Cross-sectional Area Of Visceral Fat Research Articles

Efficacy and safety of tesamorelin in people with hiv on integrase inhibitors.

Tesamorelin is the only FDA-approved therapy to treat abdominal fat accumulation in people with HIV (PWH). Phase III clinical trials were conducted prior to the introduction of integrase inhibitors (INSTIs), which are now a mainstay of HIV antiretroviral therapy. We leveraged a randomized double-blind trial of 61 PWH and metabolic dysfunction-associated steatotic liver disease to evaluate the efficacy and safety of tesamorelin 2 mg once daily versus identical placebo among participants on INSTI-based regimens at baseline. In the parent clinical trial, visceral fat cross-sectional area, hepatic fat fraction, and trunk-to-appendicular fat ratio were quantified using magnetic resonance imaging, proton magnetic resonance spectroscopy, and dual-energy x-ray absorptiometry, respectively, at baseline and 12 months. Metabolic and safety outcomes were compared between treatment arms. Among 38 participants on INSTI-based regimens at baseline, 15 individuals on tesamorelin and 16 individuals on placebo completed the 12-month study. Tesamorelin led to significant declines in visceral fat (median [interquartile range]: -25 [-93, -2] vs. 14 [3, 41] cm2, P = 0.001), hepatic fat (-4.2% [-12.3%, -2.7%] vs. -0.5% [-3.9%, 2.7%], P = 0.01), and trunk-to-appendicular fat ratio (-0.1 [-0.3, 0.0] vs. 0.0 [-0.1, 0.1], P = 0.03). Tesamorelin was well-tolerated with a similar frequency of adverse events including hyperglycemia between groups. The current analysis provides the first dedicated data on the efficacy and safety of tesamorelin among PWH on INSTI-based regimens. Despite the association of INSTI use with weight gain and adipose tissue dysfunction, tesamorelin had beneficial effects on body composition with no exacerbation of glycemic control.

Differentiation Between Ulcerative Colitis and Crohn's Disease Using Abdominal Computed Tomography in Patients With First-Time Inflammatory Bowel Disease.

Background Ulcerative colitis (UC) and Crohn's disease (CD) are classified as inflammatory bowel diseases (IBDs). However, they have different pathogeneses and treatment strategies and need to be differentiated. Purpose To determine the feasibility of differentiating UC from CD in patients with first-time IBD based on simple abdominal computed tomography (CT) findings. Methods We conducted a retrospective study of patients diagnosed with IBD for the first time at our hospital between January and December 2021. Age, sex, white blood cell count, albumin concentration, C-reactive protein concentration, visceral fat area, subcutaneous fat area, and psoas major volume were extracted and used to differentiate the two groups. Results Forty-three patients were selected. Their mean age was 35.60 ± 17.19 years, and 32 were male, while 11 were female. The visceral fat cross-sectional area was 51.80 cm2 for UC and 21.10 cm2 for CD (p < 0.01). The subcutaneous fat cross-sectional area was 108.30 cm2 for UC and 66.30 cm2 for CD (p = 0.049). The total protein concentration was 6.15 g/L for UC and 6.60 g/L for CD (p = 0.012). Receiver operating characteristic curve analysis of the visceral and subcutaneous fat cross-sectional areas showed areas under the curve, 95% confidence intervals, sensitivities, and specificities of 0.750 and 0.675, 0.603-0.897 and 0.507-0.844, 0.810 and 1.00, and 0.591 and 0.409, respectively, at cutoffs of 26.53 and 36.6 cm2. Conclusions The visceral and subcutaneous fat cross-sectional areas determined with simple abdominal CT can differentiate UC from CD in patients with first-time IBD.

Healthy US population reference values for CT visceral fat measurements and the impact of IV contrast, HU range, and spinal levels

