The sexual dimorphism of obesity

Dnmt3b deficiency in adipocyte progenitor cells ameliorates obesity in female mice

Obesity arises from chronic energy imbalance where energy intake exceeds energy expenditure. Emerging evidence supports a key role of DNA methylation in the regulation of adipose tissue development and metabolism. We recently discovered a key role of DNA methylation, catalyzed by DNA methyltransferase 1 or 3a (Dnmt1 or 3a), in the regulation of adipocyte differentiation and metabolism. Here, we aimed to investigate the role of adipocyte progenitor cell Dnmt3b, an enzyme mediating de novo DNA methylation, in energy metabolism and obesity. We generated a genetic model with Dnmt3b knockout in adipocyte progenitor cells (PD3bKO) by crossing Dnmt3b -floxed mice with platelet-derived growth factor receptor alpha (Pdgfrα)-Cre mice. Dnmt3b gene deletion in adipocyte progenitors enhanced thermogenic gene expression in brown adipose tissue, increased overall energy expenditure, and mitigated high-fat diet (HFD)-induced obesity in female mice. PD3bKO mice also displayed a lower respiratory exchange ratio (RER), indicative of a metabolic shift favoring fat utilization as an energy source. Furthermore, female PD3bKO mice exhibited improved insulin sensitivity alongside their lean phenotype. In contrast, male PD3bKO mice showed no changes in body weight but demonstrated decreased insulin sensitivity, revealing a sexually dimorphic metabolic response to Dnmt3b deletion in adipocyte progenitor cells. These findings underscore the critical role of Dnmt3b in regulating energy homeostasis, body weight, and metabolic health, with significant implications for understanding sex-specific mechanisms of obesity and metabolism.

Association between sex-specific criteria for visceral obesity and surgical site infection after gastrectomy

BACKGROUND

High visceral fat area (VFA), estimated by computed tomography (CT), is reportedly associated with surgical site infection (SSI) in patients who undergo gastrectomy for gastric cancer (GC). Given that fat distributions vary markedly according to sex, sex-specific definitions of visceral obesity should be applied. This study investigated the optimal sex-specific thresholds for VFA at the L3 level to assess the risk of SSI after gastrectomy.

METHODS

This study included 828 patients (564 males and 264 females) who underwent curative gastrectomy. Intra-abdominal or incisional infectious complications with Clavien-Dindo scores ≥ 2 were defined as SSIs. Receiver operating characteristic (ROC) analyses were used to determine the optimal sex-specific VFA cutoffs to extract patients with obesity who are at risk of developing SSI. In addition, logistic regression analyses were performed, and the corrected Akaike information criterion (AICc) was calculated to compare the capability to evaluate the possibility of SSI of our sex-specific VFA-based criteria vs the conventional VFA-based or body mass index (BMI)-based criterion.

RESULTS

SSI developed in 59 males and 16 females. Optimal VFA thresholds were 119.3 cm2 for males and 57.2 cm2 for females. Multivariate analyses revealed visceral obesity, as defined by the sex-specific criteria, to be an independent risk factor for SSI (odds ratio, 2.74; 95% CI, 1.62-4.66; P <.01). The logistic regression model with our sex-specific criteria yielded a better AICc (456.4) than the conventional (461.8) or BMI-based (467.0) criterion for obesity.

CONCLUSION

Sex-specific criteria can enhance the capability of VFA to assess the risk of SSI after gastrectomy, compared with the non-sex-specific criterion.

Conicity index and sex differences in relation to carotid plaque instability in Chinese community residents: Conicity index and carotid plaque

OBJECTIVES

The conicity index (CI), an anthropometric parameter of visceral obesity, has exhibited a strong correlation with the incidence of atherosclerosis and cardiovascular events. This study aimed to explore the relationship between CI and carotid plaque instability, as well as the potential differences between sexes in this context.

METHODS

Our cross-sectional study included a total of 44,248 participants from the China Stroke High-risk Population Screening and Intervention Program (CSHPSIP), all of whom underwent carotid ultrasound for the evaluation of carotid plaque. Multivariate logistics regression analysis and restricted cubic spline (RCS) curves were employed to examine the association between CI and the prevalence of carotid plaques and unstable plaques. A subgroup analysis was conducted to account for potential confounding variables.

RESULTS

Patients belonging to the higher CI quartiles had a greater prevalence of carotid plaque and unstable carotid plaque. After adjusting for confounding factors, each standard deviation (SD) increase in CI was associated with an odds ratio (OR) of 1.06 (95% confidence interval: 1.03-1.08) for carotid plaque and 1.03 (95% confidence interval: 1.00-1.05) for unstable carotid plaque. The RCS analysis revealed an escalating trend in the prevalence of unstable carotid plaque with increasing CI values. However, this observed trend was not evident among female participants. Furthermore, subgroup analysis revealed a more pronounced correlation between CI and carotid plaque instability in individuals with a fasting blood glucose (FBG) of ≥ 7 mmol/L and an unhealthy lifestyle characterized by physical inactivity and current smoking.

CONCLUSIONS

Our findings demonstrated that CI was significantly associated with carotid plaque and recommend CI as a promising indicator for the initial screening of atherosclerotic plaques in the future.

The Counteracting Effect of Chrysin on Dietary Fructose-Induced Metabolic-Associated Fatty Liver Disease (MAFLD) in Rats with a Focus on Glucose and Lipid Metabolism

The prevalence of metabolic syndrome has been exponentially increasing in recent decades. Thus, there is an increasing need for affordable and natural interventions for this disorder. We explored the effect of chrysin, a dietary polyphenol, on hepatic lipid and glycogen accumulation, metabolic dysfunction-associated fatty liver disease (MAFLD) activity score and oxidative stress and on hepatic and adipose tissue metabolism in rats presenting metabolic syndrome-associated conditions. Rats fed a chow diet were separated into four groups: Control (tap water), Fructose (tap water with 10% fructose), Chrysin (tap water+ chrysin (100 mg/kg body weight/d)), and Fructose + Chrysin (tap water with 10% fructose + chrysin (100 mg/kg body weight/d, daily)) (for 18 weeks). When associated with the chow diet, chrysin reduced hepatic lipid and glycogen storage, increased the hepatic antioxidant potential of glutathione and reduced de novo lipogenesis in the adipose tissue. When associated with the high fructose-diet, chrysin attenuated the increase in lipid and glycogen hepatic storage, improved the MAFLD activity score, decreased hepatic lipid peroxidation, increased the antioxidant potential of glutathione, and improved lipid and glucose metabolic markers in the liver and adipose tissue. In conclusion, our results suggest that chrysin is a beneficial addition to a daily diet for improvement of hepatic metabolic health, particularly for individuals suffering from metabolic syndrome.

Deciphering the influence of gut and oral microbiomes on menopause for healthy aging

Menopause is characterized by the cessation of menstruation and a decline in reproductive function, which is an intrinsic component of the aging process. However, it has been a frequently overlooked field of women's health. The oral and gut microbiota, constituting the largest ecosystem within the human body, are important for maintaining human health and notably contribute to the healthy aging of menopausal women. Therefore, a comprehensive review elucidating the impact of the gut and oral microbiota on menopause for healthy aging is of paramount importance. This paper presents the current understanding of the microbiome during menopause, with a particular focus on alterations in the oral and gut microbiota. Our study elucidates the complex interplay between the microbiome and sex hormone levels, explores microbial crosstalk dynamics, and investigates the associations between the microbiome and diseases linked to menopause. Additionally, this review explores the potential of microbiome-targeting therapies for managing menopause-related diseases. Given that menopause can last for approximately 30 years, gaining insights into how the microbiome and menopause interact could pave the way for innovative interventions, which may result in symptomatic relief from menopause and an increase in quality of life in women.

Association between normal weight obesity and comorbidities and events of cardiovascular diseases among adults in South China

BACKGROUND

The increased risks for cardiovascular comorbidities and cardiovascular diseases (CVD) in populations with normal weight obesity (NWO) have not been well-identified. We aimed to study their associations in an adult population in South China.

METHODS

Based on the CVD prevalence of 4% in Shenzhen and a calculated sample size of 6,000, a cross-sectional study with a multi-stage stratified cluster sampling method was conducted in Shenzhen City. The cardiovascular comorbidities being studied were abdominal obesity (AO), diabetes, hypertension, dyslipidemia, metabolic syndrome, and chronic kidney disease, while the CVD events were occurrences of myocardial infarction and strokes. Questionnaire surveys, physical examinations, and laboratory tests were performed. NWO was defined as a condition with the highest tertile of body fat percentage (BF%) among the normal body mass index (BMI) range (18.5-23.9 kg/m2). Continuous data were reported as mean [standard deviation (SD)] and categorical data as percentages (%). CVD comorbidities and CVD events and their detection rates in different groups were compared using ANONA analysis and Chi-squared test. Spearman's correlation coefficients between BF% and cardiometabolic abnormalities were calculated by partial correlation analysis. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for BF%, CVD comorbidities, and CVD events, adjusted for multiple confounders.

RESULTS

Among the total 6,240 subjects who completed the study and had BMI and BF% data available, 3,086 had normal BMI. The prevalence of NWO was 16.36%, with 13.15% for men and 19.54% for women. With confounders adjusted, the risks of AO (OR = 6.05, 95%CI = 3.40-10.75), essential hypertension (OR = 1.56, 95%CI = 1.09-2.22), dyslipidemia (OR = 1.85, 95%CI = 1.49-2.29), and metabolic syndrome (OR = 4.61, 95%CI = 2.32-9.18) were significantly increased in the populations with NWO compared with the population without NWO (P < 0.05). BF% was not significantly associated with the risk of CVD events in the total (OR = 1.56, 95%CI = 0.83-2.93), male (OR = 1.00, 95%CI = 0.44-2.30), and female populations (OR = 2.53, 95%CI = 0.91-7.06).

CONCLUSION

NWO was found to be positively associated with CVD comorbidities but not with CVD events. The current study provides a ground to conduct further studies on whether body fat affects the risk of occurrence of CVD events and the underlying mechanisms in the future.

