Risk of developing diabetes and cardiovascular disease in metabolically unhealthy normal-weight and metabolically healthy obese individuals

Prevalence and clinical characteristics of metabolically unhealthy obesity in an Iranian adult population

PURPOSE

The incidence of obesity is globally increasing and it is a predisposing factor for morbidity and mortality. This study assessed the prevalence of metabolically unhealthy (MU) individuals and its determinants according to body mass index (BMI).

MATERIALS AND METHOD

In our cross-sectional study, 891 persons aged 30 years or older participated. Participants were classified as obese (BMI ≥30 kg/m²), overweight (BMI 25-<30 kg/m² and normal weight (BMI <25 kg/m²). Metabolic health status was defined using four existing cardio-metabolic abnormalities (elevated blood pressure, elevated serum concentrations of triglyceride and fasting glucose and a low serum concentration of high density lipoprotein cholesterol). Then, two phenotypes were defined: healthy (existence of 0-1 cardio-metabolic abnormalities) and unhealthy (presence of 2 or more cardio-metabolic abnormalities).

RESULT

Overall, 10.9% (95% confidence interval (CI): 8.8-13.0) and 7.2% (95% CI: 5.5-8.9) of participants were MU obese and metabolically healthy obese, respectively. The prevalence of MU was higher in overweight (55.6%; 95% CI: 50.6-60.6, p<0.001) and obese (60.2%; 95% CI: 52.8-67.6, p=0.001) subjects than in individuals with a normal weight (37.5%; 95% CI: 29.4-42.6). Multiple logistic regression analysis showed an association of a MU state with age and dyslipidaemia in the BMI subgroups and with female sex in the normal weight individuals.

CONCLUSION

The prevalence of a MU state increased with increasing BMI. Ageing and dyslipidaemia were associated with an unhealthy metabolic state in normal weight, overweight and obese subjects and with the female sex in normal weight subjects.

Ethnic differences in metabolic cardiovascular risk among normal weight individuals: Implications for cardiovascular risk screening. The HELIUS study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) risk factors may occur among a substantial proportion of normal weight individuals, particularly among some ethnic minorities. It is unknown how many of these individuals would be missed by commonly applied eligibility criteria for cardiovascular risk screening. Thus, we aim to determine cardiovascular risk and eligibility for cardiovascular risk screening among normal weight individuals of different ethnic backgrounds.

METHODS AND RESULTS

Using the HELIUS study (Amsterdam, The Netherlands), we determined cardiovascular risk among 6910 normal weight individuals of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Moroccan and Turkish background. High cardiovascular risk was approximated by high metabolic risk based on blood pressure, HDL, triglycerides and fasting glucose. Eligibility criteria for screening were derived from Dutch CVD prevention guidelines and include age ≥ 50 y, family history of CVD, or current smoking. Ethnic group comparisons were made using logistic regression. Age-adjusted proportions of high metabolic risk ranged from 12.6% to 38.4% (men) and from 2.7% to 11.5% (women). This prevalence was higher among most ethnic minorities than the Dutch, especially among women. For most ethnic groups, 79.9%-86.7% of individuals with high metabolic risk were eligible for cardiovascular risk screening. Exceptions were Ghanaian women (58.8%), Moroccan men (70.9%) and Moroccan women (45.0%), although age-adjusted proportions did not differ between groups.

CONCLUSION

Even among normal weight individuals, high cardiovascular metabolic risk is more common among ethnic minorities than among the majority population. Regardless of ethnicity, most normal weight individuals with increased risk are eligible for cardiovascular risk screening.

Relations of major dietary patterns and metabolically unhealthy overweight/obesity phenotypes among Iranian women

OBJECTIVE

No studies have examined the contribution of major dietary patterns to MUH phenotypes in obese and overweight people based on Karelis criteria. This study was conducted to evaluate the association of major dietary patterns with MUHOW/O and MHOW/O phenotypes.

METHODS

This cross-sectional study was conducted on 290 overweight and obese women aged 18-50 (BMI≥25 kg/m2). Anthropometric measurements were assessed in all participants. The MH phenotype was defined according to the Karelis criteria. Major dietary patterns were determined using factor analysis of 21 foods groups using a valid and reliable FFQ containing 147 items. Participants' body composition was assessed by BIA. Serum HDL, LDL, TG, insulin, and hs-CRP levels were quantified by ELISA.

RESULTS

By the use of factor analysis, 3 major dietary patterns were extracted: healthy dietary pattern (HDP), western dietary pattern (WDP) and unhealthy dietary pattern (UNHDP). Binary logistic analysis showed that participants in the in the upper category of WDP had greater odds of MUH phenotype (OR = 2.33, 95%CI = 1.11-4.91, P = 0.02), after confounder factor control. Individuals with high adherence to the UNHDP score had high odds of MUH phenotype (OR = 1.75, 95%CI = 0.98-3.10, P = 0.05), after adjustment for BMI, age, and total EI, compared to those with low adherence. A positive relation was observed between WDP and levels of hs-CRP, HOMA-IR (OR = 1.94, 95%CI = 0.91-4.10, P = 0.05 and OR = 2.53, 95%CI = 1.26-5.11, P = 0.009) as well as a positive association between UHDP and plasma level of LDL (OR = 1.90, 95%CI = 1.04-3.47, P = 0.03), but an inverse association between HDP and hs-CRP level (OR = 0.56, 95%CI = 0.29-0.92, P = 0.03).

CONCLUSIONS

The present evidence indicates various significant associations among major dietary patterns and MUHOW/O phenotypes.

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.

Visceral adiposity index is a better predictor of unhealthy metabolic phenotype than traditional adiposity measures: results from a population-based study

OBJECTIVE

The present study aimed to investigate whether the visceral adiposity index (VAI) is an effective predictor to identify unhealthy metabolic phenotype by comparing normal-weight and overweight individuals.

DESIGN

A population-based cross-sectional study. Data were collected by interviews, anthropometric evaluation, dietetic, clinical and laboratory tests. The area under the receiver-operating characteristic curve (AUC) and prevalence ratio (PR), obtained from Poisson regression, were used to compare the predictive capacity of the obesity indicators evaluated (VAI, BMI, waist and neck circumference, waist-to-height and waist-to-hip ratios) and their association with the unhealthy metabolic phenotype. All analyses were stratified by sex and by nutritional status.

SETTING

Viçosa, Minas Gerais, Brazil.ParticipantsA total of 854 Brazilian adults (20-59 years old) of both sexes.

RESULTS

VAI was the best predictor for unhealthy metabolic phenotype among men (AUC = 0·865) and women (AUC = 0·843) at normal weight. VAI also had the best predictive capacity among overweight women (AUC = 0·903). Among overweight men, its accuracy (AUC = 0·830) was higher than that of waist-to-hip ratio. In the adjusted regression models, VAI was the indicator most strongly associated with the unhealthy metabolic phenotype, especially among those with normal weight (PR = 6·74; 95 % CI 3·15, 14·42 for men; PR = 7·14; 95 % CI 3·79, 13·44 for women).

CONCLUSIONS

VAI has better predictive capacity in detecting unhealthy metabolic phenotype than conventional anthropometric indicators, regardless of nutritional status and sex.