Measurements of visceral adipose tissue cross-sectional area and radiation attenuation from computed tomography (CT) scans provide useful information about risk and mortality. However, scan protocols vary, encompassing differing vertebra levels and utilizing differing phases of contrast enhancement. Furthermore, fat measurements have been extracted from CT using different Hounsfield Unit (HU) ranges. To our knowledge, there have been no large studies of healthy cohorts that reported reference values for visceral fat area and radiation attenuation at multiple vertebra levels, for different contrast phases, and using different fat HU ranges. Two-phase CT scans from 1,677 healthy, adult kidney donors (age 18–65) between 1999 and 2017, previously studied to determine healthy reference values for skeletal muscle measures, were utilized. Visceral adipose tissue cross-sectional area (VFA) and radiation attenuation (VFRA) measures were quantified using axial slices at T10 through L4 vertebra levels. T-tests were used to compare males and females, while paired t-tests were conducted to determine the effect (magnitude and direction) of (a) contrast enhancement and (b) different fat HU ranges on each fat measure at each vertebra level. We report the means, standard deviations, and effect sizes of contrast enhancement and fat HU range. Male and female VFA and VFRA were significantly different at all vertebra levels in both contrast and non-contrast scans. Peak VFA was observed at L4 in females and L2 in males, while peak VFRA was observed at L1 in both females and males. In general, non-contrast scans showed significantly greater VFA and VFRA compared to contrast scans. The average paired difference due to contrast ranged from 1.6 to − 8% (VFA) and 3.2 to − 3.0% (VFRA) of the non-contrast value. HU range showed much greater differences in VFA and VFRA than contrast. The average paired differences due to HU range ranged from − 5.3 to 22.2% (VFA) and − 5.9 to 13.6% (VFRA) in non-contrast scans, and − 4.4 to 20.2% (VFA) and − 4.1 to 12.6% (VFRA) in contrast scans. The − 190 to − 30 HU range showed the largest differences in both VFA (10.8% to 22.2%) and VFRA (7.6% to 13.6%) compared to the reference range (− 205 to − 51 HU). Incidentally, we found that differences in lung inflation result in very large differences in visceral fat measures, particularly in the thoracic region. We assessed the independent effects of contrast presence and fat HU ranges on visceral fat cross-sectional area and mean radiation attenuation, finding significant differences particularly between different fat HU ranges. These results demonstrate that CT measurements of visceral fat area and radiation attenuation are strongly dependent upon contrast presence, fat HU range, sex, breath cycle, and vertebra level of measurement. We quantified contrast and non-contrast reference values separately for males and females, using different fat HU ranges, for lumbar and thoracic CT visceral fat measures at multiple vertebra levels in a healthy adult US population.

Obesity and muscle may have synergic effect more than independent effects on brain volume in community-based elderly.

To evaluate the individual and combined effects of obesity and muscle mass on brain volume in a community-dwelling healthy older population. One thousand two hundred nine participants (M:F = 574:635, mean age 63.6 ± 6.9years) were included. The cross-sectional area of visceral fat (VF), the height-adjusted appendicular skeletal muscle mass (ASM/height2), and the ratio of thigh muscle to visceral fat (TM/VF) represented obesity, muscle mass, and their integrated value, respectively. Linear regression analysis was performed to establish associations between 215 brain compartment volumes and VF, ASM/height2, and TM/VF after adjusting for covariates. On regression analysis, TM/VF had a positive correlation to the volumes of temporal lobe and cerebellum. TM/VF was associated with volumes of 10 subcompartments. TM/VF was positively correlated with the volumes of left entorhinal cortex, right temporal pole and inferior temporal gyrus related to cognition (p< 0.05, respectively), and the volumes of cerebellum and right pallidum related to movement (p< 0.05, respectively). However, VF had a negative correlation to temporal lobe volume and ASM/height2 had no significant correlation to any of the brain lobes. VF and ASM/height2 were correlated with volumes of 5 subcompartments and one subcompartment, respectively, CONCLUSIONS: TM/VF reflects the integrated effect of obesity and muscle mass and is associated with the volume of more brain regions compared to indices of obesity or muscle mass alone. The positive effect of muscle mass and the negative effect of obesity change the volumes of brain regions related to cognition and movement which were not significantly affected by obesity or muscle mass alone. • If obesity and muscle mass were considered together, we could find more significant brain volume changes which were not found in obesity or muscle alone. • The ratio of thigh muscle to visceral fat was positively correlated with the volumes of entorhinal cortex, temporal pole, and inferior temporal gyrus related to cognition. • The ratio of thigh muscle to visceral fat was positively correlated with the volumes of cerebellum and pallidum related to movement.