The association between the healthy lifestyle index and MRI-derived body composition measurements in the UK Biobank study

A high healthy lifestyle index (HLI) score, which reflects an adequate amount of sleep, no alcohol consumption, no smoking, a moderate to high physical activity level, a high quality diet, and a normal body mass index (BMI), has been associated with reduced risk of morbidity and mortality. We examined the relationship between the HLI and measurements of adipose and lean tissue volumes measured using magnetic resonance imaging (MRI). We studied 33,002 participants in the UK Biobank study, aged 40-69 years at enrolment. Information on lifestyle components was obtained at the baseline examination (2006-2010), while MRI was performed at a later exam (2014-2020). A multilevel HLI score, constructed by assigning individual scores to each HLI component, was categorized into quartiles in multivariable linear regression analyses. Higher HLI levels were associated with lower levels of body composition parameters (visceral and subcutaneous adipose tissue, total adipose tissue, total lean tissue, muscle fat infiltration, abdominal fat ratio, weight to muscle ratio) in a dose-dependent manner (tests-for-trend p-value < 0.001 for all parameters). When BMI was excluded from the HLI score and included separately in the model, a direct association between HLI score and total lean tissue volume was observed. Higher HLI scores were associated with a better body composition profile.

Identifying joint association between body fat distribution with high blood pressure among 7 ∼ 17 years using the BKMR model: findings from a cross-sectional study in China

BACKGROUND

To investigate the joint associations between various body fat distribution parameters and high blood pressure (HBP) using the Bayesian Kernel Machine Regression (BKMR) model in school-aged children.

METHODS

A diverse sample of 7 ∼ 17 years old (N = 1423; 50.25% boys) was recruited for this study. Fat distribution parameters for multiple body parts, including trunk, legs, android region, and gynoid region fat percentage were measured. HBP was defined as either systolic or diastolic blood pressure exceeded age-, sex- and height-specific 95th percentiles. The chi-square test was utilized to compare differences between groups. The BKMR model was employed to analyze the joint effects of body fat indicators on HBP while accounting for potential confounders. Weighted Quantile Sum (WQS) model was used to characterize the relative weights of each body fat distribution parameter for HBP. Additionally, stratified analyses were performed by sexes and overweight/non overweight groups.

RESULTS

HBP prevalence was 46.86% and 35.10% for overweight and obese (OB) boys and girls, and was 17.96% and 17.28% for non-overweight and obese (non-OB) boys and girls, respectively. Increased fat percentages of trunk, android, and gynoid parts are associated with a higher risk of HBP, while increased fat percentage of the leg was associated with lower HBP risk. Android fat percentage contributed the most HBP risk in OB boys (weight = 0.34), OB girls (weight = 0.39), and non-OB girls (weight = 0.56). Leg fat percentage had significant protective effect on HBP for non-OB boys (weight=-0.22) and OB boys (weight=-0.44), while gynoid fat percentage had significant protective effect for OB girls (weight=-0.27).

CONCLUSIONS

Fat distribution of various body parts have inconsistent roles and directions in their association with HBP risk in children of different sex and weight status. We recommend that children of different sexes and weight statuses be provided with body-part-specific exercise recommendations for optimal chronic disease prevention and control benefits.

Gestational diabetes mellitus causes genome hyper-methylation of oocyte via increased EZH2

Gestational diabetes mellitus (GDM), a common pregnancy disease, has long-term negative effects on offspring health. Epigenetic changes may have important contributions to that, but the underlying mechanisms are not well understood. Here, we report the influence of GDM on DNA methylation of offspring (GDF1) oocytes and the possible mechanisms. Our results show that GDM induces genomic hyper-methylation of offspring oocytes, and at least a part of the altered methylation is inherited by F2 oocytes, which may be a reason for the inheritance of metabolic disorders. We further find that GDM exposure increases the expression of Ezh2 in oocytes. Ezh2 regulates DNA methylation via DNMT1, and Ezh2 knockdown reduces the genomic methylation level of GDF1 oocytes. These results suggest that GDM may induce oocyte genomic hyper-methylation of offspring via enhancing the Ezh2 expression recruiting more DNMT1 into nucleus.

Sex steroid hormones mediate the association between neonicotinoids and obesity among children and adolescents

BACKGROUND

Neonicotinoids are the most widely used insecticide worldwide. Toxicological and epidemiological studies suggest that exposure to neonicotinoid may be linked to the development of childhood obesity. However, the evidence is limited.

OBJECTIVE

To investigate the association between neonicotinoid exposure and obesity among U.S. children and adolescents and to explore underlying mechanism mediated by serum sex steroid hormones in these associations.

METHODS

Data from the 2015-2016 National Health and Nutrition Examination Survey were used for the analysis. Generalized linear regression was used to investigate the association between detectable neonicotinoids and ten measures of obesity. The interaction effects of multiple neonicotinoids were determined by Chi-squared Automatic Interaction Detection method. Mediation analysis was used to assess potential mediators of sex steroid hormones, including testosterone (T), estradiol (E2), T/E2, sex hormone-binding globulin (SHBG), and free androgen index (FAI).

RESULTS

Clothianidin (β = -0.29, 95 % CI: -0.57, -0.01) and N-desmethyl-acetamiprid (β = -0.19, 95 % CI: -0.35, -0.03) were associated with reduced VFI z-score. After stratification, 5-hydroxy-imidacloprid was positively associated with the risk of general obesity in males (OR=2.24, 95 % CI: 1.20, 4.20) with a probability of 52.5 %. FAI mediated 15 % of the association between neonicotinoid exposure and reduced risk of obesity, and SHBG mediated 30 % of the association between neonicotinoid exposure and increased risk of obesity.

CONCLUSION

Neonicotinoids showed associations with obesity, but the results were mixed and sex-specific. Sex steroid hormones may play a role in mediating the effects of neonicotinoids on obesity.

Sex differentially affects pro-inflammatory cell subsets in adipose tissue depots in a diet induced obesity model

Obesity is a growing pandemic that increases the risk for cardiovascular diseases, type 2 diabetes, and particularly in women also the risk of cancer and neurodegenerative disorders such as dementia and multiple sclerosis. Preclinical studies on obesity focus on male mice as they gain bodyweight faster and show a clear pro-inflammatory phenotype. Here, using male and female mice, we induced obesity by feeding a high fat diet (HFD), and compared adipose tissue (AT) inflammation at the same adiposity stage (% AT/bodyweight) between both sexes. Doing so, we identified that female mice show an increase in the number of pro-inflammatory immune cells in the visceral AT at a lower adiposity stage than male mice, but the effect of HFD is diminished with higher adiposity. Interestingly, only female mice showed an increase in immune cells in the subcutaneous AT after HFD feeding. Nonetheless, we found that pro-inflammatory cytokines in blood plasma mirror the inflammatory stage of the visceral AT in both male and female mice. Uniquely in male mice, myeloid cells in the visceral AT showed a higher inflammasome activation upon HFD. In summary, we showed that adiposity differentially affects immune cells in fat depots based on sex.

Unveiling adipose populations linked to metabolic health in obesity

Precision medicine is still not considered as a standard of care in obesity treatment, despite a large heterogeneity in the metabolic phenotype of individuals with obesity. One of the strongest factors influencing the variability in metabolic disease risk is adipose tissue (AT) dysfunction; however, there is little understanding of the link between distinct cell populations, cell-type-specific transcriptional programs, and disease severity. Here, we generated a comprehensive cellular map of subcutaneous and visceral AT of individuals with metabolically healthy and unhealthy obesity. By combining single-nucleus RNA-sequencing data with bulk transcriptomics and clinical parameters, we identified that mesothelial cells, adipocytes, and adipocyte-progenitor cells exhibit the strongest correlation with metabolic disease. Furthermore, we uncovered cell-specific transcriptional programs, such as the transitioning of mesothelial cells to a mesenchymal phenotype, that are involved in uncoupling obesity from metabolic disease. Together, these findings provide valuable insights by revealing biological drivers of clinical endpoints.

Age and duration of obesity modulate the inflammatory response and expression of neuroprotective factors in mammalian female brain

Obesity has become a global epidemic and is associated with comorbidities, including diabetes, cardiovascular, and neurodegenerative diseases, among others. While appreciable insight has been gained into the mechanisms of obesity-associated comorbidities, effects of age, and duration of obesity on the female brain remain obscure. To address this gap, adolescent and mature adult female mice were subjected to a high-fat diet (HFD) for 13 or 26 weeks, whereas age-matched controls were fed a standard diet. Subsequently, the expression of inflammatory cytokines, neurotrophic/neuroprotective factors, and markers of microgliosis and astrogliosis were analyzed in the hypothalamus, hippocampus, and cerebral cortex, along with inflammation in visceral adipose tissue. HFD led to a typical obese phenotype in all groups independent of age and duration of HFD. However, the intermediate duration of obesity induced a limited inflammatory response in adolescent females' hypothalamus while the hippocampus, cerebral cortex, and visceral adipose tissue remained unaffected. In contrast, the prolonged duration of obesity resulted in inflammation in all three brain regions and visceral adipose tissue along with upregulation of microgliosis/astrogliosis and suppression of neurotrophic/neuroprotective factors in all brain regions, denoting the duration of obesity as a critical risk factor for neurodegenerative diseases. Importantly, when female mice were older (i.e., mature adult), even the intermediate duration of obesity induced similar adverse effects in all brain regions. Taken together, our findings suggest that (1) both age and duration of obesity have a significant impact on obesity-associated comorbidities and (2) early interventions to end obesity are critical to preserving brain health.

Identification of metabolic syndrome using lipid accumulation product and cardiometabolic index based on NHANES data from 2005 to 2018

BACKGROUND

Numerous studies indicate that visceral adipose tissue (VAT) significantly contribute to metabolic syndrome (MetS) development. This study aims to assess the distinguishing value of novel obesity markers, specifically lipid accumulation products (LAP) and cardiometabolic index (CMI), in relation to MetS. Considering the gender disparity in MetS prevalence, it is essential to explore whether LAP and CMI exhibit differential distinguishing capabilities by gender.