Metabolic syndrome identifies normal weight insulin-resistant stroke patients at risk for recurrent vascular disease

BACKGROUND

The obesity paradox refers to the finding in observational studies that patients with obesity have a better prognosis after stroke than normal weight patients.

AIM

To test the hypothesis that there might be important heterogeneity within the obese stroke population, such that those with metabolic syndrome would be at higher risk for stroke or myocardial infarction and all-cause mortality compared to patients without metabolic syndrome.

METHODS

The Insulin Resistance Intervention after Stroke trial enrolled non-diabetic patients with a recent ischemic stroke or transient ischemic attack and insulin resistance. We examined the association between metabolic syndrome and outcome risk in patients with normal weight at entry (body mass index (BMI) = 18.5-24.9 kg/m²), overweight (BMI = 25-29.9 kg/m²), or obesity (BMI ≥ 30 kg/m²). Analyses were adjusted for demographic features, treatment assignment, smoking, and major comorbid conditions.

RESULTS

Metabolic syndrome was not associated with greater risk for stroke or myocardial infarction among 1536 patients who were overweight (adjusted hazard ratio (HR), 0.95; 95% confidence interval (CI): 0.69-1.31) or 1626 obese patients (adjusted HR, 1.00; 95% CI: 0.70-1.41). However, among 567 patients with a normal BMI, metabolic syndrome was associated with increased risk for stroke or myocardial infarction (adjusted HR, 2.05; 95% CI: 1.25-3.37), and all-cause mortality (adjusted HR, 1.70; 95% CI: 1.03-2.81) compared to patients without metabolic syndrome.

CONCLUSIONS

The presence of metabolic syndrome identified normal weight patients with insulin resistance but no diabetes who have a higher risk of adverse cardiovascular outcomes, compared with patients without metabolic syndrome.

Association between the metabolically healthy obese phenotype and the risk of myocardial infarction: results from the Kailuan study

Objective This study aimed to determine if the metabolically healthy obese (MHO) is associated with an increased risk of myocardial infarction (MI) in Chinese population. Design The Kailuan study is a community-based prospective cohort study. Methods BMI and metabolic syndrome (MetS) were assessed in 91 866 participants without a history of MI or stroke. Participants were categorised into six mutually exclusive groups according to the BMI-MetS status: normal weight (BMI: ≤ 18.5to < 24.0 kg/m2) without MetS (MH-NW), normal weight with MetS (MUH-NW), overweight (BMI: ≤ 24.0to < 28.0 kg/m2) without MetS (MH-OW), overweight with MetS (MUH-OW), obese (BMI ≥ 28.0 kg/m2) without MetS (MHO) and obese with MetS (MUO). The hazard ratio (HR) with 95% CI was calculated for the incidence of MI using a multivariable Cox model. Results A total of 6745 (7.34%) individuals were classified as MHO. During a median 8-year follow-up, 1167 (1.27%) participants developed MI. The MHO group had an increased risk of MI (HR: 1.76, 95% CI: 1.37-2.25) in comparison with the MH-NW group after adjusting for potential confounding variables. After a similar adjustment, the risk of MI was significantly elevated in the MUH-NW (HR: 1.62, 95% CI: 1.28-2.05), MUH-OW (HR: 1.98, 95% CI: 1.67-2.35) and MUO group (HR: 2.06, 95% CI: 1.70-2.49). Conclusions MHO subjects showed a substantially higher risk of MI in comparison with MH-NW subjects. That said, even without measurable metabolic abnormalities, obesity was associated with a higher risk of MI.

Orlistat-loaded solid SNEDDS for the enhanced solubility, dissolution, and in vivo performance

Background

The present study aimed to develop orlistat-loaded solid self-nanoemulsifying drug delivery system preconcentrate (SSP) with the minimum use of lipid excipients for the enhanced solubility, in vitro dissolution, lipase inhibition, and in vivo performance.

Materials and methods

In the screening of solubilizing vehicles, Solutol HS15 and Lauroglycol 90 were selected as the surfactant and oil phase, respectively. A pseudo-ternary phase diagram composed of Solutol HS15, Lauroglycol 90, and orlistat as an anti-obesity agent and lipid component was constructed, and the SSP regions were confirmed in terms of the particle size distribution in water, melting point by differential scanning calorimetry, and crystallinity by X-ray diffraction.

Results

Physicochemical interaction between Solutol HS15 and orlistat resulted in SSP with various melting points in the range of 26°~33°C. The representative maximum orlistat-loaded SSP (orlistat/Solutol HS15/Lauroglycol 90=55/40/5, weight ratio) showed the melting point of 32.23°C and constructed uniform nanoemulsion with the particle size of 141.7±1.1 nm dispersed in water. In the dissolution test at pH 1.2 without any detergent, the SSP reached 98.12%±0.83% until 45 minutes, whereas raw orlistat showed no significant dissolution rate. The dissolution samples containing SSP showed a lipase inhibition of 90.42%±1.58% within 45 minutes. In terms of the reduction level of fat absorption in rats, the intake group of SSP gave a significantly higher fat excretion into stool than the one observed in the raw orlistat group (P<0.05).

Conclusion

In conclusion, the suggested novel SSP formulation would be an effective and promising candidate for the treatment of obesity.

Genes that make you fat, but keep you healthy

Obesity prevalence continues to rise worldwide, posing a substantial burden on people's health. However, up to 45% of obese individuals do not suffer from cardiometabolic complications, also called the metabolically healthy obese (MHO). Concurrently, up to 30% of normal-weight individuals demonstrate cardiometabolic risk factors that are generally observed in obese individuals, the metabolically obese normal weight (MONW). Besides lifestyle, environmental factors and demographic factors, innate biological mechanisms are known to contribute to the aetiology of the MHO and MONW phenotypes, as well. Experimental studies in animal models have shown that adipose tissue expandability, fat distribution, adipogenesis, adipose tissue vascularization, inflammation and fibrosis, and mitochondrial function are the main mechanisms that uncouple adiposity from its cardiometabolic comorbidities. We reviewed current genetic association studies to expand insights into the biology of MHO/MONW phenotypes. At least four genetic loci were identified through genome-wide association studies for body fat percentage (BF%) of which the BF%-increasing allele was associated with a protective effect on glycemic and lipid outcomes. For some, this association was mediated through favourable effects on body fat distribution. Other studies that characterized the genetic susceptibility of insulin resistance found that a higher susceptibility was associated with lower overall adiposity due to less fat accumulation at hips and legs, suggesting that an impaired capacity to store fat subcutaneously or a preferential storage in the intra-abdominal cavity may be metabolically harmful. Clearly, more work remains to be done in this field, first through gene discovery and subsequently through functional follow-up of identified genes.

