Changes in body size phenotypes from childhood to adulthood and the associated cardiometabolic outcomes

AIM

To examine the effects of changes in body size phenotypes between childhood and adulthood on risks of diabetes and left ventricular hypertrophy (LVH) in adulthood.

METHODS

We included 3,351 individuals who participated as both children and adults in the Bogalusa Heart Study.

RESULTS

Compared with participants with persistently metabolically healthy normal weight (MHNW) from childhood to adulthood, MHNW children who became metabolically unhealthy in adulthood had increased diabetes burden and LVH risk in adulthood; Metabolically unhealthy normal weight (MUNW) children who became MHNW or metabolically healthy obese (MHO) as adults and individuals with persistent MHO from childhood to adulthood were not at increased risks of diabetes or LVH. The risks were increased if MHO during childhood transitioned to metabolically unhealthy obesity (MUO) by adulthood or MUO stayed from childhood to adulthood. MUO children who became MHO or MHNW as adults had decreased diabetes burden and LVH risk in adulthood.

CONCLUSIONS

Individuals maintained MHO from childhood to adulthood and MUNW children who became MHO as adults had a diabetes burden and LVH risk similar to individuals with persistent MHNW. Progression to metabolically unhealthy status and maintenance of metabolically unhealthy status, regardless of childhood BMI status, were associated with increased cardiometabolic outcomes.

Prevalence of liver cirrhosis based on the metabolic health and weight criteria: Report from the Korea National Health and Nutrition Examination Survey (KNHANES) data analysis

BACKGROUND

Recent studies have proposed two distinctive types of obesity, metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUHO), based on various physiological factors. This study sought to explore the relationship between the metabolic obesity types and the incidence of liver cirrhosis (LC) in a large nationally-representative population.

METHODS

Data on 27,629 adults with MHO or MUHO, were analyzed from the Korea National Health and Nutrition Examination Survey (KNHANES) obtained from 2015 through 2019. Four categories of metabolic health and weight (MHW) were generated for analysis: (1) MHO, (2) MUHO, (3) Metabolically unhealthy normal weight (MUHNW), and (4) Metabolically healthy normal weight (MHNW). Statistical analyzes were performed with univariate and multivariate logistic regression.

RESULTS

The prevalence of LC did not show statistically significant differences among the MHW categories: 0.5% in MHO, 0.4% in MUHO, 0.2% in MHNW, and 0.3% in MUHNW. The unadjusted analysis showed a significant association between self-reported LC and MUHO, but this association was not evident in the adjusted analysis. In the adjusted analysis of the prevalence of laboratory LC, a significant association emerged in the MUHO group, followed in descending order of magnitude by the MHO and MUHNW groups. A favorable fasting blood glucose level was the only factor associated with increased prevalence of reported LC in MUHO.

CONCLUSIONS

The study demonstrated a difference in the prevalence of LC between MHO and MUHO. Our study concludes that the MHO phenotype is a transient status with regard to metabolic abnormalities, and caution is necessary when evaluating MHO.

Independent and joint effects of body mass index and metabolic health in mid- and late-life on all-cause mortality: a cohort study from the Swedish Twin Registry with a mean follow-up of 13 Years

BACKGROUND

There is robust evidence that in midlife, higher body mass index (BMI) and metabolic syndrome (MetS), which often co-exist, are associated with increased mortality risk. However, late-life findings are inconclusive, and few studies have examined how metabolic health status (MHS) affects the BMI-mortality association in different age categories. We, therefore, aimed to investigate how mid- and late-life BMI and MHS interact to affect the risk of mortality.

METHODS

This cohort study included 12,467 participants from the Swedish Twin Registry, with height, weight, and MHS measures from 1958-2008 and mortality data linked through 2020. We applied Cox proportional hazard regression with age as a timescale to examine how BMI categories (normal weight, overweight, obesity) and MHS (identification of MetS determined by presence/absence of hypertension, hyperglycemia, low HDL, hypertriglyceridemia), independently and in interaction, are associated with the risk of all-cause mortality. Models were adjusted for sex, education, smoking, and cardiovascular disease.

