Independent associations between liver fat, visceral adipose tissue, and metabolic risk factors in men

The impact of replacing corn with elephant grass (Pennisetum purpureum) on growth performance, serum parameters, carcass traits, and nutrient digestibility in geese

This study investigated the effects of partially replacing corn with elephant grass dry matter (air drass) on growth performance, serum parameters, carcass traits, and nutrient digestibility in geese. A total of 360 one-day-old Hortobágyi geese were randomly divided into three groups: control (basic diet), 12 % elephant grass, and 24 % elephant grass. The geese were raised for 70 days. The results showed that compared to the control, 12 % elephant grass had no adverse effects on final body weight, feed/gain ratio, mortality, serum liver and kidney function markers. However, 24 % elephant grass significantly reduced the final body weight (P < 0.001) and feed/gain ratio (P = 0.026) compared to the control group. Both experiment groups had decreased serum aspartate aminotransferase (P < 0.001), alanine aminotransferase (P < 0.001), alkaline phosphatase (P < 0.001), triglycerides (P < 0.001), and total cholesterol (P < 0.001). The addition of 12 % and 24 % elephant grass reduced abdominal fat (P = 0.002), but it had no significant effect on slaughter rate, half-bore rate, full-bore rate, breast muscle rate and leg muscle rate. For nutrient digestibility, 12 % elephant grass improved neutral detergent fiber digestibility compared to the control group (P = 0.026). The 24 % grass group had reduced Ca absorption (P = 0.020). Overall, the findings suggest that partially replacing corn with 12 % elephant grass in goose diet can maintain growth performance and carcass traits.It also has no negative effect on nutrient digestibility while improving serum parameters.

Aerobic Exercise in the Management of Metabolic Dysfunction Associated Fatty Liver Disease

Sedentarism is the pandemic of modern times. It is associated with several medical conditions including obesity, type 2 diabetes mellitus, cardiovascular diseases and also liver disease, particularly metabolic dysfunction associated fatty liver disease (MAFLD). In an era when MAFLD is the most prevalent chronic liver disease worldwide, whilst no pharmacological therapy has been approved for it, exercise has proved to be effective in improving liver steatosis. Interestingly, exercise decreases liver fat even in the absence of weight loss. The challenge for the clinician is to motivate the obese patient with MAFLD, and associated co-morbidities, who has crystallized a sedentary behavior, at times when every need is at the distance of a click on the Internet, and the entire world can be visited behind a screen. In this review, the aggregate evidence on the mechanisms and effects of exercise in the management of MAFLD is summarized, with simple recommendations for everyday clinical practice.

Effect of Chronic Low Back Pain on Lumbar Spine Lordosis During Sit-to-Stand and Stand-to-Sit

OBJECTIVE

This study aimed to evaluate lumbar lordosis during sit-to-stand (STS) and stand-to-sit (SIT) in individuals with and without chronic nonspecific low back pain (CNLBP). The second objective was to investigate sex-related differences in lumbar lordosis.

METHODS

Twenty-six patients with CNLBP and 26 controls were recruited. Controls were matched with cases using a frequency matching method. Reflective markers were placed over the spinous process of T₁₂, L₃, S₂, and the anterior and posterior superior iliac spines. The participants were instructed to stand up at a self-selected pace and maintain their normal upright standing posture for 3 seconds, and then sit down. Kinematic data were recorded at a sampling frequency of 100 Hz using a motion capture system. Lumbar lordosis angle was calculated from the intersection between the line joining T₁₂ and L₃, and the line joining L₃ to S₂.

RESULTS

Lumbar lordosis was decreased in patients with CNLBP during STS and SIT compared with the asymptomatic group (mean difference = 2.68°-9.32°; P ≤ .005). Furthermore, no differences were seen in lumbar lordosis at starting position between CNLBP and asymptomatic groups during STS and SIT (mean difference = 2.68°-3.75°; P ≥ .099). Interestingly, the magnitude of the effect size suggested that the difference in lumbar lordosis values between female and male participants was relatively large (Cohen's d = -1.81 to 0.20).

CONCLUSION

Decreased lumbar lordosis in patients with CNLBP during STS and SIT could be considered as an important point during rehabilitation. Moreover, the present study showed that there is a sex-related difference among women and men in lumbar lordosis during STS and SIT tasks.

Effect of Moderate-Intensity Aerobic Exercise on Hepatic Fat Content and Visceral Lipids in Hepatic Patients with Diabesity: A Single-Blinded Randomised Controlled Trial

OBJECTIVE

Limited studies have assessed the effect of moderate-intensity continuous aerobic exercise on hepatic fat content and visceral lipids in hepatic patients with diabesity. This study was designed to evaluate hepatic fat content and visceral lipids following moderate-intensity continuous aerobic exercise in hepatic patients with diabesity.

DESIGN

A single-blinded randomised controlled trial.

METHODS

Thirty-one diabetic obese patients with nonalcoholic fatty liver disease were recruited into this study. The patients were randomly classified into exercise and control groups, fifteen patients in the exercise group and sixteen patients in the control group. The exercise group received an 8-week moderate-intensity continuous aerobic exercise program with standard medical treatment, while the control group received standard medical treatment without any exercise program. Hepatic fat content and visceral lipids were assessed before and after intervention at the end of the study.

