DXA-Derived vs Standard Anthropometric Measures for Predicting Cardiometabolic Risk in Middle-Aged Australian Men and Women

Assessment of sarcopenic obesity in patients with acromegaly

PURPOSE

Sarcopenic obesity (SO), a condition characterized by the coexistence of obesity and sarcopenia, has primarily been studied in elderly populations. However, it can also affect individuals with chronic diseases. This study aims to evaluate the prevalence of SO in patients with acromegaly.

METHODS

Observational, cross-sectional study, involving patients with acromegaly followed at a tertiary center and controls matched for age and sex. Health assessment questionnaire, physical tests, body composition and bone mineral density assessment, were performed in all participants. SO was diagnosed using criteria from ESPEN and EASO Consensus Statements.

RESULTS

48 patients with acromegaly (acromegaly group - AG, 26 women, mean age 56.3 ± 11.6, mean BMI 31.3 ± 4.9) were compared to 48 controls (control group - CG, 26 women, mean age 56.7 ± 13.7, BMI 25.5 ± 4.7). Despite having greater total and appendicular lean mass, AG showed significant impairments in physical performance, particularly in strength, gait speed and balance (p < 0.05). The prevalence of SO in the AG was 16.7%, compared to 0% in the CG (p = 0.006), and positively correlated with increased fat mass and impaired physical performance.

CONCLUSIONS

SO is present in patients with acromegaly and is associated with notable functional impairments despite increased muscle mass.

Longitudinal associations of DXA-measured visceral adipose tissue and cardiometabolic risk in middle-to-older aged adults

BACKGROUND AND AIMS

DXA-measured visceral adipose tissue (VATDXA) is associated with adverse cardiometabolic risk profiles in cross-sectional studies, but longitudinal associations have not been investigated. We examined the longitudinal associations of baseline and change in VATDXA with future cardiometabolic risk in Australian participants of the Busselton Healthy Ageing study.

METHODS AND RESULTS

We studied 3569 participants (54.7% female, aged 46-70 years) with data on VATDXA (GE Lunar Prodigy) and cardiometabolic risk factors at baseline and 6 years follow-up. The associations were examined using logistic and linear regression models, adjusting for baseline age and lifestyle factors. Mean baseline VATDXA mass was 1653 ± 880 g and 855 ± 580 g, and mean change in VATDXA +99 ± 500 g and +58 ± 312 g in males and females, respectively. Among all participants, 182 males (11.3%) and 197 females (10.1%) developed incident metabolic syndrome (MetS). Baseline VATDXA was associated with incident MetS with an adjusted odds ratio of 2.53 (95% CI: 2.03, 3.15) in males and 2.78 (2.30, 3.36) in females per SD increment. There was a graded positive association between longitudinal change in VATDXA and MetS severity z score in both sexes adjusted for baseline VAT (P < 0.001). All the above associations remained significant after further adjustment for baseline or change in BMI, waist circumference or waist-to-hip ratio in respective models (all P < 0.001).

CONCLUSIONS

Higher baseline and greater longitudinal increase in VATDXA are independently associated with raised cardiometabolic risk over time, and may serve as useful markers for identifying middle-aged individuals at increased cardiometabolic risk.

Visceral adipose tissue measured by DXA predicts metabolic syndrome in low-income community-dwelling elderly: Insights from the São Paulo Aging & Health (SPAH) study

While visceral fat measured by dual-energy X-ray absorptiometry (DXA) is accurate in identifying middle-aged people at increased cardiometabolic risk, consistent data for the elderly are still lacking. We aimed to investigate the association between DXA-derived visceral adipose tissue (VAT) and metabolic syndrome (MetS) and to establish optimal cutoffs for VAT to predict MetS in a low-income elderly Brazilian cohort. A total of 449 women and 258 men (≥65 years) from the community were enrolled in this study. Participants underwent clinical and laboratory evaluations, along with body composition analysis by Hologic Discovery A densitometer. VAT was measured in the android region of the DXA scan. MetS was diagnosed using NCEP-ATPIII criteria. Multivariate logistic regression analyzed the relationship between VAT and MetS. Receiver-operating characteristic (ROC) curve analysis evaluated VAT's predictive accuracy for MetS, with optimal cutoffs determined by Youden's test to balance sensitivity and specificity. Mean ages were 76.6 ± 4.7 years for men and 77.1 ± 4.9 years for women. Mean BMIs were 26.5 ± 3.8 kg/m2 for men and 29.0 ± 5.2 kg/m2 for women. One hundred and seventy-five (41.5 %) men and 274 (61 %) women had MetS. After adjustments for confounders, multivariate analysis showed that VAT was independently associated with MetS in both men (OR 1.41, 95%CI 1.15-1.72) and women (OR 1.33, 95%CI 1.16-1.54, per each 100 g increase). Optimal VAT cutoffs to predict MetS were 642.5 g for men (AUC = 0.740) and 600.5 g for women (AUC = 0.729). Subanalysis for non-overweight/non-obese subjects yielded lower VAT cutoffs. Thus, VAT measured by DXA was significantly associated with MetS in older adults, regardless of BMI, emphasizing the critical role of VAT in predicting MetS. Therefore, VAT by DXA holds promise for evaluating MetS risk in the elderly. Further longitudinal studies are needed to investigate VAT's impact on major cardiovascular event incidence in this demographic.

