Respiratory sinus arrhythmia in spontaneously breathing, unanesthetized newborn and adult Wistar rats.

We examined respiratory sinus arrhythmia (RSA) and possible interaction with respiratory frequency (fR) and heart rate (HR) in spontaneously breathing, unanesthetized newborn Wistar rats (2- to 5-day-old; n = 54) and the adult rats (8-week-old; n = 34). Instantaneous heart rate (inst-HR) was calculated as the reciprocal of the inter-beat-interval. For each breath, RSA was determined as the difference between the maximum and minimum inst-HR value. The absolute RSA or RSA% (RSA per HR) were calculated as the average RSA of 10 consecutive breaths. RSA (or RSA%) in the newborn rats was significantly lower than that in the adult rats. Correlation coefficient between RSA (or RSA%) and 1/fR or HR/fR, but not HR, was significant in newborn rats, whereas only that between RSA (or RSA%) and HR was significant in adult rats. The power spectrum density of heartbeat fluctuation was detectable in both age groups. The present findings suggest that RSA exists and could be influenced by fR, rather than HR, in newborn rats.

Effect of dexmedetomidine on cardiorespiratory regulation in spontaneously breathing adult rats.

PURPOSE: We examined the cardiorespiratory effect of dexmedetomidine, an α2- adrenoceptor/imidazoline 1 (I1) receptor agonist, in spontaneously breathing adult rats. METHODS: Male rats (226-301 g, n = 49) under isoflurane anesthesia had their tail vein cannulated for drug administration and their tail artery cannulated for analysis of mean arterial pressure (MAP), pulse rate (PR), and arterial blood gases (PaO2, PaCO2, pH). After recovery, one set of rats received normal saline for control recording and was then divided into three experimental groups, two receiving dexmedetomidine (5 or 50 µg·kg-1) and one receiving normal saline (n = 7 per group). Another set of rats was divided into four groups receiving dexmedetomidine (50 µg·kg-1) followed 5 min later by 0.5 or 1 mg∙kg-1 atipamezole (selective α2-adrenoceptor antagonist) or efaroxan (α2-adrenoceptor/I1 receptor antagonist) (n = 6 or 8 per group). Recordings were performed 15 min after normal saline or dexmedetomidine administration. RESULTS: Compared with normal saline, dexmedetomidine (5 and 50 µg·kg-1) decreased respiratory frequency (fR, p = 0.04 and < 0.01, respectively), PR (both p < 0.01), and PaO2 (p = 0.04 and < 0.01), and increased tidal volume (both p = 0.049). Dexmedetomidine at 5 µg·kg-1 did not significantly change minute ventilation (V'E) (p = 0.87) or MAP (p = 0.24), whereas dexmedetomidine at 50 µg·kg-1 significantly decreased V'E (p = 0.03) and increased MAP (p < 0.01). Only dexmedetomidine at 50 µg·kg-1 increased PaCO2 (p < 0.01). Dexmedetomidine (5 and 50 µg·kg-1) significantly increased blood glucose (p < 0.01), and dexmedetomidine at 50 µg·kg-1 increased hemoglobin (p = 0.04). Supplemental atipamezole or efaroxan administration similarly prevented the 50 µg·kg-1 dexmedetomidine-related cardiorespiratory changes. PRINCIPAL CONCLUSION: These results suggest that dexmedetomidine-related hypoventilation and hypertension are observed simultaneously and occur predominantly through activation of α2-adrenoceptors, but not I1 receptors, in spontaneously breathing adult rats.

Ipragliflozin Improves the Hepatic Outcomes of Patients With Diabetes with NAFLD.

