Genetic Effects on Longitudinal Changes from Healthy to Adverse Weight and Metabolic Status – The HUNT Study

Bariatric Surgery and Femoral Vein Diameter in Morbidly Obese Patients: a Cohort Study in Iran

INTRODUCTION

Considering the importance of health, the effect of obesity on the quality of life, the person's self-image, and the effect of obesity on various organs, especially the vessels, and the absence or presence of a study in Iran that investigated the effect of gastric bariatric surgery on the diameter of the femoral vein, in the present study, we investigated the effect of bariatric surgery on femoral vein diameter in morbidly obese patients referred to Imam Hossein hospital.

MATERIALS AND METHODS

The present study was a prospective cohort study on morbidly obese patients referred to the center in 2022-2023. In this study, 31 morbidly obese patients with BMI above 30 kg/m2 who were candidates for bariatric surgery were examined. Demographic data were collected using a demographic profile checklist. BMI, the diameter of common femoral veins, and the great saphenous vein were measured and recorded before and 6 months after surgery. Ultimately, the data was collected and analyzed using SPSS V.24 software.

RESULTS

In the current study, 31 patients (62 extremities) were examined. The mean age of the patients was 34.45, with a standard deviation of 8.86. Fourteen patients (45.2%) were male, and 17 (54.8%) were female. The mean diameter of the common femoral vein in the 6 months after surgery was significantly less than before surgery (11.58 (1.64) compared to 12.95 (1.84), P = 0.0001). The mean diameter of the great saphenous vein in the 6 months after surgery was significantly less than before surgery (7.30 (1.45) compared to 7.75 (1.45), P = 0.0001).

CONCLUSION

It seems that bariatric surgery causes a significant decrease in the diameter of lower limb veins (common femoral vein and great saphenous vein) compared to before surgery. However, further studies in this field are recommended.

Pathogenesis and management of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) causes ∼170 000 deaths annually worldwide. Most guidelines recommend asymptomatic small AAAs (30 to <50 mm in women; 30 to <55 mm in men) are monitored by imaging and large asymptomatic, symptomatic, and ruptured AAAs are considered for surgical repair. Advances in AAA repair techniques have occurred, but a remaining priority is therapies to limit AAA growth and rupture. This review outlines research on AAA pathogenesis and therapies to limit AAA growth. Genome-wide association studies have identified novel drug targets, e.g. interleukin-6 blockade. Mendelian randomization analyses suggest that treatments to reduce low-density lipoprotein cholesterol such as proprotein convertase subtilisin/kexin type 9 inhibitors and smoking reduction or cessation are also treatment targets. Thirteen placebo-controlled randomized trials have tested whether a range of antibiotics, blood pressure-lowering drugs, a mast cell stabilizer, an anti-platelet drug, or fenofibrate slow AAA growth. None of these trials have shown convincing evidence of drug efficacy and have been limited by small sample sizes, limited drug adherence, poor participant retention, and over-optimistic AAA growth reduction targets. Data from some large observational cohorts suggest that blood pressure reduction, particularly by angiotensin-converting enzyme inhibitors, could limit aneurysm rupture, but this has not been evaluated in randomized trials. Some observational studies suggest metformin may limit AAA growth, and this is currently being tested in randomized trials. In conclusion, no drug therapy has been shown to convincingly limit AAA growth in randomized controlled trials. Further large prospective studies on other targets are needed.

Lactoferrin-The Health-Promoting Properties and Contemporary Application with Genetic Aspects

The aim of the study is to present a review of literature data on lactoferrin's characteristics, applications, and multiple health-promoting properties, with special regard to nutrigenomics and nutrigenetics. The article presents a new approach to food ingredients. Nowadays, lactoferrin is used as an ingredient in food but mainly in pharmaceuticals and cosmetics. In the European Union, bovine lactoferrin has been legally approved for use as a food ingredient since 2012. However, as our research shows, it is not widely used in food production. The major producers of lactoferrin and the few available food products containing it are listed in the article. Due to anti-inflammatory, antibacterial, antiviral, immunomodulatory, antioxidant, and anti-tumour activity, the possibility of lactoferrin use in disease prevention (as a supportive treatment in obesity, diabetes, as well as cardiovascular diseases, including iron deficiency and anaemia) is reported. The possibility of targeted use of lactoferrin is also presented. The use of nutrition genomics, based on the identification of single nucleotide polymorphisms in genes, for example, FTO, PLIN1, TRAP2B, BDNF, SOD2, SLC23A1, LPL, and MTHFR, allows for the effective stratification of people and the selection of the most optimal bioactive nutrients, including lactoferrin, whose bioactive potential cannot be considered without taking into account the group to which they will be given.

