Recently, the beneficial effects of increased physical activity (PA) on nonalcoholic fatty liver disease (NAFLD) in obese subjects were reported. However, the optimal strength and volume of PA in ...lifestyle modification to improve NAFLD pathophysiology and be recommended as an appropriate management of this condition are unclear. The primary goal of this retrospective study was to estimate the beneficial effects of a varying volume of moderate to vigorous intensity PA (MVPA) on the improvement of NAFLD. A total of 169 obese, middle‐aged men were enrolled in a 12‐week weight reduction program through lifestyle modification consisting of dietary restrictions plus aerobic exercise. Among these obese subjects, 40 performed MVPA for <150 min·wk−1, 42 performed MVPA for 150‐250 min·wk−1, and 87 performed MVPA for >250 min·wk−1. The subjects in the MVPA ≥250 min·wk−1 group, in comparison with those in the MVPA <250 min·wk−1 group, showed significantly attenuated levels of hepatic steatosis (−31.8% versus −23.2%). This attenuation was likely independent of the detectable weight reduction. MVPA for ≥250 min·wk−1 in comparison with that for <150 min·wk−1 led to a significant decrease in the abdominal visceral adipose tissue severity (−40.6% versus −12.9%), levels of ferritin (−13.6% versus +1.5%), and lipid peroxidation (−15.1% versus −2.8%), and a significant increase in the adiponectin levels (+17.1% versus +5.6%). In association with these changes, the gene expression levels of sterol regulatory element‐binding protein‐1c and carnitine palmitoyltransferase‐1 in peripheral blood mononuclear cells also significantly decreased and increased, respectively. Conclusion: MVPA for ≥250 min·wk−1 as part of lifestyle management improves NAFLD pathophysiology in obese men. The benefits seem to be acquired through reducing inflammation and oxidative stress levels and altering fatty acid metabolism. (Hepatology 2015;61:1205–1215)
Background
Not only obesity but also sarcopenia is associated with NAFLD. The influence of altered body composition on the pathophysiology of NAFLD has not been fully elucidated. The aim of this ...study is to determine whether skeletal muscle mass to visceral fat area ratio (SV ratio) affects NAFLD pathophysiology.
Methods
A total of 472 subjects were enrolled. The association between SV ratio and NAFLD pathophysiological factors was assessed in a cross-sectional nature by stratification analysis.
Results
When the SV ratio was stratified by quartiles (
Q
1
–
Q
4
), the SV ratio showed a negative relationship with the degree of body mass index, HOMA-IR, and liver stiffness (
Q
1
, 8.9 ± 7.5 kPa, mean ± standard deviation;
Q
2
, 7.5 ± 6.2;
Q
3
, 5.8 ± 3.7;
Q
4
, 5.0 ± 1.9) and steatosis (
Q
1
, 282 ± 57 dB/m;
Q
2
, 278 ± 58;
Q
3
, 253 ± 57;
Q
4
, 200 ± 42) measured by transient elastography. Levels of leptin and biochemical markers of liver cell damage, liver fibrosis, inflammation and oxidative stress, and hepatocyte apoptosis were significantly higher in subjects in
Q
1
than in those in
Q
2
,
Q
3
, or
Q
4
. Moreover, fat contents in femoral muscles were significantly higher in subjects in
Q
1
and the change was associated with weakened muscle strength. In logistic regression analysis, NAFLD subjects with the decreased SV ratio were likely to have an increased risk of moderate-to-severe steatosis and that of advanced fibrosis.
Conclusions
Decreased muscle mass coupled with increased visceral fat mass is closely associated with an increased risk for exacerbating NAFLD pathophysiology.
This paper presents a fully integrated energy harvester that maintains >35% end-to-end efficiency when harvesting from a 0.84 mm 2 solar cell in low light condition of 260 lux, converting 7 nW input ...power from 250 mV to 4 V. Newly proposed self-oscillating switched-capacitor (SC) DC-DC voltage doublers are cascaded to form a complete harvester, with configurable overall conversion ratio from 9× to 23×. In each voltage doubler, the oscillator is completely internalized within the SC network, eliminating clock generation and level shifting power overheads. A single doubler has >70% measured efficiency across 1 nA to 0.35 mA output current ( >10 5 range) with low idle power consumption of 170 pW. In the harvester, each doubler has independent frequency modulation to maintain its optimum conversion efficiency, enabling optimization of harvester overall conversion efficiency. A leakage-based delay element provides energy-efficient frequency control over a wide range, enabling low idle power consumption and a wide load range with optimum conversion efficiency. The harvester delivers 5 nW-5 μW output power with >40% efficiency and has an idle power consumption 3 nW, in test chip fabricated in 0.18 μm CMOS technology.