RESULTS

The midlife group included 6,252 participants with a mean age of 59.6 years (range = 44.9-65.0) and 44.1% women. The late-life group included 6,215 participants with mean age 73.1 years (65.1-95.3) and 46.6% women. In independent effect models, metabolically unhealthy status in midlife increased mortality risks by 31% [hazard ratio 1.31; 95% confidence interval 1.12-1.53] and in late-life, by 18% (1.18;1.10-1.26) relative to metabolically healthy individuals. Midlife obesity increased the mortality risks by 30% (1.30;1.06-1.60) and late-life obesity by 15% (1.15; 1.04-1.27) relative to normal weight. In joint models, the BMI estimates were attenuated while those of MHS were less affected. Models including BMI-MHS categories revealed that, compared to metabolically healthy normal weight, the metabolically unhealthy obesity group had increased mortality risks by 53% (1.53;1.19-1.96) in midlife, and across all BMI categories in late-life (normal weight 1.12; 1.01-1.25, overweight 1.10;1.01-1.21, obesity 1.31;1.15-1.49). Mortality risk was decreased by 9% (0.91; 0.83-0.99) among those with metabolically healthy overweight in late-life.

CONCLUSIONS

MHS strongly influenced the BMI-mortality association, such that individuals who were metabolically healthy with overweight or obesity in mid- or late-life did not carry excess risks of mortality. Being metabolically unhealthy had a higher risk of mortality independent of their BMI.

Metabolically healthy versus unhealthy obese phenotypes in relation to hypertension incidence; a prospective cohort study

Background

Although obesity increases the risk of hypertension, the effect of obesity based on metabolic status on the incidence of hypertension is not known. This study aimed to determine the association between obesity phenotypes including metabolically unhealthy obesity (MUO) and metabolically healthy obesity (MHO) and the risk of hypertension incidence.

Methods

We conducted a prospective cohort study on 6747 adults aged 35–65 from Ravansar non-communicable diseases (RaNCD) study. Obesity was defined as body mass index above 30 kg/m² and metabolically unhealthy was considered at least two metabolic disorders based on the International Diabetes Federation criteria. Obesity phenotypes were categorized into four groups including MUO, MHO, metabolically unhealthy non obesity (MUNO), and metabolically healthy non obesity (MHNO). Cox proportional hazards regression models were applied to analyze associations with hypertension incidence.

Results

The MHO (HR: 1.37; 95% CI: 1.03–1.86) and MUO phenotypes (HR: 2.44; 95% CI: 1.81–3.29) were associated with higher hypertension risk compared to MHNO. In addition, MUNO phenotype was significantly associated with risk of hypertension incidence (HR: 1.65; 95% CI: 1.29–2.14).

Conclusions

Both metabolically healthy and unhealthy obesity increased the risk of hypertension incidence. However, the increase in metabolically unhealthy phenotype was higher.

Metabolically healthy obesity: Is it really healthy for type 2 diabetes mellitus?

Metabolically healthy obese (MHO) individuals are reported to have a lower risk of developing cardiovascular diseases in comparison with individuals with metabolic syndrome. However, the association between MHO and type 2 diabetes (T2DM) is still controversial. Some studies indicated that MHO is a favorable phenotype for T2DM, but more studies showed that MHO individuals have an increased risk of developing T2DM compared with metabolically healthy normal-weight individuals, especially among those who would acquire metabolically unhealthy obesity. This has been supported by finding insulin resistance and low-grade inflammatory responses in MHO individuals with a tendency for impaired beta-cell dysfunction. Studies also showed that liver fat accumulation increased the risk of incidence of T2DM in MHO. Here, we reviewed current literature on the relationship between MHO and T2DM, discussed the determinants for the development of diabetes in MHO, and summarized the measures for the prevention of T2DM in MHO.

Wrist circumference as a novel predictor of transition from metabolically healthy to unhealthy phenotype in overweight/obese adults: a gender-stratified 15.5-year follow-up

BACKGROUND

Individuals with transition from metabolically healthy overweight/obese (MHO) to metabolically unhealthy overweight/obese (MUO) phenotype are significantly predisposed to greater risks of cardiovascular events compared to those with a persistent MHO phenotype. The aim of this study was to evaluate the predictive performance of wrist circumference for this transition in adults over a 15.5-year follow-up.

METHODS

We included 309 males and 821 females with the age of ≥18 years old, body mass index ≥25 kg/m², and metabolically healthy status according to the criteria of the Joint Interim Statement. The incidence of MUO phenotype was evaluated for each gender, across tertiles wrist circumference, using Cox-proportional hazard models.

RESULTS

The overall rate of transition from MHO to MUO phenotype was 87.1% in males and 77.5% in females. The hazard ratios (HRs) with 95% CI across second and third tertiles of wrist circumference were 0.89 (0.64-1.24) and 1.31 (0.99-1.73) in men (P for trend =0.027); and 1.34 (1.09-1.66) and 1.61 (1.30-2.00) in women (P for trend <0.001), respectively. After multivariable adjustment, HRs across second and third tertiles of wrist circumference were 0.92 (0.64-1.32) and 1.18 (0.83-1.67) in males (p for trend =0.352), and 1.32 (1.05-1.65) and 1.34 (1.06-1.96) in females (p for trend =0.025), respectively.