Skeletal muscle transcriptome is affected by age in severely burned mice

Severe burn results in muscle wasting affecting quality of life in both children and adults. Biologic metabolic profiles are noticeably distinctive in childhood. We posit that muscle gene expression profiles are differentially regulated in response to severe burns in young animals. Twelve C57BL6 male mice, including young (5 weeks-old) and adults (11 weeks-old), received either scald burn, or sham procedure. Mouse muscle tissue was harvested 24 h later for Next Generation Sequence analysis. Our results showed 662 downregulated and 450 upregulated genes in gastrocnemius of young mice compared to adults without injury. After injury, we found 74/75 downregulated genes and 107/128 upregulated genes in both burned groups compared to respective uninjured age groups. VEGFA-VEGFR2, focal adhesion, and nuclear receptor meta-pathways were the top 3 gene pathways undergoing a differential change in response to age. Of note, the proteasome degradation pathway showed the most similar changes in both adult and young burned animals. This study demonstrates the characteristic profile of gene expression in skeletal muscle in young and adult burned mice. Prominent age effects were revealed in transcriptional levels with increased alterations of genes, miRNAs, pathways, and interactions.

Evaluation of the predictive value of different dietary antioxidant capacity assessment methods on healthy and unhealthy phenotype in overweight and obese women

Purpose

Predictive value of different dietary antioxidant capacity assessment methods on healthy and unhealthy phenotypes in overweight and obese women is still unclear. This study aimed to evaluate the predictive value of different dietary antioxidant capacity assessment methods on healthy and unhealthy phenotypes in overweight and obese women.

Methods

A total of 290 overweight and obese women were included in this cross-sectional study. Food intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). Dietary antioxidant capacity was calculated using valid databases of antioxidant value. The receiver operating characteristic (ROC) curve method was used to evaluate the predictive value of antioxidant capacity indices, including dietary antioxidant quality score (DAQS), ferric reducing ability of plasma (FRAP), total reactive antioxidant potential (TRAP), and trolox equivalent antioxidant capacity (TEAC).

Results

The results showed that the highest area under the ROC curve for predicting metabolically healthy obesity (MHO) belongs to the TRAP method (area under the curve (AUC) = 0.53). In addition, this method had the highest AUC for predicting inflammatory marker of C-reactive protein (hs-CRP) (AUC = 0.54) and the index of the homeostatic model assessment for insulin resistance (HOMA-IR) (AUC = 0.59). The highest AUC for triglyceride prediction was related to the DAQS method (AUC = 0.56). Moreover, a significant correlation of FRAP (r = -0.15, P = 0.02), TRAP (r = -0.19, P < 0.001), TEAC (r = -0.18, P< 0.001) with HOMA-IR was reached.

Conclusion

The findings of this study show that the best way to predict the status of MHO is TRAP method. This method is also the best predictor of hs-CRP and HOMA-IR. DAQS method is the best predictor for TG.

Converging vulnerability factors for compulsive food and drug use

Highly palatable foods and substance of abuse have intersecting neurobiological, metabolic and behavioral effects relevant for understanding vulnerability to conditions related to food (e.g., obesity, binge eating disorder) and drug (e.g., substance use disorder) misuse. Here, we review data from animal models, clinical populations and epidemiological evidence in behavioral, genetic, pathophysiologic and therapeutic domains. Results suggest that consumption of highly palatable food and drugs of abuse both impact and conversely are regulated by metabolic hormones and metabolic status. Palatable foods high in fat and/or sugar can elicit adaptation in brain reward and withdrawal circuitry akin to substances of abuse. Intake of or withdrawal from palatable food can impact behavioral sensitivity to drugs of abuse and vice versa. A robust literature suggests common substrates and roles for negative reinforcement, negative affect, negative urgency, and impulse control deficits, with both highly palatable foods and substances of abuse. Candidate genetic risk loci shared by obesity and alcohol use disorders have been identified in molecules classically associated with both metabolic and motivational functions. Finally, certain drugs may have overlapping therapeutic potential to treat obesity, diabetes, binge-related eating disorders and substance use disorders. Taken together, data are consistent with the hypotheses that compulsive food and substance use share overlapping, interacting substrates at neurobiological and metabolic levels and that motivated behavior associated with feeding or substance use might constitute vulnerability factors for one another. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