RESULTS

Baseline and clinical characteristics showed a nonsignificant difference between the two groups (p > 0.05). At the end of the intervention, the aerobic exercise showed significant improvements (serum triglycerides and low-density lipoproteins (LDLs), p ≤ 0.002, total cholesterol, p=0.004, visceral fats, p=0.016, glycated hemoglobin (HbA1C), p=0.022, high-density lipoproteins (HDLs), p=0.038, alanine transaminases (AL), p=0.044, intrahepatic triglyceride and HOMA-IR, p=0.046, and body mass index (BMI), p=0.047), while the control group showed a nonsignificant difference (p > 0.05). The postintervention analysis showed significant differences in favor of the aerobic exercise group (p < 0.05).

CONCLUSIONS

Moderate-intensity continuous aerobic exercise reduces the hepatic fat content and visceral lipids in hepatic patients with diabesity. Recommendations should be prescribed for encouraging moderate-intensity aerobic exercise training, particularly hepatic patients with diabesity.

Effects of high-intensity interval and moderate-intensity continuous aerobic exercise on diabetic obese patients with nonalcoholic fatty liver disease: A comparative randomized controlled trial

BACKGROUND

Some studies assessed the effect of aerobic exercise on diabetic obese patients with hepatic disease, while very limited studies compared high-intensity interval (HII) versus moderate-intensity continuous (MIC) on diabetic obese patients with non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

This study was designed to assess the effects of HII versus MIC on intrahepatic triglycerides (IHTG) and visceral lipids in diabetic obese patients with NAFLD.

DESIGN

Randomized controlled trial.

METHODS

Forty-seven diabetic obese individuals with NAFLD were enrolled in this study. The individuals were randomly divided into 16 in HII group, 15 in MIC group, and 16 in the controls. HII group received HII exercise, MIC group received 8-week MIC exercise while the control group did not receive any exercise intervention. IHTG and visceral lipids were assessed pre- and post-intervention.

RESULTS

Baseline and clinical characteristics showed nonsignificant difference among the 3 groups (P > .05). Both HII and MIC groups showed a significant reduction in hepatic fat and visceral lipids (P < .05), while the controls showed nonsignificant difference (P > .05) after completing the study intervention. Postintervention analysis showed nonsignificant changes between the HII and MIC groups (P > .05).

CONCLUSIONS

Exercise training wither HII or MIC aerobic exercise reduces IHGT and visceral lipids in diabetic obese patients with NAFLD. No differences were observed between the effects of both exercise programs on diabetic obese patients with NAFLD.

Fatty Liver Has Stronger Association With Insulin Resistance Than Visceral Fat Accumulation in Nonobese Japanese Men

Context

Asians have a high prevalence of insulin resistance, even in the nonobese state. Whereas both visceral fat accumulation (VFA) and fatty liver (FL) have been shown to be associated with insulin resistance, it is still unclear which is a better marker to predict insulin resistance in nonobese Asians.

Objective

The aim of this study was to investigate the relation between VFA or FL and insulin resistance in nondiabetic nonobese Japanese men who do not have diabetes.

Design and Participants

We studied 87 nonobese (body mass index <25 kg/m²) Japanese men without diabetes. Using a two-step hyperinsulinemic euglycemic clamp, we evaluated insulin sensitivity in adipose tissue, muscle, and liver. Intrahepatic lipid and abdominal visceral fat area were measured by ¹H-magnetic resonance spectroscopy and MRI, respectively. Subjects were divided into four groups based on the presence or absence of VFA (visceral fat area ≥100 cm²) and FL (intrahepatic lipid ≥ 5%): control (non-VFA, non-FL; n = 54), VFA only (n = 18), FL only (n = 7), and VFA plus FL (n = 8).

Results

Subjects in the FL only and VFA plus FL groups had insulin resistance in adipose tissue and muscle, as well as relatively lower hepatic insulin sensitivity. The specific insulin sensitivities in these organs were comparable in the VFA only and control groups.

Conclusions

In nonobese Japanese men without diabetes, subjects with FL only or VFA plus FL but not VFA only had insulin resistance, suggesting that FL may be a more useful clinical marker than VFA to predict insulin resistance in nonobese Japanese men without diabetes.

Comprehensive lifestyle intervention vs soy protein-based meal regimen in non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) has become one of the leading causes of liver disease in the western world. In obese patients weight reduction is recommended. Up to now there are no specific guidelines for weight loss in order to reduce hepatic fat content.

AIM

To investigate the effects of a 24-wk guided lifestyle intervention program compared to a meal replacement regimen based on soy protein.

METHODS

Twenty-six subjects with NASH participated in a randomized single-center study. They were randomly assigned to either meal replacement group (MR-G) with soy-yogurt-honey preparation or to guided lifestyle change group (LC-G) with endurance activity and nutrition counselling. Serum alanine transaminase (ALT), aspartate transaminase (AST), lipid parameters, and adipokines were measured. Liver fat content and lipid composition were determined by magnetic resonance imaging and magnetic resonance spectroscopy. Body fat mass and lean body mass were assessed using Bod Pod^® device. Pre- and post-intervention monitoring of parameters was performed. Statistical analyses were conducted with SPSS software, results were expressed as median (interquartile range).

