Metabolically healthy obesity: different prevalences using different criteria

Clinical and molecular profiling of human visceral adipose tissue reveals impairment of vascular architecture and remodeling as an early hallmark of dysfunction

Adipose tissue dysfunction is more related to insulin resistance than body mass index itself and an alteration in adipose tissue function is thought to underlie the shift from metabolically healthy to unhealthy obesity. Herein, we performed a clustering analysis that revealed distinct visceral adipose tissue gene expression patterns in patients with obesity at distinct stages of metabolic dysregulation. We have built a cross-sectional cohort that aims at reflecting the evolution of the metabolic sequelae of obesity with the main objective to map the sequential events that play a role in adipose tissue dysfunction from the metabolically healthy (insulin-sensitive) state to several incremental degrees of metabolic dysregulation, encompassing insulin resistance establishment, pre-diabetes, and type 2 diabetes. We found that insulin resistance is mainly marked by the downregulation of adipose tissue vasculature remodeling-associated gene expression, suggesting that processes like angiogenesis and adaptative expansion/retraction ability suffer early dysregulation. Prediabetes was characterized by compensatory growth factor-dependent signaling and increased response to hypoxia, while type 2 diabetes was associated with loss of cellular response to insulin and hypoxia and concomitant upregulation of inflammatory markers. Our findings suggest a putative sequence of dysregulation of biological processes that is not linear and has multiple distinct phases across the metabolic dysregulation process, ultimately culminating in the climax of adipose tissue dysfunction in type 2 diabetes. Several studies have addressed the transcriptomic changes in adipose tissue of patients with obesity. However, to the best of our knowledge, this is the first study unraveling the potential molecular mechanisms associated with the multi-step evolution of adipose tissue dysfunction along the metabolic sequelae of obesity.

Fat as a Friend or Foe of the Bone

PURPOSE OF REVIEW

The objective of this review is to summarize the literature on the prevalence and diagnosis of obesity and its metabolic profile, including bone metabolism, focusing on the main inflammatory and turnover bone mediators that better characterize metabolically healthy obesity phenotype, and to summarize the therapeutic interventions for obesity with their effects on bone health.

RECENT FINDINGS

Osteoporosis and fracture risk not only increase with age and menopause but also with metabolic diseases, such as diabetes mellitus. Thus, patients with high BMI may have a higher bone fragility and fracture risk. However, some obese individuals with healthy metabolic profiles seem to be less at risk of bone fracture. Obesity has become an alarming disease with growing prevalence and multiple metabolic comorbidities, resulting in a significant burden on healthcare and increased mortality. The imbalance between increased food ingestion and decreased energy expenditure leads to pathological adipose tissue distribution and function, with increased secretion of proinflammatory markers and harmful consequences for body tissues, including bone tissue. However, some obese individuals seem to have a healthy metabolic profile and may not develop cardiometabolic disease during their lives. This healthy metabolic profile also benefits bone turnover and is associated with lower fracture risk.

Metabolically Abnormal Non-Obese Phenotype Is Significantly Associated with All-Cause Mortality in Hemodialysis Patients

The association between obesity and all-cause mortality in patients undergoing kidney failure with replacement therapy (KFRT) has shown conflicting results. This study aimed to evaluate whether metabolic abnormalities (MA) increase the risk of all-cause mortality in these patients. Between 2009 and 2015, 1141 patients undergoing KFRT were recruited from the Clinical Research Center for End-Stage Renal Disease dataset. Patients were divided into four groups according to the presence of obesity and MA. Multivariate Cox proportional hazard analysis was performed to determine the association between the phenotypes and all-cause mortality. During a mean follow-up of 4.2 years, all-cause mortality was observed in 491 (43.0%) patients. Obesity had a 24% decreased risk of all-cause mortality compared with non-obesity. In contrast, the presence of MA showed a 1.53-fold increased risk of all-cause mortality. There was a significant interaction between obesity and MA (p = 0.006). In Cox proportional hazard analyses after adjustment of confounding factors, the metabolically abnormal non-obesity (MANO) phenotype showed a 1.63-fold increased risk of all-cause mortality compared with the metabolically healthy non-obesity phenotype. In subgroup analysis, the risk of all-cause mortality was higher in the MANO phenotype; this phenotype was significantly associated with a higher all-cause mortality in patients undergoing KFRT.

Metabolic Health and Carotid Intima-Media Thickness: Association of Different Definitions in Women

The concept of metabolic health and the metabolic syndrome is to identify subjects at a higher cardiovascular risk. However, many definitions are currently in use, and it is uncertain which is the best in identifying at-risk subjects. We performed a cross-sectional study whereby women were invited to participate and were assessed for several anthropometric and biochemical parameters. Carotid intima-media thickness (CIMT) was measured in both common carotid arteries in each participant. The study cohort consisted of 203 white premenopausal women with a mean age of 38.3 ± 5.4 years. The prevalence of the metabolically unhealthy varied from 7.3% to 61.6%, according to the definition used. The prevalence of the metabolic syndrome, as defined by the International Diabetes Federation, was 20.7%. Women with a metabolically unhealthy phenotype had a higher referent CIMT for all definitions of metabolic health. Defining metabolically unhealthy phenotype as having <2 abnormalities using the National Cholesterol Education Program Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (NCEP-ATPIII) cutoffs had the highest odds ratio for an abnormal CIMT. In conclusion, we found that in a contemporary cohort of middle-aged women, the NCEP-ATPIII definition of the metabolic syndrome was more strongly associated with atherosclerosis as determined by the CIMT than the International Diabetes Federation definition or other definitions of metabolic health; it was also more strongly associated than body mass index or waist circumference. Our results need to be validated by other investigators in other populations.

Precision medicine of obesity as an integral part of type 2 diabetes management - past, present, and future

Obesity is a complex and heterogeneous condition that leads to various metabolic complications, including type 2 diabetes. Unfortunately, for some, treatment options to date for obesity are insufficient, with many people not reaching sustained weight loss or having improvements in metabolic health. In this Review, we discuss advances in the genetics of obesity from the past decade-with emphasis on developments from the past 5 years-with a focus on metabolic consequences, and their potential implications for precision management of the disease. We also provide an overview of the potential role of genetics in guiding weight loss strategies. Finally, we propose a vision for the future of precision obesity management that includes developing an obesity-centred multidisease management algorithm that targets both obesity and its comorbidities. However, further collaborative efforts and research are necessary to fully realise its potential and improve metabolic health outcomes.

Relevance of body composition in phenotyping the obesities

Obesity is the most extended metabolic alteration worldwide increasing the risk for the development of cardiometabolic alterations such as type 2 diabetes, hypertension, and dyslipidemia. Body mass index (BMI) remains the most frequently used tool for classifying patients with obesity, but it does not accurately reflect body adiposity. In this document we review classical and new classification systems for phenotyping the obesities. Greater accuracy of and accessibility to body composition techniques at the same time as increased knowledge and use of cardiometabolic risk factors is leading to a more refined phenotyping of patients with obesity. It is time to incorporate these advances into routine clinical practice to better diagnose overweight and obesity, and to optimize the treatment of patients living with obesity.

Metabolically healthy obesity: Misleading phrase or healthy phenotype?

Obesity is a heterogenous condition with multiple different phenotypes. Among these a particular subtype exists named as metabolically healthy obesity (MHO). MHO has multiple definitions and its prevalence varies according to study. The potential mechanisms underlying the pathophysiology of MHO include the different types of adipose tissue and their distribution, the role of hormones, inflammation, diet, the intestinal microbiota and genetic factors. In contrast to the negative metabolic profile associated with metabolically unhealthy obesity (MUO), MHO has relatively favorable metabolic characteristics. Nevertheless, MHO is still associated with many important chronic diseases including cardiovascular disease, hypertension, type 2 diabetes, chronic kidney disease as well as certain types of cancer and has the risk of progression into the unhealthy phenotype. Therefore, it should not be considered as a benign condition. The major therapeutic alternatives include dietary modifications, exercise, bariatric surgery and certain medications including glucagon-like peptide-1 (GLP-1) analogs, sodium-glucose cotransporter-2 (SGLT-2) inhibitors and tirzepatide. In this review, we discuss the significance of MHO while comparing this phenotype with MUO.

Association of metabolically healthy obesity in young adulthood with myocardial structure and function

BACKGROUND

Obesity is major cause of cardiovascular diseases. Metabolically healthy obesity (MHO) may increase heart failure risk early in life, and may be reflected in impaired cardiac structure and function. Therefore, we aimed to examine the relationship between MHO in young adulthood and cardiac structure and function.

