Obesity phenotype and cardiovascular changes

Differences in the levels of inflammatory markers between metabolically healthy obese and other obesity phenotypes in adults: A systematic review and meta-analysis

AIMS

The aim of this study was to systematically review and analyze differences in the levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) comparing metabolically healthy but obese (MHO) with metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), and metabolically unhealthy obese (MUO) subjects.

DATA SYNTHESIS

We searched PubMed, Embase, Web of Science, and Scopus for studies that matched the relevant search terms. Differences in inflammatory marker levels between MHO and the other three phenotypes were pooled as standardized mean differences (SMD) or differences of medians (DM) using a random-effects model. We included 91 studies reporting data on 435,007 individuals. The CRP levels were higher in MHO than in MHNO subjects (SMD = 0.63, 95% CI: 0.49, 0.76; DM = 0.83 mg/L, 95% CI: 0.56, 1.11). The CRP levels were higher in MHO than in MUNO subjects (SMD = 0.16, 95% CI: 0.05, 0.28; DM = 0.39 mg/L, 95% CI: 0.09, 0.69). The CRP levels were lower in MHO than in MUO individuals (SMD = -0.43, 95% CI: -0.54, -0.31; DM = -0.82 mg/L, 95% CI: -1.16, -0.48). The IL-6 levels in MHO were higher than in MHNO while lower than in MUO subjects. The TNF-α levels in MHO were higher than in MHNO individuals.

CONCLUSIONS

This review provides evidence that CRP levels in MHO are higher than in MHNO and MUNO subjects but lower than in MUO individuals. Additionally, IL-6 levels in MHO are higher than in MHNO but lower than in MUO subjects, and TNF-α levels in MHO are higher than in MHNO individuals.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO number: CRD42021234948.

Obesity, Cardiorespiratory Fitness, and Cardiovascular Disease

PURPOSE OF REVIEW

Obesity, generally defined by body mass index (BMI), is an established risk factor for the development of cardiovascular disease (CVD), while cardiorespiratory fitness (CRF) decreases risk. In chronic CVD, an obesity survival paradox in which higher BMI is associated with improved prognosis has been reported. This paper will examine the effect of obesity on CVD risk, explore obesity as a risk factor in patients with established CVD, and investigate the relationship between CRF, obesity, and CVD.

RECENT FINDINGS

Through metabolic and hemodynamic changes, obesity increases the risk for CVD and contributes to the development of other cardiovascular risk factors such as diabetes, dyslipidemia, and hypertension. Obesity is associated with metabolic, hormonal, and inflammatory changes that leads to atherosclerosis increasing the risk for coronary artery disease, and myocardial remodeling increasing the risk for heart failure. However, it has also been observed that overweight/obese patients with established CVD have a better prognosis when compared to non-obese individuals termed the obesity paradox. CRF is a vital component of health associated with improved cardiovascular outcomes and furthermore has been shown to markedly attenuate or nullify the relationship between obesity and CVD risk/prognosis. Increasing CRF mitigates CVD risk factors and improves overall prognosis in CVD regardless of obesity status.

Vascular Alterations Preceding Arterial Wall Thickening in Overweight and Obese Children

Background: Childhood obesity is linked to adverse cardiovascular outcomes in adulthood. This study aimed to assess the impact of childhood obesity on the vasculature and to investigate whether vascular alteration precedes arterial wall thickening in childhood. Methods: A total of 295 overweight (body mass index [BMI] 85th to 95th percentile, n = 30) and obese (BMI ≥ 95th percentile, n = 234) children aged 7–17 years and 31 normal-weight controls with similar age and gender were prospectively recruited. We assessed anthropometric data and laboratory findings, and measured the carotid intima–media thickness (IMT), carotid artery (CA) diameter, M-mode-derived arterial stiffness indices, and velocity vector imaging parameters, including the CA area, fractional area change, circumferential strain, and circumferential strain rate (SR). Results: The mean ± standard deviation age of the participants was 10.8 ± 2.1 years; 172 (58%) children were male. Regarding structural properties, there was no difference in the IMT between the three groups. The CA diameter was significantly increased in obese children, whereas the CA area showed a significant increase beginning in the overweight stage. Regarding functional properties, contrary to β stiffness and Young’s elastic modulus, which were not different between the three groups, the circumferential SR showed a significant decrease beginning in the overweight stage and was independently associated with BMI z-scores after adjusting for covariates. Conclusion: We have demonstrated that arterial stiffening and arterial enlargement precede arterial wall thickening, and that these vascular alterations begin at the overweight stage in middle childhood or early adolescence.

Metabolically healthy obesity and metabolically obese normal weight: a review

Despite the general relationship between obesity and its co-morbidities, there are both obese individuals who scarcely present the associated pathologies (metabolically healthy obese; MHO) and individuals who present obesity alterations despite having normal weight (metabolically obese normal weight; MONW). It is still difficult to define metabolically MHO and MONW individuals because different classifications have been used in the studies reported. Indeed, different inclusion criteria have been used to discriminate between metabolically healthy and metabolically unhealthy subjects. Due to this and other reasons, such as differences in ethnicity, genetics, and lifestyle of the populations, data concerning the prevalence of MHO and MONW are very variable. The main determinants of MHO are type of growth (hypertrophy or hyperplasia), anatomical location, inflammation of adipose tissue, ectopic fat accumulation, genetic factors, and lifestyles factors. In the case of MONW, the main determinants are genetic background and lifestyle factors. With regard to treatment, it is not clear whether MHO subjects would benefit from traditional lifestyle interventions, based on diet energy restriction and increased physical activity. For MONW subjects, there is still no specialized treatment, and the therapies are the same as those used in obese subjects.

Joint influences of obesity, diabetes, and hypertension on indices of ventricular remodeling: Findings from the community-based Framingham Heart Study

Introduction

Obesity, hypertension, and diabetes are independently associated with cardiac remodeling and frequently co-cluster. The conjoint and separate influences of these conditions on cardiac remodeling have not been investigated.

Materials and methods

We evaluated 5,741 Framingham Study participants (mean age 50 years, 55% women) who underwent echocardiographic measurements of left ventricular (LV) mass (LVM), LV ejection fraction (LVEF), global longitudinal strain (GLS), mitral E/e’, left atrial end-systolic (peak) dimension (LASD) and emptying fraction (LAEF). We used multivariable generalized linear models to estimate the adjusted-least square means of these measures according to cross-classified categories of body mass index (BMI; normal, overweight and obese), hypertension (yes/no), and diabetes (yes/no).

Results

We observed statistically significant interactions of BMI category, hypertension, and diabetes with LVM, LVEF, GLS, and LAEF (p for all 3-way interactions <0.01). Overweight and obesity (compared to normal BMI), hypertension, and diabetes status were individually and conjointly associated with higher LVM and worse GLS (p<0.01 for all). We observed an increase of 34% for LVM and of 9% for GLS between individuals with a normal BMI and without hypertension or diabetes compared to obese individuals with hypertension and diabetes. Presence of hypertension was associated with higher LVEF, whereas people with diabetes had lower LVEF.

Conclusions

Obesity, hypertension, and diabetes interact synergistically to influence cardiac remodeling. These findings may explain the markedly heightened risk of heart failure and cardiovascular disease when these factors co-cluster.

Association of dietary behaviors, biochemical, and lifestyle factors with metabolic phenotypes of obesity in children and adolescents

BACKGROUND AND AIMS

To examine the association of dietary behaviors, lifestyle, and biochemical factors with metabolic phenotypes of obesity among obese Iranian children and adolescents.