CONCLUSIONS

Wrist circumference significantly predicts the transition from MHO to MUO phenotype in adults of both genders. However, it is an independent predictor of the transition only in females. Future studies are warranted to clarify the role of wrist circumference mechanisms on metabolic risk deterioration.

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.

Obesity phenotypes and their relationships with atrial fibrillation

Background

This study assessed the associations of metabolic obesity phenotypes with the risk of atrial fibrillation (Afib).

Methods

This prospective cohort study categorized Taiwanese adults according to their body mass index (BMI) and metabolic health status at baseline. We assigned the participants to the underweight (BMI < 18.5 kg/m²), normal weight (BMI = 18.5-23.9 kg/m²), and overweight/obesity groups (BMI ≥ 24 kg/m²). Metabolically healthy was defined as absence of hypertension, diabetes, and hyperlipidemia and the presence of healthy metabolic profiles.

Results

In total, 5,742 adults were included. During a median follow-up of 13.7 years, 148 patients developed Afib. Compared to the metabolically healthy normal weight group, the risk of Afib was significantly higher than those in the metabolically unhealthy overweight/obesity (hazard ratio = 2.20, 95% confidence interval [1.12-4.33]) and metabolically unhealthy normal weight groups (HR = 2.64, 95% CI [1.34-5.17]). Additionally, the point estimate suggested a 1.97-fold greater risk among the metabolically healthy overweight/obesity group, although this difference was not significant given the wide confidence interval (HR = 1.97, 95% CI [0.80-4.86]).

Conclusion

Our results demonstrated the relationships of metabolic health and weight regarding the risk of Afib in Taiwanese adults. The Afib risk among metabolic and obesity phenotypes is associated with a metabolically unhealthy status. A trend toward a higher Afib risk with obesity among metabolically healthy subjects was observed. However, the result was not robust and it still suggested further study.

Metabolically healthy obesity and unhealthy normal weight rural adults in Xinjiang: prevalence and the associated factors

BACKGROUND

This study aimed to describe the prevalence of metabolically healthy obesity (MHO) and metabolically unhealthy normal weight (MUNW) rural adults in Xinjiang and to explore their influencing factors.

METHODS

We selected 13,525 Uyghur, Kazakh and Han participants in Kashi, Yili and Shihezi areas in Xinjiang from 2009 to 2010. Weight status was classified according to body mass index. Metabolic phenotype was further defined based on the National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The prevalence of normal weight, overweight, and obesity were 51.6, 30.2, and 14.4%, respectively. The mean age of the population was 45.04 years. The prevalence of MHO was 5.5% overall and was 38.5% among obese participants. The prevalence of MUNW was 15.5% overall and was 30.1% among normal weight participants. A metabolically healthy phenotype among obese individuals was positively associated with females and vegetable consumption ≥4 plates per week. However, this was inversely associated with higher age, red meat consumption ≥2 kg per week, and larger waist circumference (WC). Conversely, a metabolically unhealthy phenotype among normal-weight individuals was positively associated with higher age, red meat consumption ≥2 kg per week, and larger WC; this was however inversely associated with vegetable consumption ≥4 plates per week.

CONCLUSIONS

The prevalence of MHO among obese adults in Xinjiang is higher than that of Han adults, while the prevalence of MUNW among normal weight adults is lower than that among Han adults. In obese and normal weight participants, higher age, more red meat consumption, and larger WC increase the risk of metabolic abnormality, and more vegetable consumption reduces the risk of metabolic abnormality.

Obesity measures, metabolic health and their association with 15-year all-cause and cardiovascular mortality in the SAMINOR 1 Survey: a population-based cohort study

Background

The mortality of metabolic-obesity phenotypes has been thoroughly studied, but it is not known if or how the association between mortality and body mass index (BMI), waist circumference or a body shape index (ABSI) differ in strata of cardiometabolic health status.

Methods

We linked data on 12,815 men and women aged 36–79 years from the SAMINOR 1 Survey with mortality data from the Norwegian Cause of Death Registry. We defined metabolically healthy and unhealthy as having zero and ≥ 1, respectively, of the following: MetS, pre-existing diabetes or cardiovascular disease (CVD), or prescribed drugs for high blood pressure, hyperglycaemia or dyslipidaemia. We defined general and abdominal obesity as BMI ≥ 30 kg/m² and waist circumference ≥ 88 cm (women) or 102 cm (men), respectively, and cross-classified these categories with metabolic status to create metabolically healthy non-obese and obese (MHNO and MHO) and metabolically unhealthy non-obese and obese (MUNO and MUO) phenotypes. We used Cox regression to estimate the hazard ratio (HR) for all-cause and CVD mortality for 1) the four phenotypes and 2) BMI, waist circumference and ABSI fitted with restricted cubic splines. We adjusted for age and lifestyle, and tested for interactions with sex and metabolic status (only continuous measures).