METHODS

A total of 3066 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study were included, who completed echocardiography in young adulthood and middle age. The participants were grouped by obesity status (body mass index ≥30 kg/m²) and poor metabolic health (≥2 criteria for metabolic syndrome) into four metabolic phenotypes as follows: metabolically healthy non-obesity (MHN), MHO, metabolically unhealthy non-obesity (MUN), metabolically unhealthy obesity (MUO). The associations of the metabolic phenotypes (MHN serving as the reference) with left ventricular (LV) structure and function were evaluated using multiple linear regression models.

RESULTS

At baseline, mean age was 25 years, 56.4% were women, and 44.7% were black. After a follow-up 25 years, MUN in young adulthood was associated with worse LV diastolic function (E/é ratio, β [95% CI], 0.73 [0.18, 1.28]), worse systolic function (global longitudinal strain [GLS], 0.60 [0.08, 1.12]) in comparison with MHN. MHO and MUO were associated with LV hypertrophy (LV mass index, 7.49 g/m² [4.63, 10.35]; 18.23 g/m² [12.47, 23.99], respectively), worse diastolic function (E/é ratio, 0.67 [0.31, 1.02]; 1.47 [0.79, 2.14], respectively), and worse systolic function (GLS, 0.72 [0.38, 1.06]; 1.35 [0.64, 2.05], respectively) in comparison with MHN. These results were consistent in several sensitivity analyses.

CONCLUSIONS

In this community-based cohort using data from the CARDIA study, obesity in young adulthood was significantly associated with LV hypertrophy, worse systolic and diastolic function regardless of metabolic status. Relationship of Baseline Metabolic Phenotypes with Young Adulthood and Midlife Cardiac Structure and Function. Adjusted for year 0 covariates: age, sex, race, educational level, smoking status, drinking status, and physical activity; metabolically healthy non-obesity was used as a reference category for comparison. ^† Criteria for metabolic syndrome are listed in Supplementary Table S6. MUN metabolically unhealthy non-obesity, MHO metabolically healthy obesity, LVMi left ventricular mass index, LVEF left ventricular ejection fraction, E/A early to late peak diastolic mitral flow velocity ratio, E/é mitral inflow velocity to early diastolic mitral annular velocity, CI confidence interval.

Metabolically unhealthy phenotype in adults with normal weight: Is cardiometabolic health worse off when compared to adults with obesity?

The concept of metabolically healthy vs. unhealthy obese (MHO vs. MUO) was expanded to non-obese individuals as obesity-related comorbidities exist in a sub-group of normal weight (NW), i.e., MHNW vs. MUNW. It is unclear if MUNW differs from MHO with respect to cardiometabolic health.

PURPOSE

The purpose of this study was to compare cardiometabolic disease risk factors between MH vs. MU across weight status, NW, and obesity.

METHOD

A total of 8160 adults were included in the study from both the 2019 and 2020 Korean National Health and Nutrition Examination Surveys. Individuals with NW vs. obesity were further stratified as MH vs. MU by using AHA/NHLBI criterion for metabolic syndrome. A retrospective pair-matched analysis with respect to sex (male/female) and age ( ± 2 years) was performed to verify our total cohort analyses/results.

RESULTS

Despite a gradual increase in BMI and waist circumference from MHNW to MUNW to MHO to MUO, the surrogate estimates of insulin resistance and arterial stiffness were higher in MUNW vs. MHO. When compared to the MHNW, MUNW and MUO showed higher odds of hypertension (MUNW: 512%, MUO: 784%), dyslipidemia (MUNW: 210%, MUO: 245%), and diabetes (MUNW: 920%, MUO: 4012%), with no difference between MHNW and MHO.

CONCLUSION

Individuals with MUNW vs. MHO have greater vulnerability to cardiometabolic disease. Our data indicate that cardiometabolic risk is not solely dependent on adiposity, suggesting that early preventive efforts for chronic disease are needed for individuals with NW yet MU.

Role of physical activity and cardiorespiratory fitness in metabolically healthy obesity: a narrative review

Obesity has been associated with a multitude of metabolic disorders, often clustering with risk factors of cardiovascular disease and type 2 diabetes mellitus, hypertension, dyslipidaemia. Overall, obesity is a worldwide, growing health concern. However, a subgroup of obese individuals with a low burden of metabolic abnormalities have been identified and described as metabolically healthy obese (MHO). Whether the MHO phenotype is protective against obesity-related metabolic disorders in the long-term is presently unclear, and current research examining the potential transition has yielded inconsistent results. In this current narrative review, we aim to provide insights on the role of physical activity (PA) and cardiorespiratory fitness (CRF) in MHO. Lifestyle factors such as PA and CRF may influence the MHO phenotype. Limited studies have characterised energy expenditure and CRF in MHO and metabolically unhealthy obese. However, higher levels of PA, less sedentary behaviour and higher CRF have been observed in MHO individuals. Considering the multiple benefits of PA, it is high time to advocate this lifestyle change beyond its influence on energy balance in a weight loss programme to improve cardiovascular and metabolic risk factors irrespective of body weight and fat mass changes. Improved CRF via increased PA, especially exercise participation, while avoiding weight gain is not only a realistic goal, but should be the primary intervention for MHO populations to prevent the transition to an abnormal metabolic state.

Trends in the prevalence of metabolically healthy and unhealthy obesity in the US adult population: analysis of eight NHANES cross-sectional survey cycles, 1999-2014

OBJECTIVE

To exam the time trend of the prevalence of metabolically healthy obesity (MHO) in the US adult population.

DESIGN

Eight cross-sectional survey cycles.

SETTING

National Health and Nutrition Examination Survey (NHANES), 1999-2014.

PARTICIPANTS

16 459 NHANES participants aged 20 years and older.

PRIMARY OUTCOME MEASURE

MHO was defined as central obesity (waist circumference ≥102 cm for men and ≥88 cm for women) without any of the following conditions: elevated levels of blood pressure (≥130/85 mm Hg), glucose (≥100 mg/dL) and triglycerides (≥150 mm/dL); reduced levels of high-density lipoprotein cholesterol (<40 mg/dL for men and <50 mg/dL for women) or any medication use for high cholesterol, hypertension or diabetes.

RESULTS

The prevalence of central obesity significantly increased from 45.2% in 1999-2000 to 56.7% in 2013-2014 (p=0.003). Over the same period, MHO prevalence among those with central obesity only slightly and non-significantly increased from 11.0% to 15.7% (p=0.38). However, MHO prevalence among women increased significantly (p=0.04) from 7.1% to 13.7%. Female gender, a younger age, being Hispanic and non-Hispanic black and high education (some college or above) were significantly (p<0.05) associated with higher prevalence of MHO.

CONCLUSIONS

While the prevalence of central obesity in the US population has increased since 1999, the prevalence of MHO among those who are centrally obese remained fairly stable.

Trends in the Prevalence of Obesity and Its Phenotypes Based on the Korea National Health and Nutrition Examination Survey from 2007 to 2017 in Korea

This study used data from the Korea National Health and Nutrition Examination Survey IV-VII from 2007 to identify the prevalence of obesity and its phenotypes (metabolically unhealthy obesity [MUO] and metabolically healthy obesity [MHO]) and their secular changes. The prevalence of obesity in Korea increased with significant secular changes observed (β=0.326, P trend <0.01) between 2007 and 2017, and especially in men (β=0.682, P trend <0.001) but not in women. The changes in the prevalence of obesity during the study period were different between men and women (P=0.001). The prevalence of MUO significantly increased only in men (β=0.565, P trend <0.01), while that of MHO increased only in women (β=0.179, P<0.05), especially in the younger age group (β=0.308, P<0.01).

Prevalence rates of metabolic health and body size phenotypes by different criteria and association with insulin resistance in a Maltese Caucasian population

INTRODUCTION

Hyperinsulinemia and insulin resistance are known to be associated with increased cardiovascular morbidity and mortality. A metabolically unhealthy phenotype is frequently used as a surrogate marker for insulin resistance. The aims of the current study were to compare the prevalence of the body size phenotypes using different definitions of metabolic health and to investigate which one of them is most strongly associated with insulin resistance in men and women.

METHODS

We conducted a cross-sectional study in a middle-aged cohort of Maltese Caucasian non-institutionalized population. Metabolic health was defined using the various currently used definitions.

