Hepatic lipid metabolism in severe human obesity

Deleterious liver-adipose crosstalk in obesity: Hydroethanolic extract of Lampaya medicinalis Phil. (Verbenaceae) counteracts fatty acid-induced fibrotic marker expression in human hepatocytes

Elevated circulating fatty acids in obesity may induce hepatic steatosis, leading to liver inflammation, fibrosis and nonalcoholic fatty liver disease (NAFLD). On the other hand, impaired communication between hepatocytes and adipose tissue (AT) in obesity influences adipose lipolysis and fibrosis, negatively affecting metabolic function. Infusions of Lampaya medicinalis Phil. (Verbenaceae) are used in Chilean folk medicine to treat inflammatory diseases. Hydroethanolic extract of lampaya (HEL) contains flavonoids that may explain its anti-inflammatory effect, but it is unknown whether HEL modulates fibrogenic processes in hepatocytes. We studied lipolysis and expression of fibrosis markers after exposure of visceral AT explants from subjects with obesity to HepG2-secreted factors. In addition, we evaluated the effect of HEL on palmitic acid (PA, C16:0) and oleic acid (OA; C18:1)-induced fibrotic marker expression in HepG2 hepatocytes. Results: Exposure to HepG2-secreted factors increased visceral AT lipolysis and expression of CTGF and collagen I. Exposure to OA/PA elevated collagen I, CTGF, fibronectin, α-smooth muscle actin, MMP-2 and MMP-9 expression in HepG2 cells, and these effects were prevented by HEL co-treatment. Conclusion: HEL effect counteracting OA/PA-induced fibrotic marker expression in HepG2 hepatocytes may represent a preventive approach against hepatic fibrosis and deleterious liver-adipose crosstalk in obesity.

Fatty Liver Disease-Alcoholic and Non-Alcoholic: Similar but Different

In alcohol-induced liver disease (ALD) and in non-alcoholic fatty liver disease (NAFLD), there are abnormal accumulations of fat in the liver. This phenomenon may be related to excessive alcohol consumption, as well as the combination of alcohol consumption and medications. There is an evolution from simple steatosis to steatohepatitis, fibrosis and cirrhosis leading to hepatocellular carcinoma (HCC). Hepatic pathology is very similar regarding non-alcoholic fatty liver disease (NAFLD) and ALD. Initially, there is lipid accumulation in parenchyma and progression to lobular inflammation. The morphological changes in the liver mitochondria, perivenular and perisinusoidal fibrosis, and hepatocellular ballooning, apoptosis and necrosis and accumulation of fibrosis may lead to the development of cirrhosis and HCC. Medical history of ethanol consumption, laboratory markers of chronic ethanol intake, AST/ALT ratio on the one hand and features of the metabolic syndrome on the other hand, may help in estimating the contribution of alcohol intake and the metabolic syndrome, respectively, to liver steatosis.

Platelets in Non-alcoholic Fatty Liver Disease

Non alcoholic steatohepatitis (NASH) is the inflammatory reaction of the liver to excessive accumulation of lipids in the hepatocytes. NASH can progress to cirrhosis and hepatocellular carcinoma (HCC). Fatty liver is the hepatic manifestation of metabolic syndrome. A subclinical inflammatory state is present in patients with metabolic alterations like insulin resistance, type-2 diabetes, obesity, hyperlipidemia, and hypertension. Platelets participate in immune cells recruitment and cytokines-induced liver damage. It is hypothesized that lipid toxicity cause accumulation of platelets in the liver, platelet adhesion and activation, which primes the immunoinflammatory reaction and activation of stellate cells. Recent data suggest that antiplatelet drugs may interrupt this cascade and prevent/improve NASH. They may also improve some metabolic alterations. The pathophysiology of inflammatory liver disease and the implication of platelets are discussed in details.

Improvement in insulin resistance and estimated hepatic steatosis and fibrosis after endoscopic sleeve gastroplasty

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the United States and is closely associated with obesity and insulin resistance (IR). Weight loss is the best treatment for NAFLD. Endoscopic sleeve gastroplasty (ESG) is a promising endoscopic procedure for treatment of obesity. Our aim is to evaluate the change in IR and estimated hepatic steatosis and fibrosis after ESG.

METHODS

One hundred eighteen patients with obesity and NAFLD underwent ESG and were followed for 2 years. Weight loss was evaluated as % total body weight loss. IR was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR). The previously validated hepatic steatosis index and NAFLD fibrosis score were used to estimate hepatic steatosis and risk of fibrosis.

RESULTS

Patients' mean body mass index was 40 ± 7 kg/m² at baseline. Eighty-four percent of patients completed 2 years of follow-up. At 2 years, the mean total body weight loss was 15.5% (95% confidence interval, 13.3%-17.8%). Patients' HOMA-IR improved significantly from 6.7 ± 11 to 3.0 ± 1.6 after only 1 week from ESG (P = .019) with continued improvement up to 2 years (P = .03). Patients' hepatic steatosis index score improved significantly, decreasing by 4 points per year (P for trend, <.001). Patients' NAFLD fibrosis score improved significantly, decreasing by 0.3 point per year (P for trend, .034). Twenty-four patients (20%) improved their risk of hepatic fibrosis from F3-F4 or indeterminate to F0-F2, whereas only 1 patient (1%) experienced an increase in the estimated risk of fibrosis (P = .02).

CONCLUSIONS

Our results suggest a significant and sustained improvement in estimated hepatic steatosis and fibrosis after ESG in patients with NAFLD. Importantly, we showed an early and weight-independent improvement in insulin resistance, which lasted for 2 years after the procedure.

A pilot study of metabolic fitness effects of weight-supported walking in women with obesity

Background

This is an exploratory pilot study of novel technology enabling people with mobility disability to walk with minimal effort, in the “sedentary range”. The study’s premise is that impairment of the leading physical activity of daily living, walking, is a major contributor to a dysmetabolic state driving many prevalent “civilization diseases” associated with insulin resistance.

Methods

We explore within-subject changes in standard oral glucose tolerance (OGT) tests including metabotropic molecules after 22 twice-weekly, 30-minute bouts of weight-supported light-moderate physical activity in 16 non-diabetic obese, otherwise healthy, reproductive-age, volunteer women walking on an “anti-gravity” lower-body positive pressure (LBPP) treadmill.

