Rina So

Moderate to vigorous physical activity volume is an important factor for managing nonalcoholic fatty liver disease: A retrospective study

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)

Best single-slice measurement site for estimating visceral adipose tissue volume after weight loss in obese, Japanese men

BackgroundAlthough the measurement site at L4–L5 for visceral adipose tissue (VAT) has been commonly accepted, some researchers suggest that additional upper sites (i.e., L1–L2 and L2–L3) are useful for estimating VAT volume. Therefore, determining the optimum measurement site remains challenging and has become important in determining VAT volume. We investigated the influence of a single-slice measurement site on the prediction of VAT volume and changes in VAT volume in obese Japanese men.MethodsTwenty-four men, aged 30–65 years with a mean BMI of 30 kg/m2, were included in a 12-week weight loss program. We obtained continuous T1-weighted abdominal magnetic resonance images from T9 to S1 with a 1.5-T system to measure the VAT area. These VAT areas were then summed to determine VAT volume before and after the program.ResultsSingle-slice images at 3–11 cm above L4–L5 had significant and high correlations with VAT volume at baseline (r = 0.94–0.97). The single-slice image with the highest correlation coefficient with respect to VAT volume was located at 5 cm above L4–L5 (r = 0.97). The highest correlation coefficient between the individual changes in VAT area and changes in VAT volume was located at 6 cm above L4–L5 (r = 0.90).ConclusionsIndividual measurement sites have different abilities to estimate VAT volume and changes in VAT volume in obese Japanese men. Best zone located at 5–6 cm above L4–L5 may be a better predictor of VAT volume than the L4–L5 image in terms of both baseline and changes with weight loss.

Association between type 2 diabetes genetic susceptibility loci and visceral and subcutaneous fat area as determined by computed tomography

Visceral fat accumulation has an important role in the development of several metabolic disorders, such as type 2 diabetes, dyslipidemia and hypertension. New genetic loci that contribute to the development of type 2 diabetes have been identified by genome-wide association studies. To examine the association of type 2 diabetes susceptibility loci and visceral fat accumulation, we genotyped 1279 Japanese subjects (556 men and 723 women), who underwent computed tomography for measurements of visceral fat area (VFA) and subcutaneous fat area (SFA) for the following single-nucleotide polymorphisms (SNPs): NOTCH2 rs10923931, THADA rs7578597, PPARG rs1801282, ADAMTS9 rs4607103, IGF2BP2 rs1470579, VEGFA rs9472138, JAZF1 rs864745, CDKN2A/CDKN2B rs564398 and rs10811661, HHEX rs1111875 and rs5015480, TCF7L2 rs7901695, KCNQ1 rs2237892, KCNJ11 rs5215 and rs5219, EXT2 rs1113132, rs11037909, and rs3740878, MTNR1B rs10830963, DCD rs1153188, TSPAN8/LGR5 rs7961581, and FTO rs8050136 and rs9939609. None of the above SNPs were significantly associated with VFA. The FTO rs8050136 and rs9939609 risk alleles exhibited significant associations with body mass index (BMI; P=0.00088 and P=0.0010, respectively) and SFA (P=0.00013 and P=0.00017, respectively). No other SNPs were significantly associated with BMI or SFA. Our results suggest that two SNPs in the FTO gene are associated with subcutaneous fat accumulation. The contributions of other SNPs are inconclusive because of a limitation of the sample power.

Multiple-slice magnetic resonance imaging can detect visceral adipose tissue reduction more accurately than single-slice imaging.

Background/Objective:Imaging methods by magnetic resonance imaging are being increasingly used to quantify visceral adipose tissue (VAT), but there is no clear consensus as to a standardized protocol. We compared the ability of two commonly used imaging protocols (multiple slice versus single slice) to detect changes in VAT with diet or exercise.Subjects/Methods:We utilized data from the participants who completed our diet (n=22) or exercise (n=35) based weight-loss interventions. The intervention mainly comprised of weekly dietary modification sessions or aerobic exercise sessions over 12 weeks. Multiple-slice images obtained from T9 to S1 and a single-slice image at L4–L5 were compared using the effect size of the VAT change. In addition, we calculated the sample size needed to compare the two imaging protocols’ ability to detect significant changes in VAT.Results:VAT and subcutaneous adipose tissue volumes and areas, and other anthropometry decreased significantly after both the diet and exercise interventions. For VAT, a single-slice image had a lower effect size (diet: 1.23; exercise: 0.49) than the multiple-slice images (diet: 1.81; exercise: 0.90). The sample size required for multiple slice was substantially lower than for the single-slice with both weight-loss interventions.Conclusions:The different image protocols may lead to different results in relative VAT changes. Furthermore, single-slice imaging required a substantially larger sample size than multiple-slice imaging, and for researchers to detect smaller changes in VAT with single-slice imaging, a larger sample size would be needed. Thus, multiple-slice imaging has advantages for assessing VAT change in future clinical research.