RESULTS

There were significant differences in the prevalence of body size phenotypes according to the different definitions. We also found significant sex differences in the predictive value of the various definitions of the metabolically unhealthy phenotype to predict insulin resistance. The strongest association was for the definition of having >2 NCEP-ATPIII criteria to characterize the metabolic unhealthy phenotype in women (odds ratio of 19.7). On the other hand, the Aguilar-Salinas et al. definition had the strongest association in men (odds ratio of 18.7).

CONCLUSIONS

We found large differences in the prevalence of the various body size phenotypes when using different definitions, highlighting the need for having standard criteria. Our data also suggest the need for sex-specific definitions of metabolic health.

Temporal trends in the prevalence of metabolically healthy overweight and obesity in Korean youth: data from the Korea National Health and Nutrition Examination Survey 2011-2019

PURPOSE

Metabolically healthy overweight/obesity (MHO) and metabolically unhealthy overweight/obesity (MUO) are distinct clinical phenotypes classified by the presence of cardiometabolic risk factors in an individual. In the present study, we investigated temporal trends in the prevalence of MHO in Korean adolescents using nationally representative data.

METHODS

Data from the Korea National Health and Nutrition Examination Survey 2011-2019 were used in this study. A total of 5,667 adolescents (3,014 boys, 53.2%) aged 10-18 years was included in this study. MHO was defined as a body mass index ≥85th percentile for the corresponding age and sex and absence of any cardiometabolic risk factors.

RESULTS

The prevalence of overweight/obesity showed an increasing trend from 18.8% (boys 17.3% and girls 20.6%) in 2011 to 23.7% (boys 24.0% and girls 23.5%) in 2019 (p for trend=0.045). The overall prevalence of MHO during 2011-2019 was 39.2%, which was higher in girls than in boys (boys 33.5%, girls 46.2%, p<0.001), and the change in prevalence of MHO from 2011 to 2019 (from 34.8% to 35.7%) was not significant. Among MUO, the most prevalent cardiometabolic risk factor was dysglycemia (48.8%), followed by elevated blood pressure (41.5%), low high-density lipoprotein cholesterol (35.0%), and high triglycerides (29.7%).

CONCLUSION

We observed a high prevalence of MHO in Korean youth with overweight/obesity. Although the prevalence of overweight/obesity increased, the prevalence of MHO was stable during 2011-2019. A risk-stratified approach based on metabolic health status can help reducing the medical and socioeconomic costs associated with obesity treatment.

Uric acid as a predictor of weight gain and cardiometabolic health in the Study of Novel Approaches to Weight Gain Prevention (SNAP) study

Young adulthood is often a period of substantial weight gain increasing risk for obesity and cardiometabolic disease. Uric acid (UA), a clinical marker of oxidative stress, is associated with cardiometabolic dysfunction in established CVD, type 2 diabetes, and CKD. Yet, few trials have examined UA as a predictor of cardiometabolic risk in young, healthy populations, particularly in the context of weight gain prevention intervention. The purpose of this ancillary study was to examine UA in the Study of Novel Approaches to Weight Gain Prevention (SNAP), a randomized, controlled trial of weight gain prevention strategies in young healthy adults. UA was examined as a predictor of weight and cardiometabolic outcomes over 6 years; the impact of weight gain prevention interventions on UA was also examined. We found that higher baseline UA was a significant predictor of less favorable BMI, triglycerides, HDL, glucose, insulin, and HOMA, independent of age, sex, baseline weight, baseline level of the outcome variable, and weight gain prevention intervention. Additionally, ≥1% weight loss was associated with lower UA. UA is a promising biomarker for future weight gain and cardiometabolic risk in young adults that may respond to weight gain prevention.Clinical trial registration: clinicaltrials.gov identifier NCT01183689.

The joint association of cardiometabolic health and weight on mortality in the multiethnic cohort

Objective: While cardiometabolic abnormalities are associated with elevated risk of morbidity, they may not occur in all individuals with obesity. Less is known about associations with mortality, especially cancer mortality. This study examined associations between cardiometabolic-weight categories and mortality from cardiovascular disease (CVD), cancer, and all causes.Methods: Cox proportional hazards regressions of time to all-cause, CVD, and cancer mortalities were used to examine associations with cardiometabolic-weight status, in the Multiethnic Cohort (n=157,865). Cardiometabolic-weight status categories were: Metabolically Healthy Normal Weight, Metabolically Healthy Obese, Metabolically Healthy Overweight, Metabolically Unhealthy Normal Weight, Metabolically Unhealthy Obese, and Metabolically Unhealthy Overweight.Results: Higher mortality, especially for all-cause and CVD, was found for all metabolically unhealthy groups no matter the weight classification when compared to the Metabolically Healthy Normal Weight category across sex-ethnic groups. For all-cause mortality, a reduction in mortality was seen for males in the Metabolically Healthy Overweight category (HR: 0.88, 95% CI: 0.84, 0.93), especially for African American, Native Hawaiian, and Latino males. Mortality was elevated in the Metabolically Healthy Obese category for all-cause and CVD mortality in both sexes (HR_range: 1.08-1.93). Few associations were seen with cancer mortality.Conclusions: Past examinations of cardiometabolic-weight status and mortality have been hampered by a lack of diversity. In a racially/ethnically diverse population, metabolically unhealthy groups exhibited a substantially higher risk of death from all causes and CVD than metabolically healthy groups. A reduction in all-cause mortality was seen for some males classified as Metabolically Healthy Overweight; however, being classified as Metabolically Healthy Obese elevated mortality risk for males and females compared to Metabolically Healthy Normal Weight. Future research is needed to examine how sex-ethnic differences in body fat distribution and changes in weight over time influence associations between cardiometabolic-weight status and mortality.

Metabolically Healthy and Unhealthy Obese Phenotypes among Arabs and South Asians: Prevalence and Relationship with Cardiometabolic Indicators

Obesity is a public health crisis in Kuwait. However, not all obese individuals are metabolically unhealthy (MuHO) given the link between obesity and future cardiovascular events. We assessed the prevalence of the metabolically healthy obese (MHO) phenotype and its relationship with high sensitivity C-reactive protein (hs-CRP), serum alanine aminotransferase (ALT), and insulin resistance (HOMA-IR) in Arab and South Asian ethnic groups in Kuwait. The national cross-sectional survey of diabetes and obesity in Kuwait adults aged 18–60 years were analysed. The harmonised definition of metabolic syndrome was used to classify metabolic health. Multinomial logistic regression analysis was used to model the relationship between the MHO and MuHO phenotypes and hs-CRP, ALT and HOMA-IR levels. Overall, the prevalence of MHO for body mass index (BMI)- and waist circumference (WC)-defined obesity was 30.8% and 56.0%, respectively; it was greater in women (60.4% and 61.8%, respectively) than men (39.6% and 38.2%, respectively). Prevalence rates were also lower for South Asians than for Arabs. The MHO phenotype had hs-CRP values above 3 µg/mL for each age group category. Men compared to women, and South Asians compared to Arabs had a lower relative risk for the MHO group relative to the MuHO group. This study shows there is high prevalence of MHO in Kuwait.

Anthropometric cut-points for discriminating diabetes and the metabolic syndrome among Arabs and Asians: the Kuwait Diabetes Epidemiology Program

This study aimed to determine anthropometric cut-points for screening diabetes and the metabolic syndrome (MetS) in Arab and South Asian ethnic groups in Kuwait and to compare the prevalence of the MetS based on the ethnic-specific waist circumference (WC) cut-point and the International Diabetes Federation (IDF) and American Heart Association/National Heart, Lung, and Blood Institute WC criteria. The national population-based survey data set of diabetes and obesity in Kuwait adults aged 18-60 years was analysed. Age-adjusted logistic regression and receiver operating characteristic (ROC) analyses were conducted to evaluate for 3589 individuals the utility of WC, waist:height ratio (WHtR) and BMI to discriminate both diabetes and ≥3 CVD risk factors. Areas under the ROC curve were similar for WC, WHtR and BMI. In Arab men, WC, WHtR and BMI cut-offs for diabetes were 106 cm, 0·55 and 28 kg/m2 and for ≥3 CVD risk factors, 97 cm, 0·55 and 28 kg/m2, respectively. In Arab women, cut-offs for diabetes were 107 cm, 0·65 and 33 kg/m2 and for ≥3 CVD risk factors, 93 cm, 0·60 and 30 kg/m2, respectively. WC cut-offs were higher for South Asian women than men. IDF-based WC cut-offs corresponded to a higher prevalence of the MetS across sex and ethnic groups, compared with Kuwait-specific cut-offs. Any of the assessed anthropometric indices can be used in screening of diabetes and ≥3 CVD risk factors in Kuwaiti Arab and Asian populations. ROC values were similar. The WC threshold for screening the MetS in Kuwaiti Arabs and South Asians is higher for women.