METHOD

The investigation included a total of 11,687 qualified individuals who participated in the NHANES survey spanning a 14-year period from 2005 to 2018. Biochemical analysis of blood and body measurements were utilized to determine LAP and CMI values for each participant. Inclusion of gender as a variable was a key factor in the examination of all data. Restricted cube plots (RCS) were utilized to analyze the strength of the relationship between LAP, CMI, and MetS. The study delved into potential connections between LAP and CMI with MetS, all-cause and cardiovascular mortality using various statistical models such as multivariate logistic regression and Cox regression.

RESULTS

The findings revealed a significant nonlinear association between CMI, LAP, and MetS (P-non-linear < 0.001), irrespective of gender, with all models exhibiting a J-shaped trend. The multivariable logistic regression analysis considered both LAP and CMI as continuous variables or tertiles, revealing significant associations with MetS in male, female, and general populations (All the P < 0.001). Although males displayed a higher risk of MetS, no gender differences were observed in the area under the curve (AUC) values of LAP and CMI for distinguishing (P > 0.005) MetS. Impressively, LAP and CMI were identified as the primary predictors of MetS in both genders from AUC (P < 0.005). More specifically, the cutoff points for distinguishing MetS in females were LAP = 49.87 or CMI = 0.56, while for males, they were LAP = 52.76 or CMI = 0.70. Additionally, the Cox regression analysis revealed that LAP and CMI were correlated with all-cause mortality in both general population and females (P < 0.005), but not in males.

CONCLUSION

In comparison to other measures of obesity, LAP and CMI demonstrated superior diagnostic accuracy for MetS in both males and females. Additionally, LAP and CMI were found to be predictive of all-cause mortality in both general population and females. These markers are cost-effective, easily accessible, and widely applicable for the early identification and screening of MetS in clinical settings.

The Modifying Effects of Lifestyle Behaviors on the Association Between Drinking Water Micronutrients and BMI Status Among Children and Adolescents Aged 7~17: A Population-Based Regional Surveillance in 2022

BACKGROUND

This study aims to investigate the potential modifying effects of lifestyle behavior on the association between drinking water micronutrients and body mass index (BMI) in a large population of children and adolescents.

METHODS

Data of the present analysis came from a comprehensive regional large-scale surveillance study in 2022, involving 172,880 children and adolescents (50.71% boys vs. 49.29% girls) aged seven to seventeen. A restricted cubic spline (RCS) analysis was utilized to examine the exposure-response association of regular drinking water indices (including fluoride, nitrate nitrogen, pH, chloride, sulfates, and total dissolved solids (TDS), total hardness (TH), and chemical oxygen demand (COD)) with BMI. Generalized linear model and logistic regression were conducted to relate BMI and quartiles of drinking water micronutrients.

RESULTS

Our findings reveal a nonlinear association between nitrate nitrogen (P for nonlinear < 0.001) and pH (P for nonlinear < 0.001) with BMI. High TH and COD levels significantly increase BMI. Notably, fluoride and chloride were associated with BMI Z-scores but not with overweight and obesity (OB). The BMI Z-score showed a more pronounced association with low and high pH levels in girls. For urban participants, increased TH levels were associated with a higher risk of OB. This study also found that adopting healthy lifestyles could mitigate the negative effects of fluoride, chloride, and sulfate on BMI Z-scores.

CONCLUSIONS

This large surveillance study provides new insights into the complex interplay between drinking water micronutrients and BMI in children and adolescents. The association of various drinking water parameters on BMI varies, necessitating ongoing focus on their effects, particularly among girls and urban individuals. Healthy lifestyle behavior could mitigate the effects of fluoride, chloride, and sulfate on BMI Z-score.

Visceral fat distribution: Interracial studies

Visceral adipose tissue, a type of abdominal adipose tissue, is highly involved in lipolysis. Because increased visceral adiposity is strongly associated with the metabolic complications related with obesity, such as type 2 diabetes and cardiovascular disease, there is a need for precise, targeted, personalized and site-specific measures clinically. Existing studies showed that ectopic fat accumulation may be characterized differently among different populations due to complex genetic architecture and non-genetic or epigenetic components, ie, Asians have more and Africans have less visceral fat vs Europeans. In this review, we summarize the effects of multiple non-genetic and genetic factors on visceral fat distribution across races. Non-genetic factors include diet, socioeconomic status, sex hormones and psychological factors, etc. We examine genetic factors of racial differences in visceral fat content as well as possible regulatory pathways associated with interracial visceral fat distribution. A comprehensive understanding of both genetic and non-genetic factors that influence the distribution of visceral fat among races, leads us to predict risk of abdominal obesity and metabolic diseases in ethnic groups that enables targeted interventions through accurate diagnosis and treatment as well as reduced risk of obesity-associated complications.

The association between lipid accumulation products and depression in U.S. adults: A cross-sectional study from NHANES 2005-2018

OBJECTIVE

The purpose of this study was to investigate the correlation between lipid accumulation products (LAP) and depression among adults in the United States.

METHODS

We analyzed data from 13,051 persons participating in the NHANES 2005-2018 cycle. The LAP index was calculated using the waist circumference (WC) and serum triglyceride (TG) levels, which reflect lipid toxicity. Participants who scored ≥10 on the Patient Health Questionnaire-9 (PHQ-9) were considered depressed. Multivariate logistic regression analyses were conducted to explore the association between the LAP index and depression. Subgroup analysis was also conducted to identify sensitive populations. Smoothed curve fitting and generalized additive model (GAM) regression were performed to verify the association between the LAP index and depression.

RESULTS

After adjusting for all potential confounders, the risk of depression increased with increasing LAP index (odds ratio [OR]=1.0011, 95% confidence interval [CI]= 1.0001-1.0021). Compared to participants in LAP quartile 1, participants in LAP quartile 3 exhibited the highest risk for depression (OR=1.43, 95% CI: 1.03-1.99). Subgroup analysis demonstrated a stronger association between the LAP index and depression in men (OR= 1.002, 95% CI= 1.001-1.004) and in those with hypertension (OR=1.002, 95% CI=1.000-1.003). Additionally, smoothed curve fitting and GAM regression demonstrated a positive linear correlation between the LAP index and depression.

CONCLUSIONS

These findings suggest that individuals with a higher LAP index may be at greater risk for depression, particularly among men and those with hypertension. Further studies are required to confirm these findings.

Sex and Size Disparities in Access to Liver Transplant for Patients With Hepatocellular Carcinoma

Importance

Women on the liver transplant waiting list are less likely to undergo a transplant than men. Recent approaches to resolving this disparity have involved adjustments to Model for End-Stage Liver Disease (MELD) scoring, but this will not affect candidates who rely on exception scores rather than calculated MELD score, the majority of whom have hepatocellular carcinoma (HCC).

Objective

To evaluate the association between female sex, candidate size, and access to liver transplant among wait-listed patients with HCC.

Design, Setting, and Participants

This retrospective cohort study used US transplant registry data of all adult (aged ≥18 years) wait-listed liver transplant candidates receiving an HCC exception score between January 1, 2010, and March 2, 2023.

Exposure

Wait-listed liver transplant candidate sex.

Main Outcomes and Measures

The association of female sex with (1) deceased-donor liver transplant (DDLT) and (2) death or waiting list removal for health deterioration were estimated using multivariable competing-risks regression. Results with and without adjustment for candidate height and weight (mediators of the sex disparity) were compared.

Results

The cohort included 31 725 candidates with HCC (mean [SD] age at receipt of exception, 61.2 [7.1] years; 76.3% men). Compared with men, women had a lower 1-year cumulative incidence of DDLT (50.8% vs 54.0%; P < .001) and a higher 1-year cumulative incidence of death or delisting for health deterioration (16.2% vs 15.0%; P = .002). After adjustment, without accounting for size, women had a lower incidence of DDLT (subdistribution hazard ratio [SHR], 0.92; 95% CI, 0.89-0.95) and higher incidence of death or delisting (SHR, 1.06; 95% CI, 1.00-1.13) compared with men. When adjusting for candidate height and weight, there was no association of female sex with incidence of DDLT or death or delisting. However, at a height cutoff of 166 cm, short women compared with short men were still less likely to undergo a transplant (SHR, 0.93; 95% CI, 0.88-0.99).

Conclusions and Relevance

In this study, women with HCC were less likely to receive a DDLT and more likely to die while wait-listed than men with HCC; these differences were largely (but not entirely) explained by sex-based differences in candidate size. For candidates listed with exception scores, additional changes to allocation policy are needed to resolve the sex disparity, including solutions to improve access to size-matched donor livers for smaller candidates.

A multidimensional analysis of the impact of obesity on immune checkpoint inhibitor therapy efficacy

BACKGROUND

Obesity is a well-known risk factor for developing malignant tumors and promoting tumor cell growth and spread. However, recent studies have shown that obese cancer patients, who typically have a worse prognosis than nonobese cancer patients, show a significant improvement in survival after receiving immune checkpoint inhibitor (ICI) therapy. This phenomenon is known as the "obesity paradox". However, this phenomenon is influenced by tumor type and sex. Therefore, this study aimed to explore the impact of obesity on immunotherapy efficacy from multiple perspectives, aiming to verify this paradox and provide new scientific evidence on the effect of obesity on ICI efficacy.

METHODS

This retrospective study evaluated the data of patients who received ICI therapy between June 2019 and August 2023. Automatic segmentation of skeletal muscle, subcutaneous fat, and visceral fat was performed using Slice-O-Matic software, and the corresponding skeletal muscle index (SMI), subcutaneous fat index (SFI) and visceral fat index (VFI) were calculated. The neutrophil-to-lymphocyte ratio (NLR) was determined by dividing the neutrophil count by the lymphocyte count. Univariate and multivariate Cox regression analyses were used to evaluate the correlation between body mass index (BMI), body composition parameters, and the NLR with overall survival (OS) and progression-free survival (PFS) in obese patients receiving ICI therapy.