Aim
The underlying mechanism of non‐obese non‐alcoholic fatty liver disease (NAFLD) has not been fully elucidated. We classified patients with NAFLD by sex and body mass index and compared their ...clinical features to clarify the background pathophysiology of non‐obese NAFLD.
Methods
A total of 404 patients with NAFLD were divided according to their body mass index (<25 non‐obese, 25 to <30 obese, and ≥30 severe obese), and were further compared with 253 patients without obesity and NAFLD (non‐NAFLD).
Results
The proportion of the individuals with non‐obese NAFLD was 25.7% in men and 27.6% in women. The male and female non‐obese NAFLD groups had lower skeletal muscle mass and muscle strength than the obese NAFLD groups. The visceral fat area, although low, was ≥100 cm2 in 59.3% of men and 43.8% of women. An increase in liver fat accumulation, hepatic fibrosis, homeostasis model assessment of insulin resistance, and leptin levels was modest in the non‐obese NAFLD group compared with a marked increase in the obese NAFLD groups. The muscle mass of the non‐obese NAFLD group was similar to that of the non‐NAFLD group, but muscle steatosis was particularly common among women. Multivariate analysis revealed that the factors contributing to increased liver fat accumulation in the non‐obese NAFLD group were visceral fat area, HbA1c, myostatin, and leptin.
Conclusions
In patients with non‐obese NAFLD, a sex difference was observed in the clinical features. In addition to increased visceral fat, decreased muscle mass and muscle strength, muscle atrophy (presarcopenia), and impaired glucose tolerance were considered to be important pathophysiological factors.
PURPOSEWeight reduction remains the most common therapy advocated for the treatment of obesity-related liver diseases. Recently, a beneficial effect of exercise regimens for liver dysfunction, ...independent of weight reduction, has been reported. Therefore, a retrospective analysis was conducted to determine whether exercise training without dietary restriction in obese, middle-age men influences the pathophysiology of abnormal liver function.
METHODSA total of 108 subjects who completed a 12-wk exercise training program without any dietary restriction were analyzed in this study; these results were compared with those of 104 subjects who completed a 12-wk dietary restriction program. Furthermore, 42 of these subjects (from both groups) who had abnormal liver function and suspicious liver fibrosis by nonalcoholic fatty liver disease fibrosis score were analyzed to obtain a more concrete outcome for exercise-training effects.
RESULTSIn exercise training, although the magnitude of body-weight reduction (−3.1% vs −8.5%), waist circumference (−4.0% vs −7.1%), and visceral adipose tissue area (−12.2% vs −22.5%) was significantly more modest than that achieved by dietary restriction, exercise training elicited equivalent reductions in serum alanine aminotransferase and gamma glutamyl transpeptidase levels (−20.6% vs −16.1% and −25.7% vs −34.0%) and equivalent improvement of insulin resistance (−29.7% vs −26.9%). Moreover, exercise training remarkably increased the serum adiponectin level (+33.4% vs +15.1%). Importantly, for subjects with abnormal liver function and suspicious liver fibrosis, exercise training was effective in reducing the serum levels of inflammation and oxidative stress markersferritin and thiobarbituric acid reactive substances (−25.0% vs +1.1% and −33.5% vs −10.5%).
CONCLUSIONSExercise training benefits the management of obesity-related liver diseases independent of detectable weight reduction. Particularly, these effects seem to be acquired through an improvement in the hepatic inflammatory condition and its related oxidative stress levels.
A dual-slope capacitance-to-digital converter for pressure-sensing is presented and demonstrated in a complete microsystem. The design uses base capacitance subtraction with a configurable capacitor ...bank to narrow down input capacitance range and reduce conversion time. An energy-efficient iterative charge subtraction method is proposed, employing a current mirror that leverages the 3.6 V battery supply available in the system. We also propose dual-precision comparators to reduce comparator power while maintaining high accuracy during slope conversion, further improving energy efficiency. The converter occupies 0.105 mm 2 in 180 nm CMOS and achieves 44.2 dB SNR at 6.4 ms conversion time and 110 nW of power, corresponding to 5.3 pJ/conv-step FoM. The converter is integrated with a pressure transducer, battery, processor, power management unit, and radio to form a complete 1.4 mm × 2.8 mm × 1.6 mm pressure sensor system aimed at implantable devices. The multi-layer system is implemented in 180 nm CMOS. The system was tested for resolution in a pressure chamber with an external 3.6 V supply and serial communication bus, and the measured resolution of 0.77 mmHg was recorded. We also demonstrated the wireless readout of the pressure data on the stack system operating completely wirelessly using an integrated battery.