Association between being metabolically healthy/unhealthy and metabolic syndrome in Iranian adults

Introduction

The prevalence of metabolically healthy obesity (MHO) varies based on different criteria. We assessed the prevalence of MHO and metabolic unhealthiness based on body mass index (BMI) and their association with metabolic syndrome (MetS) in a nation-wide study.

Methods

Data were taken from the STEPs 2016 study, from 18,459 Iranians aged ≥25 years. Demographic, metabolic, and anthropometric data were collected. Subjects were stratified by BMI, metabolic unhealthiness, and having MetS. The latter was defined based on National Cholesterol Education Program Adult Treatment Panel III 2004 (NCEP ATP III), was then assessed.

Results

The prevalence of MHO and metabolic unhealthiness in obese subjects was 7.5% (about 3.6 million) and 18.3% (about 8.9 million), respectively. Most of the metabolic unhealthy individuals were female (53.5%) or urban residents (72.9%). Low physical activity was significantly and positively associated (Odds Ratio: 1.18, 95% CI: 1.04–1.35) with metabolic unhealthiness, while being a rural residence (0.83, 0.74–0.93), and having higher education (0.47, 0.39–0.58) significantly but negatively affected it. Dyslipidemia was the most frequent MetS component with a prevalence rate of 46.6% (42.1–51.1), 62.2% (60.8–63.6), 76.3% (75.1–77.5), and 83.4% (82.1–84.6) among underweight, normal weight, overweight and obese phenotypes, respectively.

Conclusion

BMI aside, an additional set of criteria such as metabolic markers should be taken into account to identify normal weight but metabolically unhealthy individuals. Given the highest prevalence of dyslipidemia among obese subjects, further interventions are required to raise public awareness, promote healthy lifestyles and establish lipid clinics.

Effect of obesity and metabolic health on urolithiasis: A nationwide population-based study

Purpose

To investigate the risk of symptomatic urolithiasis requiring surgical treatment according to obesity and metabolic health status using a nationwide dataset of the Korean population.

Materials and Methods

Of the 5,300,646 persons who underwent health examinations between the year 2009 and 2016, within one year after the health examination, 35,137 patients who underwent surgical treatment for urolithiasis were enrolled. Participants were classified as “obese” or “non-obese” using a body mass index (BMI) cutoff of 25 kg/m². People who developed ≥1 metabolic disease component in the index year were considered “metabolically unhealthy”, while those with none were considered “metabolically healthy”.

Results

Out of 34,330 participants excluding 843 missing, 16,509 (48.1%), 4,320 (12.6%), 6,456 (18.8%), and 7,045 (20.5%) subjects were classified into the metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) group, respectively. Mean BMI was 22.1±1.9 kg/m², 22.9±1.6 kg/m², 26.9±1.8 kg/m², and 27.9±2.4 kg/m² respectively. After adjusting the age and sex, the subjects in the MUNO group had an HR (95% CI) of 1.192 (1.120–1.268), those in the MHO group, 1.242 (1.183–1.305), and those in the MUO group, 1.341 (1.278–1.407) for either extracorporeal shockwave lithotripsy or surgery, compared to those in the MHNO group.

Conclusions

Metabolically healthy, obese individuals have a higher risk of developing symptomatic urolithiasis than non-obese, unhealthy, but have a lower risk than obese, unhealthy. It suggests that metabolic health and obesity have collaborative effects, independently affecting the development of symptomatic urinary stone diseases.

Association Between Indices of Body Composition and Metabolically Unhealthy Phenotype in China: A Cross-Sectional Study

INTRODUCTION

Body composition is closely related to metabolic health status. Visceral adipose tissue (VAT) dysfunction contributes to metabolic syndrome. However, results regarding subcutaneous adipose tissue (SAT) and skeletal muscle are controversial. We aimed to determine the association of indices of body composition with abnormal metabolic phenotype in China.

METHODS

A total of 3, 954 subjects (age 50.2 ± 11.7 years) with body mass index (BMI) more than 18.5 kg/m² from Pinggu Metabolic Disease Study were analyzed. Quantitative computed tomography (QCT) was performed to measure total adipose tissue (TAT), VAT, SAT area, and lumbar skeletal muscle area (SMA). Participants were divided into six groups on the basis of BMI category (normal weight/overweight/obesity) and metabolic status (healthy/unhealthy), as defined by the presence or absence of components of the metabolic syndrome by Chinese Diabetes Society criteria.

RESULTS

63.4%, 39.5%, and 23.3% participants were classified as metabolically healthy phenotype in individuals with normal weight, overweight and obese, respectively. Individuals in the highest TAT, VAT, and VAT/TAT ratio category had higher risk of being metabolically unhealthy than individuals in the lowest group (all p<0.01). While, risk for metabolically unhealthy was reduced significantly in the highest SMA/TAT ratio category when compared with the lowest category in individuals with normal wight and overweight (both p<0.05). Risk for metabolically unhealthy was reduced significantly in the highest SAT category when compared with the lowest category (OR=0.555, 95%CI: 0.360-0.856, p=0.008) in individuals with obese after adjustment for age, sex and BMI. However, skeletal muscle index (SMI) showed no significant association with the metabolically healthy status in different BMI categories (p>0.05). The VAT and VAT/TAT ratio were better diagnostic values of indicators to differentiate metabolically unhealthy subjects from controls compared with other indicators, such as TAT, SAT, SMI, SMA/TAT ratio.

CONCLUSIONS

Higher visceral adipose tissue was closely associated with metabolically unhealthy phenotype in Chinese adults. Subcutaneous adipose tissue might be a protective factor for metabolic health status only in obese individuals.

Vitamin D is directly associated with favorable glycemic, lipid, and inflammatory profiles in individuals with at least one component of metabolic syndrome irrespective of total adiposity: Pró-Saúde Study, Brazil

Vitamin D insufficiency has been suggested as a risk factor for several metabolic disorders. The objective of the study was to investigate the association between serum 25 hydroxyvitamin D [25(OH)D] and metabolic health markers of Brazilian individuals with normal-weight, overweight or obesity. We hypothesized that serum 25(OH)D would be inversely associated with glycemic, lipid and inflammatory markers indicative of metabolic abnormality. Data of 511 individuals (33-79 years), recruited from a longitudinal investigation (Pró-Saúde Study), were analyzed cross-sectionally. Anthropometric, biochemical, body composition, socio-demographic and lifestyle data were collected. Based on body mass index (BMI; normal weight, overweight, obesity) and metabolic health (metabolically healthy (MH) and metabolically unhealthy (MU)) categories, the participants were classified into 6 phenotypes. Individuals having zero components of the metabolic syndrome were considered as "MH". MH obesity was frequent in 2.0% of the participants and 56.0% exhibited vitamin D insufficiency (<20 ng/mL). In the subgroups of the same BMI category, there were no significant differences in 25(OH)D concentrations between individuals classified as MH and MU. After adjustments (including %body fat and BMI), an inverse association was observed between 25(OH)D and visceral adipose tissue (B = -6.46, 95% confidence interval, CI: -12.87, -0.04), leptin (B = -0.09, 95% confidence interval, CI: -0.14, -0.03), insulin (B = -0.21, 95%CI: -0.34, -0.07), HOMA-IR (B = -0.06, 95%CI: -0.10, -0.02), triglycerides (B = -2.44, 95%CI: -3.66, -1.22), and TNF-α (B = -0.12, 95%CI: -0.24, -0.005) only in MU individuals. Our results indicate that the association of 25(OH)D concentrations with a favorable biochemical profile (glycemic, lipidic and inflammatory) seems to depend on the individual's overall metabolic health, suggesting more benefits from higher serum vitamin D in MU individuals, regardless of their adiposity.