Comparison of visceral fat measurement by dual-energy X-ray absorptiometry to computed tomography in HIV and non-HIV

Background/ObjectivesIndividuals with HIV are susceptible to visceral fat accumulation, which confers an increased risk of cardiometabolic disease. Advanced software to ascertain visceral fat content from dual-energy X-ray absorptiometry (DXA) has not been validated among this population. We sought to compare DXA with computed tomography (CT) in the measurement of visceral fat cross-sectional area (VAT) in HIV and non-HIV using Bland–Altman analyses.Subjects/MethodsData were combined from five previously conducted studies of individuals with HIV (n = 313) and controls without HIV (n = 144) in which paired DXA and CT scans were available. In cross-sectional analyses, DXA-VAT was compared with CT-VAT among participants with and without HIV. In longitudinal analyses, changes in VAT over time were compared between DXA and CT among participants with and without HIV receiving no intervention over 12 months and among individuals with HIV receiving tesamorelin—a medication known to reduce VAT—over 6 months.ResultsIn HIV, DXA underestimated VAT compared with CT among individuals with increased visceral adiposity. The measurement bias was −9 ± 47 cm2 overall, but became progressively larger with greater VAT (P < 0.0001), e.g., −61 ± 58 cm2 among those with VAT ≥ 200 cm2. Sex-stratified analyses revealed that the relationship between VAT and measurement bias was especially pronounced in men (P < 0.0001). Longitudinally, DXA underestimated changes in VAT, particularly among those at the extremes of VAT gain or loss (P < 0.0001). In contrast to the cross-sectional findings, the tendency for DXA to underestimate longitudinal changes in VAT was evident in both men and women. Analogous findings were seen among controls in cross-sectional and longitudinal analyses.ConclusionsDXA underestimated VAT relative to CT in men with and without HIV, who had increased visceral adiposity. DXA also underestimated changes in VAT over time in men and women, irrespective of HIV status. DXA-VAT should be used with caution among both HIV and non-HIV-infected populations.

Normal pancreatic volume in adults is influenced by visceral fat, vertebral body width and age.

The aim was to describe the pancreatic volume (PV) in a cohort of subjects with no prior history of pancreatic disease, and to explore the relationship between PV and conventional two-point measurements of the pancreas. Associations between PV, gender, age, abdominal body composition, and human height were explored as well. CT scans from 204 trauma patients (20-80years, 100 males) were evaluated. PV was measured with semi-automatic segmentation. Standardized two-point measurements of the pancreas were obtained together with L1 vertebral body size (a proxy for human height) and abdominal body composition. Associations between PV and the other parameters were explored using uni- and multivariate linear regression. The mean PV was 77.9 ± 21.7(SD) cm3 with an interindividual variability from 18.8 to 139.8cm3. The transversal diameter of the pancreatic head showed the strongest correlation to PV (r = 0.500, p < 0.001). Age, width of the L1 vertebral body, and visceral fat cross-sectional area were all independently associated with PV (all p < 0.001), while no independent association was seen for gender (p = 0.441). The pancreatic volume is subject to a large interindividual variability and is associated with age, human height and body composition, while gender had no independent influence on the pancreatic volume. Thus, future studies using PV as an outcome parameter should be evaluated in the context of anthropometric profiles.

An Assessment of the Relationship Between Abdominal Obesity and the Severity of Upper Extremity Lymphedema.

Obesity is one of the well-known initiating and aggravating factors of lymphedema. Body mass index (BMI) is typically used to define obesity, but in Asian populations, health risks are elevated at lower BMI levels, and abdominal fat may be a better obesity metric. Thus, we assessed the potential association between abdominal obesity and lymphedema severity in postoperative breast cancer patients. Thirty-three women with breast cancer-related lymphedema participated in this study. Arm circumference was measured at four locations per arm to identify the maximal circumference difference (MCD) between the affected and unaffected sides. All patients underwent lymphoscintigraphy, and we calculated the quantitative asymmetry index (QAI) of both arms. A computed tomography was also performed to assess abdominal obesity after lymphedema. Abdominal obesity was classified as a visceral fat cross-sectional area larger than 70 cm2. Fourteen women (42%) were obese (BMI ≥25 kg/m2), and 18 women (54%) had increased abdominal fat. BMI obesity and abdominal obesity were significantly correlated, but five patients were classified with abdominal obesity, despite a BMI below 25 kg/m2. The mean arm circumference difference was 2.8 ± 2.4 cm. Decreased axillary QAI was significantly correlated with obesity, and increased arm edema (MCD ≥2 cm) was significantly correlated with abdominal obesity. Abdominal obesity was significantly correlated with increased MCD and should be considered along with obesity as an aggravating factor for lymphedema severity.