RESULTS

We analyzed 219 patients with a median age of 60 years (IQR 53-69 years; 155 men and 64 women). Obese patients, particularly those with visceral fat accumulation, exhibited extended OS after ICI therapy (log-rank P = 0.027). Cox multivariate analysis revealed that the NLR (HR = 1.036; 95% CI: 0.996 to 1.078; P = 0.002) was independently associated with OS. Patients with a high NLR had worse OS than those with a low NLR.

CONCLUSIONS

This study corroborates the veracity of the "obesity paradox" under specific conditions and identifies NLR as an independent prognostic factor, with elevated NLR indicative of a poor prognosis.

The challenges of assessing adiposity in a clinical setting

To tackle the burden of obesity-induced cardiometabolic disease, the scientific community relies on accurate and reproducible adiposity measurements in the clinic. These measurements guide our understanding of underlying biological mechanisms and clinical outcomes of human trials. However, measuring adiposity and adipose tissue distribution in a clinical setting can be challenging, and different measurement methods pose important limitations. BMI is a simple and high-throughput measurement, but it is associated relatively poorly with clinical outcomes when compared with waist-to-hip and sagittal abdominal diameter measurements. Body composition measurements by dual energy X-ray absorptiometry or MRI scans would be ideal due to their high accuracy, but are not high-throughput. Another important consideration is that adiposity measurements vary between men and women, between adults and children, and between people of different ethnic backgrounds. In this Perspective article, we discuss how these critical challenges can affect our interpretation of research data in the field of obesity and the design and implementation of clinical guidelines.

The circulating and central endocannabinoid system in obesity and weight loss

Major advances have been made in obesity treatment, focusing on restoring disturbances along the gut-brain axis. The endocannabinoid system (ECS) is a neuromodulatory signaling system, present along the entire gut-brain axis, that plays a critical role in central and peripheral regulation of food intake and body weight. Evidence on the impact of weight loss on the ECS is, however, more limited. Therefore, we set out to review the existing literature for changes in central and circulating endocannabinoid levels after bariatric surgery and other weight loss strategies in humans. The PubMed, Embase and Web of Science databases were searched for relevant articles. Fifty-six human studies were identified. Most studies measuring circulating 2-arachidonoylglycerol (2-AG) found no difference between normal weight and obesity, or no correlation with BMI. In contrast, studies measuring circulating arachidonoylethanolamine (AEA) found an increase or positive correlation with BMI. Two studies found a negative correlation between BMI and cannabinoid receptor type 1 (CB1) receptor availability in the brain. Only one study investigated the effect of pharmacological weight management on circulating endocannabinoid concentrations and found no effect on AEA concentrations. So far, six studies investigated potential changes in circulating endocannabinoids after bariatric surgery and reported conflicting results. Available evidence does not univocally support that circulating endocannabinoids are upregulated in individuals with obesity, which may be explained by variability across studies in several potential confounding factors (e.g. age and sex) as well as heterogeneity within the obesity population (e.g. BMI only vs. intra-abdominal adiposity). While several studies investigated the effect of lifestyle interventions on the circulating ECS, more studies are warranted that focus on pharmacologically and surgically induced weight loss. In addition, we identified several research needs which should be fulfilled to better understand the role of the ECS in obesity and its treatments.

Sex differences in the association between short sleep duration and obesity: A systematic-review and meta-analysis

AIMS

Obesity is a leading contributor to global morbidity and mortality. Short sleep duration is significantly associated with the incidence of obesity, however, it remains unclear whether this relationship is influenced by sex. The purpose of this meta-analysis was to systematically evaluate the evidence of whether the association between short sleep duration and obesity differs between males and females.

DATA SYNTHESIS

The protocol was registered with PROSPERO (CRD42023374205). From inception through June 2023, Medline, Embase and Web of Science databases were searched for longitudinal cohort studies with minimum 12 months of observation. The quality of studies was assessed using the Newcastle-Ottawa Quality Assessment for Cohort Studies. Results were pooled using a random effects model. Results are expressed as ratio of odds ratios (ROR) with 95% confidence interval (CI). ROR directly estimates the relative strength of the association of interest (measured as odds ratio [OR] between females and males). Sensitivity analysis was performed and inconsistency between studies was assessed using I2 statistics. A total of 4582 articles were retrieved with the search strategy, of which 6 were included. The meta-analysis indicated that the association between short sleep duration and obesity incidence was statistically significant in both men [OR 1.26 (95% CI 1.13-1.40)] and women [OR 1.36 (95% CI 1.16-1.59)]. However, it did not differ significantly between sexes ROR (women/men) 1.04 (95%CI 0.79-1.36; I2 20.1%).

CONCLUSIONS

This meta-analysis indicates that women and men who subjectively report short sleep duration have similarly increased risks of incident obesity.

Activity of the hypothalamic neuropeptide Y increases in adult and decreases in old rats

Middle-aged obesity and aging anorexia with muscle loss (sarcopenia) of old people present public health burden. These alterations may appear both in humans and rodents suggesting the role for regulatory alterations. Previously, we demonstrated that biphasic changes in the weight-reducing (catabolic) effects of neuropeptides of the hypothalamus-adipose tissue axis (e.g. leptin) may contribute to both trends. With regard to the anabolic effects of the hypothalamic neuropeptide Y (NPY) inhibited by leptin, we hypothesized non-linear age-related changes with shifts in the opposite directions. We investigated the orexigenic and hypometabolic effects of intracerebroventricularly administered NPY (hyperphagia induced by NPY injection or changes in food intake, body weight, heart rate, body temperature, locomotor activity during a 7-day NPY infusion), the immunoreactivity and gene expression of NPY in the hypothalamic arcuate nucleus of male Wistar rats of five age groups from young to old. The orexigenic/hypometabolic efficacy and the immunoreactivity of NPY increased in middle-aged animals preceding the peak of adiposity observed in aging rats, then decreased preceding anorexia and weight loss in old rats. These shifts may contribute to the development of both age-related obesity and aging anorexia, sarcopenia, and should be considered in future drug development targeting the NPY system.

Sex-based differences in the associations between abdominal obesity and diabetic retinopathy in diabetic patients with normal weight

Purpose

To investigate sex-specific differences in associations of abdominal obesity indexes, systemic factors, and diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) subjects with normal body mass index (BMI).

Methods

This cross-sectional study comprised 653 T2DM subjects (402 women and 251 men) with normal BMI (18.5 kg/m2

Results

In the multivariate logistic regressions, the presence of any DR was associated with a longer duration of T2DM (OR = 1.07, p = 0.007) and higher HbA1c (OR = 1.40, p = 0.001) in women, while any DR was associated with younger age at T2DM diagnosis (OR = 0.94, p = 0.020) and higher HbA1c (OR = 1.29, p = 0.011) in men. For women, we identified a positive association between WC (OR = 1.07, p = 0.011), WHR (OR = 1.67, p = 0.002), and WHtR (OR = 1.57, p = 0.004) with any DR after adjusting for confounders, and the third tertiles of WC (OR = 2.29, p = 0.028), WHR (OR = 3.03, p = 0.003), and WHtR (OR = 2.84, p = 0.007) were at high risk of any DR. For men, there were no associations between abdominal obesity indexes and any DR in either continuous variables or categorical variables (all p > 0.05).

Main conclusions

There were sex differences in the relationships between WC, WHR, WHtR, and DR in this T2DM population with normal BMI. Our findings provide new insight into a sex-specific mechanism of DR and management of the condition.

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Key Words

• Abdominal obesity
• Body mass index
• Diabetic retinopathy
• Sex differences

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Affiliation(s)

Yuan Liu State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Kaiqun Liu State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Liqiong Xie State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Chengguo Zuo State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Lanhua Wang State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
Wenyong Huang State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China

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The association between the weight-adjusted-waist index and frailty in US older adults: a cross-sectional study of NHANES 2007-2018

Objective

This study aimed to evaluate the relationship between the weight-adjusted waist circumference index (WWI) and the frailty in American adults aged over 60 years.

Methods

We utilized data from the National Health and Nutrition Examination Surveys (NHANES) spanning from 2007 to 2018. WWI was calculated using the square root of waist circumference (cm) divided by body weight (kg). The frailty index ≥ 0.25 was employed to assess frailty. Weighted multivariate logistic regression was conducted to explore the association between WWI and frailty. Generalized Additive Modeling (GAM) was used to explore potential non-linear relationships. Receiver operating characteristic curve (ROC) analysis was used to assess the predictive ability of WWI for frailty.

Results

The study encompassed 7765 participants. Higher WWI was significantly associated with higher odds of frailty. In the fully adjusted model, each unit increase of WWI was associated with an 82% increased odds of frailty (OR: 1.82, 95% CI: 1.61 - 2.06; P < 0.001). GAM found significant nonlinear relationships and threshold effects.

Conclusion

The study presented a robust correlation between elevated WWI and increased odds of frailty among American older adults. However, these findings require further validation in large-scale, prospective studies.

Sex disparity in the association between metabolic-anthropometric phenotypes and risk of obesity-related cancer: a prospective cohort study

BACKGROUND

Sex disparity between metabolic-obesity (defined by body mass index, BMI) phenotypes and obesity-related cancer (ORC) remains unknown. Considering BMI reflecting overall obesity but not fat distribution, we aimed to systematically assess the association of our newly proposed metabolic-anthropometric phenotypes with risk of overall and site-specific ORC by sex.

METHODS

A total of 141,579 men (mean age: 56.37 years, mean follow-up time: 12.04 years) and 131,047 women (mean age: 56.22 years, mean follow up time: 11.82 years) from the UK Biobank was included, and designated as metabolic-anthropometric phenotypes based on metabolic status (metabolically healthy/unhealthy), BMI (non-obesity/obesity) and body shape (pear/slim/apple/wide). The sex-specific association of different phenotypes with overall and site-specific ORC was assessed by hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression models.