Characterisation of body size phenotypes in a middle-aged Maltese population

Obesity is increasingly recognised as being a heterogeneous disease. Some obese individuals may present a metabolically healthy profile (metabolically healthy obese (MHO)), while some normal weight individuals exhibit an adverse cardiometabolic phenotype (metabolically unhealthy normal weight individuals (MUHNW)). The objectives of the present study were to examine the prevalence and associated characteristics of the different body composition phenotypes within a Maltese cohort. This was a cross-sectional analysis involving 521 individuals aged 41 ± 5 years. The metabolically unhealthy state was defined as the presence of ≥2 metabolic syndrome components (NCEP-ATPIII parameters), while individuals with ≤1 cardiometabolic abnormalities were classified as metabolically healthy. Overall, 70 % of the studied population was overweight or obese and 30⋅7 % had ≥2 cardiometabolic abnormalities. The prevalence of MHO and MUHNW was 10⋅7 and 2⋅1 %, respectively. Individuals with the healthy phenotype were more likely to consume alcohol, participate in regular physical activity and less likely to be smokers. While the MHO phenotype had similar values for waist, hip and neck circumferences, waist-hip ratio and insulin resistance when compared with MUHNW individuals, there was a lower proportion of MHO subjects having a high fasting plasma glucose, hypertriglyceridaemia or low HDL-C when compared with the unhealthy lean individuals. A high prevalence of the metabolically unhealthy phenotype was observed in this relatively young population which may result in significant future cardiovascular disease burden if timely assessment and management of modifiable risk factors are not implemented. Furthermore, the present study suggests that the MHO phenotype is not totally benign as previously thought.

Crosstalk between Metabolic Disorders and Immune Cells

Metabolic syndrome results from multiple risk factors that arise from insulin resistance induced by abnormal fat deposition. Chronic inflammation owing to obesity primarily results from the recruitment of pro-inflammatory M1 macrophages into the adipose tissue stroma, as the adipocytes within become hypertrophied. During obesity-induced inflammation in adipose tissue, pro-inflammatory cytokines are produced by macrophages and recruit further pro-inflammatory immune cells into the adipose tissue to boost the immune response. Here, we provide an overview of the biology of macrophages in adipose tissue and the relationship between other immune cells, such as CD4+ T cells, natural killer cells, and innate lymphoid cells, and obesity and type 2 diabetes. Finally, we discuss the link between the human pathology and immune response and metabolism and further highlight potential therapeutic targets for the treatment of metabolic disorders.

Transcriptomic changes in peripheral blood mononuclear cells with weight loss: systematic literature review and primary data synthesis

Background and objectives

Peripheral blood mononuclear cells (PBMCs) have shown promise as a tissue sensitive to subtle and possibly systemic transcriptomic changes, and as such may be useful in identifying responses to weight loss interventions. The primary aim was to comprehensively evaluate the transcriptomic changes that may occur during weight loss and to determine if there is a consistent response across intervention types in human populations of all ages.

Methods

Included studies were randomised control trials or cohort studies that administered an intervention primarily designed to decrease weight in any overweight or obese human population. A systematic search of the literature was conducted to obtain studies and gene expression databases were interrogated to locate corresponding transcriptomic datasets. Datasets were normalised using the ArrayAnalysis online tool and differential gene expression was determined using the limma package in R. Over-represented pathways were explored using the PathVisio software. Heatmaps and hierarchical clustering were utilised to visualise gene expression.

Results

Seven papers met the inclusion criteria, five of which had raw gene expression data available. Of these, three could be grouped into high responders (HR, ≥ 5% body weight loss) and low responders (LR). No genes were consistently differentially expressed between high and low responders across studies. Adolescents had the largest transcriptomic response to weight loss followed by adults who underwent bariatric surgery. Seven pathways were altered in two out of four studies following the intervention and the pathway ‘cytoplasmic ribosomal proteins’ (WikiPathways: WP477) was altered between HR and LR at baseline in the two datasets with both groups. Pathways related to ‘toll-like receptor signalling’ were altered in HR response to the weight loss intervention in two out of three datasets.

Conclusions

Transcriptomic changes in PBMCs do occur in response to weight change. Transparent and standardised data reporting is needed to realise the potential of transcriptomics for investigating phenotypic features.

Registration number

PROSPERO: CRD42019106582

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-021-00692-6.

Association of Visceral Adipose Tissue and Insulin Resistance with Incident Metabolic Syndrome Independent of Obesity Status: The IRAS Family Study

OBJECTIVE

Although increasing evidence suggests that visceral adipose tissue (VAT) is a major underlying cause of metabolic syndrome (MetS), few studies have measured VAT at multiple time points in diverse populations. VAT and insulin resistance were hypothesized to differ by MetS status within BMI category in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study and, further, that baseline VAT and insulin resistance and increases over time are associated with incident MetS.

METHODS

Generalized estimating equations were used for differences in body fat distribution and insulin resistance by MetS status. Mixed effects logistic regression was used for the association of baseline and change in adiposity and insulin resistance with incident MetS across 5 years, adjusted for age, sex, race/ethnicity, and family correlation.

RESULTS

VAT and insulin sensitivity differed significantly by MetS status and BMI category at baseline. VAT and homeostatic model assessment of insulin resistance (HOMA-IR) at baseline (VAT odds ratio [OR] = 1.16 [95% CI: 1.12-2.31]; HOMA-IR OR = 1.85 [95% CI: 1.32-2.58]) and increases over time (VAT OR = 1.55 [95% CI: 1.22-1.98]; HOMA-IR OR = 3.23 [95% CI: 2.20-4.73]) were associated with incident MetS independent of BMI category.

CONCLUSIONS

Differing levels of VAT may be driving metabolic heterogeneity within BMI categories. Both overall and abdominal obesity (VAT) may play a role in the development of MetS. Increased VAT over time contributed additional risk.

Abdominal periaortic and renal sinus fat attenuation indices measured on computed tomography are associated with metabolic syndrome

OBJECTIVES

To investigate the association between abdominal periaortic (APA) and renal sinus (RS) fat attenuation index (FAI) measured on MDCT and metabolic syndrome in non-obese and obese individuals.

METHODS

Visceral, subcutaneous, RS, and APA adipose tissue were measured in preoperative abdominal CT scans of individuals who underwent donor nephrectomy (n = 84) or bariatric surgery (n = 155). FAI was defined as the mean attenuation of measured fat volume. Participants were categorized into four groups: non-obese without metabolic syndrome (n = 64), non-obese with metabolic syndrome (n = 25), obese without metabolic syndrome (n = 21), and obese with metabolic syndrome (n = 129). The volume and FAI of each fat segment were compared among the groups. Receiver operator characteristics curve analysis was used to assess the association between the FAIs and metabolic syndrome.

RESULTS

FAIs of all abdominal fat segments were significantly lower in the obese group than in the non-obese group (p < 0.001). RS, APA, and the visceral adipose tissue FAIs were significantly lower in participants with metabolic syndrome than in those without metabolic syndrome in the non-obese group (p < 0.001, p = 0.006, and p < 0.001, respectively). The area under the curve for predicting metabolic syndrome was significantly higher for APA FAI (0.790) than subcutaneous, visceral, and RS FAI in all groups (0.649, 0.647, and 0.655, respectively).

CONCLUSION

Both metabolic syndrome and obesity were associated with lower RS and APA adipose tissue FAI, and APA FAI performed best for predicting metabolic syndrome.

KEY POINTS

• The volume and FAI of RS, APA, and visceral adipose tissue showed opposite trends with regard to metabolic syndrome or obesity. • Both metabolic syndrome and obesity were associated with lower RS FAI and APA FAI. • APA FAI performed best for predicting metabolic syndrome among FAIs of abdominal fat segments.

Natural course of metabolically healthy phenotype and risk of developing Cardiometabolic diseases: a three years follow-up study

BACKGROUND

Whether the metabolically healthy obese (MHO) phenotype is a single, stable or a transitional, fluctuating state is currently unknown. The Mexican-Mestizo population has a genetic predisposition for the development of type 2 diabetes (T2D) and other cardiometabolic complications. Little is known about the natural history of metabolic health in this population. The aim of this study was to analyze the transitions over time among individuals with different degrees of metabolic health and body mass index, and evaluate the incidence of cardiometabolic outcomes according to phenotype.

METHODS

The study population consisted of a metabolic syndrome cohort with at least 3 years of follow up. Participants were apparently-healthy urban Mexican adults ≥20 years with a body mass index (BMI) ≥20 kg/m2. Metabolically healthy phenotype was defined using the criteria of the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) metabolic syndrome criteria and the subjects were stratified into 4 groups according to their BMI and metabolic health. For cardiometabolic outcomes we estimated the incidence of cardiometabolic outcomes and standardized them per 1, 000 person-years of follow-up. Finally, to evaluate the risk for transition and development of cardiometabolic outcomes, we fitted Cox Proportional Hazard regression models.