High-Intensity Aerobic Exercise Improves Both Hepatic Fat Content and Stiffness in Sedentary Obese Men with Nonalcoholic Fatty Liver Disease

We compared the effects of 12-week programs of resistance training (RT), high-intensity interval aerobic training (HIAT), and moderate-intensity continuous aerobic training (MICT). The primary goal was to evaluate the therapeutic effects of the exercise modalities for the management of nonalcoholic fatty liver disease (NAFLD). A total of 61 sedentary obese men with NAFLD were randomized into one of the following exercise regimens (RT, HIAT, or MICT). Hepatic fat content was decreased to a similar extent in the RT, HIAT, and MICT groups (−14.3% vs. −13.7% vs. −14.3%) without significant changes in weight and visceral fat. The gene expression levels of fatty acid synthesis were significantly decreased in the subjects’ monocytes. Hepatic stiffness was decreased only in the HIAT group (−16.8%). The stiffness change was associated with restored Kupffer cell phagocytic function (+17.8%) and decreased levels of inflammation such as leptin (−13.2%) and ferritin (−14.1%). RT, HIAT, and MICT were equally effective in reducing hepatic fat content, but only HIAT was effective in improving hepatic stiffness and restoring Kupffer cell function. These benefits appeared to be independent of detectable weight and visceral fat reductions; the benefits were acquired through the modulation of in vivo fatty acid metabolism and obesity-related inflammatory conditions.

Lifestyle modification decreases arterial stiffness and plasma asymmetric dimethylarginine level in overweight and obese men.

BackgroundIncreased arterial stiffness is an independent risk factor for cardiovascular disease. Arterial stiffness is higher in obese individuals than in nonobese individuals. Lifestyle modifications (i.e. exercise and dietary modification) decrease arterial stiffness in obese individuals. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase, an enzyme responsible for the generation of nitric oxide. AimThe aim of this study was to examine whether lifestyle modifications affect circulating levels of ADMA in overweight and obese men and, if they do, whether ADMA is involved in the mechanism underlying the decrease in arterial stiffness with lifestyle modification. MethodsSeventeen overweight and obese men (BMI: 29.8±0.8 kg/m2) completed a 12-week lifestyle modification program, which included aerobic exercise and dietary modification. Before and after the intervention, we evaluated brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, and plasma ADMA concentration in all participants. ResultsAfter the 12-week lifestyle modification program, BMI and baPWV decreased significantly and the plasma ADMA concentration decreased markedly in overweight and obese men. There was a significant positive correlation between percent change in baPWV and plasma ADMA concentration. ConclusionLifestyle modifications reduce arterial stiffness and plasma ADMA concentration in overweight and obese individuals. A decrease in arterial stiffness was associated with a corresponding reduction in plasma ADMA concentrations. These results suggest that reductions in ADMA may be an important mechanism underlying the beneficial effect of lifestyle modification on arterial stiffness.

Effects of lifestyle modification on central blood pressure in overweight and obese men.

ObjectiveIt has recently been recognized that increased central blood pressure is a predictor of cardiovascular disease. Central blood pressure is higher in obese individuals than in nonobese individuals. However, the effect of lifestyle modification on central systolic blood pressure in obese individuals is unclear. The aim of this study was to determine whether lifestyle modification decreases central blood pressure in overweight and obese men. MethodsThirty-nine overweight and obese men (age, 49±2 years; BMI, 30±1 kg/m2) were recruited into our study. We measured central systolic blood pressure and brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, before and after a 12-week lifestyle modification that included aerobic exercise and dietary modification. ResultsAfter the 12-week program, body mass, BMI, and waist circumstance decreased significantly. Central systolic blood pressure and baPWV were significantly decreased after the lifestyle modification in overweight and obese men. Furthermore, there was a significant correlation between the lifestyle modification-induced change in central systolic blood pressure and that in baPWV. ConclusionThis study showed for the first time that lifestyle modification-induced weight loss decreases central systolic blood pressure in overweight and obese men. The decrease in central systolic blood pressure was associated with the reduction in arterial stiffness. These results suggest that lifestyle modification-induced reduction in arterial stiffness may contribute toward the decreased central systolic blood pressure in overweight and obese men.