Results

The MHO phenotype was present in 7.8% of women and 5.8% of men. During a median follow-up of 15.3/15.2 years, 596/938 women/men had died, respectively. The MUNO and MUO groups had higher mortality than the MHNO group. Sex and phenotypes interacted with respect to CVD mortality: relative to the MHNO group, the MHO group had an adjusted HR (95% confidence interval) for CVD mortality of 1.05 (0.38–2.88) in women and 2.92 (1.71–5.01) in men. We found curvilinear associations between BMI/waist circumference and all-cause mortality irrespective of metabolic status. Corresponding relationships with CVD mortality were linear and the slope differed by sex and metabolic status. ABSI was linearly and positively associated with all-cause and CVD mortality in men.

Conclusion

The relationships between BMI, waist circumference or ABSI and mortality differed by sex, metabolic status and cause of death. Poor metabolic health substantially increases mortality regardless of obesity status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02288-9.

Influence of dietary patterns on the metabolically healthy obesity phenotype: A systematic review

AIMS

In many individuals (35%) obesity is not accompanied by cardiometabolic disorders, a condition referred to as metabolically healthy obesity. Since the effectiveness of dietary interventions for this condition is not well established, this study reviews the influence of dietary patterns on the phenotype of metabolically healthy obesity in adults and elderly.

DATA SYNTHESIS

The review was carried out following the PRISMA guidelines and registered in the PROSPERO. The search was conducted in the MEDLINE, SCOPUS, Web of Science, Science Direct, LILACS, and SciELO databases. A total of 236 articles were identified, seven of which were selected for synthesis after application of the eligibility criteria.

CONCLUSIONS

The overall result found out in this synthesis was that the greater adherence to healthy eating patterns was considered a preventive to the transition from metabolically healthy obesity to metabolic unhealthy obese phenotypes, by improving metabolic health, and reducing the risk of cardiovascular disease and mortality from all causes. In contrast, unhealthy eating patterns resulted in increased inflammation and risks of developing noncommunicable diseases. This review indicates that adherence to healthy eating patterns may interfere with metabolic phenotypes of obesity and positively affect metabolically healthy obesity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020159783.

Are people with metabolically healthy obesity really healthy? A prospective cohort study of 381,363 UK Biobank participants

AIMS/HYPOTHESIS

People with obesity and a normal metabolic profile are sometimes referred to as having 'metabolically healthy obesity' (MHO). However, whether this group of individuals are actually 'healthy' is uncertain. This study aims to examine the associations of MHO with a wide range of obesity-related outcomes.

METHODS

This is a population-based prospective cohort study of 381,363 UK Biobank participants with a median follow-up of 11.2 years. MHO was defined as having a BMI ≥ 30 kg/m² and at least four of the six metabolically healthy criteria. Outcomes included incident diabetes and incident and fatal atherosclerotic CVD (ASCVD), heart failure (HF) and respiratory diseases.

RESULTS

Compared with people who were not obese at baseline, those with MHO had higher incident HF (HR 1.60; 95% CI 1.45, 1.75) and respiratory disease (HR 1.20; 95% CI 1.16, 1.25) rates, but not higher ASCVD. The associations of MHO were generally weaker for fatal outcomes and only significant for all-cause (HR 1.12; 95% CI 1.04, 1.21) and HF mortality rates (HR 1.44; 95% CI 1.09, 1.89). However, when compared with people who were metabolically healthy without obesity, participants with MHO had higher rates of incident diabetes (HR 4.32; 95% CI 3.83, 4.89), ASCVD (HR 1.18; 95% CI 1.10, 1.27), HF (HR 1.76; 95% CI 1.61, 1.92), respiratory diseases (HR 1.28; 95% CI 1.24, 1.33) and all-cause mortality (HR 1.22; 95% CI 1.14, 1.31). The results with a 5 year landmark analysis were similar.

CONCLUSIONS/INTERPRETATION

Weight management should be recommended to all people with obesity, irrespective of their metabolic status, to lower risk of diabetes, ASCVD, HF and respiratory diseases. The term 'MHO' should be avoided as it is misleading and different strategies for risk stratification should be explored.