RESULTS

We found metabolically unhealthy and/or obesity phenotypes conveyed a higher risk in men than in women for overall ORC and colorectal cancer compared with metabolically healthy non-obesity phenotype (Pinteraction < 0.05). Of note, metabolically healthy obesity phenotype contributed to increased risks of most ORC in men (HRs: 1.58 ~ 2.91), but only correlated with higher risks of endometrial (HR = 1.89, 95% CI: 1.54-2.32) and postmenopausal breast cancers (HR = 1.17, 95% CI: 1.05-1.31) in women. Similarly, even under metabolically healthy, men carrying apple and wide shapes phenotypes (metabolically healthy apple/wide and metabolically healthy non-obesity apple/wide) suffered an increased risk of ORC (mainly colorectal, liver, gastric cardia, and renal cancers, HRs: 1.20 ~ 3.81) in comparison with pear shape or non-obesity pear shape.

CONCLUSIONS

There was a significant sex disparity between metabolic-anthropometric phenotypes and ORC risk. We advised future ORC prevention and control worth taking body shape and sex disparity into account.

Sex- and gender-based medicine in pediatric nutrition

Consistent evidence increasingly highlights the significance of integrating sex and gender medicine to ensure a precision approach according to individual patient needs. Gender discrepancies emerge across various areas, even from pediatric age. The importance of recognizing these differences in pediatric nutrition is critical for the development of targeted nutritional strategies and interventions, particularly in cases of associated pathologies, including obesity, metabolic-associated fatty liver disease, eating disorders, and inflammatory bowel disease. The review highlights the biological and sociocultural factors that contribute to different nutritional needs and health outcomes in male and female children. By examining current evidence, we underscore the necessity for precision medicine approaches in pediatric care that consider these sex- and gender-based differences. Moreover, differences in dietary requirements and dietary patterns between males and females are evident, underscoring the need for precise nutrition strategies for a more accurate management of children and adolescents. This approach is essential for improving clinical outcomes and promoting equitable healthcare practices. This review aims to provide an overview of nutrition-related medical conditions exhibiting sex- and gender-specific discrepancies, which might lead to distinct outcomes requiring unique management and prevention strategies. Future research and public health initiatives should address these differences in designing effective lifestyle education programs and nutrition interventions targeting both children and adolescents.

The effects of isocaloric diets derived from different lipid sources on zebrafish

Characterizing the effects of saturated fat intake on metabolic health and its changes remains a major challenge. Lipid diets, from different sources, vary widely in their physiological effects on health; therefore, it is important to consider the specific lipid source consumed. The objective of the study was to evaluate the effect of the imposition of isocaloric diets with different lipid sources in zebrafish (fish oil/pork lard). Depicting how metabolic, morphological and behavioral parameters might express themselves in these fishes. Forty adult female fishes were used for the experiment. The animals were divided into a control group (C), fed with unsaturated fatty acid diet, and a saturated fatty acid group (Sat). They received food three times a day, during the 11-week period. The results showed that animals in the Sat group had increased body weight, with a difference relative to the C group, from the third week of diet until the end of the experiment. At the end of the last week, the Sat group had a body weight 32% higher (P=0.0182) than the body weight of the control group. The consumption of a diet rich in saturated fatty acids did not generate signs related to stress and anxiety in zebrafish. There was an increase in glycemia at T60 and T120, with a statistically significant difference between the two moments. Animals in the Sat group showed an increase (P=0.0086) in hepatic steatosis compared to animals in the control group. The results obtained on the relationship between diet and metabolic changes are fundamental to ensure the understanding and appropriate treatment of these problems.

Association of obesity to reaction time and visual memory in schizophrenia

Background

Both overweight and cognitive deficits are common among people with schizophrenia (SZ) and schizoaffective disorder. The results in earlier studies have been inconsistent on whether overweight is associated with cognitive deficits in psychotic disorders.

Aims

Our aim in this study was to detect possible associations between obesity and cognitive deficits among study participants with SZ and schizoaffective disorder.

Methods

The study sample included 5382 participants with a clinical diagnosis of SZ or schizoaffective disorder selected from the Finnish SUPER study. Obesity was measured both with body-mass index and waist circumference. The cognitive performance was evaluated with two tests from the Cambridge automated neuropsychological test battery: Reaction time was evaluated with the 5-choice serial reaction time task. Visual memory was evaluated with the paired associative learning test. The final analysis included a total sample of 4498 participants applicable for the analysis of the reaction time and 3967 participants for the analysis of the visual memory.

Results

Obesity measured with body-mass index was associated with better performance in reaction time task among both female and male participants. Among male participants, overweight was associated with better performance in the visual memory test. The waist circumference was not associated with cognitive measures.

Conclusions

The results suggest that obesity in people with SZ or schizoaffective disorder might not be associated with cognitive deficits but instead with better cognitive performance. The results were opposite from earlier literature on the general population. More research is required to better understand whether the results might be partly caused by the differences in the etiology of obesity between the general population and people with SZ.

Impact of baseline adipose tissue characteristics on change in adipose tissue volume during a low calorie diet in people with obesity-results from the LION study

BACKGROUND/OBJECTIVES

Weight loss outcomes vary individually. Magnetic resonance imaging (MRI)-based evaluation of adipose tissue (AT) might help to identify AT characteristics that predict AT loss. This study aimed to assess the impact of an 8-week low-calorie diet (LCD) on different AT depots and to identify predictors of short-term AT loss using MRI in adults with obesity.

METHODS

Eighty-one adults with obesity (mean BMI 34.08 ± 2.75 kg/m², mean age 46.3 ± 10.97 years, 49 females) prospectively underwent baseline MRI (liver dome to femoral head) and anthropometric measurements (BMI, waist-to-hip-ratio, body fat), followed by a post-LCD-examination. Visceral and subcutaneous AT (VAT and SAT) volumes and AT fat fraction were extracted from the MRI data. Apparent lipid volumes based on MRI were calculated as approximation for the lipid contained in the AT. SAT and VAT volumes were subdivided into equidistant thirds along the craniocaudal axis and normalized by length of the segmentation. T-tests compared baseline and follow-up measurements and sex differences. Effect sizes on subdivided AT volumes were compared. Spearman Rank correlation explored associations between baseline parameters and AT loss. Multiple regression analysis identified baseline predictors for AT loss.

RESULTS

Following the LCD, participants exhibited significant weight loss (11.61 ± 3.07 kg, p < 0.01) and reductions in all MRI-based AT parameters (p < 0.01). Absolute SAT loss exceeded VAT loss, while relative apparent lipid loss was higher in VAT (both p < 0.01). The lower abdominopelvic third showed the most significant SAT and VAT reduction. The predictor of most AT and apparent lipid losses was the normalized baseline SAT volume in the lower abdominopelvic third, with smaller volumes favoring greater AT loss (p < 0.01 for SAT and VAT loss and SAT apparent lipid volume loss).

CONCLUSIONS

The LCD primarily reduces lower abdominopelvic SAT and VAT. Furthermore, lower abdominopelvic SAT volume was detected as a potential predictor for short-term AT loss in persons with obesity.

Dietary pyruvate targets cytosolic phospholipase A2 to mitigate inflammation and obesity in mice

Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation, known as meta-inflammation. This state is associated with the development of metabolic disorders such as glucose intolerance and nonalcoholic fatty liver disease. Pyruvate is a glycolytic metabolite and a crucial node in various metabolic pathways. However, its role and molecular mechanism in obesity and associated complications are obscure. In this study, we reported that pyruvate substantially inhibited adipogenic differentiation in vitro and its administration significantly prevented HFD-induced weight gain, white adipose tissue inflammation, and metabolic dysregulation. To identify the target proteins of pyruvate, drug affinity responsive target stability was employed with proteomics, cellular thermal shift assay, and isothermal drug response to detect the interactions between pyruvate and its molecular targets. Consequently, we identified cytosolic phospholipase A2 (cPLA2) as a novel molecular target of pyruvate and demonstrated that pyruvate restrained diet-induced obesity, white adipose tissue inflammation, and hepatic steatosis in a cPLA2-dependent manner. Studies with global ablation of cPLA2 in mice showed that the protective effects of pyruvate were largely abrogated, confirming the importance of pyruvate/cPLA2 interaction in pyruvate attenuation of inflammation and obesity. Overall, our study not only establishes pyruvate as an antagonist of cPLA2 signaling and a potential therapeutic option for obesity but it also sheds light on the mechanism of its action. Pyruvate's prior clinical use indicates that it can be considered a safe and viable alternative for obesity, whether consumed as a dietary supplement or as part of a regular diet.

Relationship between abdominal fat volume and bone base material pairs from dual-energy spectral computed tomography in young and middle-aged patients with metabolic syndrome

Background

Metabolic syndrome (MetS) has complex effects on bone health, and dual-energy spectral computed tomography (CT) has become increasingly valuable for bone quantification. However, the relationship between bone base material pairs (BMPs) and abdominal fat volume in patients with MetS remains underexplored. This study thus aimed to analyze the relationship between abdominal fat volume and various bone BMPs using dual-energy spectral CT in young and middle-aged patients with MetS.

Methods

Patients with MetS who underwent sleeve gastrectomy at the Center of Obesity and Metabolic Diseases, Beijing Shijitan Hospital, Capital Medical University, from June to November 2021 were retrospectively collected. The abdominal fat measurements and BMPs were acquired using dual-energy spectral CT imaging. These included the volumes of total abdominal fat (TAF), abdominal visceral fat (AVF), and abdominal subcutaneous fat (ASF), as well as bone densities based on hydroxyapatite (water), i.e., HAP (water), and calcium (water), i.e., Ca (water), BMPs. After grouping the patients by sex, we analyzed the differences in clinical and imaging features. The correlation between the clinical and imaging parameters of patients with MetS was evaluated with Pearson correlation coefficients. Age- and sex-adjusted partial correlation analysis between fat volume and bone BMPs was conducted for patients of different sexes. Additionally, multiple linear regression analyses were performed with age, sex, and TAF volume as the independent variables and with Ca (water) and HAP (water) as dependent variables.