Results

Subjects had reference base-line fasting plasma glucose and triglycerides (TG) but 2-hr OGT insulin levels of 467 ± 276 pmol • liter^-1 (mean± S.D.) indicating nascent insulin resistance, compared to post-study 308 ± 179 (p = 0.002). Fasting TG decreased from 0.80 ± 0.30 mmol • liter^-1 to 0.71 ± 0.25 (p = 0.03). Concomitantly plasma total ghrelin decreased from 69.6 ± 41.6 pmol • liter^-1 to 56.0 ± 41.3 (p = 0.008). There were no statistically significant changes in body weight or any correlations between weight change and cardiometabolic markers. However, there were robust positive correlations between changes among different classes of peptides including C-reactive protein–Interleukin 6, leptin–adiponectin, β-endorphin–oxytocin and orexin A (r ² = 0.48–0.88).

Conclusion

We conclude that brief, low-dose physical activity, walking on an anti-gravity LBPP treadmill may improve cardiometabolic risk, exhibiting favorable changes in neuro-regulatory peptides without weight loss in people with problems walking.

Nonalcoholic Fatty Liver Disease in Latinos

Nonalcoholic fatty liver disease (NAFLD) is a serious public health concern that affects almost one third of the US population. The prevalence of NAFLD varies among ethnic/racial groups, with the Latin American population being affected disproportionately. The severity of NAFLD also may be greater in the Latino population. The increased prevalence and severity of NAFLD in Latino Americans likely is related to the interplay between issues such as genetic factors, access to health care, or the prevalence of chronic diseases such as metabolic syndrome or diabetes. In this review, we summarize the current literature on the prevalence and risk factors of NAFLD that are seen to be more common in the Latino population in the United States. Finally, we discuss available treatment options, medical and surgical, that are available for NAFLD and how they affect the Latino population. Health care providers need to address modifiable risk factors that impact the natural history as well as treatment outcomes for NAFLD among Latinos. Additional efforts are needed to improve awareness and health care utilization for Latinos.

Effect of carnitine-orotate complex on glucose metabolism and fatty liver: a double-blind, placebo-controlled study

BACKGROUND AND AIM

Effective medicines have not been introduced for insulin resistance-related fatty liver. The efficacy and safety of treatment between a combination of metformin and carnitine-orotate complex and metformin alone in a 12-week, double-blind, randomized, placebo-controlled study on drug-naïve patients with impaired glucose metabolism and fatty liver were compared.

METHODS

Fifty-two patients with fasting glucose 100-240 mg/dL or glycosylated hemoglobin (HbA1c) ≥ 6.0% and alanine aminotransferase (ALT) 40-250 IU/L were randomized to receive metformin (250 mg t.i.d.), or metformin (250 mg t.i.d.) and carnitine-orotate complex (300 mg t.i.d.) for 12 weeks (n = 26 per group). The primary end-point was a change from baseline ALT level. Secondary end-points were changes in fasting glucose, HbA1c, aspartate aminotransferase levels, mitochondrial DNA (mtDNA) copy number in the peripheral blood, and urinary output of 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress.

RESULTS

The combined treatment reduced ALT level significantly more than metformin alone (-51.5 ± 33.2 IU/L vs -16.7 ± 31.3 IU/L, P = 0.001). The HbA1c levels also decreased significantly in both groups but there was no significant difference between them (-0.9% ± 1.0% vs -0.7% ± 0.9%). Treatment with the complex decreased the urinary 8-hydroxy-2'-deoxyguanosine level and increased mtDNA copy number significantly compared with metformin alone (both P < 0.05). No severe adverse events were observed.

CONCLUSION

A 12-week treatment with metformin and carnitine-orotate complex significantly improved liver function enzyme levels. This was associated with changes in oxidative stress and mtDNA copy number compared with metformin alone in patients with impaired glucose metabolism and fatty liver (clinical trial number: KCT0000193).

Nonalcoholic fatty liver disease and serum lipoproteins: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

While nonalcoholic fatty liver disease (NAFLD) is associated with the metabolic syndrome, it is not known if NAFLD plays an independent role in the atherogenic dyslipidemia phenotype.

METHODS AND RESULTS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based prospective cohort study of adults free of clinical cardiovascular disease at enrollment. We tested for a relationship between NAFLD, defined as a liver/spleen (L/S) attenuation ratio of <1 on a non-contrast cardiac CT scan, and multiple measures of fasting serum lipoprotein size, cholesterol and particle concentrations. NAFLD was present in 569 (17%) of 3362 participants. After adjustment for multiple metabolic risk factors, adiposity and measures of insulin resistance (HOMA-IR), NAFLD was independently associated with higher fasting serum triglycerides and lower serum HDL-C. Despite a lack of association with LDL-C, NAFLD was associated with higher LDL particle concentration and lower LDL particle size. Modeling the L/S ratio as a continuous variable, a severity dependent association was observed between atherogenic lipoprotein abnormalities and NAFLD.

CONCLUSION

In a large, multi-ethnic, gender balanced cohort, CT-diagnosed NAFLD was associated with the atherogenic dyslipidemia phenotype in a dose dependent fashion. These relationships persisted after adjustment for several metabolic risk factors and HOMA-IR, suggesting a possible independent pathophysiologic role between NAFLD and dyslipidemia.

Non-alcoholic steatohepatitis mimicking liver metastasis in obesity surgery

We describe a case of non-alcoholic steatohepatitis detected incidentally during laparoscopic Roux-en-Y gastric bypass (LRYGBP). A 51-year-old female patient was scheduled for elective LRYGBP. Her weight was 144.9 kg and her body mass index was 56. Liver function tests showed mild elevation in alanine transaminase. The patient had a history of hypertension and insulin resistance and had no history of alcohol abuse. During LRYGBP, the gross appearance of the liver resembled metastatic lesions but the histology confirmed the diagnosis of non-alcoholic steatohepatitis. The appearance of the liver necessitated taking biopsies, which showed Von Meyenburg complexes and moderate macrovesicular steatosis. This patient made an uneventful recovery and was discharged 2 days postoperatively.