Sodium glucose cotransporter-2 inhibitors (SGLT2is) are now widely used to treat diabetes, but their effects on nonalcoholic fatty liver disease (NAFLD) remain to be determined. We aimed to evaluate the effects of SGLT2is on the pathogenesis of NAFLD. A multicenter, randomized, controlled trial was conducted in patients with type 2 diabetes with NAFLD. The changes in glycemic control, obesity, and liver pathology were compared between participants taking ipragliflozin (50 mg/day for 72 weeks; IPR group) and participants being managed without SGLT2is, pioglitazone, glucagon-like peptide-1 analogs, or insulin (CTR group). In the IPR group (n = 25), there were significant decreases in hemoglobin A1c (HbA1c) and body mass index (BMI) during the study (HbA1c, -0.41%, P < 0.01; BMI, -1.06 kg/m2 , P < 0.01), whereas these did not change in the CTR group (n = 26). Liver pathology was evaluated in 21/25 participants in the IPR/CTR groups, and hepatic fibrosis was found in 17 (81%) and 18 (72%) participants in the IPR and CTR groups at baseline. This was ameliorated in 70.6% (12 of 17) of participants in the IPR group and 22.2 % (4 of 18) of those in the CTR group (P < 0.01). Nonalcoholic steatohepatitis (NASH) resolved in 66.7% of IPR-treated participants and 27.3% of CTR participants. None of the participants in the IPR group developed NASH, whereas 33.3% of the CTR group developed NASH. Conclusion: Long-term ipragliflozin treatment ameliorates hepatic fibrosis in patients with NAFLD. Thus, ipragliflozin might be effective for the treatment and prevention of NASH in patients with diabetes, as well as improving glycemic control and obesity. Therefore, SGLT2is may represent a therapeutic choice for patients with diabetes with NAFLD, but further larger studies are required to confirm these effects.

Case Report: Metreleptin and SGLT2 Inhibitor Combination Therapy Is Effective for Acquired Incomplete Lipodystrophy.

Childhood cancer survivors (CCSs) who have undergone bone marrow transplantation with systemic chemotherapy and whole-body irradiation often experience impaired glucose tolerance with marked insulin resistance. Incomplete acquired diabetic lipodystrophy should be considered as a late complication of bone marrow transplantation. A 24-year-old Japanese female patient with incomplete acquired lipodystrophy, a CCS of acute lymphocytic leukemia at the age of 3 years, was treated for diabetes mellitus and dyslipidemia at our hospital. Administration of multiple daily insulin injections (70 units/day), and oral administration of 500 mg/day metformin, 15 mg/day pioglitazone, and 200 mg/day bezafibrate had proven ineffective for her metabolic disorders. Subcutaneous administration of metreleptin improved her insulin resistance and hypertriglyceridemia within a month; however, it failed to maintain adequate plasma glucose levels in the long term. When oral administration of 10 mg/day empagliflozin was added to the metreleptin supplementation, her HbA1c value (National Glycohemoglobin Standardization Program) improved from 11% to 8%, which was maintained for an additional 18 months. This is the first case report of incomplete lipodystrophy that shows efficacy of a combination therapy with metreleptin and a sodium glucose cotransporter 2 (SGLT2) inhibitor for the treatment of diabetes and dyslipidemia. An SGLT2 inhibitor attenuates hyperglycemia through urinary glucose excretion and has been suggested to enhance lipid catabolism in the extra-adipose tissues, especially in the liver and skeletal muscles. Furthermore, metreleptin supplementation could enhance the action of the SGLT2 inhibitor by promoting satiety and lipolysis through the central nervous system. Combination therapy with metreleptin and an SGLT2 inhibitor was suggested to recover the volume of adipose tissue, possibly through improvement of insulin resistance in the adipose tissue. This report highlights the pathophysiological mechanism of an SGLT2 inhibitor in the improvement of glucose metabolism in non-healthy lean CCSs with insulin resistance. Administration of SGLT2 inhibitor, along with metreleptin supplementation, could be a good alternative therapy for diabetic lipodystrophy observed in CCSs.

Porphyromonas gingivalis impairs glucose uptake in skeletal muscle associated with altering gut microbiota.