RESULTS

Twenty-two subjects (MR-G, n = 11 and LC-G, n = 11) completed the study (9 women, 13 men; age 52.1 (15.0) years, body mass index (BMI) 32.3 (3.3) kg/m²). In both groups a significant weight loss was achieved (MR-G: -6.4 (3.6) kg, P < 0.01; LC-G: -9.1 (10.4) kg, P < 0.01). BMI dropped in both groups (MR-G: -2.3 (1.5) kg/m², P = 0.003; LC-G: -3.0 (3.4) kg/m², P = 0.006). Internal fat and hepatic lipid content were markedly reduced in both groups in comparable amount. There was a strong correlation between reduction in liver fat and decrease in ALT. Likewise, both groups showed an improvement in glycemic control and lipid profile. Changes in adipokines, particularly in adiponectin and leptin were closely related to intrahepatic lipid changes.

CONCLUSION

Comprehensive lifestyle intervention and meal replacement regimen have comparable effects on body and liver fat, as well as decrease in markers of hepatic inflammation among NASH patients.

A randomized controlled trial on the effectiveness of 8-week high-intensity interval exercise on intrahepatic triglycerides, visceral lipids, and health-related quality of life in diabetic obese patients with nonalcoholic fatty liver disease

BACKGROUND

Medications are limited for patients with nonalcoholic fatty liver disease (NAFLD). It has been reported that aerobic exercise is effective in reducing the characteristics of NAFLD, although unclear data have ascertained the effects of high-intensity interval aerobic exercise on health-related quality of life (HRQoL) in diabetic obese patients with NAFLD.

OBJECTIVES

This a randomized controlled trial aimed to ascertain the effectiveness of 8-week high-intensity interval exercise on intrahepatic triglycerides (IHTG), visceral lipids and HRQoL in diabetic obese patients with NAFLD.

STUDY DESIGN

Between August and December 2017, 32 diabetic obese patients with NAFLD aged 45 to 60 years (21 men and 11 women) were enrolled in this study. They were randomly assigned to 2 groups, 16 patients in each group, high-intensity interval (HII) exercise and control groups. The HII group received a program of HII aerobic exercise for 8 weeks with medications of NAFLD and the control group received only medications without any type of exercise intervention. The test of IHTG, visceral lipids, and HRQoL were recorded at the initial assessment and at the end of the program after 8 weeks.

RESULTS

There were significant differences between the 2 groups at the end of the study. These study findings exhibited significant improvements in IHTG, VO2peak, visceral lipids, glycohemoglobin, plasma glucose, and all dimensions of HRQoL in the HII group (P <.05), But there was non-significant improvement in any measure in the control group (P >.05) after the 8-week intervention.

CONCLUSION

Eight-week high-intensity interval aerobic exercise has a beneficial effect on IHTG, visceral lipids, and HRQoL in diabetic obese patients with NAFLD. Effort and awareness should be dedicated to encouraging the active lifestyle among different population, especially diabetic obese patients with NAFLD.

Visceral adipose tissue tracks more closely with metabolic dysfunction than intrahepatic triglyceride in lean Asians without diabetes

Increased visceral adipose tissue (VAT) and intrahepatic triglyceride (IHTG) are important risk factors for the development of type 2 diabetes in subjects with obesity. The relative contribution of these ectopic fat depots to cardiometabolic risk differs between populations, depends on the degree of obesity and the level of cardiorespiratory fitness, and is difficult to dissect because VAT and IHTG typically covary. The aim of this study was to evaluate the effect of an isolated increase in VAT or IHTG on insulin sensitivity and insulin secretion in apparently healthy normal-weight Asian subjects. Total body fat (dual X-ray absorptiometry), VAT and IHTG (magnetic resonance), insulin sensitivity (4-h hyperinsulinemic-euglycemic clamp), beta cell responsivity and insulin secretion rate (3-h mixed meal with mathematical modeling), and cardiorespiratory fitness (maximal oxygen consumption [V̇o2max]) were evaluated in groups of lean subjects with low or high VAT (687 ± 94 vs. 1,279 ± 197 ml, matched for IHTG; n = 13 each) and low or high IHTG (1.7 ± 0.3 vs. 6.7 ± 2.0%, matched for VAT; n = 15 each). All groups were matched for age, sex, total body fat, and V̇o2max. High-VAT subjects had ~25% lower insulin sensitivity, ~20%–40% greater beta cell responsivity and insulin secretion rate, ~35% greater fasting triglyceride concentration, and ~40% lower adiponectin concentration than low-VAT subjects (all P < 0.05). No differences were observed between low-IHTG and high-IHTG subjects. Accumulation of excess fat in the intra-abdominal area is more strongly associated with metabolic dysfunction than accumulation of liver fat in lean Asians without diabetes.

NEW & NOTEWORTHY It is not known whether metabolic abnormalities in Asians without obesity track more closely with visceral or liver fat. We found an isolated increase in visceral fat was associated with reduced insulin sensitivity, greater insulin secretion, greater triglyceride, and lower adiponectin concentrations; no differences were observed with an isolated increase in liver fat. These results suggest that visceral fat is a better correlate of metabolic dysfunction than liver fat in Asians without obesity.

Visceral and Intrahepatic Fat Are Associated with Cardiometabolic Risk Factors Above Other Ectopic Fat Depots: The Framingham Heart Study

BACKGROUND

We examined the associations among 8 different fat depots accumulated in various anatomic regions and the relationship between these fat depots and multiple cardiometabolic risk factors.

