat and resting energy expenditure but reduced M and increased CRP (P<0.05). MHD also had higher T-(P<0.05) but not A-Ghr. M was associated positively with T-Ghr and negatively with CRP in linear regression analysis in MHD. In stepwise multiple regression analysis only T-Ghr remained associated with M (P<0.05) in a model including A-Ghr and CRP.

CONCLUSIONS

Insulin sensitivity is associated negatively with systemic inflammation and positively with total plasma ghrelin in non-diabetic MHD patients. Based on available knowledge these results suggest a potential novel role of ghrelin in preserving insulin sensitivity in MHD.

Higher fasting serum insulin is associated with increased resting energy expenditure in nondiabetic schizophrenia patients

BACKGROUND

Insulin has emerged as an important determinant of food intake, energy expenditure, and weight control. This study examined the relationship between fasting serum insulin level and resting energy expenditure (REE) in a cross-sectional sample of nondiabetic schizophrenia patients.

METHODS

Subjects were recruited from an urban community mental health clinic. Each subject underwent a series of anthropometric measures and an indirect calorimetry measure. A fasting blood sample was taken for plasma glucose, serum insulin, and lipid profile.

RESULTS

Seventy-one subjects (54 male, 17 female) were included in the study. There was a significant positive relationship between REE and fasting serum insulin level (r = .39, p = .001). Stepwise multiple regression analysis was performed with various characteristics such as age, race, antipsychotic agent used, fat-free mass, BMI, waist circumference, waist-hip ratio, physical activity level, and fasting serum insulin as candidate predictors for REE. Only fat-free mass and insulin were able to enter into the regression model, which indicates that higher fat-free mass and higher fasting serum insulin level predict increased REE.

CONCLUSIONS

A higher fasting serum insulin level is associated with an increased REE, which may prevent further weight gain in nondiabetic patients with schizophrenia.

Effect of orthotopic liver transplantation (OLT) on branched-chain amino acid requirement

Little is known regarding the impact of liver transplantation on amino acid requirements in children. Since plasma levels of the branched-chain amino acids (BCAA) are decreased in the presence of normal levels of the aromatic amino acids after liver transplantation, normalization of hepatic function may not fully correct changes in BCAA metabolism that occur in the pretransplant period. The goal of the present study was to determine total BCAA requirements of children following liver transplantation. The requirement of total BCAA was determined using indicator amino acid oxidation (IAAO) in five clinically stable children (5.7 +/- 3.5 y, mean +/- SD) 1-8 y post liver transplantation. Children received in random order 6 graded intakes of total BCAA. Individual BCAA in the test diet were provided in the same proportions as present in egg protein to minimize the potential interactive effects of individual BCAA on assessment of requirement. Total BCAA requirement was determined by measuring the oxidation of L-[1-13C] phenylalanine to 13CO2 [F13CO2 in micromol/kg/h], after a primed, continuous infusion of the tracer and using a two-phase linear regression crossover regression analysis. The estimated average requirement and the upper limit of the 95% CI for total BCAA in children who have undergone liver transplantation were 172 and 206 mg/kg/d), respectively. Total BCAA requirement in children who have undergone orthotopic liver transplantation (OLT) remain increased in the post-liver transplant period when compared with healthy school aged children, but is decreased when compared with children with mild-moderate chronic cholestatic (MCC) liver disease.

Resting energy expenditure, cardiovascular risk factors and insulin resistance in obese patients

OBJECTIVE

The aim of our study was to determine whether energy expenditure modified by increasing body mass over the wide range of body mass index (BMI) was related to insulin resistance, cardiovascular risk factors and dietary intakes.

SUBJECTS AND METHODS

A population of 87 obese non-diabetic outpatients was analyzed prospectively. Indirect calorimetry, tetrapolar electrical bioimpedance, serial assessment of nutritional intake using written 3-day food records and biochemical analyses were performed.

RESULTS

The mean age was 45.1 +/- 16.7 years and the mean BMI was 35.2 +/- 5.2. Indirect calorimetry showed a resting metabolic rate (RMR) of 1,732.2 +/- 406.6 kcal/day and oxygen consumption of 266.2 +/- 63.3 ml/min. RMR corrected by fat-free mass was 36.8 +/- 14.1 kcal/day/kg. Serial assessment of nutritional intake using written 3-day food records showed a calorie intake of 1,660 +/- 551.7 cal/day, a carbohydrate intake of 168.63 +/- 76.6 g/day, a fat intake of 72.1 +/- 26.42 g/day and a protein intake of 81.1 +/- 23.3 g/day. Insulin, HOMA, systolic blood pressure, diastolic blood pressure, waist circumference, fat mass, waist-to-hip ratio were higher in the third BMI tertile than in the first and second tertiles. No differences were detected in calorie intake, carbohydrate intake, fat intake, protein intake, drinking and alcoholic habit among BMI tertiles. RMR was similar in the different tertiles and the corrected RMR by fat-free mass was higher in first tertile than in the second and third tertiles (44.2 +/- 20.7 vs. 34.5 +/- 9.1 vs. 33.1 +/- 8.5 kcal/kg/day; p < 0.05). In multivariate analysis with a dependent variable (RMR), the fat-free mass remained in the model (F = 7.8; p < 0.05), with an increase of 10.1 (95% CI 3.6-17.5) kcal/day with each 1 kg of fat-free mass adjusted by age and sex.