The fat mass and obesity-associated (FTO) gene allele rs9939609 and glucose tolerance, hepatic and total insulin sensitivity, in adults with obesity

The objective of the study was to assess associations of the rs9939609 FTO allele to glucose tolerance, hepatic and total insulin sensitivity (IS) in individuals with obesity. From a low-dose hyperinsulinemic euglycemic clamp with glucose-tracer, hepatic IS was assessed by rates of basal and suppressed glucose appearance (Ra), a measure of endogenous glucose production (EGP), and the hepatic insulin resistance index (HIR). Total IS was assessed by rates of glucose infusion (GIR), disappearance (Rd), and metabolic clearance (MCR). From a meal test we assessed IS by the Matsuda index and glucose tolerance by glucose and insulin measurements in the fasted state and postprandially for 2.5 h. The meal test was performed in 97 healthy individuals with BMI ≥35 in similar-sized risk-allele groups (n = 32 T/T, 31 A/T, and 34 A/A), and 79 of them performed the clamp. We analyzed outcomes separately for males and females, and adjusted glucose Ra, Rd, MCR, GIR, and HIR for fat mass. We did not find genotype effects on EGP. Among males, genotype A/A was associated with a significantly lower glucose Rd, MCR, and Matsuda index score relative to genotype T/T. Glucose tolerance was significantly lower in males with genotype A/T vs. T/T and A/A. For females, there were no genotype effects on hepatic or total IS, or on glucose tolerance. Independently of genotypes, females displayed a significantly better hepatic and total IS, and better glucose tolerance than males. We conclude that in subjects with similar obesity we did not register any FTO risk-allele effect on hepatic IS. A FTO risk-allele effect on total IS was registered in males only, findings which need to be reproduced in further studies. Results confirm marked differences in IS between the biological sexes and extend present knowledge by demonstrating a lower endogenous glucose production in females vs. males in uniformly obese individuals.

On the Role of Central Type-1 Cannabinoid Receptor Gene Regulation in Food Intake and Eating Behaviors

Different neuromodulatory systems are involved in long-term energy balance and body weight and, among these, evidence shows that the endocannabinoid system, in particular the activation of type-1 cannabinoid receptor, plays a key role. We here review current literature focusing on the role of the gene encoding type-1 cannabinoid receptors in the CNS and on the modulation of its expression by food intake and specific eating behaviors. We point out the importance to further investigate how environmental cues might have a role in the development of obesity as well as eating disorders through the transcriptional regulation of this gene in order to prevent or to treat these pathologies.

Genetic markers and continuity of healthy metabolic status: Tehran cardio-metabolic genetic study (TCGS)

Obese individuals can be categorized as “healthy obese” (MHO) and “unhealthy obese” (MUO) based on the presence or absence of metabolic abnormality. This study sets out to assess potential genetic causes behind persistence of healthy metabolic status in individuals categorized as “healthy obese”. This study was conducted in the framework of the Tehran cardio-metabolic genetic study (TCGS). 766 MHO subjects at the start of the study followed up 15 years for occurrence of metabolic unhealthy status. These two groups (persistent MHO, MUO) were compared regarding the presence or absence of 16 single nucleotide polymorphisms (SNPs) identified as being associated with obesity phenotype in previous studies. We used logistic regression model for assessing the association between MHO/MUO with candidate SNPs. By the end of the follow up, 206 (27%) were categorized as the persistent MHO and 560 (73%) as MUO groups. Considering interaction effect between some SNP and sex, a sex stratification analysis was applied. When the analysis was performed by gender, rs1121980 associated with a decrease, and rs7903146 with an increase in the likelihood of persistent MHO individuals. Another analysis was separately performed on postmenopausal women from both groups; it showed that rs13107325 was associated with an increase in the likelihood of persistent MHO status in this subgroup of woman. In all cases, the markers had dominant inheritance. This findings suggest that the expression of some genetic markers are associated with persistence of healthy metabolic status, in female obese individuals.