METHODS

This cross-sectional study was conducted within the framework of the fifth phase of CASPIAN study. Of 3840 students aged 7-18 years of 30 Iranian provinces, 408 subjects were diagnosed as obese; they were divided into metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) groups. Biochemical factors, anthropometric measures, dietary, and lifestyle habits were compared between groups.

RESULTS

Of the 408 obese subjects, 68 (16.7%) were the MUO; the remaining 340 (84.3%) fall in the MHO group. The MUO group had significantly higher systolic and diastolic BPs, FBS, TG, ALT, anthropometric measures, and lower HDL levels than MHO groups (all p-value < 0.05). The frequency of high birth weight (> 4000 gr) was significantly higher in the MUO group than the MHO group (p-value: 0.04). A higher percentage of individuals with breastfeeding duration ≥ 6 month was found in the MUO group (95.5% (95% CI 86.1-98.6%)) compared to MHO group (85.7% (95% CI 80.4-89.7%)) (p-value = 0.04). Among dietary and lifestyle-related behaviors, only the frequency of salty snack consumption and eating food according to the parents' request was significantly higher in the MUO group than the MHO group (p-value < 0.05).

CONCLUSION

Dietary habits and lifestyle factors may determine the obesity phenotypes in children and adolescents.

Does healthy obesity exist in the elderly? Findings from the Northern Shanghai Study

BACKGROUND AND AIMS

Metabolic unhealthiness and obesity are both associated with an increased risk of cardiovascular disease. We aimed to investigate the significance of metabolic unhealthiness and obesity in organ damages in a community-based elderly cohort.

METHODS AND RESULTS

A total of 3325 elderly participants (>65 years old) were recruited in northern Shanghai. Associations of metabolic status and obesity with organ damages were investigated. In all, 1317 (39.6%) participants were metabolically unhealthy and 481 (14.5%) were obese. Compared with metabolically healthy nonobese (MH-nonobese) individuals, metabolically healthy obese subjects had a greater left ventricular mass index (LVMI) and pulse wave velocity (PWV). Metabolically unhealthy subjects, regardless of their obesity status, had greater organ damage parameters including E/Ea, LVMI, PWV, and urine albumin-creatinine ratio (UACR) than MH-nonobese subjects (all P < 0.05). After multivariate adjustments, both metabolic unhealthiness and obesity increased the risk of left ventricular hypertrophy (LVH) (OR 1.31, 95% CI 1.10-1.57 and OR 1.63, 95% CI 1.30-2.04), diastolic dysfunction (OR 1.33, 95% CI 1.06-1.67 and OR 1.51, 95% CI 1.14-1.99), and lower extremity atherosclerosis (OR 1.44, 95% CI 1.11-1.85 and OR 2.01, 95% CI 1.49-2.70). Metabolic unhealthiness was also associated with arterial stiffness, microalbuminuria and chronic kidney disease (all P < 0.05). In a subgroup analysis, metabolic unhealthiness was associated with more organ damages in nonobese subjects, and obesity was associated with LVH and lower extremity atherosclerosis regardless of metabolic status.

CONCLUSION

Both obesity and metabolic unhealthiness were associated with organ damages. Metabolic unhealthiness was associated with more organ damages, especially in nonobese individuals. Even healthy obesity was significantly associated with cardiac and vascular impairment.

REGISTRATION NUMBER FOR CLINICAL TRIALS

NCT02368938.

Metabolically Healthy Obesity-Heterogeneity in Definitions and Unconventional Factors

The concept of heterogeneity among obese individuals in their risk for developing metabolic dysfunction and associated complications has been recognized for decades. At the origin of the heterogeneity idea is the acknowledgement that individuals with central obesity are more prone to developing type 2 diabetes and cardiovascular disease than those with peripheral obesity. There have been attempts to categorize subjects according to their metabolic health and degree of obesity giving rise to different obese and non-obese phenotypes that include metabolically unhealthy normal-weight (MUHNW), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). Individuals belonging to the MHO phenotype are obese according to their body mass index although exhibiting fewer or none metabolic anomalies such as type 2 diabetes, dyslipidemia, hypertension, and/or unfavorable inflammatory and fribinolytic profiles. However, some authors claim that MHO is only transient in nature. Additionally, the phenotype categorization is controversial as it lacks standardized definitions possibly blurring the distinction between obesity phenotypes and confounding the associations with health outcomes. To add to the discussion, the factors underlying the origin or protection from metabolic deterioration and cardiometabolic risk for these subclasses are being intensely investigated and several hypotheses have been put forward. In the present review, we compare the different definitions of obesity phenotypes and present several possible factors underlying them (adipose tissue distribution and cellularity, contaminant accumulation on the adipose tissue, dysbiosis and metabolic endotoxemia imposing on to the endocannabinoid tone and inflammasome, and nutrient intake and dietary patterns) having inflammatory activation at the center.

Metabolically Healthy, but Obese Individuals and Associations with Echocardiographic Parameters and Inflammatory Biomarkers: Results from the CARLA Study

INTRODUCTION

The research on heterogeneity among obese individuals has identified the metabolically healthy, but obese (MHO) phenotype as a distinct group that does not experience the typical cardiovascular-related diseases (CVD). It is unclear if this group differs with regard to preconditions for CVDs. Our aim was to assess differences in echocardiographic parameters and inflammatory biomarkers between MHO and metabolically healthy, normal weight individuals (MHNW).

METHODS

The analyses used data from 1412 elderly participants from a German population-based cohort study (CARLA), which collected detailed information on demographic, biochemical, and echocardiographic variables. Participants were subdivided into four groups (MHNW, MHO, MUNW (metabolically unhealthy, normal weight) and MUO (metabolically unhealthy, obese)) based on BMI≥30 kg/m² (obese or normal weight) and presence of components of the metabolic syndrome. The clinical characteristics of the 4 groups were compared with ANOVA or Chi-Square test, in addition to two linear regression models for 16 echocardiographic parameters. The difference in inflammatory biomarkers (hsCRP, IL-6 and sTNF-RI) between the groups was examined with a multinomial logistic regression model.

RESULTS

The MHO individuals were on average 64.2±8.4 years old, with a higher proportion of women (71.6%), low percentage of smokers, larger waist circumference (109.3±10.5 cm vs 89.1±10.8 cm, p<0.0001) and higher odds ratios for hsCRP, IL-6 and sTNF-RI compared to MHNW individuals. Linear regression models revealed greater left atrial (LA) diameter (2.73 (95% CI: 1.35-4.11) mm), LA volume (7.86 (95% CI: 2.88-12.83) mL), and left ventricular mass index (LVMI) (11.82 (95% CI: 4.43-19.22) g/m^1.7) in the MHO group compared to the MHNW group.

CONCLUSION

The MHO phenotype is associated with echocardiographic markers of cardiac remodeling (LA diameter, volume and LVMI) and higher odds ratios for inflammatory biomarkers.

Metabolically healthy general and abdominal obesity are associated with increased risk of hypertension

Metabolically healthy obesity refers to a subset of obese people with a normal metabolic profile. We aimed to explore the association between metabolically healthy and obesity status and risk of hypertension among Chinese adults from The Rural Chinese Cohort Study. This prospective cohort study enrolled 9137 Chinese adults without hypertension, type 2 diabetes or treatment for lipid abnormality at baseline (2007–2008) and followed up during 2013–2014. Modified Poisson regression models were used to examine the risk of hypertension by different metabolically healthy and obesity status, estimating relative risks (RR) and 95 % CI. During 6 years of follow-up, we identified 1734 new hypertension cases (721 men). After adjusting for age, sex, smoking and other confounding factors, risk of hypertension was increased with metabolically healthy general obesity (MHGO) defined by BMI (RR 1·75, 95 % CI 1·02, 3·00) and metabolically healthy abdominal obesity (MHAO) defined by waist circumference (RR 1·51, 95 % CI 1·12, 2·04) as compared with metabolically healthy non-obesity. The associations between metabolically healthy and obesity status and hypertension outcome were consistent after stratifying by sex, age, smoking, alcohol drinking and physical activity. Both MHGO and MHAO were associated with increased risk of hypertension. Obesity control programmes should be implemented to prevent or delay the development of hypertension in rural China.