METHODS

Participants were from the Framingham Heart Study Offspring and Third Generation who also participated in the multidetector computed tomography substudy in 2002-2005. Exposures were multidetector computed tomography-derived fat depots, including abdominal subcutaneous adipose tissue, abdominal visceral adipose tissue, intramuscular fat, intrathoracic fat, pericardial fat, thoracic periaortic fat, intrahepatic fat, and renal sinus fat. Multivariable-adjusted regression analyses with a forward selection procedure were performed to identify the most predictive fat depots.

RESULTS

Of 2529 participants, 51.9% were women (mean age, 51.1 years). Visceral adipose tissue had the strongest correlations with each of the other fat measures (range, 0.26-0.77) and with various cardiometabolic risk factors (range, -0.34 to 0.39). As determined by the selection models, visceral adipose tissue was the only fat depot that was associated with all cardiometabolic risk factors evaluated in this study (all P<.05). Selection models also showed that subcutaneous adipose tissue and intrahepatic fat were associated with cardiometabolic risk factors related to the traits of dysglycemia, dyslipidemia, and hypertension (all P<.05). However, only associations with visceral adipose tissue and intrahepatic fat persisted after further adjustment for body mass index and waist circumference.

CONCLUSIONS

Visceral adipose tissue and intrahepatic fat were consistent correlates of cardiometabolic risk factors, above and beyond standard anthropometric indices. Our data provide important insights for understanding the associations between variations in fat distribution and cardiometabolic abnormalities.

Agrimonia eupatoria L. (Agrimony) Extract Alters Liver Health in Subjects with Elevated Alanine Transaminase Levels: A Controlled, Randomized, and Double-Blind Trial

Agrimonia eupatoria L. has been shown to protect against liver injury due to its lipid lowering and antioxidant activities. The aim of this research was to evaluate the effect of A. eupatoria L. aqueous extract (AEE) on 80 subjects with elevated alanine transaminase (ALT) levels in a randomized, double-blind, placebo-controlled, 8-week study. This trial was conducted between January 2013 and July 2013 at the Oriental Medical Hospital (Jecheon) of Semyung University. The trial included subjects aged 20 years or older who were diagnosed with mildly to moderately elevated ALT levels (between 45 and 135 IU/L). Subjects received two capsules of placebo or AEE twice a day for 8 weeks. Adverse events were recorded. Eighty subjects were randomized to placebo or AEE groups who had similar baseline characteristics. During the 8 weeks of treatment, 11 subjects were excluded from the analysis for protocol violation or consent withdrawal; efficacy of treatment was, therefore, evaluated in 69 subjects (placebo = 35, AEE = 34). The AEE group showed a significant reduction in ALT and serum triglyceride (TG) at 8 weeks compared with the placebo group (ALT P = .044, TG P = .020). Significant group and time interactions were found in ALT (P = .038), aspartate aminotransferase (P = .040), and TG (P = .010). Alkaline phosphatase, total bilirubin, and gamma-glutamyl transferase levels were not different between the two groups. There were no reported severe adverse events during this study, and total protein, albumin, blood urea nitrogen, creatine, and total cholesterol levels were normal in both groups. AEE consumption was safe and generally well tolerated without severe adverse events.

High Intrinsic Aerobic Capacity Protects against Ethanol-Induced Hepatic Injury and Metabolic Dysfunction: Study Using High Capacity Runner Rat Model

Rats artificially selected over several generations for high intrinsic endurance/aerobic capacity resulting in high capacity runners (HCR) has been developed to study the links between high aerobic fitness and protection from metabolic diseases (Wisloff et al., Science, 2005). We have previously shown that the HCR strain have elevated hepatic mitochondrial content and oxidative capacity. In this study, we tested if the elevated hepatic mitochondrial content in the HCR rat would provide "metabolic protection" from chronic ethanol-induced hepatic steatosis and injury. The Leiber-Decarli liquid diet with ethanol (7% v/v; HCR-E) and without (HCR-C) was given to HCR rats (n = 8 per group) from 14 to 20 weeks of age that were weight matched and pair-fed to assure isocaloric intake. Hepatic triglyceride (TG) content and macro- and microvesicular steatosis were significantly greater in HCR-E compared with HCR-C (p < 0.05). In addition, hepatic superoxide dismutase activity and glutathione levels were significantly (p < 0.05) reduced in the HCR-E rats. This hepatic phenotype also was associated with reduced total hepatic fatty acid oxidation (p = 0.03) and β-hydroxyacyl-CoA dehydrogenase activity (p = 0.01), and reductions in microsomal triglyceride transfer protein and apoB-100 protein content (p = 0.01) in HCR-E animals. However, despite these documented hepatic alterations, ethanol ingestion failed to induce significant hepatic liver injury, including no changes in hepatic inflammation, or serum alanine amino transferase (ALTs), free fatty acids (FFAs), triglycerides (TGs), insulin, or glucose. High intrinsic aerobic fitness did not reduce ethanol-induced hepatic steatosis, but protected against ethanol-induced hepatic injury and systemic metabolic dysfunction in a high aerobic capacity rat model.