Evidence-based review on the effect of normal dietary consumption of fructose on blood lipids and body weight of overweight and obese individuals

Although some investigators have hypothesized that ingestion of fructose from foods and beverages is responsible for the development of hyperlipidemia or obesity, a recent evidence-based review demonstrated that there was no relationship between the consumption of fructose in a normal dietary manner and the development of hyperlipidemia or increased weight in normal weight individuals. Because overweight and obese individuals may exhibit metabolic abnormalities such as insulin resistance, impaired glucose tolerance, hyperlipedemia, and/or alterations in gut hormones involved in appetite regulation, the findings of fructose studies performed in normal weight subjects may not be particularly relevant for overweight or obese subjects. A systematic assessment of the strength and quality of the studies and their relevance for overweight or obese humans ingesting fructose in a normal dietary manner has not been performed. The purpose of this review was to critically evaluate the existing database for a causal relationship between the ingestion of fructose in a normal, dietary manner and the development of hyperlipidemia or increased body weight in overweight or obese humans, using an evidence-based approach. The results of the analysis indicate that there is no evidence which shows that the consumption of fructose at normal levels of intake causes biologically relevant changes in triglycerides (TG) or body weight in overweight or obese individuals.

Eating fast leads to insulin resistance: findings in middle-aged Japanese men and women

OBJECTIVE

To examine relationships between speed of eating and insulin resistance.

METHODS

Cross-sectional study of 2704 male (mean age and BMI: 48.2 y and 23.3 kg/m(2)) and 761 female (46.3 y and 21.8 kg/m(2)) non-diabetic Japanese civil servants, 75% clerical, and 25% manual laborers, using a two-part questionnaire on life-style factors and diet history with self-assessment of categorical speed of eating and energy intake over a 1-month period. We measured BMI, blood glucose and insulin concentrations and calculated insulin resistance using the homeostasis model assessment of insulin resistance: (HOMA-IR).

RESULTS

BMI correlated with eating rate in both sexes, and with daily energy intake in men. Multiple regression analysis of log HOMA-IR by categorical speed of eating, adjusting for age, energy intake and lifestyle factors showed a statistically significant gradual increase in HOMA-IR with increases in relative eating rate in men (p<0.001, for trend) and in women (p<0.01). Adjusting for BMI, this positive relationship appeared only in men (p=0.03).

CONCLUSIONS

Our results suggest that eating fast is independently associated with insulin resistance in middle-aged Japanese men and women.

Predictors of nonalcoholic steatohepatitis in patients undergoing bariatric surgery: when is liver biopsy indicated?

BACKGROUND

Nonalcoholic fatty liver disease is a frequent accompaniment of morbid obesity. A component of nonalcoholic fatty liver disease, steatosis, can, on occasion, lead to nonalcoholic steatohepatitis (NASH). Bariatric surgery has been shown to alter the course of this disease. Intraoperative liver biopsies might identify patients with NASH for more careful follow-up. We sought to determine noninvasive preoperative indicators of NASH.

METHODS

The patients scheduled for bariatric surgery underwent a preoperative assessment. The study variables included age, gender, race, body mass index, diabetes mellitus, hypertension, and the results of serum liver function tests and triglyceride, cholesterol, iron, and prealbumin measurements. Univariate and multivariate analyses were performed to identify significant variables associated with NASH as determined by subsequent core liver biopsies taken during open Roux-en-Y gastric bypass.

RESULTS

A total of 139 patients were entered into the study. NASH or NASH-associated fibrosis was found in 57 patients (41%). On univariate analyses, male gender (odds ratio [OR] 2.46, P = .06), diabetes mellitus (OR 2.60, P = .009), elevated serum triglyceride levels (OR 1.003, P = .02), elevated gamma glutamyl transferase (OR 1.015, P = .01), and decreased prealbumin (OR 0.94, P = .04) correlated with the presence of NASH. On multivariate analysis, only increased triglycerides (OR 1.004, P = .04) and decreased prealbumin (OR 0.88, P = .005) correlated with the presence of NASH.

CONCLUSION

NASH is a frequent accompaniment of morbid obesity in patients undergoing bariatric surgery. Univariate and multivariate analyses of the clinical parameters studied could not identify strong predictors of biopsy-verified NASH. Therefore, intraoperative biopsy remains instrumental in diagnosing NASH and providing information for additional follow-up.

FK-614, a selective peroxisome proliferator-activated receptor gamma agonist, improves peripheral glucose utilization while decreasing hepatic insulin extraction in alloxan-induced diabetic dogs

This is the first report of the effects of a nonthiazolidinedione activator of peroxisome proliferator-activated receptor (PPAR) gamma, that is, FK-614 (a benzimidazole derivative), on glucose metabolism in vivo. To investigate the effect of FK-614 on peripheral and hepatic insulin action, we performed hyperinsulinemic-hyperglycemic clamp studies combined with the triple-catheter technique and a double-tracer approach in alloxan-diabetic dogs with (n=5) or without (n=6) treatment with FK-614 (0.32 mg/kg per day orally for 10 days). Throughout the experiment, insulin was infused intraportally at 18 pmol/kg per minute and hyperglycemia (approximately 11 mmol/L) was maintained by a peripheral glucose infusion. After a 45-minute basal period (period I), a portal infusion of glucose labeled with [U-14C]-glucose, was administered for 120 minutes (period II) to measure hepatic glucose uptake. This was followed by 90-minute recovery (period III). FK-614 marginally improved peripheral insulin sensitivity, did not affect hepatic glucose uptake, and surprisingly increased tracer-determined hepatic glucose production (19.0+/-5.0 vs 10.6+/-1.7 mumol/kg per minute, P<.001). Hepatic insulin extraction was decreased by FK-614 (47.8%+/-1.6% vs 55.9%+/-3.4%, P<.01), which led to greater peripheral insulin levels and glucose utilization. FK-614 treatment also decreased the daily insulin requirements (regular insulin, 0.18+/-0.01 vs 0.32+/-0.01 U/kg per day; and NPH insulin, 0.53+/-0.02 vs 0.89+/-0.04 U/kg per day; P<.001) to maintain fasting plasma glucose at approximately 10 mmol/L for 7 days before the experiments. We conclude that FK-614 treatment, at the dose used, improves peripheral glucose utilization because of an improvement in peripheral insulin sensitivity and a decrease in insulin clearance, but impairs hepatic insulin action in alloxan-induced diabetic dogs. The reason for the effects of FK-614 on hepatic glucose and insulin metabolism is unclear but they are both consistent with reports of hepatic steatosis by PPARgamma activation when unopposed by concomitant activation of PPARalpha.