Metabolically healthy obesity increases the prevalence of stroke in adults aged 40 years or older: Result from the China National Stroke Screening survey

Debate over the cardio-cerebrovascular risk associated with metabolically healthy obesity (MHO) continues. In this study we investigated the association of MHO with the risk of stroke among 221,114 individuals aged 40 years or older based on data from the China National Stroke Screening and Prevention Project (CNSSPP), a nationally representative cross-sectional study, during 2014 to 2015. Different metabolic health and obesity phenotypes were defined according to the Adult Treatment Panel III (ATP III) criteria, where obesity was defined as a body mass index (BMI) ≥28 kg/m². Logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for stroke risk associated with different metabolically healthy phenotypes. BMI was used to estimate the mediation effect for metabolic abnormalities to stroke. Compared with the metabolically healthy non-obesity (MHNO) group, individuals with MHO (adjusted OR: 1.21, 95% CI: 1.10,1.33), metabolically unhealthy non-obesity (MUNO) (adjusted OR:1.41, 95% CI: 1.36,1.46), or metabolically unhealthy obesity (MUO) (adjusted OR: 1.70, 95% CI: 1.61,1.80) were found to have an increased risk of stroke. The findings were confirmed robustly by various sensitivity analyses and subgroup analyses. Furthermore, obesity and metabolic abnormalities had an additive interaction for stroke risk with an attributable proportion (AP) of 14.0% in females. BMI played a partial mediating role with the proportion of the effect (PE) at 11.1% in the relationship between metabolic abnormalities and stroke. This study strengthens the evidence that management and interventions in the MHO population may contribute to the primary prevention of stroke.

Lifestyle factors associated with the transition from healthy to unhealthy adiposity among black South African adults over 10 years

BACKGROUND AND AIMS

Obesity is associated with an increasing prevalence of cardiovascular diseases in Africa, but some obese individuals maintain cardiometabolic health. The aims were to track metabolically healthy overweight or obesity (MHO) over 10 years in African adults and to identify factors associated with a transition to metabolically unhealthy overweight or obesity (MUO).

METHODS AND RESULTS

The participants were the South African cohort of the international Prospective Urban and Rural Epidemiological study. From the baseline data of 1937 adults, 649 women and 274 men were followed for 10 years. The combined overweight and obesity prevalence of men (19.2%-23.8%, p = .02) and women (58%-64.7%, p < .001), and the prevalence of the metabolic syndrome in all participants (25.4%-40.2%, p < .001) increased significantly. More than a quarter (26.2%) of the women and 10.9% of men were MHO at baseline, 11.4% of women and 5.1% of men maintained MHO over 10 years, while similar proportions (12.3% of women, 4.7% of men) transitioned to MUO. Female sex, age, and total fat intake were positively associated with a transition to MUO over 10 years, while physical activity was negatively associated with the transition. HIV positive participants were more likely to be MHO at follow-up than their HIV negative counterparts.

CONCLUSIONS

One in two black adults with BMI ≥25 kg/m² maintained MHO over 10 years, while a similar proportion transitioned into MUO. Interventions should focus on lower fat intakes and higher physical activity to prevent the transition to MUO.

Effects of short-term dietary restriction on plasma metabolites and the subcutaneous fat area according to metabolic status in obese individuals: a case-control study

BACKGROUND

Research elucidating the metabolic mechanisms that differentiate subtypes of obesity has been increasing. We aimed to investigate the effects of a 12-week dietary intervention on the metabolomic profiles of obese subjects.

METHODS

Subjects followed a 12-week dietary restriction protocol consisting of a 300 kcal/day reduction in their usual caloric intake. Twenty-nine obese subjects were included and divided into two groups: the metabolic status maintenance group (n = 17, controls) and the metabolic status improvement group (n = 12, tests). We analyzed the somatometric and biochemical parameters and performed ultra-performance liquid chromatography-mass spectrometry analysis of the plasma metabolites.

RESULTS

At 12 weeks, the fat percentage, whole fat area (WFA), subcutaneous fat area (SFA) at the L1 vertebra, and the levels of triglycerides, gamma-glutamyltransferase (gamma-GT), and leptin were markedly decreased in the metabolic status improvement group, while the level of high-density lipoprotein cholesterol increased compared with that in the metabolic status maintenance group. Metabolomic profiling at 12 weeks showed substantial differences in 4-aminobutyraldehyde (p = 0.005) and 4'-apo-β-carotenal (p = 0.024) between the two groups. Furthermore, an AUC value of 0.89 was obtained for the following seven featured biomarkers: triglycerides, gamma-GT, leptin, fat percentage, WFA, and SFA at the L1 vertebra, and 4-aminobutyraldehyde.

CONCLUSIONS

We demonstrated that 4-aminobutyraldehyde and related regional fat distribution parameters were strongly associated with obesity according to metabolic status. Thus, these biomarkers are potentially valuable in confirming the efficacy of short-term interventions and predicting metabolic status in obese individuals.

