Obesity (Silver Spring, Md.)最新文献

Objective: The objective of this manuscript is to present BMI-for-age percentile curves for men and women aged 45 to 90 years.

Methods: Weighted empirical percentile estimates were calculated using data from the Canadian Longitudinal Study on Aging (CLSA) comprehensive cohort (2011-2018) according to age and sex. Statistical smoothing procedures were used to generate smoothed curves for the percentile values. Overweight and obesity were defined as BMI greater than the 85th and 95th percentile for age and sex, respectively.

Results: In order to create BMI-for-age percentile curves, n = 56,705 observations were used (n = 29,961 individuals at baseline and n = 26,744 individuals at the first follow-up visit). In men, absolute values for BMI percentiles are lower than those in women, and the decline in BMI begins earlier (i.e., at a younger age). In women, the 95th percentile threshold for BMI is highest between ages 59 and 67 years (i.e., 41 kg/m²), and in men, the 95th percentile threshold for BMI is highest between ages 51 and 62 years (i.e., 39 kg/m²).

Conclusions: BMI-for-age percentile curves demonstrate how an individual's BMI value compares with values from a reference population comprising individuals of the same age and sex. This approach has widespread utility to determine eligibility for interventions and as a tool to incorporate into clinical models of care for obesity management in an aging population.

Objective: Metabolic inflexibility to Western high-fat diets may contribute to the obesity epidemic. However, validated methods for assessing metabolic flexibility (MetFlex) to high-fat meals are currently lacking. The purpose of this study was to evaluate the reliability of a novel approach for determining MetFlex to a high-fat meal and to compare it with the gold standard for measuring MetFlex to high-carbohydrate loads.

Methods: Eight healthy adults were enrolled in our study, which consisted of the following two assessments of MetFlex: 1) MetFlex to fat, via two overnight stays in a metabolic chamber separated by 5 to 7 days; and 2) Metflex to carbohydrates, via a two-step hyperinsulinemic-euglycemic clamp measured >5 days later.

Results: Participants were predominantly White and male, with mean (SD) age of 29.4 (6.3) years and BMI of 25.4 (4.1) kg/m². MetFlex to fat displayed satisfactory test-retest reliability (intraclass correlation coefficient > 0.70) for several outcomes but showed no correlation to MetFlex measured during the clamp.

Conclusions: Overnight changes in substrate oxidation following a high-fat dinner meal represent a unique aspect of MetFlex that cannot be captured using more conventional methods. Our findings warrant prospective studies to determine whether these parameters are predictive of the development of obesity or metabolic dysfunction.

Objective: The objective of this study was to examine associations of computed tomography (CT)-derived musculoskeletal measures with demographics and traditional musculoskeletal characteristics.

Methods: The Incorporating Nutrition, Vests, Education, and Strength Training (INVEST) in Bone Health trial (NCT04076618) acquired a battery of musculoskeletal measures in 150 older-aged adults living with overweight or obesity. At baseline, CT (i.e., volumetric bone mineral density, cortical thickness, muscle radiomics, and muscle/intermuscular adipose tissue [IMAT] area and density), dual-energy x-ray absorptiometry (DXA; i.e., areal bone mineral density, total body fat mass, appendicular lean mass, and lean body mass), and strength assessments (i.e., grip and knee extensor strength) were collected, along with demographic and clinical characteristics. Analyses employed linear regression and mixed-effects models along with factor analysis for dimensionality reduction of the radiomics data.

Results: Participants were older-aged (mean [SD] age: 66 [5] years), mostly female (75%), and were living with overweight or obesity (mean [SD] BMI: 33.6 [3.3] kg/m²). Age was not significantly associated with most CT-derived bone, IMAT, or muscle measures. BMI was significantly associated with DXA and CT-derived muscle and IMAT measures, which were higher in male than female individuals (all p < 0.01). For the midthigh, muscle size was significantly related to grip and knee extensor strength (both p < 0.01).

Conclusions: Machine learning-derived CT metrics correlated strongly with DXA and muscle strength, with higher BMI linked to greater IMAT and poorer muscle quality.