Body size trajectories and cardio-metabolic resilience to obesity

Individuals with obesity do not represent a single homogenous group in terms of cardio‐metabolic health prospects. The concept of metabolically healthy obesity is a crude way of capturing this heterogeneity and has resulted in a plethora of research linking to future outcomes to show that it is not a benign condition. By contrast, very few studies have looked back in time and modelled the life course processes and exposures that explain the heterogeneity in cardio‐metabolic health and morbidity and mortality risk among people with the same body mass index (BMI) (or waist circumference or percentage body fat). The aim of the Medical Research Council New Investigator Research Grant (MR/P023347/1) ‘Body size trajectories and cardio‐metabolic resilience to obesity in three United Kingdom birth cohorts’ is to reveal the body size trajectories, pubertal development patterns and other factors (e.g. early‐life adversity) that might attenuate the positive associations of adulthood obesity makers (e.g. BMI) with cardio‐metabolic disease risk factors and other outcomes, thereby providing some degree of protection against the adverse effects of obesity. This work builds on the Principle Investigator's previous research as part of the Cohort and Longitudinal Studies Enhancement Resources initiative and focuses on secondary data analysis in the nationally representative UK birth cohort studies (initiated in 1946, 1958 and 1970), which have life course body size and exposure data and a biomedical sweep in adulthood. The grant will provide novel evidence on the life course processes and exposures that lead to some people developing a cardio‐metabolic complication or disease or dying while other people with the same BMI do not. This paper details the grant's scientific rationale, research objectives and potential impact.

Distribution of metabolic/obese phenotypes and association with diabetes: 5 years' cohort based on 22,276 elderly

AIMS

To describe the distribution and changes of different metabolic/obese phenotypes among more than 22,000 male elderly in China, and also explore the association with diabetes incidence.

METHODS

A cohort study based on 22,276 male elderly was conducted in Beijing, from 2009 to 2013. Multiple Cox model was used to calculate the relative risk.

RESULTS

There were only 53.8% of total participants who kept the same phenotype for the 5 years. On the whole, participants with metabolically unhealthy phenotypes had higher relative risks (RRs) than those with metabolically healthy phenotypes. RRs for diabetes showed an increasing trend along with metabolic abnormalities (p < 0.001). However, no statistically significant difference was found across different obese status with the same number of metabolic abnormalities. Changes of metabolic/obese status also showed the same trend. Those who had kept metabolic unhealthy had the highest RRs for diabetes incidence, which was higher than those who kept obesity.

CONCLUSIONS

Both metabolically healthy obesity and metabolically unhealthy normal weight phenotypes had an increased risk for diabetes incidence, and metabolic abnormalities might have more influence on diabetes than obesity itself. Changes of metabolic/obese status also had an important impact on diabetes incidence.

Abdominal obesity phenotypes and incident diabetes over 12 years of follow-up: The Tehran Lipid and glucose study

AIMS

To investigate future diabetes in different abdominal obesity phenotypes during 12 years of follow-up.

METHODS

For this population-based cohort, 7982 adults without diabetes including 3533 men and 4449 women, aged ≥20 years were selected from the Tehran Lipid and Glucose Study. Abdominal obesity was defined according to the national cutoffs for waist circumference (WC). Metabolic health was defined as having ≤1 metabolic abnormality based on Joint Interim Statement (JIS) criteria other than WC. Participants were classified into 4 groups of abdominal obesity phenotypes: Metabolically healthy non-abdominal obese (MHNAO), metabolically healthy abdominal obese (MHAO), metabolically unhealthy non-abdominal Obese (MUNAO), and metabolically unhealthy abdominal obese (MUAO).

RESULTS

In total, 1018 cases of incident diabetes occurred. Compared to the MHNAO phenotype, based on multivariate Cox regression models, diabetes risk was increased in all unhealthy phenotypes except the MUNAO phenotype in men. Regarding the association of the MHAO phenotype with incident diabetes, borderline statistical significance in men [HR 1.5 (95% CI: 1.0-2.36), p-value: 0.07] and statistical significance in women [HR 1.68 (95% CI: 1.08-2.6)] were detected.

CONCLUSIONS

In addition to unhealthy phenotypes except the MUNAO phenotype in men, the MHAO phenotype is also associated with incident diabetes, highlighting the importance of preventive strategies in this subgroup of abdominally obese subjects.

Cardiovascular disease outcomes in metabolically healthy obesity in communities of Beijing cohort study

OBJECTIVE

The objective of this study was to investigate the association between metabolically healthy obese (MHO) phenotype and the risk of cardiovascular disease (CVD).

METHODS

A total of 9393 subjects aged ≥40 years were enrolled in the cohort study (2011-2015). The participants were stratified by body mass index category and metabolic risk at baseline, and incidence of CVD was ascertained at follow-up.

RESULTS

The MHO accounted for 6.7%. Compared with the metabolically healthy normal weight (MHNW) group, MHO subjects demonstrated increased risk of CVD events (HR = 1.91; 95% CI, 1.13-3.24). In people with obesity, there was no significant difference on increasing risk of incidence of CVD in the metabolically unhealthy individuals compared with metabolically healthy individuals (HR = 1.19; 95% CI, 0.74-1.91). Female (OR = 1.97; 95% CI, 1.06-3.64), smoking (OR = 2.09; 95% CI, 1.06-4.10), a larger waist circumference (OR = 1.07; 95% CI, 1.03-1.10) and higher LDL cholesterol levels (OR = 1.55; 95% CI, 1.20-2.00) were independent risk factors of the development of the MHO to the metabolically unhealthy obese (MUO) phenotype.

CONCLUSIONS

The risk of CVD events of MHO phenotypes is similar to MUO phenotypes; both are higher than the MHNW phenotypes.

The Association Between Metabolically Healthy Obesity and the Risk of Proteinuria: The Kansai Healthcare Study

Background

Metabolically healthy obesity seems to be a unique phenotype for the risk of cardiometabolic diseases. However, it is not known whether this phenotype is associated with the risk of proteinuria.

Methods

Study subjects were 9,185 non-diabetic Japanese male workers aged 40–55 years who had no proteinuria, an estimated glomerular filtration rate ≥60 mL/min/1.73 m², no history of cancer, and no use of antihypertensive or lipid-lowering medications at baseline. Obesity was defined as body mass index ≥25.0 kg/m². Metabolic health was defined as the presence of no Adult Treatment Panel III components of the metabolic syndrome criteria, excluding waist circumference, and metabolic unhealth was defined as the presence of one or more metabolic syndrome components, excluding waist circumference. “Consecutive proteinuria” was considered positive if proteinuria was detected twice consecutively as 1+ or higher on urine dipstick at annual examinations to exclude chance proteinuria as much as possible.

Results

During the 81,660 person-years follow-up period, we confirmed 390 cases of consecutive proteinuria. Compared with metabolically healthy non-obesity, metabolically healthy obesity was not associated with the risk of consecutive proteinuria (multiple-adjusted hazard ratio [HR] 0.86; 95% confidence interval [CI], 0.37–1.99), but metabolically unhealthy non-obesity with ≥2 metabolic syndrome components (HR 1.77; 95% CI, 1.30–2.42), metabolically unhealthy obesity with one component (HR 1.71; 95% CI, 1.12–2.61), and metabolically unhealthy obesity with ≥2 metabolic syndrome components (HR 2.77; 95% CI, 2.01–3.82) were associated with an increased risk of consecutive proteinuria.

Conclusions

Metabolically healthy obesity did not increase the risk of consecutive proteinuria in Japanese middle-aged men.

