Morphometric Assessment as a Predictor of Outcome in Older Vascular Surgery Patients.

BACKGROUND: Frailty is a recognized predictor of poor outcome in patients undergoing surgical intervention. Frailty is intricately linked with body morphology, which can be evaluated using morphometric assessment via computerized tomographic (CT) imaging. We aimed to assess the predictive power of such objective assessments in a broad cohort of vascular surgical patients. METHODS: A consecutive series of patients aged over 65 years admitted to a vascular unit, who had undergone CT imaging of the abdomen, were analyzed. Demographic and patient-specific data were collated alongside admission relevant information. Outcomes included mortality, length of stay, health care-related costs, and discharge destination. Images were analyzed for 4 morphometric measurements: (1) psoas muscle area, (2) mean psoas density, (3) subcutaneous fat depth, and (4) intra-abdominal fat depth, all taken at the level of the fourth lumbar vertebra. RESULTS: Two hundred and ten patients were initially analyzed. Forty-four patients had significant retroperitoneal and abdominal abnormalities that limited appropriate CT analysis. Decreased subcutaneous fat depth was significantly associated with mortality, readmission within 12 months, and increased cost of health care (P < 0.01, adjusted for confounders). Psoas muscle area was significantly associated with readmission-free survival. CONCLUSIONS: Morphometric analysis predicts poorer outcome in a broad cohort of vascular surgery patients. Such assessment is likely to enhance patient counseling regarding individual risk as well as enhancing the ability to undertake risk-modified surgical audit.

Assessment of Fat distribution and Bone quality with Trabecular Bone Score (TBS) in Healthy Chinese Men.

Whether fat is beneficial or detrimental to bones is still controversial, which may be due to inequivalence of the fat mass. Our objective is to define the effect of body fat and its distribution on bone quality in healthy Chinese men. A total of 228 men, aged from 38 to 89 years, were recruited. BMD, trabecular bone score (TBS), and body fat distribution were measured by dual-energy X-ray absorptiometry. Subcutaneous and visceral fat were assessed by MRI. In the Pearson correlation analysis, lumbar spine BMD exhibited positive associations with total and all regional fat depots, regardless of the fat distribution. However, the correlation disappeared with adjusted covariables of age, BMI, HDL-C, and HbA1c%. TBS was negatively correlated with fat mass. In multiple linear regression models, android fat (and not gynoid, trunk, or limbs fat) showed significant inverse association with TBS (ß = -0.611, P < 0.001). Furthermore, visceral fat was described as a pathogenic fat harmful to TBS, even after adjusting for age and BMI (ß = -0.280, P = 0.017). Our findings suggested that body fat mass, especially android fat and visceral fat, may have negative effects on bone microstructure; whereas body fat mass contributes to BMD through mechanical loading.

Predictors for cecal insertion time: the impact of abdominal visceral fat measured by computed tomography.

BACKGROUND: Several factors affect the risk for longer cecal insertion time. OBJECTIVE: The aim of this study was to identify the predictors of longer insertion time and to evaluate the effect of visceral fat measured by CT. DESIGN: This is a retrospective observational study. PATIENTS: Outpatients for colorectal cancer screening who underwent colonoscopies and CT were enrolled. Computed tomography was performed in individuals who requested cancer screening and in those with GI bleeding. MAIN OUTCOME MEASURES: Information on obesity indices (BMI, visceral adipose tissue, and subcutaneous adipose tissue area), constipation score, history of abdominal surgery, poor preparation, fellow involvement, diverticulosis, patient discomfort, and the amount of sedation used was collected. RESULTS: The cecal insertion rate was 95.2% (899/944), and 899 patients were analyzed. Multiple regression analysis showed that female sex, lower BMI, lower visceral adipose tissue area, lower subcutaneous adipose tissue area, higher constipation score, history of surgery, poor bowel preparation, and fellow involvement were independently associated with longer insertion time. When obesity indices were considered simultaneously, smaller subcutaneous adipose tissue area (p = 0.038), but not lower BMI (p = 0.802) or smaller visceral adipose tissue area (p = 0.856), was associated with longer insertion time; the other aforementioned factors remained associated with longer insertion time. In the subanalysis of normal-weight patients (BMI <25 kg/m), a smaller subcutaneous adipose tissue area (p = 0.002), but not a lower BMI (p = 0.782), was independently associated with a longer insertion time. Longer insertion time had a positive correlation with a higher patient discomfort score (ρ = 0.51, p < 0.001) and a greater amount of midazolam use (ρ = 0.32, p < 0.001). LIMITATIONS: This single-center retrospective study includes a potential selection bias. CONCLUSIONS: In addition to BMI and intra-abdominal fat, female sex, constipation, history of abdominal surgery, poor preparation, and fellow involvement were predictors of longer cecal insertion time. Among the obesity indices, high subcutaneous fat accumulation was the best predictive factor for easier passage of the colonoscope, even when body weight was normal.