CONCLUSION

Resting energy expenditure in obese patients is not related to the BMI, insulin resistance and dietary intake. RMR is related to fat-free mass in a multivariant model.

Resting metabolic rate in severely obese diabetic and nondiabetic subjects

OBJECTIVES

To compare the resting metabolic rate (RMR) between diabetic and nondiabetic obese subjects and to develop a predictive equation of RMR for these subjects.

RESEARCH METHODS AND PROCEDURES

Obese adults (1088; mean age = 44.9 +/- 12.7 years) with BMI > or = 35 kg/m2 (mean BMI = 46.4 +/- 8.4 kg/m2) were recruited. One hundred forty-two subjects (61 men, 81 women) were diagnosed with type 2 diabetes (DM), giving the prevalence of DM in this clinic population as 13.7%. RMR was measured by indirect calorimetry, and several multivariate linear regression models were performed using age, gender, weight, height, BMI, fat mass, fat mass percentage, and fat-free mass as independent variables.

RESULTS

The severely obese patients with DM had consistently higher RMR after adjustment for all other variables. The best predictive equation for the severely obese was RMR = 71.767 - 2.337 x age + 257.293 x gender (women = 0 and men = 1) + 9.996 x weight (in kilograms) + 4.132 x height (in centimeters) + 145.959 x DM (nondiabetic = 0 and diabetic = 1). The age, weight, and height-adjusted least square means of RMR between diabetic and nondiabetic groups were significantly different in both genders.

DISCUSSION

Severely obese patients with type 2 diabetes had higher RMR than those without diabetes. The RMR of severely obese subjects was best predicted by an equation using age, gender, weight, height, and DM as variables.

Postabsorptive and insulin-stimulated energy and protein metabolism in patients with myotonic dystrophy type 1

BACKGROUND

Exaggerated insulin resistance was described as the major metabolic abnormality in myotonic dystrophy type 1 (DM1). We reported recently that the severity of the impairment in insulin-stimulated glucose metabolism in these patients was overestimated.

OBJECTIVE

The aim was to dissect out insulin action with respect to whole-body energy homeostasis and glucose, protein, and lipid metabolism in patients with DM1 to assess the relevance of insulin resistance to the heterogeneous clinical manifestations of this syndrome.

DESIGN

Ten nondiabetic patients with DM1 and 10 matched healthy control subjects were studied by means of 1) dual-energy X-ray absorptiometry; 2) a euglycemic-hyperinsulinemic clamp (40 mU. m(-2). min(-1)) combined with a primed, continuous infusion of [6,6-d(2)]glucose and [1-(13)C]leucine; 3) indirect calorimetry; and 4) localized (1)H magnetic resonance spectroscopy of the calf muscles.

RESULTS

Patients with DM1 had less lean body mass, greater fat mass, and greater intramyocellular lipid contents than did healthy control subjects. Energy expenditure and glucose and lipid metabolism did not differ significantly between the groups. In contrast, markers of proteolysis were higher in DM1 patients in the postabsorptive and insulin-stimulated conditions and were associated with lower plasma concentrations of insulin-like growth factor 1 (P < 0.03) and higher plasma concentrations of tumor necrosis factor alpha receptor 2 (P = 0.04).

CONCLUSIONS

Despite greater body fat and intramyocellular lipid contents in patients with DM1, insulin sensitivity was not significantly different between patients and control subjects. In contrast, the loss of lean body mass in patients with DM1 was associated with abnormal postabsorptive and insulin-stimulated regulation of protein breakdown. Lower plasma insulin-like growth factor 1 concentrations and higher tumor necrosis factor system activity might be involved in the muscle wasting of DM1.

Assessment of insulin sensitivity based on a fasting blood sample in men with liver cirrhosis before and after liver transplantation

BACKGROUND

Insulin resistance is a key factor in the pathogenesis of hepatogenous diabetes and influences the prognosis of chronic liver diseases. In vivo assessment of insulin resistance in humans is expensive; therefore, surrogate indices based on a fasting plasma glucose and insulin concentrations (HOMA-IS, QUICKI) were proposed. This study aimed to test whether these simple indices are reliable measures of insulin sensitivity in patients with liver cirrhosis before and after liver transplantation (LTx).

METHODS

HOMA-IS and QUICKI were compared with insulin sensitivity as assessed with the gold standard technique (insulin clamp) in 20 patients with liver cirrhosis, in 36 patients after LTx, and in 25 matched healthy subjects (predominantly men). To test whether these indices may be applied also in prospective studies, 10 patients with liver cirrhosis were studied longitudinally before and 2 years after LTx.

RESULTS

Both HOMA-IS and QUICKI were associated with insulin sensitivity in patients with liver cirrhosis (r=0.63, P=0.005 and r=0.60, P=0.009) and in LTx patients (r=0.41, P=0.02 and r=0.46, P=0.05). Both were able to detect the improvement of insulin sensitivity after LTx in the patients studied prospectively.

CONCLUSIONS

HOMA-IS and QUICKI are simple reliable tools to assess insulin sensitivity in clinical and epidemiologic investigations of chronic liver disease before and after LTx.