TRIALS REGISTRATION

This study was registered at ClinicalTrials.gov under NCT03135132 (registered 1 May 2017-retrospectively registered).

Metabolically Healthy Obesity and the Risk of Cardiovascular Disease in the General Population - Analysis of a Nationwide Epidemiological Database

BACKGROUND

Obesity and metabolic disorders frequently coexist, and both are established risk factors for cardiovascular disease (CVD). Although the phenotype of obesity without metabolic disorders, referred to as metabolically healthy obesity (MHO), is attracting clinical interest, the pathophysiological impact of MHO remains unclear.Methods and Results:Using the Japan Medical Data Center database, we studied 802,288 subjects aged ≥20 years without any metabolic disorders or a prior history of CVD. MHO, defined as obesity (body mass index ≥25 kg/m²) with no metabolic disorders, was observed in 9.8% of the study population. The subjects' mean (±SD) age was 42.8±9.4 years and 44.7% were men. The mean follow-up period was 1,126±849 days. Multivariable Cox regression analysis showed that MHO alone did not significantly increase the risk of any CVD. However, abdominal obesity alone increased the risk of heart failure and atrial fibrillation. Moreover, the coexistence of MHO and abdominal obesity increased the risk of myocardial infarction, angina pectoris, heart failure, and atrial fibrillation. The incidence of stroke was not associated with the presence of MHO and abdominal obesity.

CONCLUSIONS

Among individuals with no metabolic disorders, MHO alone did not significantly increase the subsequent CVD risk. However, individuals with comorbid MHO and abdominal obesity had a higher risk of myocardial infarction, angina pectoris, heart failure, and atrial fibrillation, suggesting the prognostic importance of abdominal obesity in subjects with MHO.

Obesity, metabolic health and omics: Current status and future directions

The growing obesity epidemic is becoming a major public health concern, and the associated costs represent a considerable burden on societies. Among the most common complications of severe obesity are the development of hypertension, dyslipidemia, type 2 diabetes, cardiovascular disease, and various types of cancer. Interestingly, some obese individuals have a favorable metabolic profile and appear to be somehow protected from the detrimental effects of excessive adipose tissue accumulation. These individuals remain normoglycemic, insulin sensitive, and hypotensive with proper blood lipid levels, despite their high body mass index and/or waist circumference. Multiple independent observations have led to the concept of the metabolically healthy obese (MHO) phenotype, yet no consensus has been reached to date regarding a universal definition or the main mechanism behind this phenomenon. Recent technological advances and the use of high-throughput analysis techniques have revolutionized different areas of biomedical research. A multi-omics approach, which is used to investigate changes at different molecular levels in an organism or tissue, may provide valuable insights into the interplay between the molecules or pathways and the roles of different factors involved in the mechanisms underlying metabolic health deterioration. The aim of this review is to present the current status regarding the use of omics technologies to investigate the MHO phenotype, as well as the results of targeted analyses conducted in MHO individuals.

Emotional states of different obesity phenotypes: a sex-specific study in a west-Asian population

BACKGROUND

The present study aimed to investigate the associations of obesity phenotypes with depression, anxiety, and stress symptoms among adults in the Tehran Lipid and Glucose Study (TLGS).

METHODS

Depression, anxiety, and stress levels of participants from the TLGS were examined among different obesity phenotypes in this cross-sectional study. Obesity was defined as body mass index (BMI) ≥30 kg/m², and metabolically unhealthy status based on having metabolic syndrome (MetS) or type 2 diabetes. Four obesity phenotypes were defined: 1) Metabolically Healthy Non-Obese (MHNO), 2) Metabolically Healthy Obese (MHO) 3) Metabolically Unhealthy Non-Obese (MUNO), and 4) Metabolically Unhealthy Obese (MUO). Emotional states of different obesity phenotypes were assessed by the Persian version of depression, anxiety, and stress scale-21 items (DASS-21). Ordinal logistic regression analysis was used to compare sex-specific odds ratios of depression, anxiety, and stress in different obesity phenotypes.

RESULTS

The mean age of 2469 men and women was 46.2 ± 15.9 and 45.6 ± 14.7, respectively. In total, women were more likely to experience higher levels of depression (30.5%), anxiety (44.2%), and stress (43.5%) symptoms compared to men. After adjusting for potential confounders, compared to MHNO men, the odds of experiencing higher anxiety levels were significantly greater in metabolically unhealthy men whether they were obese (OR: 1.78, 95% CI: 1.25-2.54; P = < 0.001) or non-obese (OR: 1.61, 95% CI: 1.17-2.21; P = < 0.001), and also in MUO women (OR: 1.73, 95% CI: 1.28-2.34; P = < 0.001) compared to MHNO women. Moreover, the odds of experiencing higher stress levels were significantly greater in MUNO men (OR: 1.40, 95% CI: 1.02-1.90; P = 0.04) compared to MHNO men and in MUO women (OR: 1.45, 95% CI: 1.07-1.96; P = 0.02) compared to MHNO women. No difference in depression levels was observed in either sex.