Skeletal muscles have a high metabolic capacity, which play key roles in glucose metabolism. Although periodontal disease increases the risk of metabolic syndrome, the relationship between periodontal bacterial infection and skeletal muscle metabolic dysfunction is unclear. We found that anti-Porphyromonas gingivalis (Pg) antibody titers positively correlated with intramuscular adipose tissue content (IMAC), fasting blood glucose, and HOMA-IR in metabolic syndrome patients. In C57BL/6J mice fed a high-fat diet, recipients of oral Pg (HFPg) had impaired glucose tolerance, insulin resistance, and higher IMAC compared to recipients of saline (HFco). The soleus muscle in HFPg mice exhibited fat infiltration and lower glucose uptake with higher Tnfa expression and lower insulin signaling than in HFco mice. Gene set enrichment analysis showed that TNFα signaling via NFκB gene set was enriched in the soleus muscle of HFPg mice. Moreover, TNF-α also decreased glucose uptake in C2C12 myoblast cells in vitro. Based on 16S rRNA sequencing, Pg administration altered the gut microbiome, particularly by decreasing the abundance of genus Turicibacter. Microbial network of the gut microbiome was dramatically changed by Pg administration. Our findings suggest that infection with Pg is a risk factor for metabolic syndrome and skeletal muscle metabolic dysfunction via gut microbiome alteration.

Decrease in fasting insulin secretory function correlates with significant liver fibrosis in Japanese non-alcoholic fatty liver disease patients.

BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is typically associated with metabolic syndrome and diabetes, and insulin resistance is involved in its pathogenesis. However, the relationship between insulin secretion and NAFLD is unclear. We aimed to characterize the relationship between fasting insulin secretory function (ISF), evaluated using the homeostatic model assessment-beta cell function (HOMA-ß) and the severity of fibrosis during NAFLD. METHODS: A-ß was calculated in 188 patients with biopsy-confirmed NAFLD, and the correlations between Log HOMA-ß and clinical parameters, including hepatic fibrosis, were calculated. RESULTS: Log HOMA-ß was significantly lower in NAFLD patients with significant fibrosis (stages 2-4) than in those in the early stages (stages 0-1) (median [interquartile range]) (2.1 [1.9-2.4] vs 2.0 [1.8-2.2], P = 0.04). The prevalence of significant fibrosis decreased with increasing Log HOMA-ß: it was 59.2% in participants with low ISF (Log HOMA-ß < 1.85), 43.6% in those with intermediate ISF (1.85 ≤ Log HOMA-ß < 2.25), and 68.0% in those with high ISF (Log HOMA-ß ≥ 2.25). Patients with lower Log HOMA-ß had lower current body mass index (BMI), BMI at 20 years of age, and peak lifetime BMI than patients with intermediate or high Log HOMA-ß. CONCLUSIONS: Fasting ISF decreased alongside the development of liver fibrosis in NAFLD, suggesting that an impaired ß cell function has a characteristic finding of significant liver fibrosis in relatively nonobese Japanese patients.

Glucagon-Like Peptide-1 Receptor Agonist Prevented the Progression of Hepatocellular Carcinoma in a Mouse Model of Nonalcoholic Steatohepatitis.

Glucagon-like peptide-1 (GLP-1) receptor agonists are used to treat diabetes, but their effects on nonalcoholic steatohepatitis (NASH) and the development of hepatocellular carcinoma (HCC) remain unclear. In this study, mice with streptozotocin- and high-fat diet-induced diabetes and NASH were subcutaneously treated with liraglutide or saline (control) for 14 weeks. Glycemic control, hepatocarcinogenesis, and liver histology were compared between the groups. Fasting blood glucose levels were significantly lower in the liraglutide group than in the control group (210.0 ± 17.3 mg/dL vs. 601.8 ± 123.6 mg/dL), and fasting insulin levels were significantly increased by liraglutide (0.18 ± 0.06 ng/mL vs. 0.09 ± 0.03 ng/mL). Liraglutide completely suppressed hepatocarcinogenesis, whereas HCC was observed in all control mice (average tumor count, 5.5 ± 3.87; average tumor size, 8.1 ± 5.0 mm). Liraglutide significantly ameliorated steatosis, inflammation, and hepatocyte ballooning of non-tumorous lesions in the liver compared with the control findings, and insulin-positive ß-cells were observed in the pancreas in liraglutide-treated mice but not in control mice. In conclusion, liraglutide ameliorated NASH and suppressed hepatocarcinogenesis in diabetic mice. GLP-1 receptor agonists can be used to improve the hepatic outcome of diabetes.