Heterogeneity of obesity phenotypes in relation to cardiovascular risk

Obesity is associated with numerous metabolic disorders, the development and progression of a wide range of conditions and diseases, primarily cardiovascular disease and type 2 diabetes. One of the widely discussed phenomena of the association of obesity with cardiovascular diseases, their complications and mortality is the phenomenon of “heterogeneity of obesity phenotypes in relation to cardiovascular risk”. Currently, two main phenotypes have been identified — metabolically healthy and metabolically unhealthy obesity. At the same time, not only the expediency of separation, but also the existence of this phenotype is widely discussed today. The article provides an overview of existing approaches to the verification of metabolic phenotypes of obesity and data relating to the epidemiology and the association of metabolically healthy obesity with the risk of cardiovascular diseases and death, and also discusses the factors that determine the features of the obesity phenotype.

Heterogeneity of obesity phenotypes in relation to cardiovascular risk

Obesity is associated with numerous metabolic disorders, the development and progression of a wide range of conditions and diseases, primarily cardiovascular disease and type 2 diabetes. One of the widely discussed phenomena of the association of obesity with cardiovascular diseases, their complications and mortality is the phenomenon of “heterogeneity of obesity phenotypes in relation to cardiovascular risk”. Currently, two main phenotypes have been identified — metabolically healthy and metabolically unhealthy obesity. At the same time, not only the expediency of separation, but also the existence of this phenotype is widely discussed today. The article provides an overview of existing approaches to the verification of metabolic phenotypes of obesity and data relating to the epidemiology and the association of metabolically healthy obesity with the risk of cardiovascular diseases and death, and also discusses the factors that determine the features of the obesity phenotype.

Obesity and cardiovascular disease: revisiting an old relationship

A wealth of clinical and epidemiological evidence has linked obesity to a broad spectrum of cardiovascular diseases (CVD) including coronary heart disease, heart failure, hypertension, stroke, atrial fibrillation and sudden cardiac death. Obesity can increase CVD morbidity and mortality directly and indirectly. Direct effects are mediated by obesity-induced structural and functional adaptations of the cardiovascular system to accommodate excess body weight, as well as by adipokine effects on inflammation and vascular homeostasis. Indirect effects are mediated by co-existing CVD risk factors such as insulin resistance, hyperglycemia, hypertension and dyslipidemia. Adipose tissue (AT) quality and functionality are more relevant aspects for cardiometabolic risk than its total amount. The consequences of maladaptive AT expansion in obesity are local and systemic: the local include inflammation, hypoxia, dysregulated adipokine secretion and impaired mitochondrial function; the systemic comprise insulin resistance, abnormal glucose/lipid metabolism, hypertension, a pro-inflammatory and pro-thrombotic state and endothelial dysfunction, all of which provide linking mechanisms for the association between obesity and CVD. The present narrative review summarizes the major pathophysiological links between obesity and CVD (traditional and novel concepts), analyses the heterogeneity of obesity-related cardiometabolic consequences, and provides an overview of the cardiovascular impact of weight loss interventions.

New lower cutoff for serum high sensitive C-reactive protein in obese women indicates the risk of metabolic syndrome

Objective, materials and methods: The aim of this cross-sectional study with a consecutive enrolment was to analyse the role of high sensitive C-reactive protein (hs-CRP) measurement in similarly obese patients with and without the metabolic syndrome (MS). Results: In total, 589 obese patients were screened, of whom 138 aged 50-75 years were enrolled. The others were rejected due to strict criteria of enrolment, so that the group was highly homogenous in numerous clinical aspects. The study group consisted of 96 patients (49 females and 47 males) with MS; 42 patients (20 females and 22 males) had isolated obesity without MS and served as a control group. hs-CRP levels were significantly higher in patients with MS (p = .0012). To find out the CRP cutoff between MS and non-MS obesity, we performed ROC curve analyses: hs-CRP lower than 1.96 mg/l was the best predictor of simple obesity without MS (sensitivity = 66.7%; specificity = 66.7%; AUC = 0.7; p = .0002). In a separate analysis, hs-CRP level lower than 1.96 mg/dl remained statistically significant as a predictor of isolated central obesity only for females. Conclusions: Already a relatively low level of hs-CRP around 2.0 mg/dl is observed in the MS, whereas patients with simple obesity without the accompanying features of MS would have hs-CRP lower than this value.

Risk of hypertension among different metabolic phenotypes: a systematic review and meta-analysis of prospective cohort studies

We performed a meta-analysis to assess the association of body mass index (BMI) and metabolic status with the risk of incident hypertension. Relevant studies were identified by searching comprehensive search via PubMed and Scopus search engines up to May 2018 and were analyzed using a random-effects model. Eight prospective studies were included in the analyses with metabolically healthy normal weight (MHNW) as the reference group. Pooled relative risks (RRs) and their 95% confidence intervals (CI) were calculated using random-effects or fixed-effect models when appropriate. Subgroup analysis was applied to define possible sources of heterogeneity. Overall, among 79090 participants, the risk of hypertension in metabolically unhealthy obese (MUHO) and metabolically healthy obese phenotypes (MHO) increased compared with the reference group (pooled effect size = 1.95, 95%CI: 1.87-2.04, P < 0.001 vs pooled effect size: 1.54, 95%CI: 1.48-1.61, P < 0.001, respectively). Also, a significant positive association between metabolically unhealthy normal weight (MUHNW) phenotype and the risk of hypertension was observed (pooled effect size = 1.48, 95%CI: 1.41-1.55, P < 0.001). Metabolically unhealthy overweight (MUHOW) and metabolically healthy overweight (MHOW) phenotypes had greater risk of hypertension compared with the MHNW phenotype (pooled effect size = 1.50, 95%CI: 1.13-1.71, P < 0.001 and pooled effect size = 1.18, 95%CI: 1.11-1.27, P < 0.001). This meta-analysis revealed that individuals with metabolic abnormality had a higher risk for hypertension and also suggests that MHOW/ MHO are not a benign condition. We are refuting the notion that overweight and obesity without metabolic abnormalities are benign conditions in all population.

Association of obesity phenotypes with electrocardiographic left ventricular hypertrophy in the general population

OBJECTIVE

Increasing evidence doubts the benign nature of metabolically healthy obesity (MHO). An investigation of the association of MHO and other obesity phenotypes with electrocardiographic left ventricular hypertrophy (ECG-LVH), a risk factor for cardiovascular disease (CVD), can give insight into the pathophysiological basis for increased risk of CVD linked to these phenotypes.

METHODS

This analysis included 3997 participants (58.7 ± 13.6 years; 51.8% women) without CVD from the NHANES-III. Metabolic syndrome was defined according to the Adult Treatment Panel III. Obesity was defined as body mass index ≥30 kg/m2. Multivariable logistic regression was used to examine the cross-sectional association between 4 obesity phenotypes (metabolically healthy non-obese (MHNO) (reference), metabolically unhealthy non-obese (MUNO), MHO and metabolically unhealthy obese (MUO) with Cornell voltage ECG-LVH.