Enzyme-Based Glucose Sensor: From Invasive to Wearable Device

Blood glucose concentration is a key indicator of patients' health, particularly for symptoms associated with diabetes mellitus. Because of the large number of diabetic patients, many approaches for glucose measurement have been studied to enable continuous and accurate glucose level monitoring. Among them, electrochemical analysis is prominent because it is simple and quantitative. This technology has been incorporated into commercialized and research-level devices from simple test strips to wearable devices and implantable systems. Although directly monitoring blood glucose assures accurate information, the invasive needle-pinching step to collect blood often results in patients (particularly young patients) being reluctant to adopt the process. An implantable glucose sensor may avoid the burden of repeated blood collections, but it is quite invasive and requires periodic replacement of the sensor owing to biofouling and its short lifetime. Therefore, noninvasive methods to estimate blood glucose levels from tears, saliva, interstitial fluid (ISF), and sweat are currently being studied. This review discusses the evolution of enzyme-based electrochemical glucose sensors, including materials, device structures, fabrication processes, and system engineering. Furthermore, invasive and noninvasive blood glucose monitoring methods using various biofluids or blood are described, highlighting the recent progress in the development of enzyme-based glucose sensors and their integrated systems.

Metabolically healthy obese and unhealthy normal weight in Iranian adult population: Prevalence and the associated factors

AIMS

The objective of this study was to determine the prevalence and the associated factors of metabolically unhealthy in normal-weight and metabolically healthy in obese.

METHODS

We analyzed the data of a representative sample of 986 participants recruited among adult population of north of Iran. Data were collected regarding demographic characteristics, lifestyle, body mass index, abdominal obesity measures, blood pressure, and lipid profiles. The participants were classified as metabolically healthy obese (MHO) and metabolically unhealthy normal-weight (MUNW). Metabolically unhealthy was defined as the presence of  ≥2 non-obese components of metabolic syndrome based on ATP III criteria.

RESULTS

The prevalence rate of MUNW and MHO accounted for 17.2% and 15.1% respectively. Mean age of participants with metabolically unhealthy was significantly greater than metabolically healthy in both normal weight and overweight/obese (P=0.001). The results of multiple logistic regression analysis showed in normal-weight individuals, a significant association of MUNW was found with age group of 50-59 years(OR=3.83, 95%CI: 1.71-8.57) and 60-70 years by OR=4.74(95%CI:1.79-12.54) as compared with age group of 20-29 years. It was also associated with current smoking. While metabolically healthy state in overweight/obese was inversely associated with age 50-59 years by OR=0.26 (95%CI:0.13-0.54) and age 60-70 years by OR=0.15 (95%CI:0.05- 0.39) and higher WC by OR=0.47 (95%CI:0.31-0.72) but positively associated with female-sex by OR=1.74 (95%CI:1.07-2.82).

CONCLUSION

Aging and smoking are significantly associated with metabolic abnormalities in normal-weight while aging, abdominal obesity negatively and female positively associated with metabolically healthy in obese.

Risk of ischemic stroke in metabolically healthy obesity: A nationwide population-based study

Background

Whether metabolically healthy obese (MHO) individuals are at increased risk of ischemic stroke is not well known. We investigated the association of the MHO phenotype with ischemic stroke.

Methods

A total of 354,083 adults (age 45.8 ± 14.2 years) from the Korean National Health Insurance Service–National Sample Cohort enrolled in 2004–2008 were followed-up for incident ischemic stroke until 2013. Subjects meeting none of the metabolic syndrome criteria were classified as ‘metabolically healthy’. The cohort was categorized into four groups according to obesity and metabolic status: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), MHO, and metabolically unhealthy obese (MUO).

Results

Ischemic stroke was newly diagnosed in 4,884 (1.4%) individuals during a mean follow-up of 7.4 ± 1.5 years. Stroke incidence rates for the MHNW, MUNW, MHO, and MUO groups were 0.56, 2.61, 0.61, and 2.76 per 1,000 person-years, respectively. While risk for stroke increased significantly in metabolically unhealthy groups, it was not increased in MHO compared to the MHNW group on multivariate analysis. In metabolically healthy individuals, obesity did not increase the risk for ischemic stroke, regardless of the severity of obesity. Meanwhile, in metabolically unhealthy individuals, being obese was significantly associated with increased risk of stroke.

Conclusions

MHO individuals were not at increased risk for ischemic stroke. However, obesity increased risk for ischemic stroke in persons with metabolic risk factors; therefore, maintaining normal weight may be more important for this population. Also, metabolic unhealthiness showed greater association than obesity with stroke.

Metabolically healthy obesity, vitamin D, and all-cause and cardiometabolic mortality risk in NHANES III

BACKGROUND & AIMS

Previous studies assessing the prognosis of metabolically healthy obesity (MHO) have been limited by a lack of a harmonized definition of MHO phenotype. Furthermore, obesity is a risk factor for vitamin D deficiency and low vitamin D status has been associated with a higher risk of mortality; however, few studies have evaluated the joint association between vitamin D, metabolic health phenotype, and mortality risk. Using a harmonized definition, we investigated whether MHO is associated with subsequent all-cause and cardiometabolic mortality, and whether serum 25-hydroxyvitamin D [25(OH)D] modifies these associations.

METHODS

This study included participants aged ≥20 years from the Third National Health and Nutrition Examination Survey (NHANES III). MHO phenotype was defined as a combination of obesity (≥30 kg/m²) and zero component of metabolic syndrome. Multivariable Cox regression was used to assess the risk of mortality across metabolic phenotypes, and the joint association between metabolic phenotype and 25(OH)D. Fine and Gray regression was performed to account for competing risk events.

RESULTS

Among 11,333 participants, a total of 2980 deaths (937 cardiometabolic death outcomes) occurred during a median follow-up of 19.1 years. In the absence of any metabolic abnormality, obesity (MHO) was not associated with a higher risk of all-cause (hazard ratio [HR], 0.89 [95% CI, 0.52-1.51]) or cardiometabolic mortality (cause-specific HR, 1.21 [95% CI 0.33-4.46]). Similar results were obtained from competing risk analysis. No significant differences in average 25(OH)D levels were observed between MHO and non-MHO participants; however, there was a significant interaction between metabolic health phenotype and serum 25(OH)D in relation to cardiometabolic mortality such that levels of serum 25(OH)D < 50 nmol/L were associated with increased risk of cardiometabolic mortality, particularly in participants within the normal-weight and obese BMI ranges.

CONCLUSIONS

Our results support the hypothesis that MHO phenotype is a benign health condition. Vitamin D deficiency may exacerbate the risk of cardiometabolic death outcomes associated with metabolic dysfunction in normal weight and obese individuals. Further research is warranted to validate our findings.

Separate and combined associations of obesity and metabolic health with coronary heart disease: a pan-European case-cohort analysis

Aims

The hypothesis of 'metabolically healthy obesity' implies that, in the absence of metabolic dysfunction, individuals with excess adiposity are not at greater cardiovascular risk. We tested this hypothesis in a large pan-European prospective study.