Objective: Implicit associations, i.e., automatically activated attitudes and intuitions, may contribute to isolated food choices and body weight. Studies of food-related implicit associations have yielded mixed results and have not explored their role in eating behaviors or dietary patterns. We examined implicit associations toward the palatability and acceptability (vs. shame) of healthy food and their relationships with self-reported eating behaviors (eating in absence of hunger) and dietary patterns (fruit, vegetable, and sugar-sweetened beverage consumption) and socioeconomic indicators.

Methods: Two US samples (i.e., Palatable Food, n = 11,504; and Acceptable Food, n = 12,128) from Project Implicit Health were analyzed. Implicit associations were measured with Implicit Association Tests. Linear and logistic regressions examined associations of implicit and related explicit self-reported responses (perceived healthy eating and acceptability of healthy food, respectively) with eating behaviors, dietary patterns, and socioeconomic indicators.

Results: One-sample t tests revealed health-favoring implicit palatability and acceptability associations. Implicit associations predicted healthier self-reported eating behaviors and dietary patterns independent of explicit responses. There were inconsistent associations with socioeconomic indicators.

Conclusions: Health-favoring implicit food-related associations uniquely contribute to healthier eating behaviors and dietary patterns. These health-favoring associations could be a promising, yet underrecognized, target to promote healthier diets in the United States.

Objective: When treated with a macronutrient-balanced hypocaloric diet, do male individuals who have overweight and obesity lose relatively more dual-energy x-ray absorptiometry (DXA)-measured lean soft tissue (LST) mass than female individuals? Are there changes in bone mineral content (BMC), and if so, how do they impact relative reductions in LST compared to fat-free mass (FFM; LST plus BMC)? Are decrements in fat, LST, and FFM predictable from the magnitude of weight loss or baseline body composition?

Methods: To answer these questions, DXA studies were conducted before and after a 9- to 12-week calorie-restriction period in 43 male and 97 female individuals who lost a mean (SD) of 10.8% (2.2%) and 10.7% (1.6%) of their baseline weight, respectively.

Results: The proportion of weight loss as LST was significantly (p < 0.001) larger in male (mean [SD], 0.33 [0.11] kg) than female individuals (0.25 [0.11] kg); BMC paradoxically increased, thereby leading to a significantly smaller reduction in FFM than LST in the male (-3.87 [1.73] kg vs. -3.92 [1.74] kg; p < 0.001) and female individuals (-2.22 [1.18] kg vs. -2.24 [1.18] kg; p < 0.001), and three different analyses showed that the composition of weight loss tracked as predicted a priori from weight change and baseline body composition.

Conclusions: These observations provide insights into and future guidance for analyzing the DXA-measured body composition changes associated with newer pharmacotherapies for weight loss.

Objective: Systemic administration of β-aminopropionitrile to inhibit lysyl oxidase (Lox) activity improves metabolism, but it exhibits a broad spectrum of effects. Clarification of the role of Lox in adipose tissue metabolism under high-fat diet (HFD) conditions is needed.

Methods: Mice with adipose tissue knockout of Lox (Lox^AKO) and wild-type mice were subjected to a 16-week HFD regimen. A detailed evaluation encompassing adipose tissue, hepatic function, and systemic metabolism was conducted. RNA sequencing analysis was used to unravel the intricate mechanisms behind the metabolic enhancements in Lox^AKO mice.

Results: Compared with the control, although there was no difference in body weight, Lox^AKO mice exhibited an improved metabolic phenotype, including enhanced insulin sensitivity, improved glucose tolerance, and reduced liver steatosis, along with reduced adipose tissue inflammation and fibrosis. Lox^AKO mice showed increased thermogenic activity in brown adipose tissue with increased uncoupling protein 1 (UCP1) expression and oxygen consumption rate. Additionally, RNA sequencing analysis revealed that adipose deletion of Lox might facilitate the metabolic processing of glucose, branched-chain amino acids, and fatty acids in brown adipose tissue.