RESULTS

Amongst the 5541 subjects, 54.2% were classified as metabolically healthy and 45.8% as unhealthy. The MHO prevalence was 39.3%. Up to a third of the population changed from their initial category to another and the higher transition rate was observed in MHO (42.9%). We also found several novel factors associated to transition to metabolically unhealthy phenotype; socioeconomic status, number of pregnancies, a high carbohydrate intake, history of obesity and consumption of sweetened beverages. Similarly, visceral adipose tissue (VAT) was a main predictor of transition; loss of VAT ≥5% was associated with reversion from metabolically unhealthy to metabolically healthy phenotype (hazard ratio (HR) 1.545, 95%CI 1.266-1.886). Finally, we observed higher incidence rates and risk of incident T2D and hypertension in the metabolically unhealthy obesity (MUHO) and metabolically unhealthy lean (MUHL) phenotypes compared to MHO.

CONCLUSIONS

Metabolic health is a dynamic and continuous process, at high risk of transition to metabolically unhealthy phenotypes over time. It is imperative to establish effective processes in primary care to prevent such transitions.

Metabolically healthy overweight in young adulthood: is it a matter of duration and degree of overweight?

BACKGROUND AND AIM

Given the controversy regarding metabolically healthy obesity, we studied the association between duration and degree of body mass index (BMI) from adolescence to early adulthood and metabolic status of both overweight/obese and under/normal weight subjects.

METHODS AND RESULTS

Participants of the EPITeen cohort were evaluated at 13, 17, 21 and 24 years (n = 1040). Duration and degree of BMI in the 11-year period was summarized through the area under the curve of BMI (BMI_AUC). Metabolic health at 24 y was defined as optimal levels of lipids, blood pressure and glucose. The association between BMI_AUC per year and metabolic health was estimated through binary logistic regression models, adjusted for confounders and stratified by BMI. The proportion of metabolically healthy overweight/obesity at 24 y was 13.4%. After adjustment for sociodemographic and behavioural factors, the increase of one kg/m² in BMI on average per year during the period between 13 and 24 y was associated with 14% lower odds of being metabolically healthy among under/normal weight participants (OR = 0.86, 95% CI 0.78-0.94); and 8% lower odds of metabolic health among obese/overweight participants (OR = 0.92, 95% CI 0.85-1.00). After additional adjustment for waist circumference, the association was attenuated, especially in the obese/overweight group (OR = 1.03, 95% CI 0.93-1.14). About 20% of the metabolically healthy obese/overweight at 13 y transitioned to metabolically unhealthy obesity/overweight at 24 y.

CONCLUSION

The results support the hypothesis that the healthy obesity phenotype could be explained by a lower exposure to adiposity, either by shorter time or lower quantity, and a more favourable body fat distribution.

Comparing an adiposopathy approach with four popular classifications schemes to categorize the metabolic profile of postmenopausal women

Numerous classifications are used to discern metabolically healthy obese (MHO) from metabolically abnormal obese (MAO) individuals. The goal of this study was to compare a single phenotype approach, adiposopathy (i.e., the plasma adiponectin/leptin ratio), with four commonly used classifications (International Diabetes Federation (IDF), Karelis, Lynch, Wildman), all based on obesity with other risk factors), for their ability to discern phenotypic differences between MAO and MHO postmenopausal women. Anthropometry, body composition, blood pressure, cardiorespiratory fitness (CRF), lipid-lipoprotein, hepatic, inflammatory, and adipokine profiles, as well as glucose-insulin homeostasis, were assessed in 79 obese sedentary postmenopausal women (60 ± 5 years; body mass index, BMI, 34.0 ± 3.7 kg/m²). Abdominal subcutaneous adipose tissue (SCAT) expression of selected genes involved in fatty acid metabolism and inflammation was used as markers of tissue state (n = 48). Beyond their intrinsic criteria, adiposopathy was almost as effective as the Karelis definition in discerning differences in MHO for adiposity (reduced body weight, BMI, waist circumference, and fat mass), lipid-lipoprotein (lower triacylglycerol and higher HDL-cholesterol levels, reduced atherogenic ratios) and adipokine (higher adiponectin and lower leptin levels) profiles, and glucose-insulin homeostasis (lower insulin resistance) as well as for some SCAT gene expression related to lipolysis and lipogenesis, but was the only one able to distinguish these subjects for greater CRF. The other classifications revealed fewer differences between MAO and MHO women. These data suggest that considering a marker of AT dysfunction such as adiposopathy either alone or in addition to other criteria could be potentially interesting in discerning the MHO phenotype.

Prevalence and Clinical Characteristics of Children and Adolescents with Metabolically Healthy Obesity: Role of Insulin Sensitivity

Obesity represents a major risk factor for metabolic disorders, but some individuals, "metabolically healthy" (MHO), show less clinical evidence of these complications, in contrast to "metabolically unhealthy" (MUO) individuals. The aim of this cross-sectional study is to assess the prevalence of the MHO phenotype in a cohort of 246 overweight/obese Italian children and adolescents, and to evaluate their characteristics and the role of insulin resistance. Homeostasis model assessment-insulin resistance (HOMA-IR), insulin sensitivity index (ISI), insulinogenic index (IGI) and disposition index (DI) were all calculated from the Oral Glucose Tolerance Test (OGTT). MHO was defined by either: (1) HOMA-IR < 2.5 (MHO-IRes), or (2) absence of the criteria for metabolic syndrome (MHO-MetS). The MHO prevalence, according to MHO-MetS or MHO-IRes criteria, was 37.4% and 15.8%, respectively. ISI was the strongest predictor of the MHO phenotype, independently associated with both MHO-IRes and MHO-MetS. The MHO-MetS group was further subdivided into insulin sensitive or insulin resistant on the basis of HOMA-IR (either < or ≥ 2.5). Insulin sensitive MHO-MetS patients had a better metabolic profile compared to both insulin resistant MHO-MetS and MUO-MetS individuals. These data underscore the relevance of insulin sensitivity to identifying, among young individuals with overweight/obesity, the ones who have a more favorable metabolic phenotype.

Metabolic health and its association with lifestyle habits according to nutritional status in Chile: A cross-sectional study from the National Health Survey 2016-2017

BACKGROUND

Lifestyle habits associate with metabolic health in overall populations. Whether such association is similar among subjects with a different nutritional status has been less studied. We aimed to (i) determine the prevalence of metabolic phenotypes in Chile, and (ii) determine the association between lifestyle habits and metabolic health according to the nutritional status.

METHODS

The National Health Survey of Chile 2016-2017 was analyzed. A metabolically unhealthy phenotype was defined as manifesting ≥3 of the following risk factors: elevated blood pressure, elevated triglycerides, elevated glucose, elevated waist circumference, or reduced high-density lipoprotein cholesterol. Individuals manifesting <2 risk factors were considered as healthy. The nutritional status was defined as normal weight (18.5 to <25 kg/m2), overweight (25 to <30 kg/m2) or obesity (≥30 kg/m2). Questionnaires were used to estimate smoking habits, alcohol intake, sedentary behavior, moderate-vigorous physical activity, fruits/vegetables consumption, and fish/seafood consumption. The association (odds ratio [95%CI]) between lifestyle habits and metabolic health was determined within each nutritional status, adjusting for age, sex, BMI (in kg/m2), and education.

RESULTS

The prevalence of a metabolically unhealthy phenotype was 36% in the overall sample. Such a prevalence was 7%, 33% and 58% among subjects with normal weight, overweight and obesity, respectively. In subjects with normal weight, the highest quartile of fruits/vegetables consumption was associated with reduced odds of having a metabolically unhealthy phenotype (0.09 [0.01-0.48]). In subjects with obesity, the highest quartile of moderate-vigorous physical activity was associated with reduced odds of having a metabolically unhealthy phenotype (0.29 [0.09-0.91]).

CONCLUSION

One third of the Chilean population manifests an unhealthy phenotype. We identified associations between lifestyle habits and metabolic health that are specific to the nutritional status. Thus, emphasizing fruits/vegetables consumption in subjects with normal weight, and physical activity in subjects with obesity, may maximize the benefits of public health interventions.

Association Metabolic Obesity Phenotypes with Cardiometabolic Index, Atherogenic Index of Plasma and Novel Anthropometric Indices: A Link of FTO-rs9939609 Polymorphism

Background

The role of metabolic states in cardiovascular risks among individuals with varying degrees of obesity is unknown. The study aimed to compare cardiometabolic index (CMI), atherogenic index of plasma (AIP), lipid accumulation product (LAP) and novel anthropometric indices in metabolic and non-metabolically obese individual with regard to the role of FTO gene in Iranian adults.