Methods and results

We conducted a case-cohort analysis in the 520 000-person European Prospective Investigation into Cancer and Nutrition study ('EPIC-CVD'). During a median follow-up of 12.2 years, we recorded 7637 incident coronary heart disease (CHD) cases. Using cut-offs recommended by guidelines, we defined obesity and overweight using body mass index (BMI), and metabolic dysfunction ('unhealthy') as ≥ 3 of elevated blood pressure, hypertriglyceridaemia, low HDL-cholesterol, hyperglycaemia, and elevated waist circumference. We calculated hazard ratios (HRs) and 95% confidence intervals (95% CI) within each country using Prentice-weighted Cox proportional hazard regressions, accounting for age, sex, centre, education, smoking, diet, and physical activity. Compared with metabolically healthy normal weight people (reference), HRs were 2.15 (95% CI: 1.79; 2.57) for unhealthy normal weight, 2.33 (1.97; 2.76) for unhealthy overweight, and 2.54 (2.21; 2.92) for unhealthy obese people. Compared with the reference group, HRs were 1.26 (1.14; 1.40) and 1.28 (1.03; 1.58) for metabolically healthy overweight and obese people, respectively. These results were robust to various sensitivity analyses.

Conclusion

Irrespective of BMI, metabolically unhealthy individuals had higher CHD risk than their healthy counterparts. Conversely, irrespective of metabolic health, overweight and obese people had higher CHD risk than lean people. These findings challenge the concept of 'metabolically healthy obesity', encouraging population-wide strategies to tackle obesity.

Obesity phenotypes and their paradoxical association with cardiovascular diseases

The pro-inflammatory state of the visceral adipose tissue (VAT) is supposed to accelerate cardiovascular (CV) and metabolic diseases in obese subjects. Some studies have recently reported an improved CV prognosis in certain obese and overweight patients as compared with leaner ones. This phenomenon, known as the "obesity paradox" (OP), has been described in many chronic diseases. This narrative review is based on the material searched for and obtained via PubMed and Web of Science up to May 2017. The search terms we used were: "obesity, paradox, adipose tissue" in combination with "cardiovascular, coronary heart disease, heart failure, arrhythmias". Using the current Body Mass Index (BMI)-based obesity definition, individuals with different clinical and biochemical characteristics are gathered together in the same category. Emerging evidence point to the existence of many "Obesity phenotypes" with different association with CV risk, accordingly to physical and life-style features. In this narrative review, we discussed if obesity phenotypes may be associated with a different CV risk, potentially explaining the OP. As a globally accepted definition of obesity is still lacking, we emphasized the need of a new approach, which should consider the heterogeneity of obesity. Better defining "obesities" and related CV risk is critical to markedly improve the classical BMI-based definition of obesity.

Body composition and development of diabetes: a 15-year follow-up study in a Japanese population

BACKGROUND/OBJECTIVES

Few longitudinal studies have examined the association between diabetes risk and body composition in Asians. The aim of this prospective cohort study was to determine the role of body composition, estimated by whole-body dual-energy X-ray absorptiometry, in the development of diabetes and to examine the impact of body composition on diabetes risk in normal weight (body mass index (BMI) <23 kg/m²) and overweight/obese groups (≥23 kg/m²).

SUBJECTS/METHODS

We measured the body composition for 1532 diabetes-free subjects (463 men and 1069 women), aged 48-79 years, at the baseline examination period from 1994-96 and followed-up to detect new cases of diabetes over the next 15 years (median 13.4 years).

RESULTS

After being adjusted for BMI and other potential confounding factors, body fat distribution was associated with diabetes risk. Percentage of trunk fat was positively associated with the development of diabetes (hazards ratio (HR) per 1 SD (95% confidential interval (CI)), 1.58 (1.10-2.28) in men, and 1.34 (0.99-1.83) in women), and percentage of leg fat was negatively associated with the development of diabetes (HR per 1 SD (95% CI), 0.68 (0.50-0.91) in men and 0.68 (0.55-0.85) in women). The estimated HRs of % trunk and leg fat on the development of diabetes differed little between normal weight and overweight/obese subjects. Appendicular lean mass was also negatively associated with diabetes risk only in normal weight men.

CONCLUSIONS

Opposite associations of trunk fat and leg fat with diabetes risk were observed. Assessment of body composition might help in the evaluation of diabetes risk.

Mexican American and South Asian population-based cohorts reveal high prevalence of type 2 diabetes and crucial differences in metabolic phenotypes

OBJECTIVE

Prevalence of type 2 diabetes varies by region and ancestry. However, most guidelines for the prevention of diabetes mellitus (DM) are based on European or non-Hispanic white populations. Two ethnic minority populations-Mexican Americans (MAs) in Texas, USA, and South Indians (SIs) in Tamil Nadu, India-have an increasing prevalence of DM. We aimed to understand the metabolic correlates of DM in these populations to improve risk stratification and DM prevention.

RESEARCH DESIGN AND METHODS

The Cameron County Hispanic Cohort (CCHC; n=3023) served as the MA sample, and the Population Study of Urban, Rural, and Semi-Urban Regions for the Detection of Endovascular Disease (PURSE; n=8080) served as the SI sample. Using design-based methods, we calculated the prevalence of DM and metabolic comorbidities in each cohort. We determined the association of DM with metabolic phenotypes to evaluate the relative contributions of obesity and metabolic health to the prevalence of DM.

RESULTS

In the CCHC (overall DM prevalence 26.2%), good metabolic health was associated with lower prevalence of DM, across age groups, regardless of obesity. In PURSE (overall prevalence 27.6%), probability of DM was not strongly associated with metabolic phenotypes, although DM prevalence was high in older age groups irrespective of metabolic health.

CONCLUSION

Our study provides robust, population-based data to estimate the prevalence of DM and its associations with metabolic health. Our results demonstrate differences in metabolic phenotypes in DM, which should inform DM prevention guidelines in non-European populations.

Relationship of Circulating Fetuin-A Levels with Body Size and Metabolic Phenotypes

BACKGROUND

Previous studies have suggested the existence of distinct body size subgroups according to metabolic health referred to as metabolically healthy obesity (MHO) and metabolically abnormal but normal weight (MANW) patients. Although nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity and metabolic syndrome, the relationship between these phenotypes and fetuin-A, a representative hepatokine, has not been explored.

METHODS

We examined the association between circulating fetuin-A levels, metabolic health phenotypes, cardiometabolic risk parameters, and subclinical atherosclerosis in 290 subjects who were randomly selected from an ongoing cohort study.

RESULTS

Fetuin-A concentrations were significantly associated with detrimental anthropometric and laboratory measurements, including increased waist circumference, blood pressure, alanine aminotransferase, fasting plasma glucose, and triglyceride levels. Furthermore, fetuin-A levels were significantly increased in the metabolically abnormal (MA) group compared to the metabolically healthy (MH) group in subjects without obesity (717.1 [632.1, 769.7] vs. 599.5 [502.0, 709.3], P = 0.001) and subjects with obesity (704.1 [595.5-880.9] vs. 612.2 [547.9-802.1], P = 0.016). In addition, brachial-ankle pulse wave velocity (baPWV), which reflects arterial stiffness, was higher in MA individuals compared to MH individuals. Multiple logistic regression analysis revealed that both individuals without obesity (P for trend = 0.017) and with obesity (P for trend = 0.028) in the higher tertiles of fetuin-A had an increased risk of MA than those in the lowest tertile.