RESULTS

There was an incremental increase in the prevalence of ECG-LVH across obesity phenotypes with the highest prevalence in the MUO followed by MHO, MUNO and then MHNO (ECG-LVH = 6.45%, 5%, 4.71%, and 1.69%, respectively, trend p-value < 0.001). Also, there was incremental increase in the strength of associations with ECG-LVH across obesity phenotypes with higher odds of ECG-LVH in the MUO (OR (95% CI): 4.12 (2.30-7.39) followed by MUNO (OR (95% CI): 2.62 (1.45-4.73) then MHO (OR (95% CI): 2.45 (1.11-5.43) compared to MHNO. The MHO association with ECG-LVH was stronger in men than women (OR (95% CI): 5.55 (1.49-20.70) vs. 1.94 (0.71-5.24) respectively; interaction p-value = 0.04).

CONCLUSIONS

Obesity phenotypes including MHO are associated with ECG-LVH, thus further questioning the concept of benign obesity.

Which obesity phenotypes predict poor health-related quality of life in adult men and women? Tehran Lipid and Glucose Study

Purpose

This study aimed to explore the association between different obesity phenotypes and health-related quality of life (HRQoL) among Tehranian men and women.

Methods

The participants of this study were 2880 healthy adults (aged>19 years) who participated in Tehran Lipid and Glucose Study (TLGS). To obtain socio-demographic and HRQoL information, participants were interviewed by trained interviewers and were stratified by body mass index categories and metabolic status. Dysmetabolic status was defined as having either metabolic syndrome or diabetes according to the Joint Interim Statement definition and American Diabetes Association. Poor HRQoL was defined as the first quartile of HRQoL scores and logistic regression analysis was used to compare sex-specific odds ratios.

Results

Mean age of participants was 47.7±15.6 and 47.8±14.2 years in men and women respectively. The most and the least common obesity phenotypes were overweight-normal metabolic status and normal weight-dysmetabolic status, respectively. Only mean scores for physical HRQoL were significantly different among obesity phenotypes in both men and women (p<0.05). In addition, after adjusting for age, marital status, level of education, job status and physical activity, the odds of reporting poor physical HRQoL was significantly higher in men (OR: 1.960, 95% CI: 1.037–3.704; p<0.05) and women (OR: 2.887, 95% CI: 1.674–4.977; p<0.001) with obese-dysmetabolic status, compared to their counterparts with normal weight-normal metabolic status. However, except for overweight-normal metabolic women, who were less likely to report poor mental HRQoL (OR: 0.638, 95% CI: 0.415–0.981; p<0.05), none of the phenotypes were associated with poor mental HRQoL in either gender.

Conclusions

Compared to those with normal weight normal metabolic status, only obese dysmetabolic individuals were more likely to report poor physical HRQoL in both genders.

Interaction of Metabolic Health and Obesity on Subclinical Target Organ Damage

BACKGROUND

Metabolically healthy obese (MHO) individuals generally show better cardiovascular prognosis compared with metabolically unhealthy counterparts, which may be related to different patterns of target organ damage (TOD). We aimed to investigate the patterns of TOD related to obesity and metabolic unhealthiness.

METHODS

A total of 659 Korean adults (mean age, 60.0 ± 11.8 years; male, 51.1%) undergoing health examinations were stratified into four groups according to obesity (body mass index ≥25.0 kg/m²) and metabolic healthiness (meeting ≤1 criteria of metabolic syndrome excluding abdominal circumference): metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), MHO, and metabolically unhealthy obese (MUO). Four measures of TOD were evaluated: arterial stiffness, renal dysfunction, left ventricular (LV) diastolic dysfunction, and LV hypertrophy (LVH).

RESULTS

In multivariable analyses, compared with the MHNO group, the MHO group showed 2.31 times higher odds for LVH, whereas, the MUNO group showed 3.14 and 6.28 times higher odds for increased arterial stiffness and renal dysfunction, respectively. Metabolic unhealthiness was associated with increased arterial stiffness [odds ratio (OR) 2.73; confidence interval (95% CI) 1.72-4.34], renal dysfunction (OR 4.02; 95% CI 1.54-10.49), and LV diastolic dysfunction (OR 2.28; 95% CI 1.14-4.55). Meanwhile, obesity showed weaker association with LVH and LV diastolic dysfunction, and was not associated with increased arterial stiffness and renal dysfunction in multivariable analyses.

CONCLUSIONS

Metabolic unhealthiness shows more association with TOD than obesity, which may contribute to the higher risk of cardiometabolic abnormalities in MUNO compared with MHO.

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

OBJECTIVE

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Association between obesity phenotypes and incident hypertension among Chinese adults: a prospective cohort study

OBJECTIVES

To explore the association between obesity phenotype and the risk of hypertension among Chinese adults.

STUDY DESIGN

A prospective cohort study.

METHODS

Two waves of data were collected in 2009 and 2011 by the China Health Nutrition Survey. According to International Diabetes Federation and Chinese obesity criteria, participants were divided into four groups: metabolically healthy non-overweight/obesity (MHNO), metabolically healthy overweight/obesity (MHO), metabolically abnormal non-overweight/obesity (MANO), and metabolically abnormal overweight/obesity (MAO). Logistic regression model was performed to estimate the risk of hypertension with obesity phenotype.

RESULTS

Among a total of 4604 adults aged 18-65 years at baseline, 467 developed hypertension during the 2-year follow-up period. After adjusting for several potential confounders, significantly increased risks for hypertension were found for participants in MHO (odd ratio [OR]: 1.78, 95% confidence interval [CI]: 1.39-2.27), MANO (OR: 1.71, 95% CI: 1.02-2.86), and MAO (OR: 3.35, 95% CI: 2.54-4.42) group compared with the MHNO group.

CONCLUSION

Metabolically abnormal individuals, regardless of their body weight status, showed significantly higher risks for hypertension compared with healthy non-overweight/obese group. Furthermore, MHO individuals had significantly increased risk of incident hypertension.

Obesity, arterial function and arterial structure - a systematic review and meta-analysis

OBJECTIVE

Obesity is an established risk factor for cardiovascular disease. The mechanisms by which obesity affects cardiovascular risk have not been fully elucidated. This paper reports a comprehensive systematic review and meta-analysis on obesity and two key aspects of vascular health using gold-standard non-invasive measures - arterial endothelial function (brachial flow-mediated dilatation) and subclinical atherosclerosis (carotid intima-media thickness).

METHODS

Electronic searches for 'Obesity and flow-mediated dilatation' and 'Obesity and intima-media thickness' were performed using Ovid Medline and Embase databases. A meta-analysis was undertaken for brachial flow-mediated dilatation and carotid intima-media thickness to obtain pooled estimates for adults with obesity and those with healthy weight.

RESULTS

Of the 5,810 articles retrieved, 19 studies on flow-mediated dilatation and 19 studies on intima-media thickness were included. Meta-analysis demonstrated that obesity was associated with lower flow-mediated dilatation (-1.92 % [95% CI -2.92, -0.92], P = 0.0002) and greater carotid intima-media thickness (0.07 mm [95% CI 0.05, 0.08], P < 0.0001).

CONCLUSIONS

Obesity is associated with poorer arterial endothelial function and increased subclinical atherosclerosis, consistent with these aspects of vascular health at least partially contributing to the increased risk of cardiovascular events in adults with obesity. These estimated effect sizes will enable vascular health benefits in response to weight loss treatment to be put in greater perspective, both in the research setting and potentially also clinical practice.