Using SRM-MS to quantify nuclear protein abundance differences between adipose tissue depots of insulin-resistant mice

Insulin resistance (IR) underlies metabolic disease. Visceral, but not subcutaneous, white adipose tissue (WAT) has been linked to the development of IR, potentially due to differences in regulatory protein abundance. Here we investigate how protein levels are changed in IR in different WAT depots by developing a targeted proteomics approach to quantitatively compare the abundance of 42 nuclear proteins in subcutaneous and visceral WAT from a commonly used insulin-resistant mouse model, Lepr(db/db), and from C57BL/6J control mice. The most differentially expressed proteins were important in adipogenesis, as confirmed by siRNA-mediated depletion experiments, suggesting a defect in adipogenesis in visceral, but not subcutaneous, insulin-resistant WAT. Furthermore, differentiation of visceral, but not subcutaneous, insulin-resistant stromal vascular cells (SVCs) was impaired. In an in vitro approach to understand the cause of this impaired differentiation, we compared insulin-resistant visceral SVCs to preadipocyte cell culture models made insulin resistant by different stimuli. The insulin-resistant visceral SVC protein abundance profile correlated most with preadipocyte cell culture cells treated with both palmitate and TNFα. Together, our study introduces a method to simultaneously measure and quantitatively compare nuclear protein expression patterns in primary adipose tissue and adipocyte cell cultures, which we show can reveal relationships between differentiation and disease states of different adipocyte tissue types.

A body shape index and heart rate variability in healthy indians with low body mass index

Background. One third of Indian population is said to be suffering from chronic energy deficiency (CED), with increased risk of developing chronic diseases. A new anthropometric measure called A Body Shape Index (ABSI) is said to be a better index in predicting risks for premature mortality. ABSI is also in part said to be a surrogate of visceral fat. Objective. The present study aimed to explore the association between indices of HRV (heart rate variability), BMI, WC, and ABSI in healthy Indian males with low BMI (BMI < 18.5 kg/m²) and to compare with normal BMI group (BMI 18.5 to 24.9 kg/m²). Methodology. ABSI and BMI were derived from anthropometric parameters, namely, height, weight, and waist circumference in 178 males aged 18 to 78 years. Subjects were categorized into two groups based on their BMI. Results and Conclusions. Power spectral analysis of HRV demonstrated a significant negative correlation between Log HF (high frequency) and ABSI in both low BMI [−24.2 (9.4), P < 0.05] and normal BMI group [−23.41 (10.1), P < 0.05] even after controlling for age. Thus even with slight increase in BMI among low BMI individuals, there could be a greater risk of cardiovascular morbidity and mortality.

Non-alcoholic fatty liver disease (NAFLD) is associated with low level of physical activity: a population-based study

BACKGROUND

High intensity exercise improves metabolic status and may potentially mobilise hepatic fat.

AIM

To assess the level of physical activity (PA) of subjects with non-alcoholic fatty liver disease (NAFLD).

METHODS

Data were obtained from NHANES (2003-2006). Activity counts obtained from accelerometer readings (ActiGraph, Fort Walton Beach, FL), from 7 consecutive days quantified total PA and time spent engaged in different levels of activity. All measures were counts/minutes/day: (sedentary <100; light 100-0027; moderate, 2020-5999 and vigorous, 6000+). NAFLD was defined as a fatty liver index >60 (FLI) in the absence of other chronic liver disease. Subjects with NAFLD were compared to controls using stratum-specific Chi-squared and t-tests. Simple linear regression analyses (with Taylor series linearised variance estimation and weighting) were used to determine the association between PA levels and NAFLD. P-values <0.05 were considered significant. Statistical analyses were conducted using sudaan version 10.1 and sas version 9.1.

RESULTS

We included 3056 participants. NAFLD patients were older, had higher BMI, larger waist circumference, higher sum of skinfolds, more likely to have insulin resistance (HOMA > 3.0) and type-2 diabetes (all P-values <0.01). Average PA for NAFLD subjects was about 28.7 counts/minute/day less than controls (P < 0.01). Furthermore, NAFLD subjects spent less time participating in activity at any level (P < 0.01). Subjects with NAFLD and DM were in the lowest quartile of average PA as well as moderate-vigorous PA (P < 0.01).

CONCLUSIONS

Data from this study show that non-alcoholic fatty liver disease patients have low level of physical activity and, when they have diabetes mellitus, they perform at the lowest quartile of physical activity and moderate-vigorous physical activity.

Comparison of activity level among patients with chronic liver disease

PURPOSE

To determine whether self-reported maximal and daily activity levels are impaired among patients with nonalcoholic fatty liver disease (NAFLD), hepatitis C (HCV) and hepatitis B (HBV).

METHODS

Clinicodemographic, diagnostic, self-report and standard laboratory data were obtained. Univariate, multivariate and regression analyses were performed comparing group maximal (Maximum Activity Score [MAS]) and daily activity scores (Adjusted Activity Score [AAS]), adjusted for age and gender.

RESULTS

Two hundred twenty-two patients completed activity-level self-reports (mean age [52.4 ± 10.0 years], BMI [28.3 ± 6.58], 31.2% NAFLD, 48.3% HCV, 20.3% HBV). On multivariate analysis, significantly higher MAS (p < 0.05) and AAS in HBV patients correlated with absence of cirrhosis, younger age, male gender (higher MAS) and lower BMI (higher AAS). Lowest activity levels were found primarily in obese patients (p < 0.009). Compared with population norms, NAFLD and HCV cohorts scored mildly disabled on MAS; the HBV cohort scored low normal. Mild disability on AAS was observed in patients with HBV; moderate disability in those with NAFLD, HCV.

CONCLUSIONS

All groups had significantly lower activity levels than population norms. Nonobese patients showed significantly less disability than obese patients. Patients with NAFLD and HCV are likely to have lower levels than those with HBV without cirrhosis. This presents an additional risk factor for disability and mortality.