CONCLUSIONS

This study demonstrates that fetuin-A levels are significantly associated with metabolic health phenotypes, such as MHO and MANW, in Korean adults.

Evidence of genetic predisposition for metabolically healthy obesity and metabolically obese normal weight

Obesity has evolved into a global pandemic that constitutes a major threat to public health. The majority of obesity-related health care costs are due to cardiometabolic complications, such as insulin resistance, dyslipidemia, and hypertension, which are risk factors for Type 2 diabetes and cardiovascular disease. However, many obese individuals, often called metabolically healthy obese (MHO), seem to be protected from these cardiometabolic complications. Conversely, there is a group of individuals who suffer from cardiometabolic complications despite being of normal weight; a condition termed metabolically obese normal weight (MONW). Recent large-scale genomic studies have provided evidence that a number of genetic variants show an association with increased adiposity but a favorable cardiometabolic profile, an indicator for the genetic basis of the MHO and MONW phenotypes. Many of these loci are located in or near genes that implicate pathways involved in adipogenesis, fat distribution, insulin signaling, and insulin resistance. It has been suggested that a threshold for subcutaneous adipose tissue expandability may be at play in the manifestation of MHO and MONW, where expiry of adipose tissue storage capacity could lead to ectopic lipid accumulation in non-adipose tissues such as liver, muscle, heart, and pancreatic beta cells. Understanding the genetic aspects of the mechanisms that underpin MHO and MONW is crucial to define appropriate public health action points and to develop effective intervention measures.

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.

Risk of diabetes according to the metabolic health status and degree of obesity

AIM

To determine the progression rates from metabolically healthy or unhealthy normal weight, overweight and obese phenotype to type 2 diabetes (T2D) in a non-diabetic high risk population in Isfahan, Iran.

METHODS

T2D incidence during a mean (SD) follow-up of 10.1 (2.3) years was examined among 1,982 non-diabetic first-degree relatives (FDR) of patients with T2D 30-70 years old. Participants were divided into 6 groups based on body mass index and metabolic syndrome component, except waist circumference, at baseline: metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW) and metabolically unhealthy obese (MUO).

RESULTS

The MHO, MUOW, and MUO individuals at baseline were associated with incidence of T2D, independently of age and gender. MHO were 3 times (OR 2.96; 95% CI 1.07, 8.24) and MUOW were 2.75 times (95% CI 1.17, 6.45) more likely to develop T2D than those with MHNW. There was excess risk in MUO than MHO (OR 3.86; 95% CI 1.64, 9.11).

CONCLUSIONS

Obesity was a risk factor for T2D, even in the absence of any metabolic abnormalities. Metabolic abnormalities were a stronger predictor of incident T2D than obesity.

Incidence of components of metabolic syndrome in the metabolically healthy obese over 9 years follow-up: the Atherosclerosis Risk In Communities study

Background

Some obese adults are not afflicted by the metabolic abnormalities often associated with obesity [the “metabolically healthy obese” (MHO)], however, they may be at increased risk of developing cardiometabolic abnormalities in the future. Little is known about the relative incidence of individual components of metabolic syndrome (MetSyn).

Methods

We used data from a multi-center, community-based cohort aged 45–64 years at recruitment [the Atherosclerosis Risk in Communities (ARIC) study] to examine the first appearance of any MetSyn component, excluding waist circumference. Body mass index (BMI, kg/m²) and cardiometabolic data were collected at four triennial visits. Our analysis included 3,969 adults who were not underweight and free of the components of MetSyn at the initial visit. Participants were classified as metabolically healthy normal weight (MHNW), over weight (MHOW) and MHO at each visit. Adjusted hazard ratios (HR) and 95% confidence intervals were estimated with proportional hazards regression models.

Results

The relative rate of developing each risk factor was higher among MHO than MHNW with the strongest association noted for elevated fasting glucose [MHO vs. MHNW, HR: 2.33 (1.77, 3.06)]. MHO was also positively associated with elevated triglycerides [HR: 1.63 (1.27, 2.09)], low HDL-C [HR: 1.68 (1.32, 2.13)] and elevated blood pressure [HR: 1.54 (1.26, 1.88)]. A similar, but less pronounced pattern was noted among the MHOW vs. MHNW.

Conclusions

We conclude that even among apparently healthy individuals, obesity and overweight are related to more rapid development of at least 1 cardiometabolic risk factor, and that elevations in blood glucose develop most rapidly.

The Definition and Prevalence of Obesity and Metabolic Syndrome

Increase in prevalence of obesity has become a worldwide major health problem in adults, as well as among children and adolescents. Furthermore, total adiposity and truncal subcutaneous fat accumulation during adolescence are positively and independently associated with atherosclerosis at adult ages. Centrally accumulation of body fat is associated with insulin resistance, whereas distribution of body fat in a peripheral pattern is metabolically less important. Obesity is associated with a large decrease in life expectancy. The effect of extreme obesity on mortality is greater among younger than older adults. In this respect, obesity is also associated with increased risk of several cancer types. However, up to 30% of obese patients are metabolically healthy with insulin sensitivity similar to healthy normal weight individuals, lower visceral fat content, and lower intima media thickness of the carotid artery than the majority of metabolically "unhealthy" obese patients.Abdominal obesity is the most frequently observed component of metabolic syndrome. The metabolic syndrome; clustering of abdominal obesity, dyslipidemia, hyperglycemia and hypertension, is a major public health challenge. The average prevalence of metabolic syndrome is 31%, and is associated with a two-fold increase in the risk of coronary heart disease, cerebrovascular disease, and a 1.5-fold increase in the risk of all-cause mortality.

Association of the Cardiometabolic Staging System with Individual Engagement and Quality of Life in the US Adult Population

OBJECTIVE

The aim of this study was to examine the relationships of Cardiometabolic Disease Staging (CMDS), a validated five-stage system for assessing risk for diabetes, cardiovascular mortality, and all-cause mortality, with measures of individual engagement and health-related quality of life (HRQOL) in the US adult population.

METHODS

Data from the 2011-2014 National Health and Nutrition Examination Survey were used to derive the CMDS stages, five participant engagement measures, and four HRQOL measures among adult participants ≥ 40 years of age. Analyses accounted for the complex sampling design and sample weights.

RESULTS

Higher CMDS was associated with greater participant awareness of cardiometabolic risk, but after adjusting for covariates, only Stage 4 remained significant (odds ratio: 5.08; 95% CI: 3.25, 7.94). Higher CMDS was associated with receiving recommendations to engage in a healthy lifestyle, not meeting 2008 physical activity guidelines, and fewer leisure time moderate activities after controlling for covariates. For HRQOL measures, Stage 4 was associated with a higher likelihood of perceiving health as fair or poor (odds ratio: 4.85; 95% CI: 2.42, 9.73).

CONCLUSIONS

Higher CMDS was associated with greater individual awareness of risk, less leisure time physical activity, and worse self-rated health. CMDS is a clinically practical method for identifying individuals for targeted preventive strategies.

Metabolically healthy obesity: a friend or foe?