Epidemiological survey of hemoglobin A1c and liver fibrosis in a general population with non-alcoholic fatty liver disease.

AIM: The association between glycemia and liver fibrosis was analyzed using hemoglobin A1c (HbA1c) and the Fibrosis-4 (FIB-4) index in a large general population cohort that underwent a health checkup. METHODS: A total of 6927 subjects without hepatitis B or C virus infection or habitual alcohol intake were enrolled. Non-alcoholic fatty liver disease (NAFLD) was diagnosed by ultrasonography and potential liver fibrosis (FIB-4 index ≥1.3) in NAFLD was analyzed in relation to HbA1c level. Factors associated with potential liver fibrosis of NAFLD were also analyzed. RESULTS: The overall frequency of NAFLD was 27.9% (1935 subjects) and the frequency of NAFLD by HbA1c level (<4.9%, 5.0-5.9%, 6.0-6.9%, 7.0-7.9%, ≥8.0%) was 16%, 27%, 54%, 53%, and 54%, respectively. Among the 1935 NAFLD cases, the frequency of potential liver fibrosis was 25.2% (487 subjects) overall and 19%, 22%, 30%, 52%, and 31%, respectively, by HbA1c category. From multivariate analysis, an HbA1c level ≥6.5% was significantly associated with potential liver fibrosis (P = 0.017, hazard ratio = 1.7). CONCLUSIONS: The prevalence of NAFLD and liver fibrosis of NAFLD increased according to glycemia, up to 8.0% HbA1c. Measuring HbA1c and calculating the FIB-4 index in health checkups could help to identify potential cases of liver fibrosis of NAFLD, which should then be further evaluated using other techniques to confirm liver fibrosis.

Author Correction: Periodontal pathogenic bacteria, Aggregatibacter actinomycetemcomitans affect non-alcoholic fatty liver disease by altering gut microbiota and glucose metabolism.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Supplementation with branched-chain amino acids ameliorates hypoalbuminemia, prevents sarcopenia, and reduces fat accumulation in the skeletal muscles of patients with liver cirrhosis.

BACKGROUND: Liver cirrhosis induces marked metabolic disorders, protein-energy malnutrition, and sarcopenia. The objective of the study reported here was to investigate the effects of dietary branched-chain amino acids (BCAAs) on systemic glucose metabolism, skeletal muscle, and prognosis of patients with liver cirrhosis. METHODS: Japanese patients with liver cirrhosis (n = 21) were enrolled into a longitudinal study in which their diets were supplemented with BCAAs. We evaluated glucose metabolism and analyzed the skeletal muscle area index (SAI) and intramuscular adipose tissue content (IMAC) using computed tomography. RESULTS: After 48 weeks of supplementation with BCAAs, there were no changes in glucose metabolism and skeletal muscle findings. In patients with ameliorated hypoalbuminemia, IMAC was significantly decreased and SAI was preserved concomitant with decreasing 90- and 120-min post-challenge plasma glucose levels (P < 0.01 each). In patients without increased albumin levels, IMAC was significantly increased and the SAI was significantly decreased (P < 0.01 each). Liver-related event-free survival rates for 72 months were 63.6% in patients with decreased IMAC and 20.0% in patients with increased IMAC. CONCLUSIONS: Amelioration of hypoalbuminemia associated with BCAA supplementation correlated with decreased fat accumulation in skeletal muscle, maintenance of skeletal muscle mass, and improved glucose sensitivity, all factors which may contribute to improving the survival of patients with liver cirrhosis.

Periodontal pathogenic bacteria, Aggregatibacter actinomycetemcomitans affect non-alcoholic fatty liver disease by altering gut microbiota and glucose metabolism.