The Clinical Usefulness of Measurement of Visceral Fat Area Using Multi-Frequency Bioimpedance: The Association with Cardiac and Renal Function In General Population with Relatively Normal Renal Function

Background: This study was performed to determine the clinical usefulness of measurement of visceral fat area (VFA) using bioimpedance analysis in relation with left ventricular hypertrophy (LVH), diastolic dysfunction parameters, and decreased estimated glomerular filtration rate (eGFR). Methods: A cross-sectional analysis was performed on 1028 patients with eGFR≥60 ml/min/1.73m², aged 40 - 64 years, and who underwent routine health check-ups. Subjects were divided into tertiles based on their VFA. Associations of VFA with echocardiographic parameters and eGFR were evaluated. Results: Across the VFA teriltes, there was a significant trend for increasing left ventricular mass index (LVMi), left atrial diameter (LAD), and ratio of early mitral inflow velocity to peak mitral annulus velocity (E/E' ratio) and that for decreasing ratio of early to late mitral inflow peak velocities (E/A ratio) and eGFR. In multivariate linear regression analysis, log-transformed VFA was significantly associated with increased LVMi, LAD, and E/E' ratio, and with decreased E/A ratio and eGFR. After adjustment for body mass index, log-transformed VFA remained as a significant determinant for E/A ratio. Conclusion: VFA may be associated with LV structure and diastolic function, and decreased eGFR in middle-aged adults with normal or mildly impaired renal function.

Prevalence of overweight/obesity, abdominal obesity and metabolic syndrome and atypical cardiometabolic phenotypes in the adult Romanian population: PREDATORR study

PURPOSE

The objectives were to assess the prevalence of overweight/obesity, abdominal obesity and metabolic syndrome (MetS), and to evaluate the characteristics of the metabolically unhealthy lean (MUHL) and metabolically healthy overweight/obese (MHO) phenotypes in a Romanian population-based sample from the PREDATORR study.

METHODS

PREDATORR was an epidemiological study with a stratified, cross-sectional, cluster random sampling design. Participants were classified into four cardiometabolic phenotypes based on the BMI, the cut-off value being 25 kg/m(2), and the presence of MetS (defined according to the Harmonization definition 2009): MUHL, MHO, metabolically healthy lean (MHL) and metabolically unhealthy overweight/obese (MUHO).

RESULTS

Overall, 2681 subjects aged 20-79 years were included in the analysis. The overall age and sex-adjusted prevalence of obesity was 31.90 %, overweight was 34.7 %, abdominal obesity was 73.90 % and MetS was 38.50 %. The age- and sex-adjusted prevalence of MHO phenotype was 31.60 %, while MUHL phenotype prevalence was 3.90 %. MUHL and MHO participants had a cardiometabolic profile, kidney function and CVD risk intermediary between MHL and MUHO. MUHL had higher odds of being associated with CVD risk (OR 5.8; p < 0.001), abdominal obesity, prediabetes, diabetes, hypertriglyceridemia and hypo-HDL cholesterolemia than MHL, while MHO phenotype was associated with hypo-HDL cholesterolemia (OR 3.1; p = 0.002), prediabetes (OR 2.9; p < 0.001) and abdominal obesity.

CONCLUSIONS

PREDATORR study showed a high prevalence of obesity/overweight, abdominal obesity and MetS in the adult Romanian population, and their association with kidney function and several cardiometabolic factors.

The association of incident hypertension with metabolic health and obesity status: definition of metabolic health does not matter

OBJECTIVE

Metabolically healthy obese (MHO) phenotype refers to obese individuals with a favourable metabolic profile. Its prognostic value remains controversial and may partly depend on differences in how the phenotype is defined. We aimed to investigate whether the MHO phenotype is associated with future development of incident hypertension in a Korean population according to various definitions of metabolic health.

SUBJECTS AND METHODS

The study population comprised 31 033 Koreans without hypertension. Participants were stratified into metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) by body mass index (cut-off value, 25·0 kg/m(2) ) and metabolic health state, using four different definitions: Adult Treatment Panel (ATP)-III, Wildman, Karelis and the homoeostasis model assessment (HOMA) criteria.

RESULTS

Over the median follow-up period of 35·0 months (range, 4·5-81·4 months), 4589 of the 31 033 individuals (14·8%) developed incident hypertension. Compared with the MHNO group, the MHO group showed increased association with incident hypertension with multivariate-adjusted odds ratios of 1·56 (95% confidence interval [CI], 1·41-1·72), 1·58 (95% CI 1·42-1·75), 1·52 (95% CI 1·35-1·71) and 1·46 (95% CI 1·33-1·61), when defined by ATP-III, Wildman, Karelis and HOMA criteria, respectively.

CONCLUSION

MUO individuals showed the highest association with the incident hypertension (adjusted odds ratios up to 2·00). MHO subjects showed an approximately 1·5-fold higher association with incident hypertension than their nonobese counterpart regardless of the definition of metabolic health used. Thus, considering both metabolic health and obesity is important for the assessment of potential cardiovascular outcomes.

Does Metabolically Healthy Obesity Exist?

The relationship between obesity and other metabolic diseases have been deeply studied. However, there are clinical inconsistencies, exceptions to the paradigm of "more fat means more metabolic disease", and the subjects in this condition are referred to as metabolically healthy obese (MHO).They have long-standing obesity and morbid obesity but can be considered healthy despite their high degree of obesity. We describe the variable definitions of MHO, the underlying mechanisms that can explain the existence of this phenotype caused by greater adipose tissue inflammation or the different capacity for adipose tissue expansion and functionality apart from other unknown mechanisms. We analyze whether these subjects improve after an intervention (traditional lifestyle recommendations or bariatric surgery) or if they stay healthy as the years pass. MHO is common among the obese population and constitutes a unique subset of characteristics that reduce metabolic and cardiovascular risk factors despite the presence of excessive fat mass. The protective factors that grant a healthier profile to individuals with MHO are being elucidated.

Influence of Obesity and Metabolic Disease on Carotid Atherosclerosis in Patients with Coronary Artery Disease (CordioPrev Study)

BACKGROUND

Recent data suggest that the presence of associated metabolic abnormalities may be important modifiers of the association of obesity with a poorer prognosis in coronary heart disease. We determined the influence of isolated overweight and obesity on carotid intima media thickness (IMT-CC), and also assessed whether this influence was determined by the presence of metabolic abnormalities.

METHODS

1002 participants from the CordioPrev study were studied at entry. We determined their metabolic phenotypes and performed carotid ultrasound assessment. We evaluated the influence of obesity, overweight and metabolic phenotypes on the IMT-CC.

RESULTS

Metabolically sick participants (defined by the presence of two or more metabolic abnormalities) showed a greater IMT-CC than metabolically healthy individuals (p = 4 * 10(-6)). Overweight and normal weight patients who were metabolically healthy showed a lower IMT-CC than the metabolically abnormal groups (all p<0.05). When we evaluated only body weight (without considering metabolic phenotypes), overweight or obese patients did not differ significantly from normal-weight patients in their IMT-CC (p = 0.077). However, obesity was a determinant of IMT-CC when compared to the composite group of normal weight and overweight patients (all not obese).

CONCLUSIONS

In coronary patients, a metabolically abnormal phenotype is associated with a greater IMT-CC, and may be linked to a higher risk of suffering new cardiovascular events. The protection conferred in the IMT-CC by the absence of metabolic abnormality may be blunted by the presence of obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00924937.

Adiposity has no direct effect on carotid intima-media thickness in adolescents and young adults: Use of structural equation modeling to elucidate indirect & direct pathways

BACKGROUND

Carotid intima-media thickness (cIMT) is associated with CV events in adults. Thicker cIMT is found in youth with CV risk factors including obesity. Which risk factors have the most effect upon cIMT in youth and whether obesity has direct or indirect effects is not known. We used structural equation modeling to elucidate direct and indirect pathways through which obesity and other risk factors were associated with cIMT.

METHODS

We collected demographics, anthropometrics and laboratory data on 784 subjects age 10-24 years (mean 18.0 ± 3.3 years). Common, bulb and internal carotid cIMT were measured by ultrasound. Multivariable regression analysis was performed to assess independent determinants of cIMT. Analyses were repeated with structural equation modeling to determine direct and indirect effects.