Can pancreatic cancer behavior be predicted based on computed tomography measurements of fat and muscle mass?

Introduction:Many studies purport that obesity, and specifically visceral fat, impact survival after pancreaticoduodenectomy for pancreatic adenocarcinoma. However, these studies involve crude measures of obesity [eg, body mass index (BMI)] or visceral fat [eg, linear measurements on computed tomographic (CT) scans]. Some studies purport that weight loss and muscle wasting (ie, sarcopenia) presage poor survival in these patients. This study was undertaken to accurately measure and reexamine the impact of visceral fat, subcutaneous fat, and sarcopenia on pancreatic cancer.Materials and methods:CT scans of 100 patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma were reviewed using specialized software to precisely determine the cross-sectional area (CSA) of subcutaneous fat, visceral fat, and psoas muscles at the level of L5 vertebra. In addition, linear measurements of subcutaneous fat and visceral fat were undertaken. Measures of cancer progression included tumor (T) status, nodal (N) status, American Joint Committee on Cancer stage, and overall survival after resection. Regression analysis was utilized, with and without standardization of all measurements to body size. Median data are presented.Results:The median patient age was 67 years, with a BMI of 24 kg/m2. Cancer stage was IIB for 60% of patients. BMI, CSA of visceral fat, CSA for subcutaneous fat, CSA for psoas muscles, and linear measurements of visceral and subcutaneous fat were not significantly related to any measures of cancer progression or survival. Standardization to body size did not demonstrate any relationships with cancer progression or survival.Conclusions:Precise and reproducible measures of visceral fat, subcutaneous fat, and muscle mass, even when standardized to body size, do not predict cancer progression or survival in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma. Pancreatic cancer biology and behavior is too complex to predict with a CT scanner. The main focus of pancreatic cancer research should continue to be at the molecular, genetic, and immunologic levels.

Association of visceral fat area with abdominal skeletal muscle distribution in overweight Japanese adults

Quantitative evaluation of visceral fat mass and skeletal muscle mass is important for health promotion. Recently, some studies suggested the existence of adipocyte-myocyte negative crosstalk. If so, abdominal skeletal muscles may easily and negatively affected not only by the age but also the visceral fat because age-related reduction in abdominal region is greater compared with limbs. We cross-sectionally examined the existence of quantitative associations between visceral fat area and abdominal skeletal muscle distribution in overweight people. A total of 230 Japanese males and females who aged 40-64 years and whose body mass index (BMI) was 28.0-44.8kg/m2 participated in this study. The cross-sectional area (CSA) of the visceral fat, subcutaneous fat, and abdominal skeletal muscles, namely, the rectus abdominis, abdominal oblique, erector spinae, and iliopsoas muscles were measured by the computed tomography images. Stepwise regression analyses revealed the existence of sex difference in the relation between visceral fat CSA and other morphological variables. In males, BMI was a positive, and the iliopsoas muscle group CSA was a negative contributor of the visceral fat CSA. In females, both age and BMI were selected as positive contributors. These data suggested that the visceral fat CSA may negatively associated with iliopsoas muscle group CSA in males. In females, the visceral fat CSA was not significantly related to the distribution of the abdominal skeletal muscle groups.

The Relationships between Metabolic Disorders (Hypertension, Dyslipidemia, and Impaired Glucose Tolerance) and Computed Tomography-Based Indices of Hepatic Steatosis or Visceral Fat Accumulation in Middle-Aged Japanese Men.