Obesity is associated with a reduced life expectancy, largely because obese individuals are at an increased risk of type 2 diabetes, cardiovascular disease, and several types of cancer. Much interest has recently focused on the concept of "all obesity is not created equally." Obese individuals without the metabolic abnormalities that commonly accompany excess adiposity, a condition known as metabolically healthy obesity (MHO), account for a substantial proportion of the obese adult population. Numerous possible mechanisms underlying MHO have been suggested, including adipose tissue distribution and inflammation. However, the prognostic value of MHO is controversial and considerably challenging. The lack of a standard definition for metabolic health and obesity as well as the dynamic properties of MHO may have contributed to these inconsistent results. This review aimed to present several current issues regarding MHO including its definition, epidemiology, natural course, suggested mechanisms, and clinical implications in the context of patient prognosis.

Influence of the definition of "metabolically healthy obesity" on the progression of coronary artery calcification

OBJECTIVES

Debates whether metabolically healthy obesity (MHO) increases the cardiovascular risk might be due to the metabolic instability of MHO or the absence of a perfect definition of MHO. Therefore, we aimed to investigate the influence of the MHO phenotype on the coronary artery calcium score (CACS) progression according to definition of MHO.

METHODS

We analyzed a retrospective cohort with a CACS of 0 at baseline and available serial CACS measurements taken ≥ 12 months apart (n = 1,218). Obesity was defined as BMI ≥ 25 kg/m2, and MHO was defined as obesity accompanied by ≤ 1 (MHO class I) or 0 (MHO class II) components of metabolic syndrome (MetS).

RESULTS

During a median follow-up of 45 months, 32.2% of MHO class I and 10.2% of MHO class II subjects developed MetS. Compared to non-obese/metabolically healthy subjects (reference group), hazard ratios (HR) for development of MetS were 2.174 (95% confidence interval [CI]: 1.513-3.124) and 1.166 (95% CI: 0.434-3.129) for MHO class I and II subjects, respectively. The MHO class I subjects showed a significantly increased risk of CACS progression as compared to the reference group (HR: 1.653; 95% CI: 1.144-2.390), whereas MHO class II subjects did not (HR: 1.195; 95% CI: 0.514-2.778). Among subjects with MHO class I, no significant CACS progression was observed in the subjects who maintained metabolic health during follow-up (HR: 1.448; 95% CI: 0.921-2.278).

CONCLUSIONS

The risks of metabolic deterioration and CACS progression were significant in subjects with MHO class I, but not in those with MHO class II.

Metabolically Healthy Obesity and Ischemic Heart Disease: A 10-Year Follow-Up of the Inter99 Study

CONTEXT

Recent studies have suggested that a subgroup of obese individuals is not at increased risk of obesity-related complications. This subgroup has been referred to as metabolically healthy obese.

OBJECTIVE

To investigate whether obesity is a risk factor for development of ischemic heart disease (IHD) irrespective of metabolic health.

DESIGN

In all, 6238 men and women from the Danish prospective Inter99 study were followed during 10.6 (standard deviation = 1.7) years.

SETTING

General community.

PARTICIPANTS

Participants were classified according to body mass index and four metabolic risk factors (low high-density lipoprotein cholesterol, elevated blood pressure, triglycerides, and fasting plasma glucose). Metabolically healthy individuals were defined as having no metabolic risk factors, and metabolically unhealthy individuals were defined as having a minimum of one.

MAIN OUTCOME MEASURES

IHD.

RESULTS

During follow-up, 323 participants developed IHD. Metabolically healthy obese men had increased risk of IHD compared with metabolically healthy normal-weight men [hazard ratio (HR), 3.1; 95% confidence interval (CI), 1.1 to 8.2)]. The corresponding results for women were less pronounced (HR, 1.8; 95% CI, 0.7 to 4.8). Being metabolically healthy but overweight was not associated with higher risk of IHD in men (HR, 1.1; 95% CI, 0.5 to 2.4), and in women the risk was only slightly increased and insignificant (HR, 1.5; 95% CI, 0.8 to 3.0). A substantial proportion of metabolically healthy individuals became metabolically unhealthy after 5 years of follow-up. When these changes in exposure status were taken into account, slightly higher risk estimates were found.

CONCLUSIONS

Being obese is associated with higher incidence of IHD irrespective of metabolic status, and we question the feasibility of denoting a subgroup of obese individuals as metabolically healthy.

Cardiometabolic Abnormalities Among Normal-Weight Persons From Five Racial/Ethnic Groups in the United States: A Cross-sectional Analysis of Two Cohort Studies

BACKGROUND

The relationship between body weight and cardiometabolic disease may vary substantially by race/ethnicity.

OBJECTIVE

To determine the prevalence and correlates of the phenotype of metabolic abnormality but normal weight (MAN) for 5 racial/ethnic groups.

DESIGN

Cross-sectional analysis.

SETTING

2 community-based cohorts.

PARTICIPANTS

2622 white, 803 Chinese American, 1893 African American, and 1496 Hispanic persons from MESA (Multi-Ethnic Study of Atherosclerosis) and 803 South Asian participants in the MASALA (Mediators of Atherosclerosis in South Asians Living in America) study.

MEASUREMENTS

Prevalence of 2 or more cardiometabolic abnormalities (high fasting glucose, low high-density lipoprotein cholesterol, and high triglyceride levels and hypertension) among normal-weight participants was estimated. Correlates of MAN were assessed by using log-binomial models.

RESULTS

Among normal-weight participants (n = 846 whites, 323 Chinese Americans, 334 African Americans, 252 Hispanics, and 195 South Asians), the prevalence of MAN was 21.0% (95% CI, 18.4% to 23.9%) in whites, 32.2% (CI, 27.3% to 37.4%) in Chinese Americans, 31.1% (CI, 26.3% to 36.3%) in African Americans, 38.5% (CI, 32.6% to 44.6%) in Hispanics, and 43.6% (CI, 36.8% to 50.6%) in South Asians. Adjustment for demographic, behavioral, and ectopic body fat measures did not explain racial/ethnic differences. After adjustment for age, sex, and race/ethnicity-body mass index (BMI) interaction, for the equivalent MAN prevalence at a BMI of 25.0 kg/m2 in whites, the corresponding BMI values were 22.9 kg/m2 (CI, 19.5 to 26.3 kg/m2) in African Americans, 21.5 kg/m2 (CI, 18.5 to 24.5 kg/m2) in Hispanics, 20.9 kg/m2 (CI, 19.7 to 22.1 kg/m2) in Chinese Americans, and 19.6 kg/m2 (CI, 17.2 to 22.0 kg/m2) in South Asians.

LIMITATION

Cross-sectional study design and lack of harmonized dietary data between studies.

CONCLUSION

Compared with whites, all racial/ethnic minority groups had a statistically significantly higher prevalence of MAN, which was not explained by demographic, behavioral, or ectopic fat measures. Using a BMI criterion for overweight to screen for cardiometabolic risk may result in a large proportion of racial/ethnic minority groups being overlooked.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Metabolically healthy obese women have longer telomere length than obese women with metabolic syndrome

Introduction

Obesity is the principal component in the Metabolic Syndrome (MetS) that determines the progression of metabolic complications. Metabolically healthy obese (MHO) individuals seem to be protected against those complications. Telomere length (TL) as a novel marker of cellular aging had a complex relationship to the MetS. The principal aim of this study was to investigate the TL in MHO, and to study the association between TL and the worsening of the metabolic condition.