Conclusions: These findings indicate that adipocyte Lox deletion improves metabolic adaptability under an HFD, highlighting Lox as a promising therapeutic target for obesity-associated metabolic disorders.

Objective: The aim of this study was to investigate the relationship between obesity (OB) progression and brain structural changes.

Methods: T1-weighted magnetic resonance images were acquired from 258 participants with overweight (OW) or OB and 74 participants with normal weight. Participants with OW or OB were divided into four groups according to BMI grades. Two-sample t tests compared disparities between the four subgroups and the participants with normal weight. We used causal structural covariance networks to examine the progressive impact of OB on brain structure.

Results: With increasing BMI values, reductions in gray matter volume originated in the left caudate nucleus, medial orbitofrontal cortex, and left insula and expanded to the right hippocampus and left lateral orbitofrontal cortex and then to the right parahippocampal gyrus, left precuneus, and left dorsolateral prefrontal cortex (p < 0.05, false discovery rate corrected). The left caudate nucleus and medial orbitofrontal cortex are the primary hubs of the directional network, exhibiting positive causality to the right hippocampus and left dorsolateral prefrontal cortex. Moreover, the right hippocampus is identified as an important transition hub.

Conclusions: These findings suggest that changes in gray matter volume in individuals with OB may originate from reward/motivation processing regions, subsequently progressing to inhibitory control/learning memory regions, providing a new reference direction for clinical intervention and treatment of OB.

Objective: We investigated how a maternal Western diet (WD) affects milk microRNA (miRNA) profile and associates with metabolic programming in adipose tissues in pups. We also explored the impact of betaine supplementation during suckling, as betaine levels are reported to be reduced in WD-fed dams' milk.

Methods: A microarray analysis was performed to profile miRNA expression in dams' milk. Betaine levels were measured in the milk of dams and the plasma of their offspring. We also analyzed the expression of miRNA target genes in white and brown adipose tissues through gene expression analysis.

Results: Our findings confirm decreased betaine levels in the milk of WD-fed dams and the plasma of their offspring. The miRNA screening identified 37 deregulated miRNAs (36 downregulated), with the following 6 as the most relevant: miR-223-3p; miR-32-5p; let-7i-5p; miR-140-5p; miR-29a-3p; and miR-29c-3p (downregulated). Some of their target genes were upregulated in brown and white adipose tissues, particularly those related to thermogenesis and browning. Betaine supplementation in pups demonstrated a slight protective effect in females by enhancing thermogenic capacity.

Conclusions: Our results underscore the profound impact of a maternal WD on milk miRNA composition, potentially influencing gene expression, thermogenesis, and adiposity in the offspring, with sex-related differences.

Objective: Childhood obesity (OB) is influenced by complex gene-environmental interaction. While genetics of adult OB have been extensively studied, polygenic childhood OB in non-European populations is still underexplored. Furthermore, in a developing nation such as India, how the environmental component strongly modulated by the socioeconomic status (SES) shapes the genetic susceptibility is crucial to understand.

Methods: A two-staged genome-wide association study (GWAS; N = 5673) and an independent exome-wide association study (ExWAS; N = 4963) were performed using a generalized linear model assuming additive effect to identify the common and rare genetic variants respectively associated with childhood OB. Rare-variant burden testing was also performed. We used the gene expression profiles and regulatory data from public databases to explain the novel associations. The implications of SES as a potential modifier of genetic susceptibility were evaluated.

Results: GWAS identified novel associations in TCF7L2, IMMP2L, IPMK, CDC5L, SNTG1, and MX1, whereas ExWAS uncovered CNTN4, COQ4, TNFRSF10D, FLG-AS1, and BMP3. Both GWAS and ExWAS validated known associations in FTO and MC4R. Furthermore, rare-variant testing highlighted the role of 101 genes. We also observed that SES can modulate the inherent susceptibility to OB.

Conclusions: Our study identified genetic variants associated with childhood OB and highlighted the gene-environmental interaction in childhood OB.