Molecular pathway analysis associates alterations in obesity-related genes and antipsychotic-induced weight gain

OBJECTIVE

Antipsychotics often induce excessive weight gain. We hypothesised that individuals with genetic variations related to known obesity-risk genes have an increased risk of excessive antipsychotic-induced weight gain (AIWG). This hypothesis was tested in a subset of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) trial data set.

METHODS

The CATIE trial compared effects and side effects of five different antipsychotics through an 18-month period. Based on the maximum weight gain recorded, excessive weight gain was defined as >7% weight gain. Cytoscape and GeneMANIA were instrumental in composing a molecular pathway from eight selected genes linked to obesity. Genetic information on a total of 495.172 single-nucleotide polymorphisms (SNPs) were available from 765 (556 males) individuals. Enrichment test was conducted through ReactomePA and Bioconductor. A permutation test was performed, testing the generated pathway against 105 permutated pathways (p ≤ 0.05). In addition, a standard genome-wide association study (GWAS) analysis was performed.

RESULT

GWAS analysis did not detect significant differences related to excessive weight gain. The pathway generated contained 28 genes. A total of 2067 SNPs were significantly expressed (p < 0.01) within this pathway when comparing excessive weight gainers to the rest of the sample. Affected genes including PPARG and PCSK1 were not previously related to treatment-induced weight gain.

CONCLUSIONS

The molecular pathway composed from high-risk obesity genes was shown to overlap with genetics of patients who gained >7% weight gain during the CATIE trial. This suggests that genes related to obesity compose a pathway of increased risk of excessive AIWG. Further independent analyses are warranted that may confirm or clarify the possible reasoning behind.

Polymorphisms in genes that affect the variation of lipid levels in a Brazilian pediatric population with sickle cell disease: rs662799 APOA5 and rs964184 ZPR1

This cross-sectional study investigated associations between SNPs in metabolizing lipid genes, alpha-thalassemia and laboratory parameters in two forms of sickle cell disease (SCD), sickle cell anemia (SCA) and hemoglobin SC disease (HbSC) in a pediatric population. Among the groups SCA and HbSC was found a higher proportion of increased triglycerides (TG) in SCA. High levels of TG were significantly associated with lower hemoglobin (p = 0.006) and HDL-C (p = 0.037), higher white blood cell count (p = 0.027), LDH (p = 0.004) and bilirubins (p < 0.05) in SCD. Patients with HDL-C ≤40 mg/dL had higher markers hemolytic levels. Therapy of HU significantly influenced several hematological and biochemical parameters but not lipid fractions. Genotypes of the APOA5 rs662799 were not associated with lipid levels. The G-risk allele rs964184/ZPRI ZNF259/ZPR1 gene (GC + GG genotypes) was associated with increased levels of TG in children ≥10 years old (p = 0.045) and the atherogenic ratio TG/HDL-C (p = 0.032) in SCD. The use of HU improves levels of hemolysis and inflammation markers in SCD with high TG and, while not interfering with lipid levels, seems to overlap the effect of the G-risk allele in on them. This study reported for the first time that rs964184 SNP could be a genetic modifier of TG in SCD.

Dephosphorylation of clustered phosphoserine residues in human Grb14 by protein phosphatase 1 and its effect on insulin receptor complex formation

The physical interaction of the human growth factor receptor-bound protein 14 (hGrb14) and the insulin receptor (IR) represses insulin signaling. With respect to the recruiting mechanism of hGrb14 to IR respond to insulin stimulus, our previous reports have suggested that phosphorylation of Ser³⁵⁸ , Ser³⁶² , and Ser³⁶⁶ in hGrb14 by glycogen synthase kinase-3 repressed hGrb14-IR complex formation. In this study, we investigated phosphatase-mediated dephosphorylation of the hGrb14 phosphoserine residues. An in vitro phosphatase assay with hGrb14-derived synthetic phosphopeptides suggested that protein phosphatase 1 (PP1) is involved in the dephosphorylation of Ser³⁵⁸ and Ser³⁶² . Furthermore, coimmunoprecipitation experiments suggested that insulin-induced hGrb14-IR complex formation was repressed by the substitution of Ser³⁵⁸ or Ser³⁶² with glutamic acid. These findings suggested that phosphate groups on Ser³⁵⁸ and Ser³⁶² in hGrb14 are dephosphorylated by PP1, and the dephosphorylation facilitates hGrb14-IR complex formation.