Difference by sex but not by race/ethnicity in the visceral adipose tissue-depressive symptoms association: the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Prior studies have investigated the association of clinical depression and depressive symptoms with body weight (i.e. body mass index (BMI) and waist circumference), but few have examined the association between depressive symptoms and intra-abdominal fat. Of these a limited number assessed the relationship in a multi-racial/ethnic population. METHODS: Using data on 1017 men and women (45-84 years) from the Multi-Ethnic Study of Atherosclerosis (MESA) Body Composition, Inflammation and Cardiovascular Disease Study, we examined the cross-sectional association between elevated depressive symptoms (EDS) and CT-measured visceral fat mass at L2-L5 with multivariable linear regression models. EDS were defined as a Center for Epidemiological Studies Depression score ≥16 and/or anti-depressant use. Covariates included socio-demographics, inflammatory markers, health behaviors, comorbidities, and body mass index (BMI). Race/ethnicity (Whites [referent group], Chinese, Blacks and Hispanics) and sex were also assessed as potential modifiers. RESULTS: The association between depressive symptoms and visceral fat differed significantly by sex (p=0.007), but not by race/ethnicity. Among men, compared to participants without EDS, those with EDS had greater visceral adiposity adjusted for BMI and age (difference=122.5 cm2, 95% CI=34.3, 210.7, p=0.007). Estimates were attenuated but remained significant after further adjustment by socio-demographics, inflammatory markers, health behaviors and co-morbidities (difference=94.7 cm2, 95% CI=10.5, 178.9, p=0.028). Among women, EDS was not significantly related to visceral adiposity in the fully adjusted model. CONCLUSIONS: Sex, but not race/ethnicity, was found to modify the relationship between EDS and visceral fat mass. Among men, a significant positive association was found between depressive symptoms and visceral adiposity. No significant relationship was found among women.

Alcohol consumption and its relation to visceral and subcutaneous adipose tissues in healthy male Koreans.

AIMS: The purpose of the present study is to investigate the association of alcohol with visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) distribution and metabolic syndrome (MetS). DESIGN: We conducted a cross-sectional study in 951 healthy male Korean participants who underwent health checkups. We measured the cross-sectional areas of VAT and SAT by computed tomography of the abdomen and performed a study of alcohol consumption based on questionnaire responses and a 24-hour dietary recall assessment. We analyzed the relationship of alcohol consumption with VAT, SAT, and MetS. RESULTS: Alcohol consumption showed a negative association with SAT (ß = -18.76, p = 0.047) but a positive association with VAT (ß = 17.70, p = 0.037), independent of other factors. The adjusted odds ratios for MetS for those who consumed <7, 7 to <14, 14 to <28, and ≥28 standard drinks per week were 0.99 (0.59-1.68), 1.49 (0.84-2.63), 1.95 (1.10-3.45), and 1.99 (1.07-3.70), respectively (p for linear trend = 0.042). CONCLUSIONS: Alcohol consumption is associated with decreased SAT and increased VAT accumulation. Further, alcohol consumption of ≥14 standard drinks is associated with an increased risk of MetS. Light-to-moderate drinking, which has been regarded to lower the risk of cardiovascular diseases, did not show a protective effect on adipose tissue accumulation.

Body electrical loss analysis (BELA) in the assessment of visceral fat: a demonstration.

BACKGROUND: Body electrical loss analysis (BELA) is a new non-invasive way to assess visceral fat depot size through the use of electromagnetism. BELA has worked well in phantom measurements, but the technology is not yet fully validated. METHODS: Ten volunteers (5 men and 5 women, age: 22-60 y, BMI: 21-30 kg/m(2), waist circumference: 73-108 cm) were measured with the BELA instrument and with cross-sectional magnetic resonance imaging (MRI) at the navel level, navel +5 cm and navel -5 cm. The BELA signal was compared with visceral and subcutaneous fat areas calculated from the MR images. RESULTS: The BELA signal did not correlate with subcutaneous fat area at any level, but correlated significantly with visceral fat area at the navel level and navel +5 cm. The correlation was best at level of navel +5 cm (R(2) = 0.74, P < 0.005, SEE = 29.7 cm(2), LOOCV = 40.1 cm(2)), where SEE is the standard error of the estimate and LOOCV is the root mean squared error of leave-one-out style cross-validation. The average estimate of repeatability of the BELA signal observed through the study was ±9.6 %. One of the volunteers had an exceptionally large amount of visceral fat, which was underestimated by BELA. CONCLUSIONS: The correlation of the BELA signal with the visceral but not with the subcutaneous fat area as measured by MRI is promising. The lack of correlation with the subcutaneous fat suggests that subcutaneous fat has a minor influence to the BELA signal. Further research will show if it is possible to develop a reliable low-cost method for the assessment of visceral fat either using BELA only or combining it, for example, with bioelectrical impedance measurement. The combination of these measurements may help assessing visceral fat in a large scale of body composition. Before large-scale clinical testing and ROC analysis, the initial BELA instrumentation requires improvements. The accuracy of the present equipment is not sufficient for such new technology.