CONCLUSIONS

Our results showed that men and women with various obesity phenotypes experienced different anxiety and stress levels. While MUO women and all metabolically unhealthy men experienced more anxiety and stress levels than MHNO individuals, none of the obesity phenotypes were associated with depression. These findings provide insight into recognizing the psychological consequences of different phenotypes of obesity in both sexes and utilizing future health promotion planning.

Predictors of Metabolic Complications in Obese Indian Children and Adolescents

OBJECTIVE

To identify predictors of metabolic complications in obese Indian children and adolescents.

METHODS

This cross-sectional study included 282 obese children and adolescents [188 boys, mean (SD) age of 11.7 (3.1) y, body mass index standard deviation score (BMI SDS) 2.4 (0.6)] who underwent metabolic work-up (oral glucose tolerance test, SGPT, lipid profile) and adiposity assessment (waist circumference and Dual energy X-ray absorptiometry).

RESULTS

One hundred and fifteen subjects (40.8%) had no metabolic complication (metabolic healthy obesity) with similar prevalence across BMI SDS categories (38.8% for BMI SDS below 2, 42.1% for 2-3 and 40.4% for those above 3). Normal birth weight (odds ratio 3.2, 95% confidence interval 1.0-10.1, p = 0.04), negative family history of type 2 diabetes (odds ratio 1.81, 95% confidence interval 1.0-3.3, p = 0.04) and younger age [11.3 (3.1) y as against 12.1 (3.1) y, p = 0.03] were associated with metabolically healthy obesity. No difference in BMI SDS [2.4 (0.6) as against 2.4 (0.6), p = 0.7], waist circumference SDS [2.0 (0.7) as against 2.2 (0.9), p = 0.07], waist to height ratio [0.6 (0.05) as against 0.6 (0.05), p = 0.1], DXA derived fat percentage [48.6 (5.4)% as against 47.8% (5.2), p = 0.2], android to gynoid ratio [1.05 (0.1) as against 1.06 (0.1), p = 0.08] and fat mass index [13.8 (3.5) as against 13.8 (3.3), p = 0.9] was observed in the two groups.

CONCLUSIONS

A substantial proportion of obese children and adolescents do not develop metabolic complications. Birth weight and family history of type 2 diabetes are the only predictors of complications. Further exploration is needed to identify interventional targets.

A favorable metabolic profile in metabolically healthy obesity is associated with physical activity level rather than abdominal fat volume in Japanese males

[Purpose] To determine the potential factors for difference in metabolic profiles between metabolically healthy obesity and metabolically unhealthy obesity, we investigated the difference in abdominal fat volume, metabolic characteristics, and physical activity levels between metabolically healthy obesity and metabolically unhealthy obesity identified with cardiovascular disease risk factors in Japanese males. [Participants and Methods] Of 305 volunteers recruited, 130 obese males (age: 46.9 ± 8.9 years; body mass index: 29.6 ± 3.5 kg/m²) met the criteria for the study. They were divided into two groups; metabolically healthy obesity and metabolically unhealthy obesity according to cardiovascular disease risk factors including low-density lipoprotein cholesterol. Abdominal fat volumes were measured using magnetic resonance imaging. Cardiovascular disease risk factors and metabolic characteristics were evaluated by blood pressure and blood parameters. Physical activity levels were measured using an accelerometer. [Results] Despite the fact that metabolically healthy obesity had a more favorable metabolic profile than the metabolically unhealthy obesity, no significant differences in visceral and subcutaneous fat volumes were found between the two groups. Moreover, the metabolically healthy obesity had a significantly greater physical activity expenditure and moderate-to-vigorous physical activity level than the metabolically unhealthy obesity. [Conclusion] A more favorable metabolic profile in metabolically healthy obesity may be associated with physical activity level rather than abdominal fat volumes in Japanese males.

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.