IMPLICATIONS FOR REHABILITATION

• Hepatitis B (HBV), hepatitis C (HCV), and nonalcoholic fatty liver disease (NAFLD) patients had significantly lower activity levels than expected for their age and gender, as measured by the Human Activity Profile (HAP). • Overweight and normal weight chronic liver disease (CLD) patients showed significantly less disability than obese chronic liver disease patients. • Patients with NAFLD and HCV are likely to participate in low levels of activity that require fewer metabolic equivalents for completion, adding an additional risk factor for disability and mortality. • Targeting low activity level in CLD patients, and decreasing BMI below the obesity threshold, may reduce disability and risk of mortality.

Managing the combination of nonalcoholic fatty liver disease and metabolic syndrome

INTRODUCTION

Metabolic syndrome (MetS) and nonalcoholic fatty liver disease (NAFLD) are part of the same metabolic defect, both having insulin resistance as the main pathogenic mechanism and sharing similar outcomes (i.e., cardiovascular and liver-related mortality). The prevalence of NAFLD is expected to rise, owing to the increasing worldwide prevalence of obesity and MetS; therefore, the identification of factors responsible for disease progression is essential to devise therapeutic strategies.

AREAS COVERED

The available and potential future treatments for NAFLD in combination with MetS are reviewed in this paper, following an extensive literature search and personal experience.

EXPERT OPINION

All NAFLD patients should be evaluated for their metabolic, cardiovascular and liver-related risk. Weight loss through lifestyle intervention remains the most comprehensive and safe treatment of NAFLD and associated MetS; however, > 50% of patients fail to achieve target weight loss. Pharmacologic treatment seems to be important for these patients and for NAFLD cases with more advanced liver disease. It temporarily reverses metabolic alterations, but liver disease progresses after the treatment is stopped. Although current treatments are unsatisfactory, new drugs have been proposed and a few innovative compounds are in the pipeline of pharmaceutical companies. Before pharmacologic treatment can be routinely recommended for NAFLD, long-term randomized trials are needed, along with assessments of the safety and benefits of drugs on proper histological outcomes or validated surrogate markers. The intensive control of individual features of MetS remains mandatory.

The thin-fat phenotype and global metabolic disease risk

PURPOSE OF REVIEW

There has been a great deal of interest in the thin-fat phenotype evident in Asian Indians and its risk associations in the epidemic of noncommunicable chronic disease associated with it. The cause of this phenotype is probably related to lifestyle and environment; however, genotypic and epigenetic modifications in utero also have been considered.

RECENT FINDINGS

The thin-fat phenotype occurs when fat is added to an already thin frame. This may occur with rural-urban migration, when positive energy balance occurs in a migrating population who were predominantly thin and physically active to begin with. The role of the pre-existing skeletal muscle mass and its interaction with newly deposited fat must be considered. The thin-fat phenotype may be programmed during fetal growth, but the evidence for this phenomenon is still not completely clear. Finally, although there is increased chronic disease morbidity at lower BMI and younger age in south Asian populations, BMI-related mortality does not appear to follow this trend.

SUMMARY

At present, the weight of evidence appears to link the thin-fat phenotype to an environmental and lifestyle phenomenon occurring in previously thin people. This is particularly relevant in India, given the pace of transition over the last two decades.

Orlistat 60 mg reduces visceral adipose tissue: a 24-week randomized, placebo-controlled, multicenter trial

It is well established that abdominal obesity or upper body fat distribution is associated with increased risk of metabolic and cardiovascular disease. The purpose of the present study was to determine if a 24 week weight loss program with orlistat 60 mg in overweight subjects would produce a greater change in visceral adipose tissue (VAT) as measured by computed tomography (CT) scan, compared to placebo. The effects of orlistat 60 mg on changes in total fat mass (EchoMRI-AH and BIA), ectopic fat (CT) and glycemic variables were assessed. One-hundred thirty-one subjects were randomized into a multicenter, double-blind placebo controlled study in which 123 subjects received at least one post baseline efficacy measurement (intent-to-treat population). Both orlistat-and placebo-treated subjects significantly decreased their VAT at 24 weeks with a significantly greater loss of VAT by orlistat treated subjects (-15.7% vs. -9.4%, P < 0.05). In addition, orlistat-treated subjects had significantly greater weight loss (-5.93 kg vs. -3.94 kg, P < 0.05), total fat mass loss (-4.65 kg vs. -3.01 kg, P < 0.05) and trended to a greater loss of intermuscular adipose tissue and content of liver fat compared with placebo-treated subjects. This is the first study to demonstrate that orlistat 60 mg significantly reduces VAT in addition to total body fat compared to placebo treated subjects after a 24 week weight loss program. These results suggest that orlistat 60 mg may be an effective weight loss tool to reduce metabolic risk factors associated with abdominal obesity.

Does physical inactivity cause nonalcoholic fatty liver disease?

While physical activity represents a key element in the prevention and management of many chronic diseases, we and others believe that physical inactivity is a primary cause of obesity and associated metabolic disorders. Unfortunately, accumulating evidence suggests that we have engineered physical activity out of our normal daily living activity. One such consequence of our sedentary and excessive lifestyle is nonalcoholic fatty liver disease (NAFLD), which is now considered the most common cause of chronic liver disease in Westernized societies. In this review, we will present evidence that physical inactivity, low aerobic fitness, and overnutrition, either separately or in combination, are an underlying cause of NAFLD.