Evaluation of visceral adipose tissue thresholds for elevated metabolic syndrome risk across diverse populations: A systematic review

Beyond obesity, excess levels of visceral adipose tissue (VAT) significantly contribute to the risk of developing metabolic syndrome (MetS), although thresholds for increased risk vary based on population, regions of interest, and units of measure employed. We sought to determine whether a common threshold exists that is indicative of heightened MetS risk across all populations, accounting for sex, age, BMI, and race/ethnicity. A systematic literature review was conducted in September 2023, presenting threshold values for elevated MetS risk. Standardization equations harmonized the results from DXA, CT, and MRI systems to facilitate a comparison of threshold variations across studies. A total of 52 papers were identified. No single threshold could accurately indicate elevated risk for both males and females across varying BMI, race/ethnicity, and age groups. Thresholds fluctuated from 70 to 165.9 cm2, with reported values consistently lower in females. Generally, premenopausal females and younger adults manifested elevated risks at lower VAT compared to their older counterparts. Notably, Asian populations exhibited elevated risks at lower VAT areas (70-136 cm2) compared to Caucasian populations (85.6-165.9 cm2). All considered studies reported associations of VAT without accommodating covariates. No single VAT area threshold for elevated MetS risk was discernible post-harmonization by technology, units of measure, and region of interest. This review summarizes available evidence for MetS risk assessment in clinical practice. Further exploration of demographic-specific interactions between VAT area and other risk factors is imperative to comprehensively delineate overarching MetS risk.

Association between A/G ratio and arterial stiffness among Chinese type 2 diabetics: A cross-sectional study

BACKGROUND

The android-to-gynoid fat ratio (A/G ratio), an emerging indicator of obesity independent of body mass index (BMI), has yet to be conclusively associated with arterial stiffness in type 2 diabetes mellitus (T2DM). This study aimed to construct a nomogram to estimate arterial stiffness risk in diabetics and explore the interaction effect between A/G ratio and traditional obesity indicators on arterial stiffness.

METHODS

1313 diabetics were divided into 2 groups based on arterial stiffness identified by brachial ankle pulse wave velocity (baPWV), and demographic and clinical features were measured. The LASSO and multivariate logistics regression were used to develop the nomogram. Calibration curve, decision curve analysis (DCA) and receiver operating characteristic (ROC) were applied to assess calibration and clinical usefulness. Interaction effect analysis was performed to quantify the interactive relationship of A/G ratio and obesity indicators on arterial stiffness.

RESULTS

6 independent predictors (age, gender, A/G ratio, SBP, LDL-C and HbA1C) were screened to construct a nomogram prediction model. The calibration curve demonstrated satisfactory agreement between predicted and actual probability, and the nomogram exhibited clinical beneficial at the threshold between 8 % and 95 % indicated by DCA. The area under curve (AUC) was 0.918 and 0.833 for training and external set, respectively. Further investigation revealed A/G ratio and BMI acted positively synergistically towards arterial stiffness, and in BMI-based subgroup analysis, elevated A/G ratio was a significant risk factor for arterial stiffness, especially in normal BMI.

CONCLUSIONS

A/G ratio showed a substantial association with arterial stiffness, and the nomogram, incorporating age, gender, A/G ratio, SBP, LDL-C, and HbA1c, exhibited high predictive value. A/G ratio measurement in BMI-normal individuals assisted in identifying cardiovascular diseases early.

White adipocyte dysfunction and obesity-associated pathologies in humans

The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.

Standardization of dual-energy x-ray visceral adipose tissue measures for comparison across clinical imaging systems

OBJECTIVE

Excess visceral adipose tissue (VAT) is a major risk factor for metabolic syndrome (MetS) and clinical guidelines have been proposed to define VAT levels associated with increased risk. The aim was to standardize VAT measures between two dual-energy x-ray absorptiometry (DXA) manufacturers who provide different VAT estimates to support standardization of measures across imaging modalities.

METHODS

Scans from 114 individuals (ages 18-81 years) on GE HealthCare (GEHC) and Hologic DXA systems were compared via Deming regression to standardize VAT between the two systems, validated in a separate sample (n = 15), with κ statistics to assess agreement of VAT measurements for classifying patients into risk categories.

RESULTS

The GEHC and Hologic VAT measures were highly correlated and validated in the separate data set (r2  = 0.97). VAT area measures substantially agreed for metabolic risk classification (weighted κ = 0.76) with no significant differences in the population mean values.

CONCLUSIONS

VAT measures can be estimated from GEHC and Hologic scans that classify individuals in a substantially similar way into metabolic risk categories, and systematic bias between the measures can be removed using simple regression equations. These findings allow for DXA VAT measures to be used in complement to other imaging modalities, regardless of whether scans used GEHC or Hologic systems.