RESULTS

Multivariable regression models explained 11%-22% of variation of cIMT. Age, sex and systolic blood pressure (BP) z-score were significant determinants of all cIMT segments. Body mass index (BMI) z-score, race, presence of type 2 diabetes mellitus (T2DM), hemoglobin A1c (HbA1c) and non-HDL were significant for some segments (all p = 0.05). The largest direct effect on cIMT was age (0.312) followed by BP (0.228), Blood glucose control (0.108) and non-HDL (0.134). BMI only had a significant indirect effect through blood glucose control, BP & non-HDL. High sensitivity C-reactive protein (CRP) had a small indirect effect through blood glucose control (all p = 0.05).

CONCLUSIONS

Age and BP are the major factors with direct effect on cIMT. Glucose and non-HDL were also important in this cohort with a high prevalence of T2DM. BMI only has indirect effects, through other risk factors. Traditional CV risk factors have important direct effects on cIMT in the young, but adiposity exerts its influence only through other CV risk factors.

Metabolically Healthy Obesity and Carotid Intima-Media Thickness: Effects of Cardiorespiratory Fitness

OBJECTIVE

To test the hypothesis that cardiorespiratory fitness modifies the association between metabolically healthy obesity (MHO) phenotype and carotid intima-media thickness.

PATIENTS AND METHODS

We evaluated 3838 men (mean age, 51 ± 6 years) who participated in the general health examination program at Samsung Medical Center, Seoul, South Korea, between January 2, 2008, and December 31, 2008. Participants were divided into 4 groups on the basis of body habitus and metabolic health status using the Asia-Pacific criteria. On the basis of Asian criteria, MHO was defined as body mass index greater than or equal to 25 kg/m(2) with less than 3 metabolic abnormalities. Cardiorespiratory fitness (fitness) was directly measured by using peak oxygen uptake and divided into unfit (lower tertile of fitness) and fit (middle and upper tertiles of fitness) categories on the basis of age-specific peak oxygen uptake percentiles. The prevalence of subclinical carotid atherosclerosis was defined as a mean carotid intima-media thickness greater than the 75th percentile.

RESULTS

Compared with metabolically healthy normal weight (MHNW), MHO was associated with a higher prevalence of subclinical carotid atherosclerosis (odds ratio, 1.39; 95% CI, 1.12-1.72) after adjusting for potential confounding variables. Using multivariate logistic regression analysis, we found that the MHO unfit group had 2.00 times (95% CI, 1.48-2.73) and the metabolically unhealthy obesity unfit group had 1.84 times (95% CI, 1.26-2.67) higher risk of subclinical carotid atherosclerosis as compared with the MHNW fit group (reference group). However, MHO fit (OR, 1.25; 95% CI, 0.97-1.62) and metabolically unhealthy obesity fit (OR, 1.31; 95% CI, 0.90-1.92) groups had odds ratios for subclinical carotid atherosclerosis similar to those of the MHNW fit group.

CONCLUSION

Metabolically healthy obesity was associated with a higher prevalence of subclinical carotid atherosclerosis, but this association was attenuated by increasing levels of cardiorespiratory fitness.

Association between metabolically unhealthy overweight/obesity and chronic kidney disease: the role of inflammation

AIM

Our study explored the association between subtypes of increased fat mass (with or without associated metabolic alterations) and the presence of chronic kidney disease (CKD).

METHODS

In this cross-sectional survey in China, body mass index (BMI) was used to assess fat mass. Metabolically healthy was defined as no insulin resistance or any metabolic syndrome components except abdominal obesity. We also used two previous definitions of metabolically healthy. Multiple logistic regression models were used. Normal weight with metabolic health was designated the reference group. Three other subgroups included normal weight with metabolic unhealthiness, overweight/obesity with metabolic health and overweight/obesity with metabolic unhealthiness.

RESULTS

Of the 2324 subjects, 11.77% overweight/obese subjects were metabolically healthy. Compared with normal-weight subjects who were metabolically healthy, overweight/obese subjects who were metabolically healthy did not have an increased risk of CKD (OR: 0.79, 95% CI: 0.29–2.14; P = 0.64), whereas overweight/obese subjects who were metabolically unhealthy had a significantly higher risk of CKD (OR: 2.47, 95% CI: 1.5–3.95; P < 0.001). Normal-weight subjects who were metabolically unhealthy also had a higher risk of CKD, but the P value was of borderline significance. On further adjusting for C-reactive protein (CRP) levels, ORs were much attenuated, but did not alter the associations observed. Using two other definitions of metabolically healthy resulted in similar results.

CONCLUSION

Metabolically unhealthy overweight/obesity, but not metabolically healthy overweight/obesity, is associated with an increased risk of CKD. Inflammation might mediate at least part of the association between metabolic changes and CKD prevalence.

Obesity with metabolic abnormality is associated with the presence of carotid atherosclerosis in Korean men: a cross-sectional study

BACKGROUND

Obesity is a risk factor for cardiovascular disease, but metabolic disturbances can also lead to the development of this disease. Therefore, we investigated the associations between obesity subtype, considering both body weight and metabolic disturbances, and carotid atherosclerosis as a predictor of cardiovascular disease in Korean men.

METHODS

Data from a total of 980 men were analysed in this study. Obesity subtypes were classified as normal weight without metabolic syndrome (metabolically healthy normal weight; MHNW), obesity without metabolic syndrome (metabolically healthy, but obese; MHO), normal weight with metabolic syndrome (metabolically abnormal, but normal weight; MANW) and obesity with metabolic syndrome (metabolically abnormal obese; MAO). Carotid intima-media thickness (CIMT) and carotid plaque were assessed using a high-resolution B-mode ultrasound system. Carotid atherosclerosis was defined as a mean CIMT value >0.9 mm or the presence of carotid plaque.

RESULTS

Mean CIMT in the MAO subtype was significantly higher than that in the MHNW control group (0.790 ± 0.019 vs. 0.747 ± 0.013 mm; p < 0.001). The presence of carotid plaque was positively associated with MAO subtype [adjusted odds ratio (aOR) 1.49, 95 % confidence interval (CI) 1.02-2.16; p = 0.039], but not with MHO or MANW, compared to the MHNW control group. The MAO subtype showed a positive association with the presence of carotid atherosclerosis (aOR 1.68, 95 % CI 1.17-2.42; p = 0.006).

CONCLUSIONS

Only the MAO subtype showed a higher CIMT value and positive associations with carotid plaque and carotid atherosclerosis, but not with MHO and MANW subtypes, compared to the MHNW control. Additional prospective studies are needed to evaluate preclinical carotid atherosclerosis according to the subtypes of obesity.

Association of metabolically healthy obesity with subclinical coronary atherosclerosis in a Korean population

OBJECTIVE

The degree of subclinical coronary atherosclerosis detected by coronary multidetector computed tomography (MDCT) in four groups defined by the state of metabolic health and obesity in an asymptomatic Korean population was compared.

METHODS

The data of 4009 asymptomatic subjects who participated in a routine health screening examination were collected. Significant coronary artery stenosis defined as >50% stenosis, plaque, and coronary artery calcium scores (CACS) were assessed by MDCT. Participants were stratified by BMI (cut-off value, 25 kg/m(2) ) and metabolically healthy state, which was defined by Wildman criteria.

RESULTS

Metabolically healthy obese (MHO) subjects had a significantly higher prevalence of significant subclinical coronary atherosclerotic burden compared with metabolically healthy nonobese (MHNO) subjects. The adjusted odds ratios of the MHO group for various coronary MDCT findings (MHNO group as the reference), such as coronary artery stenosis, any plaque, calcified plaque, mixed plaque, CACS > 0, and CACS > 100, were 1.87 (95% CI 1.15-3.03), 1.31 (1.01-1.71), 1.40 (1.05-1.86), 1.57 (1.01-2.48), 1.38 (1.04-1.82), and 1.69 (1.03-2.78), respectively.