Effect of gender on intra-abdominal fat in teenagers and young adults

BACKGROUND

Adult men accumulate greater intra-abdominal fat (IAF) than adult women, a difference closely related to gender differences in cardiometabolic disease risk in the elderly. However, the time when this gender difference appears is a matter of controversy.

OBJECTIVE

We examine the influence of gender on IAF deposition in lean, overweight and obese teenagers and young adults.

MATERIALS AND METHODS

We measured subcutaneous abdominal fat (SAF) and IAF in 505 healthy sexually mature teenagers and young adults (254 males, 251 females; 15-22 years) using a single CT scan at the level of the umbilicus.

RESULTS

Regardless of body size, young females had greater SAF values than young males. Although lean females had higher IAF values than lean males (13.7 ± 7.8 vs. 11.2 ± 5.4; P = 0.001), overweight and obese females and males had strikingly similar IAF values (23.4 ± 11.1 vs. 23.1 ± 9.5; P = 0.88 and 36.5 ± 20.4 vs. 38.8 ± 13.2; P = 0.59, respectively). In contrast, the ratio of IAF/SAF was greater in males than females, except in the very obese. Multiple regression analysis indicated that while gender was a strong predictor of SAF in lean and overweight subjects (P's < 0.0001), it did not influence IAF after adjusting for height and weight (P = 0.35 and 0.65, respectively) in overweight and obese subjects.

CONCLUSION

Overweight and obese young women have similar absolute amounts of IAF as young men.

Relationships between fat deposition in the liver and skeletal muscle and insulin sensitivity in Japanese individuals: a pilot study

PURPOSE

To evaluate the relationships between insulin sensitivity (IS), body fat accumulation, and aerobic capacity in middle- to older-aged Japanese participants with visceral adiposity.

PARTICIPANTS AND METHODS

Aerobic capacity was measured during an incremental ramp exercise test. Computed tomography was used to measure visceral (VFA) and subcutaneous (SFA) fat area, the fat in liver-to-spleen ratio (L/S), and low-density skeletal muscle area (LDMA). IS was assessed using euglycemic-hyperinsulinemic clamps.

RESULTS

A total of 11 males and 9 females, age 58 ± 9 years (mean ± standard deviation), body mass index 29 ±4.1 kg/m(2), and VFA 190 ±53 cm(2) participated in this study. In unadjusted models, VFA, LDMA, and L/S were significantly correlated with IS, which remained in adjusted models for LDMA and L/S, but not for VFA. In multiple stepwise regression analysis including sex, age, body fat, VFA, SFA, alcohol consumption, and aerobic capacity (oxygen uptake at the lactate threshold), L/S, and LDMA accounted for 70% of the total variance in IS. Percentage body fat and SFA, but not VFA, were significantly correlated with high molecular-weight adiponectin levels (r = 0.58, P < 0.01 and r = 0.54, P < 0.05, respectively). IS and L/S were significantly and negatively correlated with tumor necrosis factor-α (r = -0.67 and -0.63, respectively; both P < 0.01) and plasminogen activator inhibitor-1 (r = -0.58, P < 0.01 and -0.52, P < 0.05, respectively), whereas LDMA was not.

CONCLUSION

These findings indicate that ectopic fat deposition in the liver and skeletal muscle may be associated with peripheral IS independently of body fat accumulation and aerobic capacity in middle- to older-aged Japanese individuals with visceral adiposity. Because of the small sample size, additional larger studies are needed to provide further insight into these preliminary findings.

Exercise and fat accumulation in the human liver

PURPOSE OF REVIEW

Fat accumulation in the liver is strongly associated with metabolic dysfunction. Regular exercise improves many cardiometabolic risks factors; however, its effect on intrahepatic triglyceride (IHTG) content remains elusive. This article summarizes available data regarding the effects of exercise on IHTG.

RECENT FINDINGS

Several but not all observational studies report negative associations of habitual physical activity and cardiorespiratory fitness with IHTG and the prevalence of fatty liver. Aerobic exercise training in combination with hypocaloric diet reduces IHTG by a considerable amount (20-60%), even when weight loss is mild (<5%); hence weight loss per se may not be a critical factor. Longitudinal studies involving exercise training without dietary restriction and no weight loss demonstrate that increased cardiorespiratory fitness and reduced intra-abdominal adiposity are not invariably associated with liver fat depletion, whereas relatively large exercise-induced reductions in IHTG content (20-40%) can occur even in the absence of changes in body weight, body composition, or visceral adipose tissue. Although the majority of studies have examined aerobic training, resistance exercise has also been shown to be inversely associated with the prevalence of fatty liver in humans and effectively reduces IHTG content in animals.

SUMMARY

Exercise does hold promise as an effective treatment for hepatic steatosis; this field of research is still in its infancy, and there is much more to be learned.