In nondiabetic, human immunodeficiency virus-infected patients with lipodystrophy, hepatic insulin extraction and posthepatic insulin clearance rate are decreased in proportion to insulin resistance

In healthy, nondiabetic individuals with insulin resistance, fasting insulin is inversely correlated to the posthepatic insulin clearance rate (MCRi) and the hepatic insulin extraction (HEXi). We investigated whether similar early mechanisms to facilitate glucose homeostasis exist in nondiabetic, human immunodeficiency virus (HIV)-infected patients with and without lipodystrophy. We studied 18 HIV-infected patients with lipodystrophy (LIPO) on antiretroviral therapy and 25 HIV-infected patients without lipodystrophy (controls) of whom 18 were on antiretroviral therapy and 7 were not. Posthepatic insulin clearance rate was estimated as the ratio of posthepatic insulin appearance rate to steady-state plasma insulin concentration during a euglycemic hyperinsulinemic clamp (40 mU.m-2 .min-1). Posthepatic insulin appearance rate during the clamp was calculated, taking into account the remnant endogenous insulin secretion, which was estimated by deconvolution of C-peptide concentrations. Hepatic extraction of insulin was calculated as 1 minus the ratio of fasting posthepatic insulin delivery rate to fasting endogenous insulin secretion rate. Compared with controls, LIPO displayed increased fasting insulin (130%, P < .001), impaired insulin sensitivity index (M value, -29%, P < .001), and reduced MCRi (-17%, P < .01). Hepatic extraction of insulin was similar between groups (LIPO, 55%; controls, 57%; P > .8). In LIPO, HEXi and MCRi correlated inversely with fasting insulin (r = -0.56, P < .02 and r = -0.68, P < .002) and positively with M value (r = 0.63, P < .01 and r = 0.65, P < .004). In controls, MCRi correlated inversely with fasting insulin (r = -0.47, P < .02) and positively with M value (r = 0.57, P < .004); however, the correlations between HEXi and these parameters were insignificant (P > .1). Our data suggest that HEXi and MCRi are decreased in proportion to the degree of insulin resistance in nondiabetic HIV-infected patients with lipodystrophy.

Angiotensin II type 1 receptor blocker ameliorates overproduction and accumulation of triglyceride in the liver of Zucker fatty rats

The effects of angiotensin II type 1 receptor blocker (ARB) on triglyceride (TG) metabolism associated with insulin resistance were explored in Zucker fatty (ZF) rats. Olmesartan medoxomil, a newly developed ARB, was given as a 0.01% drinking solution ad libitum to ZF and Zucker lean (ZL) rats for 4 wk. Olmesartan lowered blood pressure in both strains to the same extent. ZF rats had a markedly low insulin sensitivity index (SI) and glucose effectiveness (SG), together with significantly increased glucose levels. Olmesartan treatment substantially elevated both SI and SG. The ZF rats were hyperlipidemic, with plasma TG levels sixfold higher than those of the ZL rats. Olmesartan remarkably decreased the plasma free fatty acid level in the ZF rats, but it did not exert a significant effect on the plasma TG level. The TG secretion rate assessed by the Triton WR-1339 technique was almost six times higher in the ZF than in the ZL rats, and olmesartan treatment suppressed this TG overproduction by one-half. The TG content in the liver was ten times higher in the ZF than in the ZL rats, and olmesartan halved this high hepatic TG content without affecting the cholesterol content. The fatty liver developed in the ZF rats was ameliorated by olmesartan treatment. Olmesartan treatment had no significant effects on TG metabolism or insulin sensitivity in the ZL rats. Taken in sum, ARB improves the overproduction and accumulation of TG in the liver associated with insulin resistance, and it does so through mechanisms independent of its hypotensive action.

Effects of surgical treatment of the metabolic syndrome on liver fibrosis and cirrhosis

BACKGROUND

Both weight loss and gastrointestinal surgery for obesity can cause liver disease, making their role in the treatment of obesity-related liver disease controversial.

METHODS

Six hundred eighty-nine severely obese women (n=551) and men (n=138), BMI=47+/-9 kg.m(-2) (mean+/-SD), without known liver disease, underwent biliopancreatic diversion (BPD) with liver biopsy. Fourteen patients (2%) had cryptogenic cirrhosis, 11 of whom underwent multiple repeat biopsies. After 38+/-18 kg weight loss, 104 of the 689 patients underwent routine second biopsies during reoperations 41+/-25 months after BPD. All biopsy specimens were graded for steatosis, fibrosis, and inflammation by a blinded hepatopathologist.

RESULTS

All 689 patients lost weight accompanied by improvements in the metabolic syndrome. Among the 104 patients who underwent reoperation, severe fibrosis (grade 3-5) decreased in 28 whereas mild fibrosis (grade 1-2) appeared in 42. Increased fibrosis was related to low-normal serum albumin, uncontrolled diarrhea, low intake of alcohol, and menopausal status. Fibrosis and inflammation decreased over time (P<.01). The 11 patients with cirrhosis exhibited decreased fibrosis from a mean grade 5 to grade 3, as well as reduced inflammation, Mallory bodies, and glycogenated nuclei. Seven patients had disappearance and 2 regression of nodules and fibrous bridging.

CONCLUSIONS

The metabolic syndrome of obesity is a determinant of liver fibrosis and cirrhosis, treatable by substantial weight loss after malabsorptive surgery.

Visceral fat and liver fat are independent predictors of metabolic risk factors in men

We examined the independent associations among abdominal adipose tissue (AT), liver fat, cardiorespiratory fitness (CRF), and lipid variables in 161 Caucasian men who had a wide variation in adiposity. We measured AT and liver fat by computed tomography and CRF by a maximal exercise test on a treadmill. Visceral AT remained a significant (P <or= 0.05) predictor of plasma triglycerides (TG), high-density-lipoprotein cholesterol (HDL-C), and total cholesterol (TC)/HDL-C ratio (TC/HDL-C) after statistical control for abdominal subcutaneous AT, CRF, and alcohol consumption. Abdominal subcutaneous AT was not a significant (P >or= 0.05) correlate of any lipid variable after control for visceral AT and CRF. Furthermore, subdivision of subcutaneous AT into deep and superficial depots did not alter these observations. Visceral AT was the strongest correlate of liver fat and remained so after control for abdominal subcutaneous AT, CRF, and alcohol consumption (r = -0.34, P < 0.01). In contrast, abdominal subcutaneous AT and CRF were not significant (P > 0.10) correlates of liver fat after control for visceral AT. Visceral AT remained a significant (P < 0.01) correlate of TG, HDL-C, and TC/HDL-C independent of liver fat. However, liver fat was also a significant correlate (P <or= 0.05) of fasting glucose and TG independent of visceral AT. These observations reinforce the importance of visceral obesity in the pathogenesis of dyslipidemia in men, and they suggest that visceral AT and liver fat carry independent health risk.