Obesity, metabolic syndrome, and primary hypertension

Primary hypertension is the dominant form of arterial hypertension in adolescents. Disturbed body composition with, among other things, increased visceral fat deposition, accelerated biological maturation, metabolic abnormalities typical for metabolic syndrome, and increased adrenergic drive constitutes the intermediary phenotype of primary hypertension. Metabolic syndrome is observed in 15-20% of adolescents with primary hypertension. These features are also typical of obesity-related hypertension. Metabolic abnormalities and metabolic syndrome are closely associated with both the severity of hypertension and the risk of target organ damage. However, even though increased body mass index is the main determinant of blood pressure in the general population, not every hypertensive adolescent is obese and not every obese patient suffers from hypertension or metabolic abnormalities typical for metabolic syndrome. Thus, the concepts of metabolically healthy obesity, normal weight metabolically unhealthy, and metabolically unhealthy obese phenotypes have been developed. The risk of hypertension and hypertensive target organ damage increases with exposure to metabolic risk factors which are determined by disturbed body composition and visceral obesity. Due to the fact that both primary hypertension and obesity-related hypertension present similar pathogenesis, the principles of treatment are the same and are focused not only on lowering blood pressure, but also on normalizing body composition and metabolic abnormalities.

Epigenetic approach in obesity: DNA methylation in a prepubertal population which underwent a lifestyle modification

BACKGROUND

Metabolically healthy obesity (MHO) is a considerably controversial concept as it is considered a transitory condition towards the development of different pathologies (type 2 diabetes, insulin resistance, or cardiovascular disease). MHO is closely related to lifestyle and environmental factors. Epigenetics has become an essential biological tool to analyze the link between obesity and metabolic status. The aim of this study was to determine whether MHO status is conditioned by the DNA methylation (DNAm) of several genes related to lipid metabolism (lipoprotein lipase, retinoid X receptor alpha, liver X receptor, stearoyl-CoA desaturase, sterol regulatory element binding factor 1), and inflammation (LEP) in peripheral blood mononuclear cells (PBMCs) from 131 prepubertal subjects with MHO phenotype after lifestyle modifications with personalized Mediterranean diet (MedDiet) combined with a physical activity (PA) program.

RESULTS

The DNAm of all studied genes were significantly modified in the population after 12 months of lifestyle modifications (MedDiet and PA). In addition, associations were found between the DNAm studies and BMI, homeostatic model assessment of insulin resistance, monounsaturated fatty acid and polyunsaturated fatty acid, moderate-vigorous PA, fat mass, and adherence to MedDiet.

CONCLUSIONS

It was found that DNAm of genes related to lipid metabolism and inflammation are also present in childhood and that this methylation profile can be modified by interventions based on MedDiet and PA.

Effect of metabolically healthy obesity on the development of arterial stiffness: a prospective cohort study

Background

Metabolically healthy obesity (MHO) has been reported to be associated with the development of vascular damage by the carotid intima-media thickness, but the relationship between metabolic health and obesity phenotypes and arterial stiffness is still unknown. Our hypothesized that different metabolic health and obesity phenotypes might be associated with the development of arterial stiffness, and that subjects in MHO phenotype might not have increased risks of arterial stiffness compared with those in metabolically healthy nonobesity phenotype (MHNO), while metabolic unhealthy individuals might have increased risks of arterial stiffness.

Methods

A prospective cohort of 2076 participants (aged 36-48 years) who were enrolled in the Hanzhong Adolescent Hypertension Cohort Study in 2017 was analyzed in a cross-sectional analysis. A subgroup of 202 participants from 2005 to 2017 was selected by an isometric sampling method and was included in the final longitudinal analysis.

Results

We identified four metabolic health and obesity phenotypes for both the cross-sectional and longitudinal analyses as follows: MHNO, metabolically unhealthy nonobesity (MUNO), MHO, and metabolically unhealthy obesity (MUO). In the cross-sectional analysis, individuals with the MHO phenotype had the lowest brachial-ankle pulse wave velocity (baPWV) levels of the four phenotypes (P < 0.001), and participants with the MHO phenotype had a similar risk of arterial stiffness after fully adjustment [odds ratio (OR) = 0.99 (0.61-1.60)] as the MUNO subjects. Subjects with metabolically unhealthy status had a significantly higher risk of arterial stiffness than the MHNO individuals, particularly females (P < 0.005). In the longitudinal analysis, subjects with the MUNO and MUO phenotypes had a significantly higher risk of arterial stiffness than the MHNO individuals after adjustment for age and sex [OR = 5.21 (2.26-12.02), OR = 3.32 (1.18-9.32), respectively].

Conclusions

The MHO phenotype did not significantly increase the progression of arterial stiffness. Metabolically unhealthy individuals (MUNO, MUO), regardless of obesity status, showed a worse effect for the development of arterial stiffness, particularly females.

Trial registration

NCT02734472. Registered 12 April 2016 - Retrospectively registered, http:www.clinicaltrials.gov.