Increasing evidence indicates that periodontitis affects non-alcoholic fatty liver disease (NAFLD). We examined the relationship between periodontal bacterial infection and clinical/biochemical parameters in 52 NAFLD patients. Anti-Aggregatibacter actinomycetemcomitans (Aa) antibody titers correlated positively with visceral fat, fasting plasma insulin, and HOMA-IR; and negatively with the liver/spleen ratio. C57BL/6J mice (8-weeks-old) were given Aa or saline (control) for 6 weeks, and were fed either normal chow (NCAa, NCco) or high-fat diet (HFAa and HFco). NCAa and HFAa mice presented impaired glucose tolerance and insulin resistance compared to control mice. HFAa mice showed higher hepatic steatosis than HFco animals. Liver microarray analysis revealed that 266 genes were differentially expressed between NCAa and NCco mice. Upregulated genes in Aa-administrated mice were enriched for glucagon signaling pathway, adipocytokine signaling pathway and insulin resistance. Consistently, plasma glucagon concentration was higher in NCAa mice. In addition, Akt phosphorylation was lower in the liver of NCAa/HFAa than in NCco/HFco mice. Based on 16S rRNA sequencing, Aa administration changed composition of the gut microbiota. Metagenome prediction in gut microbiota showed upregulation of fatty acid biosynthesis and downregulation of fatty acid degradation in Aa-administered mice. Thus, infection with Aa affects NAFLD by altering the gut microbiota and glucose metabolism.

Influence of muscle fiber type composition on early fat accumulation under high-fat diet challenge.

OBJECTIVE: To investigate whether differences in muscle fiber types affect early-stage fat accumulation, under high fat diet challenge in mice. METHODS: Twelve healthy male C57BL/6 mice experienced with short-term (6 weeks) diet treatment for the evaluation of early pattern changes in muscular fat. The mice were randomly divided into two groups: high fat diet (n = 8) and normal control diet (n = 4). Extra- and intra-myocellular lipid (EMCL and IMCL) in lumbar muscles (type I fiber predominant) and tibialis anterior (TA) muscle (type II fiber predominant) were determined using magnetic resonance spectroscopy (MRS). Correlation of EMCL, IMCL and their ratio between TA and lumbar muscles was evaluated. RESULTS: EMCL increased greatly in both muscle types after high fat diet. IMCL in TA and lumbar muscles increased to a much lower extent, with a slightly greater increase in TA muscles. EMCLs in the 2 muscles were positively correlated (r = 0.84, p = 0.01), but IMCLs showed a negative relationship (r = -0.84, p = 0.01). In lumbar muscles, high fat diet significantly decreased type I fiber while it increased type II fiber (all p≤0.001). In TA muscle, there was no significant fiber type shifting (p>0.05). CONCLUSIONS: Under short-time high fat diet challenge, lipid tends to initially accumulate extra-cellularly. In addition, compared to type II dominant muscle, Type I dominant muscle was less susceptible to IMCL accumulation but more to fiber type shifting. These phenomena might reflect compensative responses of skeletal muscle to dietary lipid overload in order to regulate metabolic homeostasis.

Biphasic effect of alcohol intake on the development of fatty liver disease.

BACKGROUND: Fatty liver is an important clinical feature not only in alcoholic and non-alcoholic fatty liver diseases, but in other chronic liver diseases as well. Our aim was to elucidate the effect and relationship between habitual alcohol intake and obesity in the development of fatty liver disease. METHODS: We enrolled 8,029 subjects undergoing abdominal ultrasonography with general medical examinations, and analyzed the factors associated with fatty liver based on daily alcohol intake, body mass index (BMI), and waist circumference. RESULTS: For fatty liver, BMI, waist circumference, total cholesterol, triglycerides, and fasting plasma glucose were significant and independent risk factors. Heavy alcohol intake (50 g/day) was a significant risk factor for fatty liver in women (odds ratio [OR], 3.35). Analysis based on the presence or absence of obesity revealed that moderate alcohol intake was a significant negative risk factor for fatty liver in both male and female obese (BMI ≥25 kg/m(2)) subjects (OR, 0.74 for non-obese and 0.39 for obese patients, respectively). Heavy alcohol intake was also a significant negative risk factor in obese males (0.62). In contrast, heavy alcohol intake was a risk factor in non-obese males (OR, 1.29) and in all females (OR, 2.22 for non-obese and 6.6 for obese patients, respectively). CONCLUSIONS: The influence of alcohol intake on fatty liver differed depending on the level of alcohol consumption, gender, and the presence of obesity, and showed biphasic effects.