Effects of Radiation on Fatty Liver and Metabolic Coronary Risk Factors among Atomic Bomb Survivors in Nagasaki

In order to clarify the basic mechanism(s) linking radiation exposure and coronary heart disease (CHD), we here collected ultrasonographic data on fatty liver and measured levels of metabolic CHD risk factors from November 1990 through October 1992 in 1,517 Nagasaki atomic bomb survivors (575 men and 942 women). Using a cross-sectional study design, we examined the effects of radiation dose on fatty liver and CHD risk factors by means of a multiple logistic regression model. Fatty liver was related to the metabolic CHD risk factors associated with insulin resistance syndrome: obesity, hypertension, hypercholesterolemia, low high density lipoprotein (HDL)-cholesterol, hypertriglyceridemia, and abnormal glucose metabolism. Radiation dose was positively related to fatty liver, low HDL-cholesterol, and hypertriglyceridemia, whereas it had no effects on obesity, hypertension, hypercholesterolemia, or abnormal glucose metabolism. The present results suggested that radiation dose was related to 1) fatty liver, which clustered the metabolic CHD risk factors associated with insulin resistance syndrome and 2) atherogenic lipid profiles. It is suggested that these associations are involved in the basic mechanism(s) linking radiation exposure and CHD.

Activities of overt and latent diacylglycerol acyltransferases (DGATs I and II) in liver microsomes of ob/ob mice

The effect of the ob/ob mutation on microsomal overt and latent acyl CoA:diacylglycerol acyl transferase activities (DGATs I and II) in liver microsomes of mice was investigated. Overt and latent hepatic DGAT activities for 16-week-old lean Ob/? mice were 0.42+/-0.14 and 1.57+/-0.04 micromol/mg/min, respectively. For ob/ob mice DGAT I and II activities were 1.17+/-0.28 and 3.09+/-0.78 micromol/mg/min, respectively. The hepatic triacylglycerol (TAG) concentration of 16-week-old mice was increased three-fold in ob/ob mice relative to those in lean controls. The data suggest that the increased rate of hepatic TAG secretion and intracellular accumulation in ob/ob mice is accompanied by parallel increases in the activities of both DGATs.

[Studies on the risk factors for fenofibrate-induced elevation of liver function tests]

We evaluated risk factors for elevation of liver function test values after administration of fenofibrate to 45 hyperlipidemic patients. The effects of 23 factors of physical examinations, clinical laboratory test values, and the background of the patients on the elevation of liver function test values were analyzed by the logistic regression method. The increase of the values of liver function tests was found to be correlated with BMI, serum levels of triglycerides, and ALP before therapy, especially sex, serum gamma-GTP level before therapy and reduced serum triglyceride levels. These results suggest that caution must be exercised to avoid liver dysfunction in patients treated with fenofibrate.

Morbidity of severe obesity

Although obesity is an easy diagnosis to make, its etiologies, pathophysiology, and symptomatology are extraordinarily complex. Progress in surgical technique and anesthesiological management has substantially improved the safety of performing operations on the severely obese in the last 20 years. These improvements have occurred more or less empirically, without a full understanding of etiology or pathophysiology, although this has advanced concomitantly with improvements in practice. This review has attempted to provide a framework to facilitate progress in the neglected areas of patient selection and choice of operation, in an effort to improve long-term outcome. Despite the disparate etiologies of obesity and its diverse comorbidities and complications, there are unifying interdependent pathogenetic mechanisms of great relevance to the practice of antiobesity surgery. The rate of eating, whether driven by HPA dysfunction, ambient stress, or related hereditary susceptibility factors including the increased energy demands of an expanded body fat mass, participates in a cycle that results in disordered satiety (see Fig. 3). This leads to substrate overload, causing extensive metabolic abnormalities such as atherogenesis, insulin resistance, thrombogenesis, and carcinogenesis. This interpretation of the pathophysiology of obesity ironically accords with the original meaning of the word obesity: "to overeat." The ultimate solution to the problem of obesity--preventing it--will not be forthcoming until the food industry is forced to lower production and change its marketing strategies, as the liquor and tobacco industries in the United States were compelled to do. This cannot occur until the large and fast-growing populations of industrialized nations become educated in the personal implications of the energy principle. Regardless of whether school curricula are modified to prioritize health education, the larger problems of cultural and economic change remain for the groups most susceptible to obesity. In this context, antiobesity surgery will continue to thrive, especially in the absence of effective alternatives.

Improvements in cardiovascular risk profile with large-volume liposuction: a pilot study

In this study, the authors investigated the physiologic effects of the altered body composition that results from surgical removal of large amounts of subcutaneous adipose tissue. Fourteen women with body mass indexes of greater than > 27 kg/m2 underwent measurements of fasting plasma insulin, triglycerides, cholesterol, body composition by dual-energy x-ray absorptiometry (DXA), resting energy expenditure, and blood pressure before and after undergoing large-volume ultrasound-assisted liposuction. There were no significant intraoperative complications. Body weight had decreased by 5.1 kg (p < 0.0001) by 6 weeks after liposuction, with an additional 1.3-kg weight loss (p < 0.05) observed between 6 weeks and 4 months after surgery, for a total weight loss of 6.5 kg (p < 0.00006). Body mass index decreased from (mean +/- SEM) 28.8 +/- 2.3 to 26.8 +/- 1.5 kg/m2 (p < 0.0001). This change in body weight was primarily the result of decreases in body fat mass: as assessed by DXA, lean body mass did not change (43.8 +/- 3.1 kg to 43.4 +/- 3.6 kg, p = 0.80), whereas DXA total body fat mass decreased from 35.7 +/- 6.3 to 30.1 +/- 6.5 kg (p < 0.0001). There were significant decreases in fasting plasma insulin levels (14.9 +/- 6.5 mIU/ml before liposuction versus 7.2 +/- 3.2 mIU/ml 4 months after liposuction, p < 0.007), and systolic blood pressure (132.1 +/- 7.2 versus 120.5 +/- 7.8 mmHg, p < 0.0002). Total cholesterol, high-density lipoprotein cholesterol, plasma triglycerides, and resting energy expenditure values were not significantly altered after liposuction. In conclusion, over a 4-month period, large-volume liposuction decreased weight, body fat mass, systolic blood pressure, and fasting insulin levels without detrimental effects on lean body mass, bone mass, resting energy expenditure, or lipid profiles. Should these improvements be maintained over time, liposuction may prove to be a valuable tool for reducing the comorbid conditions associated with obesity.