CONCLUSIONS

Our data illustrate that MHO subjects have substantial subclinical coronary atherosclerotic burden. Thus, it is important to consider the metabolic health state and obesity in evaluating cardiovascular risk.

Metabolically healthy obesity from childhood to adulthood - Does weight status alone matter?

Up to 30% of obese people do not display the "typical" metabolic obesity-associated complications. For this group of patients, the term "metabolically healthy obese (MHO)" has been established during the past years and has been the focus of research activities. The development and severity of insulin resistance as well as (subclinical) inflammations seems to play a key role in distinguishing metabolically healthy from metabolically non-healthy individuals. However, an internationally consistent and accepted classification that might also include inflammatory markers as well as features of non-alcoholic fatty liver disease is missing to date, and available data - in terms of prevalence, definition and severity - are heterogeneous, both during childhood/adolescence and during adulthood. In addition, the impact of MHO on future morbidity and mortality compared to obese, metabolically non-healthy as well as normal weight, metabolically healthy individuals is absolutely not clear to date and even conflicting. This review summarizes salient literature related to that topic and provides insight into our current understanding of MHO, covering all age spans from childhood to adulthood.

Visceral adiposity and skeletal muscle mass are independently and synergistically associated with left ventricular structure and function: the Korean Genome and Epidemiology Study

BACKGROUND

Obesity and low muscle mass may coexist as age-related changes in body composition. We aimed to investigate the effect of visceral adiposity and skeletal muscle mass on left ventricular (LV) structure and function in the general population.

METHODS

A total of 1941 participants without known cardiovascular disease were enrolled from the Korean Genome and Epidemiology Study. Visceral fat area (VFA) was assessed by computed tomography. Appendicular skeletal muscle mass (ASM) was estimated by dual-energy X-ray absorptiometry and was used as a percentage of body weight (ASM/Wt). LV structure and function were assessed by tissue Doppler imaging (TDI) echocardiography.

RESULTS

Across VFA tertiles, ASM increased, but ASM/Wt decreased (all P<0.001). In multivariate models adjusted for conventional cardiovascular risk factors, LV mass index and LV diastolic parameters, such as left atrial dimension, TDI Ea velocity, and E/Ea ratio, were significantly impaired as VFA increased. On the other hand, an increase in ASM/Wt was associated with a decrease in LV mass index and improvement of LV diastolic parameters. With regard to LV mass index and TDI Ea velocity, VFA and ASM/Wt showed synergistic effects (all P interaction<0.05). When both VFA and ASM/Wt were simultaneously included in the same model, both remained independent predictors of LV mass index and TDI Ea velocity.

CONCLUSIONS

More visceral fat and less muscle mass are independently and synergistically associated with an increase in LV mass index and impairment of LV diastolic parameters. Further research is needed to explore the complex mechanisms underlying these associations.

Current issues in the identification and treatment of metabolically healthy but obese individuals

A unique subset of obese individuals who appear to be protected from the development of metabolic disturbances has been identified in the medical literature and is termed metabolically healthy but obese (MHO). Part of the issue is that there are no clear accepted criteria on the definition of MHO and the biological mechanisms to explain this phenotype are still unknown which render findings and/or conclusions difficult to interpret and making the application of this concept difficult in clinical practice. With the current definitions, the true prevalence of the MHO phenotype in the general population varies widely from approximately 3-57% of obese adults. In several prospective studies, the MHO individual has been associated with a similar risk of developing type 2 diabetes, cardiovascular disease and mortality when compared to healthy normal weight subjects; however, there is evidence to refute this concept. Furthermore, the current evidence cannot confirm that MHO subjects are permanently protected from the risk of developing metabolic disturbances associated with obesity. Currently, no standard practice guidelines for the treatment of MHO can be proposed, however, a regular surveillance of the waist circumference and cardio-metabolic risk factors such as elevated triglycerides, glycaemia, HOMA, C-reactive protein and low HDL, as well as the prevention of any further weight gain seem to represent the most prudent and sound attitude in the management of MHO subjects.

Association of metabolically abnormal but normal weight (MANW) and metabolically healthy but obese (MHO) individuals with arterial stiffness and carotid atherosclerosis

OBJECTIVE

Despite recent interest in differential impact of body size phenotypes on cardiovascular outcomes and mortality, studies evaluating the association between body size phenotypes and indicators of atherosclerosis are limited. This study investigated the relationship of metabolically abnormal but normal weight (MANW) and metabolically healthy but obese (MHO) individuals with arterial stiffness and carotid atherosclerosis in Korean adults without cardiovascular disease.

METHODS

A total of 1012 participants (575 men and 437 women, mean age 50.8 years), who underwent a health examination between April 2012 and May 2013 were prospectively enrolled based on inclusion and exclusion criteria. Study subjects were classified according to body mass index (BMI) and the presence/absence of metabolic syndrome.

RESULTS

The prevalence of metabolically healthy normal weight (MHNW), MANW, MHO, and metabolically abnormal obese (MAO) were 54.84%, 6.42%, 22.83%, and 15.91%, respectively. Individuals with MANW had significantly higher brachial-ankle pulse wave velocity and maximal carotid intima-media thickness values than those with MHO, after adjusting for age and gender (P = 0.026 and P = 0.018, respectively). The odds ratio (OR) of arterial stiffness and carotid atherosclerosis in the MANW group were significantly higher than in the MHNW group in unadjusted models. Furthermore, multivariable models showed that increased OR of carotid atherosclerosis in the MANW group persisted even after adjusting for confounding factors (OR = 2.98, 95% CI = [1.54, 5.73], P = 0.011).

CONCLUSIONS

Compared to MHNW or MHO subjects, Korean men and women with the MANW phenotype exhibited increased arterial stiffness and carotid atherosclerosis.

CLINICAL TRIALS NO

NCT01594710.

Carotid Intima Media Thickness Is Independently Associated with Male Gender, Middle Age, and IGF-1 in Metabolically Healthy Obese Individuals

Background/Aims. The effect of benign obesity on subclinical cardiovascular disease is still questionable. The purpose of this study was to assess carotid intima media thickness (CIMT), as a marker of subclinical atherosclerosis, and to evaluate its relation to age, sex, and IGF-1 in metabolically healthy obese (MHO) subjects. Methods. A total of 75 MHO subjects and 80 age, and sex matched healthy nonobese control subjects were included in the study. Body mass index (BMI), waist circumference (WC), blood pressure, fasting plasma glucose, fasting insulin, HOMA-IR, lipid profile, insulin like growth factor-1 (IGF-1), and CIMT were assessed in all subjects. Results. MHO subjects had significantly higher CIMT and lower IGF-1 than healthy nonobese controls. Mean CIMT was significantly higher in MHO men age subgroup range from 30 to 50 years than in their age range matched (premenopausal) MHO women subgroup. In MHO subjects, CIMT was positively correlated with age, BMI, WC, SBP, HOMA-IR, TG, and LDL-C, and negatively correlated with IGF-1. Regression analysis revealed that middle age, male sex and IGF-1 remained independently associated with CIMT in MHO subjects. Conclusion. CIMT is elevated and IGF-1 is reduced in MHO subjects, and CIMT is independently associated with male gender, middle age, and IGF-1. Definition of healthy obesity may be broadened to include IMT measurement.