Anthropometric indicators of insulin resistance.

Some studies have analyzed the efficacy of anthropometric indicators in predicting insulin resistance (IR), for they are more economic and accessible. In this study, the objective was to discuss the measures and anthropometric indices that have been associated with IR. A bibliographic review was done, based on Scielo, Science Direct and Pubmed. Among these studies, waist and sagittal abdominal diameter presented better predictive capacity for IR, with more consistent results. The waist-to-thigh, waist-to-size, neck-to-thigh ratios, the conicity and the sagittal index have showed positive results; nevertheless, more studies are necessary to consolidate them as predictors to IR. The obtained results, with the use of body mass index and of the waist-to-hip ratio, were inconsistent. In the Brazilian population, the realization of studies evaluating the performance of these indicators in predicting IR is suggested, since the results of the studies conducted in other populations are not always applicable to ours, due to ethnic differences resulting from the great miscegenation in the country.

Indicadores antropométricos de resistência à insulina / Anthropometric indicators of insulin resistance

Alguns estudos têm analisado a eficiência de indicadores antropométricos em predizer resistência à insulina (RI), por serem mais econômicos e acessíveis. Neste estudo, objetivou-se discutir sobre as medidas e índices antropométricos que têm sido associados à RI. Realizou-se um levantamento bibliográfico nas bases Scielo, Science Direct e Pubmed. Dentre os estudos analisados, perímetro da cintura e diâmetro abdominal sagital apresentaram melhor capacidade preditiva para RI, com resultados mais consistentes. As relações cintura/coxa, cintura/estatura, pescoço/coxa, o índice de conicidade e o índice sagital demonstraram resultados positivos, contudo mais estudos são necessários para consolidá-los como preditores de RI. Os resultados obtidos com o uso do índice de massa corporal e da relação cintura/quadril foram mais inconsistentes. Sugere-se a realização de estudos avaliando o desempenho desses indicadores em predizer RI na população brasileira, pois resultados de estudos feitos com outras populações muitas vezes não são aplicáveis à nossa, devido às diferenças étnicas resultantes da grande miscigenação no País.

Some studies have analyzed the efficacy of anthropometric indicators in predicting insulin resistance (IR), for they are more economic and accessible. In this study, the objective was to discuss the measures and anthropometric indices that have been associated with IR. A bibliographic review was done, based on Scielo, Science Direct and Pubmed. Among these studies, waist and sagittal abdominal diameter presented better predictive capacity for IR, with more consistent results. The waist-to-thigh, waist-to-size, neck-to-thigh ratios, the conicity and the sagittal index have showed positive results; nevertheless, more studies are necessary to consolidate them as predictors to IR. The obtained results, with the use of body mass index and of the waist-to-hip ratio, were inconsistent. In the Brazilian population, the realization of studies evaluating the performance of these indicators in predicting IR is suggested, since the results of the studies conducted in other populations are not always applicable to ours, due to ethnical differences resulting from the great miscegenation in the country.

Sonographic assessment of abdominal fat distribution in infancy.

There is growing evidence that not only the total amount of fat, but also the distribution of body fat determines risks for metabolic and cardiovascular disease. Developmental studies on factors influencing body fat distribution have been hampered by a lack of appropriate techniques for measuring intraabdominal fat in early life. Sonography, which is an established method for assessing abdominal fat distribution in adults, has not yet been evaluated in infants. To adapt the sonographic measurement of abdominal fat distribution to infants and study its reliability. The Generation R study, a population-based prospective cohort study. We included 212 one- and 227 two-year old Dutch infants in the present analysis. Sixty-two infants underwent replicate measurements to assess reproducibility. We developed a standardized protocol to measure the thickness of (1) subcutaneous and (2) preperitoneal fat in the upper abdomen of infants. To this end we defined infancy specific measurement areas to quantify fat thickness. Reproducibility of fat measurements was good to excellent with intraclass correlation coefficients of 0.93-0.97 for intra-observer agreement and of 0.89-0.95 for inter-observer agreement. We observed a pronounced increase in preperitoneal fat thickness in the second year of life while subcutaneous fat thickness increased only slightly, resulting in an altered body fat distribution. Gender did not significantly influence fat distribution in the first two years of life. Our age specific protocol for the sonographic measurement of central subcutaneous and preperitoneal fat is a reproducible method that can be instrumental for investigating fat distribution in early life.