Pilot study of liraglutide effects in non-alcoholic steatohepatitis and non-alcoholic fatty liver disease with glucose intolerance in Japanese patients (LEAN-J).

AIM: Non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome, is associated with an increased risk of developing lifestyle-related diseases including type 2 diabetes, cardiovascular disease and cerebral vessel disease. No current drug therapy provides the ideal effects of decreasing hepatic inflammation while simultaneously improving liver fibrosis. Liraglutide is a glucagon-like peptide-1 receptor agonist that affects the histological findings in patients with non-alcoholic steatohepatitis (NASH). This study was conducted to evaluate the effect and action of liraglutide for biopsy-proven NASH. METHODS: After lifestyle modification intervention for 24 weeks, subjects whose hemoglobin A1c levels failed to improve to less than 6.0% and/or whose alanine aminotransferase levels were not lower than baseline, received liraglutide at 0.9 mg/body per day for 24 weeks. RESULTS: Of 27 subjects, 26 completed the lifestyle modification intervention. Nineteen subjects received liraglutide therapy for 24 weeks. Body mass index, visceral fat accumulation, aminotransferases and glucose abnormalities improved significantly. Repeated liver biopsy was performed in 10 subjects who continued liraglutide therapy for 96 weeks. Six subjects showed decreased histological inflammation as determined by NASH activity score and stage determined by Brunt classification. We saw no significant adverse events during therapy with liraglutide. CONCLUSION: Our pilot study demonstrated that treatment with liraglutide had a good safety profile and significantly improved liver function and histological features in NASH patients with glucose intolerance.

Upper limit of normal serum alanine aminotransferase levels in Japanese subjects.

AIM: Serum alanine aminotransferase (ALT) is important for screening, diagnosis and management of chronic liver diseases. The incidence of non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH), which is considered a hepatic manifestation of lifestyle-related diseases, is increasing worldwide. However, the upper limit of the normal ALT level has not yet been established because of not excluding many lifestyle-related diseases. The aim of this study was to evaluate the upper limit of normal serum ALT levels in Japanese subjects. METHODS: We analyzed the serum ALT levels of 11 404 Japanese subjects negative for hepatitis B surface antigen and hepatitis C virus antibody, and who received health check-ups. Lifestyle factors related to ALT levels were determined by multivariate analysis. Subjects with all factors identified by multivariate analysis within the normal range were defined as "healthy" subjects. The 90th percentile of ALT levels in healthy subjects was defined as the upper limit of normal ALT. RESULTS: Whereas alcohol intake was not a significant factor, the following were independently associated with ALT concentration by multivariate analysis: sex; age; body mass index; waist circumference; concentrations of total cholesterol, high-density lipoprotein cholesterol, triglycerides and fasting blood glucose; and fatty liver on ultrasonography. Healthy subjects consisted of 1462 (21.2%) men and 2046 (45.4%) women, and the 90th percentiles of the ALT levels in the two groups were 29 and 23 IU/L, respectively. CONCLUSION: The upper limits of normal ALT when considering lifestyle factors in Japanese subjects were 29 IU/L in men and 23 IU/L in women.

Efficacy of ezetimibe for reducing serum low-density lipoprotein cholesterol levels resistant to lifestyle intervention in patients with non-alcoholic fatty liver disease.