Beyond BMI: The "Metabolically healthy obese" phenotype & its association with clinical/subclinical cardiovascular disease and all-cause mortality -- a systematic review

Background

A subgroup has emerged within the obese that do not display the typical metabolic disorders associated with obesity and are hypothesized to have lower risk of complications. The purpose of this review was to analyze the literature which has examined the burden of cardiovascular disease (CVD) and all-cause mortality in the metabolically healthy obese (MHO) population.

Methods

Pubmed, Cochrane Library, and Web of Science were searched from their inception until December 2012. Studies were included which clearly defined the MHO group (using either insulin sensitivity and/or components of metabolic syndrome AND obesity) and its association with either all cause mortality, CVD mortality, incident CVD, and/or subclinical CVD.

Results

A total of 20 studies were identified; 15 cohort and 5 cross-sectional. Eight studies used the NCEP Adult Treatment Panel III definition of metabolic syndrome to define “metabolically healthy”, while another nine used insulin resistance. Seven studies assessed all-cause mortality, seven assessed CVD mortality, and nine assessed incident CVD. MHO was found to be significantly associated with all-cause mortality in two studies (30%), CVD mortality in one study (14%), and incident CVD in three studies (33%). Of the six studies which examined subclinical disease, four (67%) showed significantly higher mean common carotid artery intima media thickness (CCA-IMT), coronary artery calcium (CAC), or other subclinical CVD markers in the MHO as compared to their MHNW counterparts.

Conclusions

MHO is an important, emerging phenotype with a CVD risk between healthy, normal weight and unhealthy, obese individuals. Successful work towards a universally accepted definition of MHO would improve (and simplify) future studies and aid inter-study comparisons. Usefulness of a definition inclusive of insulin sensitivity and stricter criteria for metabolic syndrome components as well as the potential addition of markers of fatty liver and inflammation should be explored. Clinicians should be hesitant to reassure patients that the metabolically benign phenotype is safe, as increased risk cardiovascular disease and death have been shown.

A metabolically healthy obese phenotype in hispanic participants in the IRAS family study

OBJECTIVE

Some obese individuals appear to be protected from developing type 2 diabetes mellitus and cardiovascular disease (CVD). This has led to characterizing body size phenotypes based on cardiometabolic risk factors specifically as obese or overweight, and as metabolically healthy (MH) or metabolically abnormal (MA) based upon blood pressure, lipids, glucose homeostasis, and inflammatory parameters. The aim of this study was to measure the prevalence of and describe fat distribution across these phenotypes in a minority population.

DESIGN AND METHODS

Hispanic participants (N = 1054) in the IRAS Family Study were categorized into different body size phenotypes. Computed tomography (CT) abdominal scans were evaluated for measures of nonalcoholic fatty liver disease (NAFLD) and abdominal fat distribution. Statistical models adjusting for familial relationships were estimated.

RESULTS

Seventy percent (70%) of the Hispanic cohort was overweight (32%) or obese (38%). Forty-one percent (n = 138) of overweight participants and 19% (n = 74) of obese participants met criteria for MH. Adjusted analyses showed the MH phenotype was associated with lower visceral adipose tissue (VAT) and higher liver density (indicating lower fat content) in obese participants (p = 0.0005 and p = 0.0002, respectively), and lower VAT but not liver density in overweight participants (p = 0.008 and p = 0.162, respectively) compared to their MA counterparts. Odds of NAFLD were reduced in MH obese (OR = 0.34, p = 0.0007) compared to MA obese. VAT did not differ between MH obese or overweight and normal weight groups.

CONCLUSIONS

These findings suggest that lower levels of visceral and liver fat, despite overall increased total body fat, may be a defining feature of MH obesity in Hispanic Americans.

Docosahexaenoic acid supplementation does not improve Western diet-induced cardiomyopathy in rats

Obesity increases risk for cardiomyopathy in the absence of hypertension, diabetes or ischemia. The fatty acid milieu, modulated by diet, may modify myocardial structure and function, lending partial explanation for the array of cardiomyopathic phenotypy. We sought to identify gross, cellular and ultrastructural myocardial changes associated with Western diet intake, and subsequent modification with docosahexaenoic acid (DHA) supplementation. Wistar and Sprague-Dawley (SD) rats received 1 of 3 diets: control (CON); Western (WES); Western + DHA (WES+DHA). After 12 weeks of treatment, echocardiography was performed and myocardial adiponectin, fatty acids, collagen, area occupied by lipid and myocytes, and ultrastructure were determined. Strain effects included higher serum adiponectin in Wistar rats, and differences in myocardial fatty acid composition. Diet effects were evident in that both WES and WES+DHA feeding were associated with similarly increased left ventricular (LV) diastolic cranial wall thickness (LVW(cr/d)) and decreased diastolic internal diameter (LVID(d)), compared to CON. Unexpectedly, WES+DHA feeding was associated additionally with increased thickness of the LV cranial wall during systole (LVW(cr/s)) and the caudal wall during diastole (LVW(ca/d)) compared to CON; this was observed concomitantly with increased serum and myocardial adiponectin. Diastolic dysfunction was present in WES+DHA rats compared to both WES and CON. Myocyte cross sectional area (CSA) was greater in WES compared to CON rats. In both fat-fed groups, transmission electron microscopy (TEM) revealed myofibril degeneration, disorganized mitochondrial cristae, lipid inclusions and vacuolation. In the absence of hypertension and whole body insulin resistance, WES+DHA intake was associated with more global LV thickening and with diastolic dysfunction, compared to WES feeding alone. Myocyte hypertrophy, possibly related to subcellular injury, is an early change that may contribute to gross hypertrophy. Strain differences in adipokines and myocardial fatty acid accretion may underlie heterogeneous data from rodent studies.

Prognostic implications for insulin-sensitive and insulin-resistant normal-weight and obese individuals from a population-based cohort

BACKGROUND

There are few prospective data on the prognosis of insulin-sensitive and insulin-resistant normal-weight (NW) or obese individuals.

OBJECTIVES

The estimated liver fat content, incidences of hyperglycemia and cardiovascular disease, and all-cause and cardiovascular mortality rates were investigated in a population-based cohort of 1658 individuals who were categorized according to BMI and insulin resistance as defined by HOMA-IR values ≥2.5 and the presence of metabolic syndrome.

DESIGN

This was a prospective cohort study with a 9-y follow-up. Anthropometric values, blood pressure, and blood metabolic variables were measured, and information on vital status was collected from demographic files at follow-up.

RESULTS

A total of 137 of 677 NW individuals (20%) were classified as insulin resistant and normal weight (IR-NW), and 72 of 330 obese individuals (22%) were classified as insulin sensitive and obese (IS-obese). Incidences of diabetes, impaired fasting glucose, and cardiovascular events were 0.4%, 6.3%, and 3.3%, respectively, in insulin-sensitive and normal-weight (IS-NW) individuals (reference category); 5.8%, 10.2%, and 6.6%, respectively, in IR-NW individuals; and 5.6%, 8.3%, and 8.3%, respectively, in IS-obese individuals. In a multiple logistic regression model, risks of incident hyperglycemia and cardiovascular events increased in both groups compared with in the reference category [HR (95% CI): 2.54 (1.42, 4.55) and 1.98 (0.86, 4.54) in IR-NW subjects; 2.16 (1.01, 4.63) and 2.76 (1.05, 7.28) in IS-obese subjects]. The estimated liver fat content significantly increased during follow-up only in the IR-NW group in the same model. Cardiovascular mortality was 2-3-fold higher in IR-NW and IS-obese than in IS-NW individuals in a Cox regression model.

CONCLUSIONS

Our data refute the existence of healthy obese phenotypes because IS-obese individuals showed increased cardiometabolic risk. The existence of unhealthy NW phenotypes is supported by their increased risk of incident hyperglycemia, fatty liver, cardiovascular events, and death.