Correlation between fatty liver and coronary risk factors: a population study of elderly men and women in Nagasaki, Japan

The relation between fatty liver, detected by ultrasonography as a marker of visceral fat accumulation, and coronary risk factors was studied in 810 elderly men and 1,273 elderly women in Nagasaki, Japan from 1990 to 1992. The prevalence of fatty liver was 3.3% in the male and 3.8% in the female non-obese participants (BMI, body mass index < 26.0 kg/m2) and 21.6% in the male and 18.8% in the female obese participants (26.0 kg/m2 < or = BMI). Fatty liver was significantly (p < 0.01) related to hypercholesterolemia and hypertriglyceridemia in the men and to hypertension, hypercholesterolemia, low-HDL cholesterol, hypertriglyceridemia and diabetes mellitus or impaired glucose tolerance (DM+IGT) in the women independent of age, obesity, smoking and drinking. Non-obesity with fatty liver, rather than obesity with or without fatty liver, had the highest odds ratio for hypertension and low-HDL cholesterol in the men and for hypercholesterolemia, low-HDL cholesterol, hypertriglyceridemia and DM+IGT in the women. The prevalence of fatty liver is the same in elderly men and women, and fatty liver is an independent correlate of coronary risk factors in the elderly.

Metabolic correlates of eating behavior in severe obesity

BACKGROUND

The benefit of spreading energy intake over many small meals ('nibbling') rather than few large ones ('gorging') for control of blood glucose, serum lipids and body fat accretion has been known for 60 y, but the mechanisms are poorly understood. Men exhibit more of a gorging eating pattern than women and are also more prone to the metabolic complications of obesity, as are women with a 'male', central distribution of adipose tissue. We have shown correlations between central fat distribution, and other components of the metabolic 'Syndrome X' and fatty infiltration of the liver. Here we study relationships between eating rate and fat distribution and test the hypothesis that gorging might be associated with fatty liver.

SUBJECTS AND METHODS

In 30 non-alcoholic, non-diabetic, severely obese women (body mass index, BMI=47+/-1 kg/m(2); mean+/-s.e.m.) with a mean age of 36+/-1 y and 16 men (BMI: 52+/-3) age 38+/-2 y, who were candidates for anti-obesity surgery, we measured eating rate using an eating monitor, and fat distribution by the waist-hip circumference ratio (WHR). In addition in the 17 women and 11 men who had surgery, serum lipids were analyzed and routine liver biopsies were evaluated for steatosis by a pathologist blinded to the conditions of the study.

RESULTS

Men ate significantly faster than women (188+/-28 vs 123+/-9 g/min; P<0.01), and had more liver fat (score: 2.7+/-03 vs 1.5+/-0.3; P<0.01), with no statistically significant sex differences in s-cholesterol or s-triglycerides. Eating rate correlated with WHR (r=0.46; P<0.01, n=46), liver fat (r=0.55; P<0.01), and s-triglycerides (r=0.42; P<0.05) adjusting for sex. Liver fat correlated with WHR (r=0.50; P<0.05), s-triglycerides (r=0.70; P<0.01) and s-cholesterol (r=0.50; P<0.05), while there were no significant correlations with BMI or body weight. In multivariate analysis eating rate (32%), meal size (8%) and WHR (6%) contributed 46% of the variance in liver fat.

CONCLUSION

We showed increased eating rates in severely obese men and women with central fat distribution. Furthermore, increased eating rates were associated with fatty liver and elevated serum lipids. Eating rate in severely obese women and men may be a determinant of the metabolic syndrome.

Subcutaneous lipectomy causes a metabolic syndrome in hamsters

The insulin resistance syndrome X is related to excess intra-abdominal adipose tissue. With lipectomy of >50% of subcutaneous adipose tissue (SQAT) in nonhibernating, adult female Syrian hamsters on high-fat (HF; 50 calorie%) diet and measurements of oral glucose tolerance, oral [(14)C]oleic acid disposal, serum triglycerides, serum leptin, liver fat, perirenal (PR) adipose tissue cellularity, and body composition, we studied the role of SQAT. Sham-operated (S) animals on HF or low-fat (LF; 12.5 calorie%) diets served as controls. After 3 mo there was no visible regrowth of SQAT but HF diet led to similar levels of body weight and body fat in lipectomized and sham-operated animals. Lipectomized (L) animals had more intra-abdominal fat as a percentage of total body fat, higher insulinemic index, a strong trend toward increased liver fat content, and markedly elevated serum triglycerides compared with S-HF and S-LF. Liver and PR adipose tissue uptake of fatty acid were similar in L-HF and S-HF but reduced vs. S-LF, and were inversely correlated with liver fat content and insulin sums during the oral glucose tolerance test. In summary, lipectomy of SQAT led to compensatory fat accumulation implying regulation of total body fat mass. In conjunction with HF diet these lipectomized hamsters developed a metabolic syndrome with significant hypertriglyceridemia, relative increase in intra-abdominal fat, and insulin resistance. We propose that SQAT, via disposal and storage of excess ingested energy, acts as a metabolic sink and protects against the metabolic syndrome of obesity.

Effects of a low-fat, high-carbohydrate diet on VLDL-triglyceride assembly, production, and clearance

Low-fat, high-carbohydrate (LF/HC) diets commonly elevate plasma triglyceride (TG) concentrations, but the kinetic mechanisms responsible for this effect remain uncertain. Subjects with low TG (normolipidemic [NL]) and those with moderately elevated TG (hypertriglyceridemic [HTG]) were studied on both a control and an LF/HC diet. We measured VLDL particle and TG transport rates, plasma nonesterified fatty acid (NEFA) flux, and sources of fatty acids used for the assembly of VLDL-TG. The LF/HC diet resulted in a 60% elevation in TG, a 37% reduction in VLDL-TG clearance, and an 18% reduction in whole-body fat oxidation, but no significant change in VLDL-apo B or VLDL-TG secretion rates. Significant elevations in fasting apo B-48 concentrations were observed on the LF/HC in HTG subjects. In both groups, fasting de novo lipogenesis was low regardless of diet. The NEFA pool contributed the great majority of fatty acids to VLDL-TG in NL subjects on both diets, whereas in HTG subjects, the contribution of NEFA was somewhat lower overall and was reduced further in individuals on the LF/HC diet. Between 13% and 29% of VLDL-TG fatty acids remained unaccounted for by the sum of de novo lipogenesis and plasma NEFA input in HTG subjects. We conclude that (a) whole-food LF/HC diets reduce VLDL-TG clearance and do not increase VLDL-TG secretion or de novo lipogenesis; (b) sources of fatty acids for assembly of VLDL-TG differ between HTG and NL subjects and are further affected by diet composition; (c) the presence of chylomicron remnants in the fasting state on LF/HC diets may contribute to elevated TG levels by competing for VLDL-TG lipolysis and by providing a source of fatty acids for hepatic VLDL-TG synthesis; and (d) the assembly, production, and clearance of elevated plasma VLDL-TG in response to LF/HC diets therefore differ from those for elevated TG on higher-fat diets.