BackgroundMost studies on the relationships between metabolic disorders (hypertension, dyslipidemia, and impaired glucose tolerance) and hepatic steatosis (HS) or visceral fat accumulation (VFA) have been cross-sectional, and thus, these relationships remain unclear. We conducted a retrospective cohort study to clarify the relationships between components of metabolic disorders and HS/VFA.MethodsThe participants were 615 middle-aged men who were free from serious liver disorders, diabetes, and HS/VFA and underwent multiple general health check-ups at our institution between 2009 and 2013. The data from the initial and final check-ups were used. HS and VFA were assessed by computed tomography. HS was defined as a liver to spleen attenuation ratio of ≤1.0. VFA was defined as a visceral fat cross-sectional area of ≥100 cm2 at the level of the navel. Metabolic disorders were defined using Japan’s metabolic syndrome diagnostic criteria. The participants were divided into four groups based on the presence (+) or absence (-) of HS/VFA. The onset rates of each metabolic disorder were compared among the four groups.ResultsAmong the participants, 521, 55, 24, and 15 were classified as HS(-)/VFA(-), HS(-)/VFA(+), HS(+)/VFA(-), and HS(+)/VFA(+), respectively, at the end of the study. Impaired glucose tolerance was more common among the participants that exhibited HS or VFA (p = 0.05). On the other hand, dyslipidemia was more common among the participants that displayed VFA (p = 0.01).ConclusionsIt is likely that VFA is associated with impaired glucose tolerance and dyslipidemia, while HS might be associated with impaired glucose tolerance. Unfortunately, our study failed to detect associations between HS/VFA and metabolic disorders due to the low number of subjects that exhibited fat accumulation. Although our observational study had major limitations, we consider that it obtained some interesting results. HS and VFA might affect different metabolic disorders. Further large-scale longitudinal studies are needed to reveal the relationships between the components of metabolic disorders and HS/VFA.

Potential Risks And Distribution Pattern Of Intramuscular Fat In Obese Children

PURPOSE: The purpose of this study was to assess relationship between IMF and physiological and biochemical variables. METHODS: Thirty-seven obese boys and girls participated in this study (age, 10.4 ± 2.1 years; height, 146.2 ± 13.4 cm; weight, 56.1 ± 16.5 kg; percentage of overweight, 41.1 ± 16.8%). This study was conducted a part of treatment of the subjects and was approved by the institutional review board of local committees. Computed tomography (CT) images were taken at the mid-thigh and umbilicus levels. Using the CT images, IMF index of the quadriceps femoris (QF), hamstrings (HM) and adductor (AD) muscle groups based on mean grey scale level of the interested muscle groups and visceral fat cross-sectional area (CSA) were calculated. For the mid-thigh CT image, skeletal muscle CSA and subcutaneous fat was also calculated. Plasma triglyceride, FFA, HDL-cholesterol, total-cholesterol, AST, ALT, glucose and HbA1c were measured from fasting blood drop. RESULTS: IMF index of QF, HM and AD was significantly different in all comparisons: HM was the lowest (1066 ± 6), meaning largest IMF depot, and QF was the highest (1080 ± 3), meaning smallest IMF depot. Stepwise regression analysis revealed that QF CSA, visceral fat CSA, and triglyceride were extracted to predict IMF index in QF (R=0.707, P < 0.01). For IMF index in HM, visceral fat CSA, age, triglyceride, percentage of overweight, and sex were extracted (R=0.806, P < 0.01). Interestingly, percentage of overweight was the only extracted variable to predict IMF index in AD (R=0.529, P < 0.01). CONCLUSIONS: These results suggest that muscle-specific IMF deposition pattern was observed in obese children and that intramuscular fat in each muscle group may have physiological and biochemical specific roles.

Skeletal muscle utilization of free fatty acids in women with visceral obesity.

Visceral obesity is strongly associated with insulin resistance. One potential cause is increased availability of FFA. Alternatively, it has been proposed that there is impaired oxidation of lipid in individuals at risk for obesity. The extent to which either concept involves skeletal muscle is uncertain. To examine these opposing hypotheses, 17 healthy lean and obese premenopausal women, among whom cross-sectional area of visceral fat ranged from 18 to 180 cm2, participated in leg balance studies for measurement of FFA and glucose utilization during basal and insulin-stimulated conditions. A metabolic profile of skeletal muscle, based on enzyme activity, was determined in vastus lateralis muscle obtained by percutaneous biopsy. Visceral fat content was negatively correlated with insulin sensitivity (rates of leg glucose uptake and storage), but insulin resistance was not caused by glucose-FFA competition. During hyperinsulinemia, neither leg FFA uptake nor oxidation was increased in women with visceral obesity. During fasting conditions, however, rates of FFA uptake across the leg were negatively correlated with visceral adiposity as were activities of muscle carnitine palmitoyl transferase and citrate synthase. In summary, visceral adiposity is clearly associated with skeletal muscle insulin resistance but this is not due to glucose-FFA substrate competition. Instead, women with visceral obesity have reduced postabsorptive FFA utilization by muscle.