Impact of a FTO gene risk variant on variables of energy metabolism in adults with obesity class 2 and 3

Purpose

The metabolic consequences of carrying a FTO obesity-promoting risk allele have not been fully elucidated and may be confounded by obesity per se. Against this background, we investigated the impact of FTO allele (SNP rs9939609) on fasting and postprandial energy expenditure and fasting substrate expenditure in a study population of uniformly and similarly obese individuals.

Procedures

We studied a similar number of participants with BMI classes 2–3 (median BMI 42.8 kg/m²) who were either homozygote for the non-risk allele TT (n = 33, numbers increased by enrichment), heterozygote (AT) (n = 32), or homozygote for the risk allele AA (n = 35).

Major findings

Basal metabolic rate and postprandial energy expenditure did not differ between FTO-groups. However, fasting respiratory quotient (RQ) was increased in those carrying ≥1 risk allele (p = 0.008), whereas postprandial RQ was not.

Conclusion

In this study population, the FTO-risk allele associates with fasting reduced fat and increased carbohydrate oxidation.

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Fasting RQ associates with FTO risk allele in comparably obese subjects.

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The association remained after adjusting for gender effects.

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FTO risk not associated with meal-related energy utilization.

Role of Endocannabinoids on Sweet Taste Perception, Food Preference, and Obesity-related Disorders

The prevalence of obesity and obesity-related disorders such as type 2 diabetes (T2D) and metabolic syndrome has increased significantly in the past decades, reaching epidemic levels and therefore becoming a major health issue worldwide. Chronic overeating of highly palatable foods is one of the main responsible aspects behind overweight. Food choice is driven by food preference, which is influenced by environmental and internal factors, from availability to rewarding properties of food. Consequently, the acquisition of a dietary habit that may lead to metabolic alterations is the result of a learning process in which many variables take place. From genetics to socioeconomic status, the response to food and how this food affects energy metabolism is heavily influenced, even before birth. In this work, we review how food preference is acquired and established, particularly as regards sweet taste; towards which flavors and tastes we are positively predisposed by our genetic background, our early experience, further lifestyle, and our surroundings; and, especially, the role that the endocannabinoid system (ECS) plays in all of this. Ultimately, we try to summarize why this system is relevant for health purposes and how this is linked to important aspects of eating behavior, as its function as a modulator of energy homeostasis affects, and is affected by, physiological responses directly associated with obesity.

Dopamine receptor D2 polymorphism is associated with alleviation of obesity after 8-year follow-up: a retrospective cohort study in obese Chinese children and adolescents

OBJECTIVE

The aim of this study was to explore the association of dopamine receptor D2 (DRD2) polymorphism and alleviation of obesity in children and adolescents after 8-year follow-up.

METHODS

This retrospective cohort study included obese children and adolescents with a follow-up period of 8 years. Baseline clinical characteristics and DRD2 polymorphisms (including rs1076562, rs2075654, and rs4586205) were extracted from medical records. A follow-up visit was performed in May 2017 to collect related data including height, weight, diet compliance, and exercise compliance.

RESULTS

One hundred and nine obese children and adolescents were included in the current study. Among three DRD2 single nucleotide polymorphisms, only rs2075654 had a statistically significant association with alleviation of obesity, as the alleviation rate for minor allele carriers (68.6% for TC+TT) was higher compared to the major allele homozygote (43.3% for CC). After adjusting for all related factors, the hazard ratio of rs2075654 minor allele carriers for the alleviation of obesity was 3.34 (95% confidence interval (CI): 1.30‒8.58).

CONCLUSIONS

The rs2075654 polymorphism of DRD2 is related to long-term obesity alleviation in obese Chinese children and adolescents.

Prevalence of polymorphisms in the ANKK1, DRD2, DRD3 genes and metabolic syndrome in refractory schizophrenia

OBJECTIVE

to estimate the prevalence of TaqIA, -141C and rs6280 polymorphisms of the ANKK1, DRD2 and DRD3 genes and evaluate their association with the occurrence of metabolic syndrome in patients with refractory schizophrenia.

METHOD

cross-sectional study conducted in the Extended Western Region of Minas Gerais, with refractory schizophrenic patients using the antipsychotic clozapine. Sociodemographic, clinical, anthropometric, biochemical and genetic data were collected. Univariate analysis of the data was performed.