Hostility is associated with visceral, but not subcutaneous, fat in middle-aged African American and white women.

OBJECTIVE: To examine the cross-sectional association between hostility and measures of abdominal fat (visceral, subcutaneous) in middle-aged African American and white women. Because fat-patterning characteristics are known to differ by race, we were particularly interested in examining whether these associations were similar for women of both racial/ethnic groups. METHODS: Participants were 418 (45% African American, 55% white) middle-aged women from the Chicago site of the Study of Women's Health Across the Nation. Visceral and subcutaneous fat were measured by computed tomographic scans and hostility was assessed via questionnaire. Multivariate linear regression models were conducted to test associations among race/ethnicity, hostility, and measures of abdominal fat. RESULTS: In models adjusted for race/ethnicity and total percent fat, higher levels of hostility were associated with a greater amount of visceral fat (B = 1.8, standard error = 0.69, p = .01). This association remained significant after further adjustments for education, and multiple coronary heart disease (CHD) risk factors. Hostility was not associated with subcutaneous fat (p = .8). Although there were significant racial/ethnic differences in hostility (p < .001) and the amount of total body (p < .001), subcutaneous (p < .001) and visceral fat (p < .001), the associations between hostility and measures of abdominal fat did not differ for African American compared with white women (race/ethnicity x hostility interaction, p = .67 for visceral, p = .85 for subcutaneous). CONCLUSIONS: Hostility may affect CHD risk in women via the accumulation of visceral fat. Despite significant black-white differences in fat patterning and overall CHD risk, the association between hostility and visceral fat seems to be similar for both African American and white women.

Automated assessment of whole-body adipose tissue depots from continuously moving bed MRI: a feasibility study.

PURPOSE: To present an automated algorithm for segmentation of visceral, subcutaneous, and total volumes of adipose tissue depots (VAT, SAT, TAT) from whole-body MRI data sets and to investigate the VAT segmentation accuracy and the reproducibility of all depot assessments. MATERIALS AND METHODS: Repeated measurements were performed on 24 volunteer subjects using a 1.5 Tesla clinical MRI scanner and a three-dimensional (3D) multi-gradient-echo sequence (resolution: 2.1 x 2.1 x 8 mm(3), acquisition time: 5 min 15 s). Fat and water images were reconstructed, and fully automated segmentation was performed. Manual segmentation of the VAT reference was performed by an experienced operator. RESULTS: Strong correlation (R = 0.999) was found between the automated and manual VAT assessments. The automated results underestimated VAT with 4.7 +/- 4.4%. The accuracy was 88 +/- 4.5% and 7.6 +/- 5.7% for true positive and false positive fractions, respectively. Coefficients of variation from the repeated measurements were: 2.32 % +/- 2.61%, 2.25% +/- 2.10%, and 1.01% +/- 0.74% for VAT, SAT, and TAT, respectively. CONCLUSION: Automated and manual VAT results correlated strongly. The assessments of all depots were highly reproducible. The acquisition and postprocessing techniques presented are likely useful in obesity related studies.

Increased visceral fat and decreased energy expenditure during the menopausal transition.