Serum lipid responses to a eucaloric high-complex carbohydrate diet in different obesity phenotypes

OBJECTIVE

To determine whether the eucaloric substitution of complex carbohydrates for dietary fat (15% of daily energy intake) affects plasma lipid concentrations differently in upper-body obese, lower-body obese, and nonobese women.

DESIGN

We studied 23 premenopausal women before and after dietary intervention.

MATERIAL AND METHODS

After the 23 subjects achieved weight maintenance on their usual high-fat diet (43% fat, 37% carbohydrates, and 20% protein), the 7 upper-body obese, 8 lower-body obese, and 8 nonobese women consumed a eucaloric, high-complex carbohydrate, low-fat diet (27% fat, 53% carbohydrates, and 20% protein) for 4 weeks in the Clinical Research Center. Before and after the high-carbohydrate diet, body composition and plasma lipids and apoproteins were measured.

RESULTS

After the high-carbohydrate diet, fasting plasma triglyceride concentrations increased (from 1.50 +/- 0.14 mmol/L to 2.00 +/- 0.25 mmol/L; P = 0.04) in upper-body obese women but were not significantly changed in lower-body obese (1.37 +/- 0.28 mmol/L and 0.96 +/- 0.12 mmol/L) or nonobese (0.70 +/- 0.08 mmol/L and 0.73 +/- 0.08 mmol/L) women. The hypertriglyceridemia was present before the evening meal and throughout the night in upper-body obese women. Plasma cholesterol and high-density lipoprotein cholesterol were not significantly affected by the change in diet. No changes in plasma apoprotein concentrations or body composition occurred that could account for the dietary-induced hypertriglyceridemia in the women with upper-body obesity.

CONCLUSION

The hypertriglyceridemic response to a high-complex carbohydrate, low-fat diet may be obesity phenotype specific. These findings suggest that further studies of this phenomenon should be focused on this obesity phenotype and further emphasize the importance of assessing body fat distribution when treatment outcomes are determined.

Body fat topography as an independent predictor of fatty liver

Abdominal (truncal) fat distribution reflected by an elevated waist to hip ratio (WHR) predicts metabolic abnormalities such as diabetes and dyslipidemia as well as hypertension and stroke, all of which are associated with obesity. The pathogenesis is not known, although elevated splanchnic serum free fatty acid levels and reduced hepatic insulin clearance have been implicated. WHR and body fat (BF) by 40K-counting and 3H2O were measured before liver biopsy during antiobesity surgery in 68 severely obese women (body mass index [BMI], 48.9 +/- 1.1 SEM) and 15 men (BMI, 49.0 +/- 3.1) without histories of liver disease, diabetes, or hepatotoxic exposure. Biopsies were graded for fat content semiquantitatively (0 to 4+) by the hepatologist who was blinded to the patients' clinical characteristics. All 15 men had fatty infiltration (score, 2.5 +/- 0.3 v 1.4 +/- 0.1 in women; P < .001). The correlation between WHR and liver fat was .44 (P < .0005), while BF (-.16), weight (.15), or BMI (.04) did not correlate significantly with steatosis (all NS). As expected, percentage body fat (BF%) was greater in women than in men (40.3 +/- 0.8 kg v 33.9 +/- 2.0, P < .007), and accordingly liver fat was inversely related to BF% (r = -.32, P < .002). Steatosis was significantly greater in 14 men (2.5 +/- 0.3) than in 20 women (1.7 +/- 0.3, P < .04) matched for BF%. In multiple regression analysis R2 = .49, P < .0001), WHR and sex accounted for the variance in liver fat content without any further contribution from weight, BMI, BF, or BF%.(ABSTRACT TRUNCATED AT 250 WORDS)

Disproportional changes in the rates of biliary bile acid, phospholipid and cholesterol secretion in the SHR/N-corpulent rat

Lean and obese male rats of the SHR/N-cp strain were fed a plain chow diet ad libitum and studied at 11-13 weeks of age. Compared to their lean littermates the obese animals manifested 2-4-fold higher plasma levels of cholesterol, triacylglycerol and glucose. In the obese rats, the mass of the liver was increased more than 70% and there was a significant increase in the total hepatic content of free cholesterol (42%), cholesteryl ester (2.9-fold) and triacylglycerol (7.4-fold). Despite the difference in liver mass, the rate of bile secretion was the same in the lean and obese groups. Bile acid pool size was 2.5-fold greater in the obese rats and this was reflected in an enhanced rate of biliary bile acid secretion. In contrast, there was little or no increase in biliary cholesterol and phospholipid secretion, so the relative content (molar percentage) of these lipids decreased significantly in the obese animals. In both the lean and obese groups, biliary cholesterol and phospholipid output could be enhanced by the intravenous administration of taurocholate, but the proportion of both lipids in the bile of the obese rats remained significantly lower than in their lean controls. Thus the difference in biliary lipid composition between the two groups is not due to a limited availability of cholesterol and phospholipid for transport into bile, but more likely reflects a difference in the reaction whereby the secretion of cholesterol and phospholipid is coupled to the transport of bile acids across the canalicular membrane.

Changes in lipid metabolism in diet-induced obesity

Mature male Sprague-Dawley rats fed a powdered Purina Chow diet containing corn oil and condensed milk (CM) were compared to rats fed a Purina Chow diet (control). CM rats gained more weight and consumed more calories over a 73-day period than the control rats. The increased weight gain and body fat in CM rats was accompanied by increased cell number in retroperitoneal and inguinal but not epididymal fat pads while cell size was unchanged in all three pads. After obesity had developed there was an increase in insulin levels, lipolysis, hepatic fatty acid synthesis, and fatty acid oxidation. While CM rats demonstrated hyperinsulinemia and hyperglycerolemia, they maintained normal glucagon and glucose levels. They demonstrated higher rates of fatty acid synthesis in isolated hepatocytes but not in vivo, suggesting that a greater potential for fatty acid synthesis in CM rats was masked in vivo by the inhibitory action of dietary lipids. Beta-oxidation of (1-14C) palmitate in vivo and in vitro, and in vivo ketogenesis were greater in CM than in chow fed rats. These studies demonstrate that, after the development of obesity, CM rats, like genetically obese Zucker rats, are hyperinsulinemic and have elevated levels of fatty acid synthesis. However, unlike obese Zucker rats, CM rats displayed an increase in beta-oxidation. These studies suggest that increased insulin levels and hepatic fatty acid synthesis may contribute to dietary obesity (as they do to genetic obesity), whereas increased fatty acid oxidation in dietary obesity may be a compensatory response to maintain a lower body weight.