Body Fat Distribution and Female Infertility: a Cross-Sectional Analysis Among US Women

At present, the effect of body fat distribution on female reproductive health is still inconclusive. The purpose of our study was to analyze the correlation between female infertility rates and the fat mass portion of the android region to the gynoid region (the A/G ratio) among US women of reproductive age. Female infertility is defined as a failure to get pregnant after 12 months of unprotected sexual activity. A total of 3434 women of reproductive age were included in this study as part of the 2013-2018 National Health and Nutrition Examination Survey (NHANES). The A/G ratio was used to assess the body fat distribution of participants. Based on the comprehensive study design and sample weights, it was determined that the A/G ratio was associated with female infertility primarily through logistic regression analyses. After adjusting for potential confounders, the multivariate regression analysis indicated an increase in the A/G ratio was correlated with an increase in the prevalence of female infertility (OR = 4.374, 95% CI:1.809-10.575). Subgroup analyses showed an increased prevalence of infertility in non-Hispanic Whites (P = 0.012), non-diabetic individuals (P = 0.008), individuals under 35 years old (P = 0.002), and individuals with secondary infertility (P = 0.01). The trend tests and smooth curve fitting illustrate a linear trend between the A/G ratio and female infertility. Future researches are warranted to confirm the causal relationship between body fat distribution and female infertility, which may provide an insight into future prevention and treatment of female infertility.

Body weight and fat trajectories of Black and White women in the first postpartum year

OBJECTIVE

The aim of this study was to examine changes in body weight and fat in Black and White women during the first postpartum year and to determine whether there is preferential retention of fat mass and abdominal fat.

METHODS

Body composition was quantified by dual-energy x-ray absorptiometry in Black (n = 49) and White (n = 85) women at 6 to 8 weeks, 6 months, and 12 months after delivery of a singleton infant.

RESULTS

Weight, fat mass, percent body fat, and fat in the trunk, android, gynoid, and limb regions decreased from 6 to 8 weeks to 12 months in White women, but not in Black women (fat mass, adjusted mean [SE]: 29.6 [1.3] to 26.9 [1.3] kg in White women and 34.5 [1.5] to 36.8 [1.8] kg in Black women). In the entire sample, fat mass was higher at 6 months than at 6 to 8 weeks, independent of weight change; visceral fat was higher at 12 months (686 [45] g) than at 6 to 8 weeks (611 [42] g) and 6 months (626 [43] g); and android fat was higher at 12 months than at 6 months, independent of fat change.

CONCLUSIONS

Black women were less likely than White women to lose weight and fat in the postpartum period. There was preferential retention of fat in the abdominal area.

Association between body fat distribution and kidney stones: Evidence from a US population

Objectives

We aimed to evaluate the relationship between the proportion of Android to Gynoid ratio and the incidence of kidney stones among US adults.

Methods

Participants aged 20-59 years from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) database were selected to assess the association between Android to Gynoid ratio and kidney stone prevalence using logistic regression analysis, subgroup analysis and calculation of dose-response curves.

Results

This study ultimately included 10858 participants, of whom 859 self-reported a history of kidney stones. And after adjusting for all confounders, an increased Android to Gynoid ratio was associated with an increased prevalence of kidney stones (OR=2.75, 95% CI:1.62-4.88). And subgroup analysis showed an increased prevalence of kidney stones in women (OR=3.55, 95% CI: 1.54-8.22), non-diabetic (OR=2.59, 95% CI: 1.45-4.60), 60 > age ≥ 40 years (OR=3.51, 95% CI: 1.83-6.71), Mexican-American (OR=4.35, 95% CI: 1.40- 13.53) and white (OR=3.86, 95% CI: 1.82-8.18) groups, there was a significant positive association between A/G ratio and kidney stones. In contrast, in the hypertensive subgroup, the A/G ratio was associated with kidney stones in all groups.

Conclusions

Higher Android to Gynoid ratio is associated with a high prevalence of kidney stone disease.

Osteosarcopenia—The Role of Dual-Energy X-ray Absorptiometry (DXA) in Diagnostics

Osteoporosis and sarcopenia lead to increased mortality, but their early diagnosis allows preventive measures and treatment to be implemented. The dual-energy X-ray absorptiometry (DXA) method enables the assessment of both bone mineral density (BMD) and bone quality based on the trabecular bone score (TBS), the Bone Strain Index (BSI), hip structure analysis (HSA), and comprehensive hip axis length (HAL). The main complications of osteoporosis are fractures, and a BMD value or T-score together with TBS can be also applied in fracture risk calculation using the Fracture Risk Assessment Tool (FRAX). In recent years, the interest in sarcopenia has increased. There are many methods for assessing the quality, quantity and function of muscles. Total body DXA provides information not only about the BMD of the whole skeleton or the amount of lean tissue (identified as fat-free mass), but also about the amount and distribution of adipose tissue. Some parameters obtained from DXA measurements related to muscle and/or fat mass are used in the assessment of osteosarcopenia. The following article presents a wide range of possibilities for the use of the DXA method in the diagnosis of osteosarcopenia because DXA is a useful technique for the diagnosis of bone density and body composition together.