Methods

In total, 165 individuals were recruited into this cross-sectional study. Individuals grouped into four groups: metabolic healthy normal-weight (MHNW) individuals, metabolically unhealthy normal-weight (MUNW) individuals, metabolically healthy obese (MHO) individuals and metabolic unhealthy obese (MUO) individuals. The dietary intake was evaluated by food frequency questionnaire (FFQ). The cardiovascular indices (CMI, AIP and LAP) were calculated. A variety of anthropometric indices were calculated, including body adiposity Index (BAI), weight-adjusted-waist index (WWI), A body shape index (ABSI) and waist-height ratio (WHR). The genotypes of FTO-rs9939609 subjects were detected by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results

The individuals with metabolically unhealthy phenotypes (MUO, MUNW) have higher levels of triglyceride and cardiovascular indices (AIP, LAP and CMI) than the individuals with metabolic healthy phenotypes (MHO, MHNW). With a similar degree of obesity, the anthropometric indices (BAI, WWI and WHR) levels were higher in metabolic unhealthy groups than metabolically healthy groups. The highest frequency of obesity-risk allele AA of FTO gene was observed in MUO, MHO, MUNW and MHNW, respectively.

Conclusion

Normal-weight individuals with metabolic unhealthy status are at higher risk for cardiovascular diseases than obese individuals with metabolically healthy status. The genotype frequencies of obesity-risk allele AA of FTO gene were higher in obesity phenotypes than metabolic phenotypes.

Impact of metabolically healthy obesity on carotid intima-media thickness - The Brazilian Longitudinal Study of Adult Health

BACKGROUND AND AIMS

Obesity increases the risk of metabolic abnormalities, which contributes to elevated cardiovascular risk. However, the independent role of obesity in the development of cardiovascular disease is still debatable. There are individuals with an obesity phenotype without metabolic abnormalities: "metabolically healthy obesity" (MHO). This study evaluates the association between MHO and carotid intima-media thickness (CIMT), an early marker of subclinical atherosclerosis.

METHODS AND RESULTS

This is a cross-sectional analysis of the baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We used a strict definition to classify MHO: body mass index ≥30 kg/m² and meeting none of the four metabolic syndrome criteria. Data from 10,335 participants were analyzed. The obesity prevalence in our population was 21.2% (n = 2191). The prevalence of MHO was 5.6% (n = 124). When individuals were stratified according to metabolic health, we found the metabolically healthy individuals were younger, more likely to be women and never smokers. The mean CIMT of the sample was 0.81 mm (±0.20). The mean CIMT of the metabolically healthy subsample was 0.70 mm (±0.13) in individuals without obesity and 0.76 mm (±0.13) in individuals with obesity (p < 0.001). The mean CIMT of the metabolically unhealthy subsample was 0.81 mm (±0.20) in individuals without obesity and 0.88 mm (±0.20) in individuals with obesity (p < 0.001). These findings remained essentially unchanged after multivariate adjustment for confounding factors.

CONCLUSION

The concept of MHO, even with the strict definition, seems inadequate, as even in this population, obesity is associated with higher CIMT levels.

Metabolically healthy obesity: facts and fantasies

Although obesity is typically associated with metabolic dysfunction and cardiometabolic diseases, some people with obesity are protected from many of the adverse metabolic effects of excess body fat and are considered "metabolically healthy." However, there is no universally accepted definition of metabolically healthy obesity (MHO). Most studies define MHO as having either 0, 1, or 2 metabolic syndrome components, whereas many others define MHO using the homeostasis model assessment of insulin resistance (HOMA-IR). Therefore, numerous people reported as having MHO are not metabolically healthy, but simply have fewer metabolic abnormalities than those with metabolically unhealthy obesity (MUO). Nonetheless, a small subset of people with obesity have a normal HOMA-IR and no metabolic syndrome components. The mechanism(s) responsible for the divergent effects of obesity on metabolic health is not clear, but studies conducted in rodent models suggest that differences in adipose tissue biology in response to weight gain can cause or prevent systemic metabolic dysfunction. In this article, we review the definition, stability over time, and clinical outcomes of MHO, and discuss the potential factors that could explain differences in metabolic health in people with MHO and MUO - specifically, modifiable lifestyle factors and adipose tissue biology. Better understanding of the factors that distinguish people with MHO and MUO can produce new insights into mechanism(s) responsible for obesity-related metabolic dysfunction and disease.

Metabolically Healthy Obesity and Bariatric Surgery

A peculiar category of persons with obesity lacking common metabolic disturbances has been depicted and termed as metabolically healthy obesity (MHO). Yet, although MHO patients are free of obesity-associated complications, they might not be entirely precluded from developing cardio-metabolic disorders. Among patients with morbid obesity (MO) who are referred to bariatric surgery, a subset of metabolically healthy MO (MHMO) has been identified and the question arises if these patients would benefit from surgery in terms of mitigating the peril of cardio-metabolic complications. We revisited the pathophysiological mechanisms that define MHO, the currently available data on the cardio-metabolic risk of these patients and finally we reviewed the benefits of bariatric surgery and the urge to better characterize MHMO before submission to surgery.

Metabolically Healthy Obesity

Obesity contributes to reduced life expectancy, impaired quality of life, and disabilities, mainly in those individuals who develop cardiovascular diseases, type 2 diabetes, osteoarthritis, and cancer. However, there is a large variation in the individual risk to developing obesity-associated comorbid diseases that cannot simply be explained by the extent of adiposity. Observations that a proportion of individuals with obesity have a significantly lower risk for cardiometabolic abnormalities led to the concept of metabolically healthy obesity (MHO). Although there is no clear definition, normal glucose and lipid metabolism parameters-in addition to the absence of hypertension-usually serve as criteria to diagnose MHO. Biological mechanisms underlying MHO lower amounts of ectopic fat (visceral and liver), and higher leg fat deposition, expandability of subcutaneous adipose tissue, preserved insulin sensitivity, and beta-cell function as well as better cardiorespiratory fitness compared to unhealthy obesity. Whereas the absence of metabolic abnormalities may reduce the risk of type 2 diabetes and cardiovascular diseases in metabolically healthy individuals compared to unhealthy individuals with obesity, it is still higher in comparison with healthy lean individuals. In addition, MHO seems to be a transient phenotype further justifying therapeutic weight loss attempts-even in this subgroup-which might not benefit from reducing body weight to the same extent as patients with unhealthy obesity. Metabolically healthy obesity represents a model to study mechanisms linking obesity to cardiometabolic complications. Metabolically healthy obesity should not be considered a safe condition, which does not require obesity treatment, but may guide decision-making for a personalized and risk-stratified obesity treatment.

Beta-Cell Function, Self-rated Health, and Lifestyle Habits in 64-Year-Old Swedish Women with Metabolically Healthy Obesity Phenotype

Background

A subset of obese individuals do not present metabolic abnormalities that commonly define the metabolic syndrome (MetS). This is referred to as a metabolically healthy obese (MHO) phenotype. The aim of the present study was to evaluate the prevalence of the MHO phenotype and its relationship with beta cell dysfunction by measuring C-peptide and proinsulin, anthropometric-, metabolic- and lipid appearance, as well as lifestyle behaviors and self-rated health in a cohort of 64-year-old Swedish women.

Methods

The National Cholesterol Education Program definition was used to assess MetS. We defined normal weight as body mass index (BMI) 18.5–24.9 kg/m² and obesity as BMI ≥30 kg/m² to categorize participants as metabolically healthy normal weight, MHO, and metabolically unhealthy obese.

Results

The MHO phenotype represented 36.3% of obese participants and 16.3% of total participants. The MHO group were at greater risk of having proinsulin levels >11 pmol/L, indicating impaired beta cell function. Further, homeostatic model assessment for insulin resistance, fasting plasma levels of insulin, and C-peptide showed significant trends, with the MHO phenotype group having intermediate levels among three groups. Health behaviors such as leisure time physical activity and alcohol intake were also intermediate in individuals with the MHO phenotype.

Conclusion

In this study, we demonstrate that over a third of the obese women in our sample were MHO. Further, women with the MHO phenotype showed intermediate profiles considering beta cell function and insulin resistance, as well as metabolic variables, and tended to rate their general health as worse than otherwise similar individuals of normal weight.