[Enzymatic changes and protein metabolism in the early and late postoperative phase during intravenous feeding]

119 metabolically healthy surgical patients, who had to undergo elective intraabdominal surgery, were separated into upper - cholecystectomy, gastric resection - and lower - colonic and sigma surgery - intraabdominal procedures and divided into 8 groups with different infusion regimens. During the early postoperative period, patients with upper abdominal surgery had significantly higher postoperative enzyme changes compared with patients with lower abdominal surgery. Patients with cholecystectomy had the significantly highest postoperative enzyme changes. On postoperative day 6 the enzyme changes showed a significant dependence from the duration of total parenteral nutrition, the chosen calorie-nitrogen ratio, and the chosen energy substrate, Xylitol or glucose. We could show a significant negative correlation between the extent of the stimulation of hepatic lipid synthesis and the protein parameters. Of all chosen infusion regimens, Xylitol in a dosis of 0.11 g/kg BW x h together with the high amino acid infusion rate of 1.76 g/kg BW x day had the most favourable effect on the extent of stimulation of hepatic lipid synthesis, the late postoperative enzyme changes, and the synthesis rate of visceral proteins. This study could demonstrate that different intraabdominal surgical procedures need a more specific nutritional therapy.

Regulation of lipid synthesis in hepatocytes from lean and obese Zucker rats

Fatty acid synthesis and CO2 production were evaluated in hepatocytes from lean and obese Zucker rats in the presence of 3H2O, and several carbon precursors. The incorporation of 3H2O into fatty acids was greater in obese compared to lean rats in both the isolated hepatocyte and in vivo. The rates of incorporation of 3H2O into fatty acids and cholesterol in hepatocytes of both lean and obese rats were linear for 2 hr, in the absence or presence of 16.7 mM glucose. Rates of fatty acid synthesis were higher in the presence of 16.7 mM glucose compared to the absence of glucose in both lean and obese while rates of cholesterol synthesis were similar. The incorporation of 3H2O into fatty acids, but not into cholesterol, was correlated with increasing glucose concentration and was 2 to three-fold higher in hepatocytes of obese compared to lean rats in the presence of several carbon precursors. Differences in CO2 production between lean and obese rats suggested increased pentose phosphate shunt activity, decreased pyruvate dehydrogenase activity, and lower tricarboxylic acid cycle activity in obese rats. Fatty acid synthesis and CO2 production from 3H2O and [U-14C]glucose in hepatocytes of lean and obese rats was similarly elevated by insulin and depressed by glucagon at several concentrations, suggesting that hepatocytes of obese animals respond to these hormones. These data indicate that rates of hepatic fatty acid synthesis although higher in obese rats respond to modulation in a fashion which is similar to the response in lean rats. The present studies suggest that the oxidation of several carbon precursors in the tricarboxylic acid cycle is diminished in obese compared to lean rats, but pentose phosphate shunt activity is greater in the obese Zucker rats.

Effects of jejuno-ileal bypass on serum lipoproteins and glucose tolerance in severely obese patients

Plasma insulin and blood glucose during oral glucose tolerance tests (OGTT) and serial determinations of serum lipoprotein fractions before and after jejuno-ileostomy in twenty severely obese (mean weight 137 kg) patients with a mean age of 29 years revealed statistically significant postoperative decreases in all parameters concomitant with a mean weight loss of 42 kg. Before the operation the patients were hyperinsulinaemic and had elevated blood glucose levels during OGTT though no patient had overt diabetes. Serum triglyceride and total cholesterol levels were normal but HDL cholesterol was significantly lower than in controls. During follow-up at least until body weight had levelled off a mean 19 months post-operative, there were statistically significant reductions in blood glucose and plasma insulin as well as serum total cholesterol and lipoprotein fractions. There was no change in serum triglycerides. The low preoperative HDL levels decreased. In a subgroup of these patients we have earlier shown postoperative increases in arterial tissue cholesterol coincident with the present significant decreases in HDL as well as in LDL cholesterol. Correlations between total cholesterol and lipoprotein cholesterol values in serum and blood glucose and plasma insulin at fast and during OGTT and changes in these parameters demonstrate interrelationships between lipid and carbohydrate metabolism. The bypass procedure most likely reduces the intestinal synthesis of HDL which in turn may increase hepatic cholesterol synthesis. Evidently there is a multifactorial aetiology for the low HDL levels in the severely obese both before and after jejuno-ileostomy.

Vagotomy as a treatment for morbid obesity

Based on animal experiments, on the original clinical observations of Dragstedt, and on similarities with appetitive behavior after jejunoileostomy, truncal vagotomy has been attempted as a treatment for morbid obesity in 13 patients with a mean weight of 123 kg. Weight decreases of 20 to 30 kg (range, 2 to 64 kg) have been observed so far. Impaired gastric emptying alone does not seem to account for the decreases. Possibly, improved glucose tolerance with reduction of hyperinsulinemia and other hormonal and/or neural effects are responsible for weight loss and lack of "hunger." The period of observation is short, yet 2 of the 13 patients seem to be failures, of whom one had gastric hyposecretion before operation. It is too early to consider the procedure for general clinical use, which must await further research efforts.

Mechanism and treatment of hypertriglyceridaemia in gout

Using the Intralipid lipid tolerance test we could not demonstrate any direct effect of serum triglyceride on uric acid or any influence of hyperuricaemia on triglyceride removal. This result supports previous studies suggesting that hyperuricaemia and hypertriglyceridaemia are linked through the association of obesity and alcohol excess rather than a direct cause and effect mechanism. It was possible to demonstrate significant reductions of serum triglyceride in patients with gout by reducing either their alcohol intake or body weight. Reduction of serum uric acid by probenecid had no effect on serum triglyceride or cholesterol. Similarly, allopurinol had no significant effect on serum triglyceride, but a significant fall of serum cholesterol was observed.