Results

A total of 112 young and middle-aged patients with MetS were included in this study, including 85 females and 27 males. Compared to male patients with MetS, the females with MetS exhibited higher lumbar Ca (water) and HAP (water) BMPs, with lower volumes of TAF and AVF and a smaller abdominal circumference (P<0.01). The volumes of TAF, AVF, and ASF were negatively correlated with the average Ca (water) and HAP (water) BMPs in the first to third lumbar vertebrae (L1-L3) (P<0.05). Ca (water) and HAP (water) BMPs decreased with age and increasing TAF volume (P<0.001). The fitted equations for the relationship between bone BMPs with age, sex, and TAF volume were as follows: (I) bone Ca (water) BMP = 76.469 - 0.500 age + 6.762 sex - 0.002 TAF volume; (II) bone HAP (water) BMP =171.704 - 1.138 age + 11.825 sex - 0.004 TAF volume.

Conclusions

In young and middle-aged patients with MetS, the abdominal fat volume was negatively correlated with lumbar bone Ca (water) and HAP (water) BMPs, implying that increased abdominal fat volume may play a crucial role in the pathogenesis of osteopenia among those with MetS. The reduction of bone Ca (water) and HAP (water) with high abdominal fat volume may hold clinical significance for fracture risk in individuals with MetS.

Sex-Related Differences in the Associations between Adiponectin and Serum Lipoproteins in Healthy Subjects and Patients with Metabolic Syndrome

The strong associations between the serum levels of adiponectin and the lipoprotein subclasses observed in healthy subjects are much weaker in patients with metabolic syndrome (MS). However, the impact of sex on these associations remained unexplored. Therefore, in the present study, we examined associations between adiponectin and the lipoprotein subclasses, analyzed by nuclear magnetic resonance spectroscopy, separately in healthy females and males, as well as in females and males with MS. We observed negative correlations between adiponectin and VLDL, IDL, and small-dense LDL in healthy males, but neither in healthy females nor in females or males with MS. Additionally, adiponectin was positively correlated with some HDL subclasses in healthy males and females with MS, but not in healthy females or males with MS. Adjusting for age and either body mass index, waist circumference, C-reactive protein, or interleukin-6 weakened the associations between adiponectin and VLDL and IDL but not small-dense LDL. The adjustment weakened the associations between adiponectin and HDL in healthy males but not in females with MS. Based on our results, we conclude that sex and the presence of MS are strong determinants of the associations between adiponectin and serum lipoproteins and that the complex regulatory network comprising adiponectin and other molecular players involved in the regulation of lipoprotein metabolism is primarily operative in healthy males and females with MS.

FGF21 mediating the Sex-dependent Response to Dietary Macronutrients

Sex is key variable influencing body composition and substrate utilization. At rest, females maintain greater adiposity than males and resist the mobilization of fat. Males maintain greater lean muscle mass and mobilize fat readily. Determining the mechanisms that direct these sex-dependent effects is important for both reproductive and metabolic health. Here, we highlight the fundamental importance of sex in shaping metabolic physiology and assess growing evidence that the hepatokine fibroblast growth factor-21 (FGF21) plays a mechanistic role to facilitate sex-dependent responses to a changing nutritional environment. First, we examine the importance of sex in modulating body composition and substrate utilization. We summarize new data that point toward sex-biased effects of pharmacologic FGF21 administration on these endpoints. When energy is not limited, metabolic responses to FGF21 mirror broader sex differences; FGF21-treated males conserve lean mass at the expense of increased lipid catabolism, whereas FGF21-treated females conserve fat mass at the expense of reduced lean mass. Next, we examine the importance of sex in modulating the endogenous secretion of FGF21 in response to changing macronutrient and energy availability. During the resting state when energy is not limited, macronutrient imbalance increases the secretion of FGF21 more so in males than females. When energy is limited, the effect of sex on both the secretion of FGF21 and its metabolic actions may be reversed. Altogether, we argue that a growing literature supports FGF21 as a plausible mechanism contributing to the sex-dependent mobilization vs preservation of lipid storage and highlight the need for further research.

Association between two novel anthropometric measures and type 2 diabetes in a Chinese population

AIMS

To investigate the associations of conicity index (C-index) and relative fat mass (RFM) with incident type 2 diabetes mellitus (T2DM) among adults in China.

MATERIALS AND METHODS

A total of 10 813 participants aged over 18 years in Shenzhen Longhua district were enrolled in a follow-up study conducted from 2018 to 2022. The participants were categorized based on quartiles (Q) of C-index and RFM. The Cox proportional hazards model was performed to examine the relationships between C-index, RFM and the risk of T2DM.

RESULTS

After adjusting for potential confounding factors, including age, sex, occupation, marital status, education level, smoking status, alcohol consumption, physical exercise, hypertension status, fasting blood glucose (FBG) and total cholesterol (TC), both C-index and RFM showed positive and independent associations with risk of T2DM. The multivariable-adjusted hazard ratios (95% confidence intervals) for T2DM risk in participants in C-index Q3 and Q4 compared with those in C-index Q1 were 1.50 (1.12, 2.02) and 1.73 (1.29, 2.30), and 1.94 (1.44, 2.63), 3.18 (1.79, 5.64), 4.91 (2.68, 9.00) for participants in RFM Q2, Q3 and Q4 compared with RFM Q1. These differences were statistically significant (all p < 0.05).

CONCLUSION

C-index and RFM are strongly associated with new-onset T2DM and could be used to identify the risk of diabetes in large-scale epidemiological studies.

Sex difference in the association of dietary fiber intake with visceral fat volume in Japanese adults

PURPOSE

Dietary fiber is a possible nutritional component which aids in the prevention of visceral fat accumulation. We examined the association between dietary fiber intake and visceral fat volume (VFV) by sex, and further analysed the association by major food sources of dietary fiber.

METHODS

In this cross-sectional study, we measured VFV in 2779 Japanese (1564 men and 1215 women) aged 40-89 who underwent positron emission tomography/computed tomography for cancer screening between 2004 and 2005. Dietary fiber intake was calculated based on a validated semi-quantitative food frequency questionnaire. The association between dietary fiber intake and VFV was investigated using multivariate linear regression models after adjustment for potential confounders.

RESULTS

Total, soluble, and insoluble fiber intakes were inversely associated with VFV in men (Q1: 3740 cm3, Q4: 3517 cm3, Ptrend: 0.0006 for total fiber), but not in women (Q1: 2207 cm3, Q4: 2193 cm3,Ptrend: 0.88 for total fiber). Statistically significant sex difference was observed (Pinteraction = 0.001 for total fiber). Subgroup analyses by major food sources revealed that dietary fiber intakes from beans, vegetables and fruits showed an inverse association with VFV in men, while cereal fiber intake showed a tendency toward a positive association in both sexes (Q1: 3520 cm3, Q4: 3671 cm3, Ptrend: 0.05 in men, Q1: 2147 cm3, Q4: 2227 cm3, Ptrend: 0.10 in women).

CONCLUSION

We observed a sex-specific association between dietary fiber intake and VFV in Japanese adults. This study suggests that efforts against visceral fat accumulation should take account of the source of dietary fiber.

Beyond reproduction: unraveling the impact of sex hormones on cardiometabolic health

This review thoroughly explores the multifaceted roles of sexual hormones, emphasizing their impact beyond reproductive functions and underscoring their significant influence on cardiometabolic regulation. It analyzes the broader physiological implications of estrogen, testosterone, and progesterone, highlighting their effects on metabolic syndrome, lipid metabolism, glucose homeostasis, and cardiovascular health. Drawing from diverse molecular, clinical, and therapeutic studies, the paper delves into the intricate interplay between these hormones and cardiometabolic processes. By presenting a comprehensive analysis that goes beyond traditional perspectives, and recognizing sexual hormones as more than reproductive agents, the review sheds light on their broader significance in health and disease management, advocating for holistic and personalized medical approaches.

The DNA methyltransferase inhibitor decitabine blunts the response to a high-animal fat and protein diet in mice

Increasing evidence hints that DNA hypermethylation may mediate the pathogenic response to cardiovascular risk factors. Here, we tested a corollary of that hypothesis, that is, that the DNA methyltransferase inhibitor decitabine (Dec) ameliorates the metabolic profile of mice fed a moderately high-animal fat and protein diet (HAFPD), a proxy of cardiovascular risk-associated Western-type diet. HAFPD-fed mice were exposed to Dec or vehicle for eight weeks (8W set, 4-32/group). To assess any memory of past exposure to Dec, we surveyed a second mice set treated as 8W but HAFPD-fed for further eight weeks without any Dec (16W set, 4-20/group). In 8W, Dec markedly reduced HAFPD-induced body weight gain in females, but marginally in males. Characterization of females revealed that Dec augmented skeletal muscle lipid content, while decreasing liver fat content and increasing plasma nonesterified fatty acids, adipose insulin resistance, and-although marginally-whole blood acylcarnitines, compared to HAFPD alone. Skeletal muscle mitochondrial DNA copy number was higher in 8W mice exposed to HAFPD and Dec, or in 16W mice fed HAFPD only, relative to 8W mice fed HAFPD only, but Dec induced a transcriptional profile indicative of ameliorated mitochondrial function. Memory of past Dec exposure was tissue-specific and sensitive to both duration of exposure to HAFPD and age. In conclusion, Dec redirected HAFPD-induced lipid accumulation toward the skeletal muscle, likely due to augmented mitochondrial functionality and increased lipid demand. As caveat, Dec induced adipose insulin resistance. Our findings may help identifying strategies for prevention and treatment of lipid dysmetabolism.

The association between fat distribution and α1-acid glycoprotein levels among adult females in the United States

BACKGROUND

Visceral fat accumulation and obesity-induced chronic inflammation have been proposed as early markers for multiple disease states, especially in women. Nevertheless, the potential impact of fat distribution on α1-acid glycoprotein(AGP), a marker of inflammation, remains unclear. This research was conducted to investigate the relationships among obesity, fat distribution, and AGP levels.