Association of metabolically healthy obesity and elevated risk of coronary artery calcification: a systematic review and meta-analysis

Background

Metabolically healthy obesity (MHO) is defined as obesity with less than two parameters of metabolic abnormalities. Some studies report that MHO individuals show similar risk of cardiovascular disease (CVD) compared with metabolically healthy non-obese (MHNO) individuals, but the results are conflicting. Coronary artery calcium (CAC) reflects the extent of coronary atherosclerosis and is a useful tool to predict future risk of CVD. The objective of this meta-analysis was to investigate whether MHO is associated with elevated risk of CAC.

Method

We searched Cochrane, PubMed, and Embase up to April 19, 2019. Prospective cohort and cross-sectional studies examining the association between MHO subjects and CAC were included with MHNO as the reference. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random-effect models. Subgroup analysis and meta-regression were applied to define possible sources of heterogeneity. We conducted this research following a pre-established protocol registered on PROSPERO (CRD 42019135006).

Results

A total of nine studies were included in this review and six studies with 23,543 participants were eligible for the meta-analysis. Compared with MHNO subjects, MHO had a higher odds of CAC (OR 1.36, 95% CI [1.11 to 1.66]; I² = 39%). In the subgroup analysis, the risk associated with MHO participants was significant in cohort studies (OR = 1.47, 95% CI [1.15,1.87], I² = 0%), and borderline significant in cross-sectional studies. The risk of CAC was also significant in MHO participants defined by Adult Treatment Panel III (ATP III) (OR = 1.55, 95% CI [1.25,1.93], I² = 0%). The univariate meta-regression model showed that age and smoking status were possible effect modifiers for MHO and CAC risk.

Conclusion

Our meta-analysis showed that MHO phenotypes were associated with elevated risk of CAC compared with MHNO, which reflects the extent of coronary atherosclerosis. People with obesity should strive to achieve normal weight even when only one metabolic abnormality is present.

Angiogenesis in obesity

PURPOSE

Angiogenesis is considered as a major progenitor in the progression of obesity. The current manuscript enumerates the extrinsic role of angiogenesis in obesity.

RESULT

High caloric diet and lack of physical exercise are the most common causes of obesity and related metabolic conditions. A grossly elevated levels of fat in adipose tissue escalate certain complications which further worsen the state of obesity. Enlargement of white adipose tissue (WAT), deposition of fat mass, proliferation of endothelial cells, production of inflammatory cytokines induces the formation of denovo capillaries from parent microvasculature. Also, several intracellular signaling pathways precipitate obesity. Though, angiostatic molecules (endostatin, angiostatin and TNP-470) have been designed to combat obesity and associated complications.

CONCLUSION

Adipose tissue trigger growth of blood capillaries, and in turn adipose tissue endothelial cells promote pre-adipocyte proliferation. Modulation of angiogenesis and treatment with angiostatic substances may have the potential to impair the progression of obesity.

Metabolic Health, Insulin, and Breast Cancer: Why Oncologists Should Care About Insulin

Studies investigating the potential link between adult pre-menopausal obesity [as measured by body mass index (BMI)] and triple-negative breast cancer have been inconsistent. Recent studies show that BMI is not an exact measure of metabolic health; individuals can be obese (BMI > 30 kg/m²) and metabolically healthy or lean (BMI < 25 kg/m²) and metabolically unhealthy. Consequently, there is a need to better understand the molecular signaling pathways that might be activated in individuals that are metabolically unhealthy and how these signaling pathways may drive biologically aggressive breast cancer. One key driver of both type-2 diabetes and cancer is insulin. Insulin is a potent hormone that activates many pathways that drive aggressive breast cancer biology. Here, we review (1) the controversial relationship between obesity and breast cancer, (2) the impact of insulin on organs, subcellular components, and cancer processes, (3) the potential link between insulin-signaling and cancer, and (4) consider time points during breast cancer prevention and treatment where insulin-signaling could be better controlled, with the ultimate goal of improving overall health, optimizing breast cancer prevention, and improving breast cancer survival.

Association of Serum 25-Hydroxyvitamin D Level With Metabolic Phenotypes of Obesity in Children and Adolescents: The CASPIAN-V Study

Background and Objective: Different metabolic phenotypes of obesity are related to cardiometabolic risk factors in children and adolescents. Vitamin D, as one important factor, could be related to different subgroups of metabolic obesity and might affect metabolic disorders. The purpose of this study was to evaluate the relationship between serum 25-hydroxyvitamin D concentration and subsets of metabolic phenotypes of obesity in children and adolescents. Methods: This nationwide cross-sectional study was conducted in the framework of the fifth survey of a national surveillance program, the CASPIAN study. Overall, 2,594 students aged 7-18 years were assessed for 25-hydroxyvitamin D status. Metabolic syndrome (MetS) was defined according to the ATP III criteria modified for the pediatric age group. Participants were classified into four metabolic phenotypes of obesity according to categories of the BMI and metabolic status: "metabolically healthy obese" (MHO), "metabolically non-healthy non-obese" (MNHNO), "metabolically non-healthy obese" (MNHO), and "metabolically healthy non-obese" (MHNO). Multinomial logistic regression analysis was performed for evaluating the association of 25-hydroxyvitamin D status with different metabolic phenotypes of obesity. Results: In this study, 85.2% of participants were classified as MHNO, 11.0 % as MHO, 2.5% as MNHNO, and 1.3% as MNHO. The frequency of hypovitaminosis D was more prevalent in MNHO (85.3%) than in other phenotypes (MHNO: 70%; MHO: 76.5%; MNHNO: 78.1%, respectively; p < 0.05). In the multivariate model, hypovitaminosis D significantly increased the odds of being MHO (OR: 1.46; 95% CI: 1.07-1.77) and MNHO (OR: 2.89; 1.05-8.31) compared to the healthy group. Likewise, in multivariate model, per each unit (ng/mL) increment in 25-hydroxyvitamin D concentration, the odds of MNHNO and MNHO decreased significantly by 7% (OR: 0.93; 0.91-0.96) and 6% (OR: 0.94; 0.91-0.98) respectively. Conclusion: Our results support the hypothesis that 25-hydroxyvitamin D concentration is associated with metabolic obesity phenotypes. Longitudinal studies are necessary to assess the clinical impacts of this finding.

Metabolic Health-The Role of Adipo-Myokines

Obesity is now a worldwide epidemic. In recent years, different phenotypes of obesity, ranging from metabolically healthy normal weight to metabolically unhealthy obese, were described. Although there is no standardized definition for these phenotypes or for metabolic health, the influence of lifestyle and early-life factors is undisputed. In this context, the ratio of muscle-to-fat tissue seems to play a crucial role. Both adipose tissue and skeletal muscle are highly heterogeneous endocrine organs secreting several hormones, with myokines and adipokines being involved in local autocrine/paracrine interactions and crosstalk with other tissues. Some of these endocrine factors are secreted by both tissues and are, therefore, termed adipo-myokines. High (cardiorespiratory) fitness as a surrogate parameter for an active lifestyle is epidemiologically linked to “better” metabolic health, even in the obese; this may be partly due to the role of adipo-myokines and the crosstalk between adipose and muscle tissue. Therefore, it is essential to consider (cardiovascular) fitness in the definition of metabolically healthy obese/metabolic health and to perform longitudinal studies in this regard. A better understanding of both the (early-life) lifestyle factors and the underlying mechanisms that mediate different phenotypes is necessary for the tailored prevention and personalized treatment of obesity.

[Prevalence of metabolic health in Mallorca obese patients]

Introduction

Aims: to assess the prevalence of metabolic health in Mallorca obese patients. Methods: participants were classified in metabolically healthy obese (MHO) and metabolically non-healthy obese (MNHO). Food, toxic and lifestyle habits, time of obesity evolution, breastfeeding, obesity in childhood and family history of obesity and diabetes mellitus, as well as glycemia, total cholesterol, HDL-cholesterol and triglyceridemia were evaluated in 457 obese patients. Results: prevalence of MHO was 49.2% and that of MNHO was 50.8%. MHO phenotype decreased with age. All patients showed inadequate habits. Consumption of fruits, salads and vegetables, tobacco and physical activity were similar between both groups; 37.4% of patients consumed sugary sweet drinks, and 52.9% consumed alcohol, higher in MNHO (4.3%) than in MHO (0.4%). MNHO showed higher values of BMI, abdominal circumference, fat percentage and visceral fatty index, as well as all metabolically studied outcomes. Conclusions: more than half of assessed obese population showed metabolic complications, but all obese population showed similar inadequate food and lifestyle habits. Increase of age, low educational level, years of obesity evolution, and visceral localization of fat are associated with a metabolically non-healthy status. Criteria to define and typify the metabolic state of obese subjects should be unified.