AIM: To investigate the efficacy of ezetimibe and lifestyle intervention for treating patients with non-alcoholic fatty liver disease (NAFLD) and residual dyslipidemia via a combination of ezetimibe and lifestyle intervention. METHODS: Patients with NAFLD with residual dyslipidemia after a 6-month lifestyle intervention program were included. After completion of the 6-month program, the patients received p.o. administration of ezetimibe at 10 mg/day, in addition to lifestyle intervention, for 6 months. RESULTS: Of the 59 patients with NAFLD who had participated in the 6-month lifestyle intervention program between 2007 and 2012, 21 with residual dyslipidemia (10 males and 11 females) were enrolled. Median age was 58 years (range, 27-75), median bodyweight was 63.0 kg (range, 39.4-109.0), median body mass index was 25.4 kg/m2 (range, 18.2-37.1), median alanine aminotransferase was 23 IU/L (14-73), median high-density lipoprotein (HDL) was 58 mg/dL (range, 37-93), median triglycerides (TG) was 105 mg/dL (range, 42-216) and median low-density lipoprotein (LDL) was 153 (66-209) mg/dL. After 6 months of treatment with ezetimibe, serum LDL levels were improved in 15 of 20 (75%) patients (P = 0.0015), while no improvements were observed in the remaining five patient (25%). Ezetimibe was discontinued in one patient who developed skin rash. CONCLUSION: Ezetimibe is effective for treating residual dyslipidemia after lifestyle intervention in patients with NAFLD.

Severity of non-alcoholic steatohepatitis is associated with substitution of adipose tissue in skeletal muscle.

BACKGROUND AND AIMS: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is now focusing on its organ cross-talk with not only adipose tissue but also systemic skeletal muscle. Cross-sectional and longitudinal studies were conducted to determine the role of intramuscular adipose tissue content (IMAC) measured by computed tomography on the severity of NAFLD/non-alcoholic steatohepatitis (NASH). METHODS: Two hundred eight Japanese patients with NAFLD/NASH diagnosed by liver biopsy were enrolled into a cross-sectional study. Twenty-one patients were enrolled in a longitudinal study and received a programmed diet and exercise intervention, in some cases the combination of pharmacotherapy. We measured IMAC in the multifidus muscle and biochemical parameters, and conducted liver histology to assess NAFLD/NASH status. RESULTS: Histopathological stage in terms of simple steatosis and Brunt's classification was significantly correlated with IMAC (P < 0.01). Multivariate logistic regression analysis indicated that risk factors associated with the severity of NASH were IMAC and aging (IMAC: odds ratio = 2.444, P < 0.05; Age: odds ratio = 2.355, P < 0.05). The interventions improved histopathological changes in 11 patients with NASH as well as IMAC. CONCLUSION: These results suggest that skeletal muscle fat accumulation may have been linked to the pathogenesis and severity of NASH.

The pathological role of visceral fat accumulation in steatosis, inflammation, and progression of nonalcoholic fatty liver disease.

BACKGROUND: Our previous studies have indicated a close association between visceral fat accumulation and hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). This study investigated whether visceral fat accumulation was related to the pathogenesis and disease progression of nonalcoholic steatohepatitis (NASH)/NAFLD. METHODS: First, a total of 550 subjects who underwent a health checkup and measurement of visceral fat accumulation, done with a bioelectrical impedance analyzer (X-SCAN; Owa Medical, Fukuoka, Japan), were included. The relationship between visceral fat accumulation and biochemical parameters was examined. Second, a total of 74 patients with NASH/NAFLD who underwent liver biopsy were reviewed. Visceral fat accumulation was determined by abdominal computed tomography. The association between visceral fat accumulation and the histopathological grade/stage determined by the NAFLD activity score and Brunt's classification was evaluated. RESULTS: There was a significant relationship between visceral fat accumulation and glucose, triglyceride, and alanine aminotransferase (ALT; r = 0.423, P < 0.01). In stepwise regression analysis, visceral fat area (VFA), serum triglyceride level, and serum low-density lipoprotein (LDL)-cholesterol level were selected as predictor variables for serum ALT level, in a continuous manner (serum ALT level = -1.359 + 0.143 × VFA + 0.046 × triglyceride + 0.059 × LDL, R(2) = 0.217, P < 0.001). In patients with NASH, there was no correlation between histological grade and the visceral fat volume. Visceral fat accumulation in patients with stage 3/4 advanced NASH was greater than that in patients with stage 1/2 early NASH (P < 0.05). CONCLUSIONS: These results suggest that visceral fat accumulation plays a role in steatosis and fibrosis in the pathogenesis and prognosis of NAFLD.