METHODS

A cross-sectional observational study was performed using blood samples from adult females recruited through the National Health and Nutrition Examination Survey from 2015 to 2018. Serum levels of AGP were measured using the Tina-quant α-1-Acid Glycoprotein Gen.2 assay. Based on the fat distribution data obtained from dual-energy X-ray absorptiometry assessments, body mass index (BMI), total percent fat (TPF), android percent fat (APF), gynoid percent fat (GPF), android fat/gynoid fat ratio (AGR), visceral percent fat (VPF), subcutaneous percent fat (SPF), visceral fat/subcutaneous fat ratio (VSR) were used as dependent variables. To investigate the link between fat distribution and AGP, multivariate linear regression analysis was utilized. Furthermore, a sensitivity analysis was also performed.

RESULTS

The present study included 2,295 participants. After adjusting for covariates, BMI, TPF, APF, GPF, VPF, and SPF were found to be positively correlated with AGP levels (BMI: β = 23.65 95%CI:20.90-26.40; TPF: β = 25.91 95%CI:23.02-28.80; APF: β = 25.21 95%CI:22.49-27.93; GPF: β = 19.65 95%CI:16.96-22.34; VPF: β = 12.49 95%CI:9.08-15.90; SPF: β = 5.69, 95%CI:2.89-8.49; AGR: β = 21.14 95%CI:18.16-24.12; VSR: β = 9.35 95%CI:6.11-12.59, all P < 0.0001). All the above indicators exhibited a positive dose-response relationship with AGP. In terms of fat distribution, both AGR and VSR showed positive associations with AGP (P for trend < 0.0001). In particular, when compared to individuals in tertile 1 of AGR, participants in tertiles 2 and 3 had 13.42 mg/dL (95% CI 10.66-16.18) and 21.14 mg/dL (95% CI 18.16-24.12) higher AGP levels, respectively. Participants in the highest tertile of VSR were more likely to exhibit a 9.35 mg/dL increase in AGP compared to those in the lowest tertile (95% CI 6.11-12.59).

CONCLUSIONS

Overall, this study revealed a positive dose-dependent relationship between fat proportion/distribution and AGP levels in women. These findings suggest that physicians can associate abnormal serum AGP and obesity with allow timely interventions.

Machine learning allows robust classification of visceral fat in women with obesity using common laboratory metrics

The excessive accumulation and malfunctioning of visceral adipose tissue (VAT) is a major determinant of increased risk of obesity-related comorbidities. Thus, risk stratification of people living with obesity according to their amount of VAT is of clinical interest. Currently, the most common VAT measurement methods include mathematical formulae based on anthropometric dimensions, often biased by human measurement errors, bio-impedance, and image techniques such as X-ray absorptiometry (DXA) analysis, which requires specialized equipment. However, previous studies showed the possibility of classifying people living with obesity according to their VAT through blood chemical concentrations by applying machine learning techniques. In addition, most of the efforts were spent on men living with obesity while little was done for women. Therefore, this study aims to compare the performance of the multilinear regression model (MLR) in estimating VAT and six different supervised machine learning classifiers, including logistic regression (LR), support vector machine and decision tree-based models, to categorize 149 women living with obesity. For clustering, the study population was categorized into classes 0, 1, and 2 according to their VAT and the accuracy of each MLR and classification model was evaluated using DXA-data (DXAdata), blood chemical concentrations (BLDdata), and both DXAdata and BLDdata together (ALLdata). Estimation error and R 2 were computed for MLR, while receiver operating characteristic (ROC) and precision-recall curves (PR) area under the curve (AUC) were used to assess the performance of every classification model. MLR models showed a poor ability to estimate VAT with mean absolute error ≥ 401.40 andR 2 ≤ 0.62 in all the datasets. The highest accuracy was found for LR with values of 0.57, 0.63, and 0.53 for ALLdata, DXAdata, and BLDdata, respectively. The ROC AUC showed a poor ability of both ALLdata and DXAdata to distinguish class 1 from classes 0 and 2 (AUC = 0.31, 0.71, and 0.85, respectively) as also confirmed by PR (AUC = 0.24, 0.57, and 0.73, respectively). However, improved performances were obtained when applying LR model to BLDdata (ROC AUC ≥ 0.61 and PR AUC ≥ 0.42), especially for class 1. These results seem to suggest that, while a direct and reliable estimation of VAT was not possible in our cohort, blood sample-derived information can robustly classify women living with obesity by machine learning-based classifiers, a fact that could benefit the clinical practice, especially in those health centres where medical imaging devices are not available. Nonetheless, these promising findings should be further validated over a larger population.

Comparative analysis of body mass index and obesity-related anthropometric indices for mortality prediction: a study of the Namwon and Dong-gu cohort in Korea

OBJECTIVES

This study investigated the associations between several obesity-related anthropometric indices and mortality in middle-aged and elderly populations to compare the indices' predictive ability with that of the body mass index (BMI).

METHODS

We analyzed data on 12 indices calculated from 19,805 community-based cohort participants (average age, 63.27 years; median follow-up, 13.49 years). Each index was calculated using directly measured values of height, weight, waist circumference (WC), and hip circumference (HC). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for each index using Cox regression and evaluated mortality prediction with the Harrell concordance index (c-index).

RESULTS

Adding anthropometric indices to the basic mortality model (c-index, 0.7723; 95% CI, 0.7647 to 0.7799) significantly increased the predictive power of BMI (c-index, 0.7735; 95% CI, 0.7659 to 0.7811), a body shape index (ABSI; c-index, 0.7735; 95% CI, 0.7659 to 0.7810), weight-adjusted waist index (WWI; c-index, 0.7731; 95% CI, 0.7656 to 0.7807), and waist to hip index (WHI; c-index, 0.7733; 95% CI, 0.7657 to 0.7809). The differences between the BMI model and the other 3 models were not statistically significant.

CONCLUSIONS

In predicting all-cause mortality, the ABSI, WWI, and WHI models based on WC or HC had stronger predictive power than conventional risk factors but were not significantly different from the BMI model.

Imaging-based body fat distribution and diabetic retinopathy in general US population with diabetes: an NHANES analysis (2003-2006 and 2011-2018)

BACKGROUND

Limited studies have investigated the correlation between fat distribution and the risk of diabetic retinopathy (DR) in the general population with diabetes. The relationship between obesity and DR remains inconclusive, possibly due to using simple anthropometric measures to define obesity. This study investigates the relationships between the android-to-gynoid fat ratio (A/G ratio, measured using dual-energy X-ray absorptiometry) and DR within the US population with diabetes.

METHODS

The study used a population-based, cross-sectional approach based on the 2003-2006 and 2011-2018 data of the National Health and Nutrition Examination Survey (NHANES). Multivariable logistic regression analyses were performed on participants with diabetes to evaluate the contribution of body mass index (BMI), waist-to-height ratio (WHtR), and A/G ratio to the prevalence of DR.

RESULTS

The prevalence of DR was 22.2, 21.2, and 17.6% among participants with A/G ratios <1.0, 1.0-1.2, and ≥1.2, respectively. After adjusting sex, age, ethnicity, diabetes duration, hemoglobin A1c level, blood pressure level, and non-high-density lipoprotein cholesterol level, a higher A/G ratio (≥1.2) was independently associated with decreased odds of DR (odds ratio [OR], 0.565; 95% CI: 0.372-0.858) compared with the A/G ratio of 1.0-1.2. Associations between a higher A/G ratio and DR remained statistically significant after adjusting for BMI (OR, 0.567; 95% CI: 0.373-0.861) and WHtR (OR, 0.586; 95% CI: 0.379-0.907). Moreover, these associations remained statistically significant in analyses using the ethnic-specific tertiles for the A/G ratio. In sex-stratified models, these correlations remained in males. There was a significant inverse association between the A/G ratio and diabetes duration in males, which persisted after multivariable adjustments (p < 0.05).

CONCLUSIONS

A novel finding indicates that a higher A/G ratio is associated with a reduced likelihood of DR in males with diabetes. The results from NHANES underscore the importance of considering imaging-based fat distribution as a critical indicator in clinical practice.

Sex- and Gender-Related Differences in Obesity: From Pathophysiological Mechanisms to Clinical Implications

Obesity, primarily characterized by excessive fat accumulation, is a multifactorial chronic disease with an increasing global prevalence. Despite the well-documented epidemiology and significant advances in understanding its pathophysiology and clinical implications, the impact of sex is typically overlooked in obesity research. Worldwide, women have a higher likelihood to become obese compared to men. Although women are offered weight loss interventions more often and at earlier stages than men, they are more vulnerable to psychopathology. Men, on the other hand, are less likely to pursue weight loss intervention and are more susceptible to the metabolic implications of obesity. In this narrative review, we comprehensively explored sex- and gender-specific differences in the development of obesity, focusing on a variety of biological variables, such as body composition, fat distribution and energy partitioning, the impact of sex steroid hormones and gut microbiota diversity, chromosomal and genetic variables, and behavioural and sociocultural variables influencing obesity development in men and women. Sex differences in obesity-related comorbidities and varying effectiveness of different weight loss interventions are also extensively discussed.

Sex differences in the association between vitamin D and prediabetes in adults: A cross-sectional study

BACKGROUND/OBJECTIVES

Vitamin D status has been shown to be associated with prediabetes risk. However, epidemiologic evidence on whether sex modulates the association between vitamin D and prediabetes is limited. The present study investigated sex-specific associations between vitamin D and prediabetes.

SUBJECTS/METHODS

The Kuwait Wellbeing Study, a population-based cross-sectional study, enrolled nondiabetic adults. Prediabetes was defined as 5.7 ≤ HbA1c% ≤6.4; 25-hydroxyvitamin D (25(OH)D) was measured in venous blood and analyzed as a continuous, dichotomous (deficiency: <50 nmol/L vs. insufficiency/sufficiency ≥50 nmol/L), and categorical (tertiles) variable. Associations were evaluated by estimating adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs), while stratifying by sex.