Lifestyle Modification Decreases Arterial Stiffness in Overweight and Obese Men: Dietary Modification vs. Exercise Training

Obesity and increased arterial stiffness are independent risk factors for cardiovascular disease. Arterial stiffness is increased in obese individuals than in age-matched nonobese individuals. We demonstrated that dietary modification and exercise training are effective in reducing arterial stiffness in obese persons. However, the differences in the effect on arterial stiffness between dietary modification and exercise training are unknown. The purpose of the current study was to compare the effect of dietary modification and aerobic exercise training on arterial stiffness and endothelial function in overweight and obese persons. Forty-five overweight and obese men (48 ± 1 year) completed either a dietary modification (well-balanced nutrient, 1680 kcal/day) or an exercise-training program (walking, 40-60 min/day, 3 days/week) for 12 weeks. Before and after the intervention, all participants underwent anthropometric measurements. Arterial stiffness was measured based on carotid arterial compliance, brachial-ankle pulse wave velocity (baPWV), and endothelial function was determined by circulating level of endothelin-1 (ET-1) and nitric oxide metabolite (nitrites/nitrate as metabolite: NOx). Body mass and waist circumference significantly decreased after both intervention programs. Weight loss was greater after dietary modification than after exercise training (-10.1 ± 0.6 kg vs. -3.6 ± 0.5 kg, p < .01). Although arterial stiffness and the plasma levels of ET-1 and NOx were improved after dietary modification or exercise training, there were no differences in those improvements between the 2 types of interventions. Exercise training improves arterial function in obese men without as much weight loss as after dietary modification.

Effect of aerobic exercise training followed by a low-calorie diet on metabolic syndrome risk factors in men

BACKGROUND AND AIMS Whether low-volume, high-intensity, interval training (HIIT) is an adequate exercise method for improving metabolic risk factors is controversial. Moreover, it is not known if performing a short-term, low-calorie diet intervention (LCDi) after a HIIT program affects risk factors. This study investigated how an 8-week, 3 times/week exercise intervention (EXi) incorporating either HIIT or moderate-intensity continuous training (MICT) followed by a 4-week LCDi affects risk factors. METHODS AND RESULTS Twenty-six male workers with metabolic risk factors (47.4 ± 7.1 years; cardiorespiratory capacity (VO2peak) of 28.5 ± 3.9 ml/kg/min) were randomly assigned to either the HIIT (3 sets of 3-min cycling with a 2-min active rest between sets, 180 kcal) or MICT (45 min, 360 kcal) group. After the EXi, all subjects participated in a 4-week LCDi (4 counseling sessions). During the EXi, VO2peak improved more (P < 0.05) through HIIT (25.4 ± 14.6%) than through MICT (14.9 ± 12.8%), whereas improvements in body fat and HDL cholesterol were similar. During the LCDi, some risk factors improved further (P < 0.05) without any group differences, while VO2peak in the HIIT group decreased (P < 0.05) to the same level as in the MICT group. CONCLUSION VO2peak increased more with HIIT than with MICT during the EXi despite HIIT having a lower exercise volume than MICT, but this advantage of HIIT promptly disappeared through detraining. An intervention strategy consisting of 8 weeks of either HIIT or MICT followed by a 4-week LCDi has a positive effect on metabolic risk factors. CLINICAL TRIAL REGISTRATION UMIN11352.

Acceleration training for improving physical fitness and weight loss in obese women

BACKGROUND Reducing body weight and visceral adipose tissue (VAT) are the primary goals for maintaining health in obese individuals as compared to those of normal weight, but it is also important to maintain physical fitness for a healthy life after weight-loss. Acceleration training (AT) has recently been indicated as an alternative to resistance training for elite athletes and also as a component of preventive medicine. However, it is unclear whether combining AT with a weight-loss diet will improve physical fitness in obese individuals. The present study aimed to determine the synergistic effects of AT on body composition and physical fitness with weight-loss program in overweight and obese women. METHODS Twenty-eight obese, middle-aged women were divided into two groups as follows: diet and aerobic exercise group (DA; BMI: 29.3 ± 3.0 kg/m2); and diet, aerobic exercise and acceleration training group (DAA; BMI: 31.2 ± 4.0 kg/m2). Both groups included a 12-week weight-loss program. Body composition, visceral adipose tissue (VAT) area and physical fitness (hand grip, side-to-side steps, single-leg balance with eyes closed, sit-and-reach and maximal oxygen uptake) were measured before and after the program. RESULT Body weight, BMI, waist circumference and VAT area decreased significantly in both groups. Hand grip (2.1 ± 3.0 kg), single-leg balance (11.0 ± 15.4 s) and sit-and-reach (6.5 ± 4.8 cm) improved significantly only in the DAA group. CONCLUSIONS Our findings indicate that combining AT with classical lifestyle modifications is effective at reducing VAT, and it may enhance muscle strength and performance in overweight and obese women.