Fitness versus fatness: moving beyond weight loss in nonalcoholic fatty liver disease

The rapid emergence of nonalcoholic fatty liver disease (NAFLD) as a cause of both liver-related morbidity and mortality and cardiometabolic risk has led to the search for effective lifestyle strategies to reduce liver fat. Lifestyle intervention comprising dietary restriction in conjunction with increased physical activity has shown clear hepatic benefits when weight loss approximating 3%-10% of body weight is achieved. Yet, the poor sustainability of weight loss challenges the current therapeutic focus on body weight and highlights the need for alternative strategies for NAFLD management. Epidemiologic data show an independent relationship between liver fat, physical activity, and fitness, and a growing body of longitudinal research demonstrates that increased physical activity participation per se significantly reduces hepatic steatosis and serum aminotransferases in individuals with NAFLD, independent of weight loss. Mechanistic insights to explain this interaction are outlined, and recommendations for the implementation of lifestyle intervention involving physical activity are discussed. In light of the often poor sustainability of weight loss strategies, and the viability of physical activity therapy, clinicians should assess physical fitness and physical activity habits, educate patients on the benefits of fitness outside of weight loss, and focus on behavior change which promotes physical activity adoption.

gamma-Glutamyltransferase, obesity, physical activity, and the metabolic syndrome in indigenous Australian adults

The aim of this study is to examine the association between obesity, metabolic syndrome, physical activity, and elevated gamma-glutamyltransferase (GGT) among Indigenous Australian adults who did not drink alcohol. A cross-sectional study of 791 Indigenous adults in rural North Queensland communities was conducted between 1999 and 2001. Measures included serum GGT, fasting glucose, cholesterol, and triglycerides; resting blood pressure, BMI, and waist circumference; and self-reported physical activity, alcohol intake, and tobacco smoking. Central obesity measured by waist circumference in this population was significantly associated with elevated GGT independently of lifestyle behaviors (Adjusted odds ratio (OR) = 2.7, 95% confidence interval (CI): 1.2-6.0). Metabolic syndrome (International Diabetes Federation definition) was also strongly associated with increased GGT (OR = 2.6, 95% CI: 1.5-4.6). Habitual physical activity may be slightly protective (OR = 0.9, 95% CI: 0.5-1.6) in this group, but this was not clearly demonstrated in this study. Prevention of type 2 diabetes and cardiovascular disease in this population should emphasize "waist loss" and metabolic health through dietary and other interventions.

Rats selectively bred for low aerobic capacity have reduced hepatic mitochondrial oxidative capacity and susceptibility to hepatic steatosis and injury

Fatty liver has been linked to low aerobic fitness, but the mechanisms are unknown. We previously reported a novel model in which rats were artificially selected to be high capacity runners (HCR) and low capacity runners (LCR) that in a sedentary condition have robustly different intrinsic aerobic capacities. We utilized sedentary HCR/LCR rats (generation 17; max running distance equalled 1514 +/- 91 vs. 200 +/- 12 m for HCR and LCR, respectively) to investigate if low aerobic capacity is associated with reduced hepatic mitochondrial oxidative capacity and increased susceptibility to hepatic steatosis. At 25 weeks of age, LCR livers displayed reduced mitochondrial content (reduced citrate synthase activity and cytochrome c protein) and reduced oxidative capacity (complete palmitate oxidation in hepatic mitochondria (1.15 +/- 0.13 vs. 2.48 +/- 1.1 nm g(-1) h, P < 0.0001) and increased peroxisomal activity (acyl CoA oxidase and catalase activity) compared to the HCR. The LCR livers also displayed a lipogenic phenotype with higher protein content of both sterol regulatory element binding protein-1c and acetyl CoA carboxylase. These differences were associated with hepatic steatosis in the LCR including higher liver triglycerides (6.00 +/- 0.71 vs. 4.20 +/- 0.39 nmol g(-1), P = 0.020 value), >2-fold higher percentage of hepatocytes associated with lipid droplets (54.0 +/- 9.2 vs. 22.0 +/- 3.5%, P = 0.006), and increased hepatic lipid peroxidation compared to the HCR. Additionally, in rats aged to natural death, LCR livers had significantly greater hepatic injury (fibrosis and apoptosis). We provide novel evidence that selection for low intrinsic aerobic capacity causes reduced hepatic mitochondrial oxidative capacity that increases susceptibility to both hepatic steatosis and liver injury.

Exercise and the fatty liver

Fatty liver is an increasingly prevalent condition that is associated with several metabolic derangements, thus necessitating the development of effective therapeutic interventions. Growing evidence from cross-sectional studies suggest that physical activity may be a promising therapy for fatty liver. Unfortunately, longitudinal evidence supporting this observation in humans is sparse, as the majority of intervention studies have examined the relationship between liver fat and physical activity in conjunction with caloric and dietary fat restriction. Studies in rats demonstrate a beneficial effect of exercise on liver fat, mainly in situations of high fat feeding or obesity. Thus, the independent contribution of physical activity on variations in liver fat is unknown, but remains a promising intervention that requires further investigation. There is some evidence to suggest that both physical activity and liver fat are independent correlates of cardiovascular and type 2 diabetes risk. The relative contribution of each remains unclear, but implies that both should be considered when developing therapeutic interventions for chronic metabolic disease.

Non-alcoholic fatty liver disease and the metabolic syndrome: An update

Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). NAFLD is estimated to affect approximate 30% of the general US population and is considered the hepatic manifestation of the metabolic syndrome. Recent findings linking the components of the metabolic syndrome with NAFLD and the progression to nonalcoholic steatohepatitis (NASH) will be reviewed; in particular, the role of visceral adipose tissue, insulin resistance, and adipocytokines in the exacerbation of these conditions. While no therapy has been proven effective for treating NAFLD/NASH, common recommendations will be discussed.