This population-based cross-sectional study aimed to determine whether the triglyceride-glucose index (TyG index) is associated with sarcopenic obesity (SO) and whether it would be a helpful ...indicator of SO.
A total of 3821 participants aged ≥ 60 years were selected for the study group, and 4919 participants aged 20-39 years were included as a reference group. The participants were allocated to sarcopenia, obesity, and SO groups depending on if their body mass index (BMI) was ≥25 kg/m
and their sarcopenia index was ≤1 standard deviation (SD) lower than the mean of the reference group. The sex-specific differences and trends among the participants were analyzed by using the TyG index tertiles, and appropriate cut-off values of the TyG index for SO were calculated.
As the TyG index increased, BMI increased, but the sarcopenia index decreased in both sexes. Males and females in the middle and highest tertiles of the TyG index were 1.775 and 3.369, and they were 1.993 and 3.157 times more likely to have SO, respectively. The cut-off values of the TyG index for SO in males and females were ≥8.72 and 8.67, respectively.
A high TyG index is positively associated with SO, and the TyG index may be considered a potential indicator of SO.
Bioenergy produced from co-digestion of sewage sludge (SS) and rice straw (RS) as raw materials, without pretreatment and additional nutrients, was compared for the one-stage system for producing ...methane (CH4) and the two-stage system for combined production of hydrogen (H2) and CH4 in batch experiments under thermophilic conditions. In the first stage H2 fermentation process using untreated RS with raw SS, we obtained a high H2 yield (21 ml/g-VS) and stable H2 content (60.9%). Direct utilization of post-H2 fermentation residues readily produced biogas, and significantly enhanced the CH4 yield (266 ml/g-VS) with stable CH4 content (75–80%) during the second stage CH4 fermentation process. Overall, volatile solids removal (60.4%) and total bioenergy yield (8804 J/g-VS) for the two-stage system were 37.9% and 59.6% higher, respectively, than the one-stage system. The efficient production of bioenergy is believed to be due to a synergistically improved second stage process exploiting the well-digested post-H2 generation residues over the one-stage system.
•High H2 yield from raw feedstock obtained through seeding non-heated raw sludge.•H2 fermentation performed from untreated RS by raw SS under TS conditions of 17.0%.•H2 fermentation is an effective pretreatment for solubilization of organic wastes.•Direct use of post-H2 fermentation residues significantly enhanced CH4 production.•Highest bioenergy yield attained in the two-stage process of co-digestion.
The concept of metabolically obese, normal weight (MONW) has emerged to describe individuals with a normal body mass index (BMI) who are at a relatively high risk of chronic diseases. However, BMI ...itself is a suboptimal index for the assessment of the health risks associated with visceral fat. The triglyceride-glucose (TyG) index is considered to be a reliable and cost-effective marker of insulin resistance. Therefore, in the present study, we aimed to determine the TyG index cut-off values that could be used to define MONW in older people and to determine the usefulness of these values for the prediction of chronic diseases.
A total of 4,721 participants in the Korea National Health and Nutritional Examination Survey who were ≥ 60 years of age and did not have underweight or obesity were included. MONW was defined using the criteria for metabolic syndrome (MS), and the TyG index was calculated on the basis of the fasting plasma triglyceride and glucose concentrations. Chronic diseases, including T2DM, hypertension, and non-alcoholic fatty liver disease (NAFLD), were diagnosed.
The prevalence of MS increased from the lowest to the highest TyG index tertile. The cut-off values of the TyG index for MONW were calculated as 8.88 and 8.80 for males and females, respectively. MONW, defined using these cut-off values, was associated with high odds ratios for NAFLD, T2DM, and hypertension in both males and females.
The TyG index cut-off values calculated in the present study can be used to discriminate individuals with MONW from other older individuals without obesity and to predict the risk of chronic diseases. These findings show that the TyG index is an effective and cost-efficient method of assessing the risk of chronic diseases in people with MONW.
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