Age-related fat deposition in multifidus muscle could be a marker for nonalcoholic fatty liver disease.

BACKGROUND: Although nonalcoholic fatty liver disease (NAFLD) is associated with visceral obesity, the relationship between visceral fat accumulation and skeletal muscle steatosis in patients with NAFLD has not been established. We evaluated: (1) the relationship between multifidus muscular tissue steatosis, visceral fat accumulation, and biochemical data in a cross-sectional study, and (2) the influence of weight reduction on multifidus muscular tissue steatosis in a longitudinal study. METHODS: Three hundred thirty-three NAFLD patients were enrolled. Hepatic steatosis, visceral fat area, and the multifidus muscle/subcutaneous fat attenuation ratio (MM/F ratio) were evaluated by computed tomography. To evaluate how weight reduction produced by diet and exercise affected the MM/F ratio, changes in the MM/F ratio were compared between weight reduction and non-weight reduction groups. RESULTS: There was a gender difference in MM/F ratios. The MM/F ratio was significantly correlated with age (male r = 0.613, P < 0.01; female r = 0.440, P < 0.01). The MM/F ratio was positively correlated with visceral fat area (male: r = 0.262, P < 0.01; female: r = 0.214, P < 0.01). A decrease in the MM/F ratio, concomitant with reduced visceral fat accumulation, led to alleviation of hepatic steatosis in 20 patients with weight reduction, but not in 22 patients without weight reduction. CONCLUSIONS: The MM/F ratio was closely related to aging and visceral fat accumulation. The MM/F ratio was improved by weight reduction, indicating that fat accumulation in the multifidus muscle evaluated by computed tomography might be a therapeutic indicator of NAFLD.

Evaluation of acoustic radiation force impulse elastography for fibrosis staging of chronic liver disease: a pilot study.

BACKGROUND: Acoustic radiation force impulse (ARFI) is a new technology integrated into conventional B-mode ultrasonography. ARFI is used to evaluate tissue stiffness in several organs, but this method has not been applied for liver fibrosis. AIM: The aim of this study was to determine whether ARFI elastography is useful for the evaluation of liver fibrosis. METHODS: This study enrolled 55 consecutive patients with chronic liver disease who underwent a liver biopsy for histological assessment of liver fibrosis by the Metavir scoring system. Liver stiffness of the 55 patients and 25 healthy volunteers was evaluated by ARFI elastography and was expressed as the shear wave velocity. Cut-off values were determined using receiver-operating characteristic (ROC) curves. RESULTS: Histological liver fibrosis was evaluated by Metavir scoring; F0: six cases, F1: 14 cases, F2: nine cases, F3: nine cases and F4: 17 cases. Liver stiffness determined by ARFI elastography was correlated with histological liver fibrosis (P<0.0001). The areas under the ROC curves were 0.94 (95% confidence intervals, 0.87-0.99) for F2-F4, 0.94 (0.88-0.99) for F3-F4 and 0.96 (0.91-1.01) for F4. The cut-off values of the shear wave velocity were as follows: >1.34 m/s for F2-F4 (sensitivity 91.4%, specificity 80%); >1.44 m/s for F3-F4 (sensitivity 96.2%, specificity 79.3%); and >1.80 m/s for F4 (sensitivity 94.1%, specificity 86.8%). CONCLUSIONS: Ultrasonic ARFI elastography is a novel, non-invasive and reliable method for the assessment of liver fibrosis in patients with chronic liver disease.