RESULTS

A total of 384 participants (214 males and 170 females) were included in the current analysis, with a median age of 40.5 (interquartile range: 33.0-48.0) years. The prevalence of prediabetes was 35.2%, and 63.0% of participants had vitamin D deficiency. Assessments of statistical interaction between sex and 25(OH)D status were statistically significant (PSex × 25(OH)D Interaction < 0.05). In the sex-stratified analysis, after adjustment for confounding factors, decreased 25(OH)D levels were associated with increased prevalence of prediabetes in males (aPRDeficiency vs. In-/Sufficiency: 2.35, 95% CI: 1.36-4.07), but not in females (aPRDeficiency vs. In-/Sufficiency: 1.03, 95% CI: 0.60-1.77). Moreover, the prevalence of prediabetes differed between males and females at 25(OH)D levels of ≤35 nmol/L, with a higher prevalence of prediabetes in males compared to females. Such a sex-specific difference was not observed at 25(OH)D levels of >35 nmol/L.

CONCLUSIONS

Sex modified the association between vitamin D levels and prediabetes, with an inverse association observed among males, but not among females. Moreover, the observed sex-disparity in the prevalence of prediabetes was only pronounced at 25(OH)D levels of ≤35 nmol/L.

Comparison of triglyceride-glucose index and anthropometric obesity indices in predicting severe grades of hepatic steatosis in nonalcoholic fatty liver disease among non-diabetic obese individuals

Background and Aim

The triglyceride glucose index (TyG) has been proposed as a promising indicator of both insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). However, the efficacy of the TyG index in predicting NAFLD has not been adequately studied, particularly in obese individuals.

Materials and Methods

We analyzed 190 morbidly obese individuals. The TyG index, anthropometric obesity indices, homeostatic model assessment (HOMA-IR), and biochemical parameters were compared. NAFLD was diagnosed by hepatic ultrasonography and classified into four grades (0, 1, 2, and 3). Individuals in grades 2 and 3 are considered to have severe steatosis, while those in grades 0 and 1 do not.

Results

The area under the curve (AUC) values of the TyG index, body mass index, neck circumferences, waist-to-hip ratio, and HOMA-IR did not differ significantly in predicting severe steatosis (0.640, 0.742, 0.725, 0.620, and 0.624 respectively). However, the AUC values of waist circumference and alanine aminotransferase provided better predictions than the TyG index (0.782, 0.744, and 0.640 respectively).

Conclusion

The TyG index is highly effective in predicting both the presence and severity of NAFLD. However, it did not outperform simple obesity indices in predicting NAFLD and its severity in obese patients.

Association of Sex Differences on Weight Loss and Complications Following Bariatric Surgery

INTRODUCTION

Sex as a biologic variable remains largely understudied, even for the most commonly performed operations. The most effective treatment for obesity and obesity-associated comorbidities is bariatric surgery. There are limited data to describe potential differences in outcomes between male and female patients, particularly with regards to weight loss. Within this context, we examined weight loss and complications up to 1 y following sleeve gastrectomy or gastric bypass within a statewide bariatric quality improvement collaborative.

METHODS

We performed a retrospective cohort study among patients who had bariatric surgery. Using a state-wide bariatric-specific data registry, all patients who underwent gastric bypass or sleeve gastrectomy between June 2006 and June 2022 were identified. The primary outcome was percent excess body weight loss and change in body mass index (BMI) at 1 y. The secondary outcome was 30-d risk-adjusted complications.

RESULTS

Among 107,504 patients, the majority (n = 85,135; 79.2%) were female and most patients (n = 49,731; 58%) underwent sleeve gastrectomy. Compared to female patients, male patients were older (47.6 y versus 44.8 y; P < 0.0001), had higher baseline weight (346.6 lbs versus 279.9 lbs; P < 0.0001), had higher preoperative BMI (49.9 kg/m2versus 47.2 kg/m2; P < 0.0001), and higher prevalence of most comorbid conditions including hypertension, hyperlipidemia, diabetes, and sleep apnea (P < 0.0001). Compared to female patients, male patients experienced greater total body weight loss (105.1 lbs versus 84.9 lbs; P < 0.0001) and higher excess body weight loss (60.0% versus 58.8%; P < 0.0001) but had higher BMI overall (34.0 kg/m2versus 32.8 kg/m2; P < 0.0001) at 1-y follow-up. Males had higher rates of serious complications (2.5% versus 1.9%; P < 0.0001), leak and perforation (0.5% versus 0.4%; P < 0.0001), venous thromboembolism (0.7% versus 0.4%; P < 0.0001), and medical complications (1.5% versus 1%; P < 0.0001).

CONCLUSIONS

In this study we found that both males and females experienced excellent weight loss with a low risk of complications following bariatric surgery. Male sex was associated with slightly greater weight loss and slightly higher incidence of complications. However, although statistically significant, clinically, the differences in weight loss was not. Due to males having higher prevalence of comorbidities, providers should consider referring males earlier for bariatric surgery which may improve outcomes for this population.

Evaluating Sex-specific Differences in Abdominal Fat Volume and Proton Density Fat Fraction at MRI Using Automated nnU-Net-based Segmentation

Sex-specific abdominal organ volume and proton density fat fraction (PDFF) in people with obesity during a weight loss intervention was assessed with automated multiorgan segmentation of quantitative water-fat MRI. An nnU-Net architecture was employed for automatic segmentation of abdominal organs, including visceral and subcutaneous adipose tissue, liver, and psoas and erector spinae muscle, based on quantitative chemical shift-encoded MRI and using ground truth labels generated from participants of the Lifestyle Intervention (LION) study. Each organ's volume and fat content were examined in 127 participants (73 female and 54 male participants; body mass index, 30-39.9 kg/m2) and in 81 (54 female and 32 male participants) of these participants after an 8-week formula-based low-calorie diet. Dice scores ranging from 0.91 to 0.97 were achieved for the automatic segmentation. PDFF was found to be lower in visceral adipose tissue compared with subcutaneous adipose tissue in both male and female participants. Before intervention, female participants exhibited higher PDFF in subcutaneous adipose tissue (90.6% vs 89.7%; P < .001) and lower PDFF in liver (8.6% vs 13.3%; P < .001) and visceral adipose tissue (76.4% vs 81.3%; P < .001) compared with male participants. This relation persisted after intervention. As a response to caloric restriction, male participants lost significantly more visceral adipose tissue volume (1.76 L vs 0.91 L; P < .001) and showed a higher decrease in subcutaneous adipose tissue PDFF (2.7% vs 1.5%; P < .001) than female participants. Automated body composition analysis on quantitative water-fat MRI data provides new insights for understanding sex-specific metabolic response to caloric restriction and weight loss in people with obesity. Keywords: Obesity, Chemical Shift-encoded MRI, Abdominal Fat Volume, Proton Density Fat Fraction, nnU-Net ClinicalTrials.gov registration no. NCT04023942 Supplemental material is available for this article. Published under a CC BY 4.0 license.

Adiposity indicators exhibit depot- and sex-specific associations with multimorbidity onset: A cohort study of the UK Biobank

AIM

This study investigated the depot- and sex-specific associations of adiposity indicators with incident multimorbidity and comorbidity pairs.

MATERIALS AND METHODS

We selected 382 678 adults without multimorbidity (≥2 chronic diseases) at baseline from the UK Biobank. General obesity, abdominal obesity and body fat percentage indices were measured.

RESULTS

Cox proportional hazard regression analyses of general obesity indices revealed that for every one-unit increase in body mass index, the risk of incident multimorbidity increased by 5.2% (95% confidence interval 5.0%-5.4%). A dose-response relationship was observed between general obesity degrees and incident multimorbidity. The analysis of abdominal obesity indices showed that for every 0.1 increment in waist-to-height ratio and waist-to-hip ratio, the risk of incident multimorbidity increased by 42.0% (37.9%-46.2%) and 27.9% (25.7%-30.0%), respectively. Central obesity, as defined by waist circumference, contributed to a 23.2% increased risk of incident multimorbidity. Hip circumference and hip-to-height ratio had protective effects on multimorbidity onset. Consistent findings were observed for males and females. Body fat percentage elevated 3% (0.2%-5.9%) and 5.3% (1.1%-9.7%) risks of incident multimorbidity in all adults and females, respectively. Arm fat percentages elevated 5.3% (0.8%-9.9%) and 19.4% (11.0%-28.5%) risks of incident multimorbidity in all adults and males, respectively. The general obesity indices, waist circumference, waist-to-height ratio, waist-to-hip ratio and central obesity increased the onset of comorbidity pairs, whereas hip circumference and hip-to-height ratio decreased the onset of comorbidity pairs. These adiposity indicators mainly affect diabetes mellitus-related comorbidity onset in males and hypertensive-related comorbidity onset in females.

CONCLUSIONS

Adiposity indicators are predictors of multimorbidity and comorbidity pairs and represent a promising approach for intervention.

Investigation on the influence of the skin tone on hyperspectral imaging for free flap surgery

Hyperspectral imaging (HSI) is a new emerging modality useful for the noncontact assessment of free flap perfusion. This measurement technique relies on the optical properties within the tissue. Since the optical properties of hemoglobin (Hb) and melanin overlap, the results of the perfusion assessment and other tissue-specific parameters are likely to be distorted by the melanin, especially at higher melanin concentrations. Many spectroscopic devices have been shown to struggle with a melanin related bias, which results in a clinical need to improve non-invasive perfusion assessment, especially for a more pigmented population. This study investigated the influence of skin tones on tissue indices measurements using HSI. In addition, other factors that might affect HSI, such as age, body mass index (BMI), sex or smoking habits, were also considered. Therefore, a prospective feasibility study was conducted, including 101 volunteers from whom tissue indices measurements were performed on 16 different body sites. Skin tone classification was performed using the Fitzpatrick skin type classification questionnaire, and the individual typology angle (ITA) acquired from the RGB images was calculated simultaneously with the measurements. Tissue indices provided by the used HSI-device were correlated to the possible influencing factors. The results show that a dark skin tone and, therefore, higher levels of pigmentation influence the HSI-derived tissue indices. In addition, possible physiological factors influencing the HSI-measurements were found. In conclusion, the HSI-based tissue indices can be used for perfusion assessment for people with lighter skin tone levels but show limitations in people with darker skin tones. Furthermore, it could be used for a more individual perfusion assessment if different physiological influencing factors are respected.