RESULTS

seventy-two patients participated in the study and the occurrence of Metabolic Syndrome was observed in 47.2% of them. There was no association between Metabolic Syndrome and the studied polymorphisms. There was a statistically significant difference in the low HDL parameter with homozygous genotype for the C allele of the -141C polymorphism of the DRD2 gene.

CONCLUSION

a high prevalence of MS was evidenced. The -141C polymorphism was associated with low HDL. Genetic analysis and identification of metabolic alterations in this group of patients can guide drug treatment and provide a better quality of life.

Circulating omentin-1 might be associated with metabolic health status in different phenotypes of body size

OBJECTIVE

Adipokines are mediators of body composition and are involved in obesity complications. This study aimed to assess the association of circulating omentin-1, vaspin, and RBP-4 with body composition indices and metabolic health status (MHS) in different phenotypes of body size.

SUBJECTS AND METHODS

A total of 350 subjects were included in the current cross-sectional study. Body composition was measured using a body composition analyzer, and serum concentrations of omentin-1, vaspin, and RBP-4 were assessed by ELISA kits.

RESULTS

Circulating omentin-1 was significantly (OR = 1.81, 95% CI: 1.00-1.91, P = 0.01) and marginally (OR = 1.63, 95%CI: 1.00-1.75, P = 0.06) associated with MHS in the overweight and obese subjects, respectively. But no association was seen between omentin-1 and MHS in normal-weight subjects. Serum levels of vaspin and RBP-4 were not correlated with MHS. Furthermore, a significant positive correlation was observed between circulating omentin-1 and body mass index (BMI) as well as fat percentage (P = 0.02) in the MHS group. Serum vaspin concentrations were not related to body composition components in both groups. In addition, in the MHS group, circulating RBP-4 was positively correlated with fat percentage and fat mass (FM) (p < 0.0001) and was negatively correlated with fat-free mass (FFM) and total body water (TBW) (p < 0.0001). In contrast, in the metabolically unhealthy group, RBP-4 was negatively correlated with fat percentage, FM, and BMI (p < 0.0001) and was positively correlated with FFM and TBW (p < 0.0001).

CONCLUSIONS

This study showed that circulating levels of omentin-1 are useful predictors of metabolic health status in overweight and obese people.

Effects of single genetic variants and polygenic obesity risk scores on disordered eating in adolescents - The HUNT study

PURPOSE

Improving the understanding of the role of genetic risk on disordered eating (DE).

METHODS

A case-control study including 1757 (F: 979, M: 778) adolescents (aged 13-19 years) from the Nord-Trøndelag Health Study (HUNT), an ethnically homogenous Norwegian population based study. Cases and controls were defined using a shortened version of the Eating Attitude Test. Logistic regression was employed to test for associations between DE phenotypes and 24 obesity and eating disorder susceptibility SNPs, and the joint effect of a subset of these in a genetic risk score (GRS).

RESULTS

COMT was shown to be associated with poor appetite/undereating (OR: 0.6, CI 95%: 0.43-0.83, p = 0.002). Independent of obesity associations, the weighted GRS was associated to overeating in 13-15 year old females (OR: 2.07, CI 95%: 1.14-3.76, p = 0.017). Additionally, a significant association was observed between the GRS and loss of control over eating in the total sample (OR: 1.62, CI 95%: 1.01-2.61, p = 0.046).

CONCLUSIONS

The COMT variant (rs4680) was associated with poor appetite/undereating. Our study further confirms prior findings that obesity risk also confers risk for loss of control over eating; and overeating amongst girls.

Metabolically healthy obesity across the life course: epidemiology, determinants, and implications

In recent years, different subphenotypes of obesity have been described, including metabolically healthy obesity (MHO), in which a proportion of obese individuals, despite excess body fat, remain free of metabolic abnormalities and increased cardiometabolic risk. In the absence of a universally accepted set of criteria to classify MHO, the reported prevalence estimates vary widely. Our understanding of the determinants and stability of MHO over time and the associated cardiometabolic and mortality risks is improving, but many questions remain. For example, whether MHO is truly benign is debatable, and whether risk stratification of obese individuals on the basis of their metabolic health status may offer new opportunities for more personalized approaches in diagnosis, intervention, and treatment of diabetes remains speculative. Furthermore, as most of the research to date has focused on MHO in adults, little is known about childhood MHO. In this review, we focus on the epidemiology, determinants, stability, and health implications of MHO across the life course.