OBJECTIVE: This study assessed longitudinal changes in body composition, fat distribution and energy balance in perimenopausal women. We hypothesized that total fat and abdominal body fat would increase at menopause due to decreased energy expenditure (EE) and declining estrogen, respectively. DESIGN: Observational, longitudinal study with annual measurements for 4 years. SUBJECTS: Healthy women (103 Caucasian; 53 African-American), initially premenopausal. During follow-up, lack of menstruation for 1 year and follicle-stimulating hormone >30 mIU ml(-1) defined a subject as postmenopausal. MEASUREMENTS: Fat and lean mass (dual-energy X-ray absorptiometry), visceral (VAT) and subcutaneous abdominal fat (SAT) (computed tomography), dietary intake (4-day food record), serum sex hormones and physical activity (tri-axial accelerometry). Twenty-four hour EE was measured by whole-room calorimeter in a subset of 34 women at baseline and at year 4. RESULTS: Body fat and weight increased significantly over time only in those women who became postmenopausal by year 4 (n=51). All women gained SAT over time; however, only those who became postmenopausal had a significant increase in VAT. The postmenopausal group also exhibited a significant decrease in serum estradiol. Physical activity decreased significantly 2 years before menopause and remained low. Dietary energy, protein, carbohydrate and fiber intake were significantly higher 3-4 years before the onset of menopause compared with menopause onset. Twenty-four hour EE and sleeping EE decreased significantly with age; however, the decrease in sleeping EE was 1.5-fold greater in women who became postmenopausal compared with premenopausal controls (-7.9 vs -5.3%). Fat oxidation decreased by 32% in women who became postmenopausal (P<0.05), but did not change in those who remained premenopausal. CONCLUSION: Middle-aged women gained SAT with age, whereas menopause per se was associated with an increase in total body fat and VAT. Menopause onset is associated with decreased EE and fat oxidation that can predispose to obesity if lifestyle changes are not made.

Visceral adipose tissue, a potential risk factor for carotid atherosclerosis: results of the Multicultural Community Health Assessment Trial (M-CHAT).

BACKGROUND AND PURPOSE: The association between abdominal obesity and atherosclerosis is believed to be due to excess visceral adipose tissue (VAT), which is associated with traditional risk factors. We hypothesized that VAT is an independent risk factor for atherosclerosis. METHODS: Healthy men and women (N=794) matched for ethnicity (aboriginal, Chinese, European, and South Asian) and body mass index range (<25, 25 to 29.9, or > or =30 kg/m(2)) were assessed for VAT (by computed tomography scan), carotid atherosclerosis (by ultrasound), total body fat, cardiovascular risk factors, lifestyle, and demographics. RESULTS: VAT was associated with carotid intima-media thickness (IMT), plaque area, and total area (IMT area and plaque area combined) after adjusting for demographics, family history, smoking, and percent body fat in men and women. In men, VAT was associated with IMT and total area after adjusting for insulin, glucose, homocysteine, blood pressure, and lipids. This association remained significant with IMT after further adjustment for either waist circumference or the waist-to-hip ratio. In women, VAT was no longer associated with IMT or total area after adjusting for risk factors. CONCLUSIONS: VAT is the primary region of adiposity associated with atherosclerosis and likely represents an additional risk factor for carotid atherosclerosis in men. Most but not all of this risk can be reflected clinically by either the waist circumference or waist-hip ratio measures.

Comparison of anthropometric, area- and volume-based assessment of abdominal subcutaneous and visceral adipose tissue volumes using multi-detector computed tomography.

PURPOSE: Cross-sectional imaging may enable accurate localization and quantification of subcutaneous and visceral adipose tissue. The reproducibility of multi-detector computed tomography (MDCT)-based volumetric quantification of abdominal adipose tissue and the ability to depict age- and gender-related characteristics of adipose tissue deposition have not been reported. METHODS: We evaluated a random subset of 100 Caucasian subjects (age range: 37-83 years; 49% women) of the Framingham Heart Study offspring cohort who underwent MDCT scanning. Two readers measured subcutaneous and visceral adipose tissue volumes (SAV and VAV; cm(3)) and areas (SAA and VAA; cm(2)) as well as abdominal sagital diameter (SD) and waist circumference (WC). RESULTS: Inter-reader reproducibility was excellent (relative difference: -0.34+/-0.52% for SAV and 0.59+/-0.93% for VAV, intra-class correlation (ICC)=0.99 each). The mean SAA/VAA ratio was significantly different from the mean SAV/VAV ratio (2.0+/-1.2 vs 1.7+/-0.9; P<0.001). The ratio of SAV/VAV was only weakly inversely associated with SD (ICC=-0.32, P=0.01) and not significantly associated with WC (ICC=-0.14, P=0.14) or body mass index (ICC=-0.17, P=0.09). The mean SAV/VAV ratio was significantly different between participants <60 vs >60 years (1.9+/-1.0 vs 1.5+/-0.7; P<0.001) and between men and women (1.2+/-0.5 vs 2.2+/-0.9; P<0.001). CONCLUSION: This study demonstrates that MDCT-based volumetric quantification of abdominal adipose tissue is highly reproducible. In addition, our results suggest that volumetric measurements can depict age- and gender-related differences of visceral and subcutaneous abdominal adipose tissue deposition. Further research is warranted to assess whether volumetric measurements may substantially improve the predictive value of obesity measures for insulin resistance, type 2 diabetes mellitus and other diseases.