Material and methods

We have determined the absolute TL (aTL) in 400 women (mean age of 46.76 ± 15.47 years; range: 18–86 years), grouped according to the metabolic condition in three groups: metabolically healthy non-obese women (MHNO), MHO and obese women with MetS (MSO); and grouped according to the number of components of MetS.

Results

We found that MHO displays significantly higher aTL than MSO (p = 0.033; r = -4.63; 95% CI r = -8.89 / -0.37), but did not differ from MHNO. A decrease in aTL with the progressive increase in the number of MetS components was also observed (p < 0.001; r = -2.06; 95% CI r = -3.13 / -0.99). In this way, our results indicate that aTL is influenced by the presence of MetS, but it is not affected by the presence of obesity.

Discussion

We found that shorter aTL is not associated with MHO, but is related to MetS and with the increased number of metabolic abnormalities.

Regulators of mitochondrial quality control differ in subcutaneous fat of metabolically healthy and unhealthy obese monkeys

OBJECTIVE

Obesity exists with and without accompanying cardiometabolic disease, termed metabolically unhealthy obesity (MUO) and healthy obesity (MHO), respectively. Underlying differences in the ability of subcutaneous (SQ) fat to respond to nutrient excess are emerging as a key pathway. This study aimed to document the first spontaneous animal model of MHO and MUO and differences in SQ adipose tissue.

METHODS

Vervet monkeys (Chlorocebus aethiops; N = 171) were screened for metabolic syndrome. A subset of MHO and MUO monkeys (n = 6/group) had SQ fat biopsies collected for histological evaluations and examination of key mitochondrial proteins.

RESULTS

Obesity was seen in 20% of monkeys, and within this population, 31% were healthy, which mirrors human prevalence estimates. MUO monkeys had more than 60% lower adiponectin concentrations despite similar fat cell size, uncoupling protein 3, and activated macrophage abundance. However, alternatively activated/anti-inflammatory macrophages were 70% lower. Deficiencies of 50% or more in mitochondrial quality control regulators and selected mitochondrial fission and fusion markers were observed in the SQ fat of MUO monkeys despite comparable mitochondrial content.

CONCLUSIONS

A novel and translatable spontaneously obese animal model of MHO and MUO, occurring independently of dietary factors, was characterized. Differences in mitochondrial quality and inflammatory cell populations of subcutaneous fat may underpin divergent metabolic health.

Obesity is more closely related with hepatic steatosis and fibrosis measured by transient elastography than metabolic health status

OBJECTIVE

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) involves multiple concomitant events induced by obesity and metabolic health condition. This study aimed to assess the risk of NAFLD according to metabolic health and obesity status using transient elastography (TE).

MATERIALS AND METHODS

A total of 2198 asymptomatic adults without chronic liver disease and who underwent a medical health check-up were recruited. Subjects were categorized into four groups according to metabolic health and obesity statuses: metabolically healthy non-obese (MHNO); metabolically unhealthy non-obese (MUNO); metabolically healthy obese (MHO); and metabolically unhealthy obese (MUO). Hepatic steatosis was defined as controlled attenuation parameter (CAP)≥238dB/m, and significant liver fibrosis was defined as liver stiffness measurement (LSM) >7.0kPa, as defined by TE.

RESULTS

Compared with MHNO group, the odds ratios (ORs) [95% confidence interval (CI)] for hepatic steatosis were 2.94 [2.32-3.71], 4.62 [3.52-6.07], and 12.02 [9.08-15.92] in the MUNO, MHO, and MUO groups, respectively (P<0.001) in crude model. Regarding liver fibrosis, there was no significant difference in the ORs in MUNO group (ORs: 0.95 [95% CI, 0.33-2.78], P value = 0.929), whereas there was a significant increase in the ORs in MHO group compared with MHNO group (ORs: 4.32 [95% CI, 1.73-10.76], P=0.002) in the fully adjusted model.

CONCLUSION

Our results show that MHO was associated with both liver steatosis and fibrosis assessed by transient elastography. Our results suggest that a healthy metabolic profile does not protect obese adults from hepatic steatosis or fibrosis, indicating that obesity itself might contribute to liver fibrosis.

Metabolic syndrome among non-obese adults in the teaching profession in Melaka, Malaysia

Background

Non-obese individuals could have metabolic disorders that are typically associated with elevated body mass index (BMI), placing them at elevated risk for chronic diseases. This study aimed to describe the prevalence and distribution of metabolically obese, non-obese (MONO) individuals in Malaysia.

Methods

We conducted a cross-sectional study involving teachers recruited via multi-stage sampling from the state of Melaka, Malaysia. MONO was defined as individuals with BMI 18.5–29.9 kg/m² and metabolic syndrome. Metabolic syndrome was diagnosed based on the Harmonization criteria. Participants completed self-reported questionnaires that assessed alcohol intake, sleep duration, smoking, physical activity, and fruit and vegetable consumption.

Results

A total of 1168 teachers were included in the analysis. The prevalence of MONO was 17.7% (95% confidence interval [CI], 15.3–20.4). Prevalence of metabolic syndrome among the normal weight and overweight participants was 8.3% (95% CI, 5.8–11.8) and 29.9% (95% CI, 26.3–33.7), respectively. MONO prevalence was higher among males, Indians, and older participants and inversely associated with sleep duration. Metabolic syndrome was also more prevalent among those with central obesity, regardless of whether they were normal or overweight. The odds of metabolic syndrome increased exponentially from 1.9 (for those with BMI 23.0–24.9 kg/m²) to 11.5 (for those with BMI 27.5–29.9 kg/m²) compared to those with BMI 18.5–22.9 kg/m² after adjustment for confounders.

Conclusions

The prevalence of MONO was high, and participants with BMI ≥23.0 kg/m² had significantly higher odds of metabolic syndrome. Healthcare professionals and physicians should start to screen non-obese individuals for metabolic risk factors to facilitate early targeted intervention.

•

The prevalence of metabolic syndrome among the non-obese teachers was 17.7%.

•

The odds of metabolic syndrome increased exponentially from a BMI of 23.0 kg/m².

•

Metabolic syndrome was more prevalent among males, Indians, and older teachers.

Association Between the Visceral Adiposity Index and Homeostatic Model Assessment of Insulin Resistance in Participants With Normal Waist Circumference

We assessed the correlation between the visceral adiposity index (VAI; a useful indicator of adipose distribution and function) and homeostatic model assessment of insulin resistance (HOMA-IR) in participants with normal waist circumference. A cross-sectional study was conducted, which included 1834 Chinese adults. The blood pressure, anthropometric measurements, fasting and postprandial blood glucose, fasting insulin, and lipid profiles were measured. The VAI and HOMA-IR were calculated. Participants were divided into 4 groups according to the HOMA-IR level, and the correlation between the VAI and HOMA-IR was analyzed. The VAI gradually increased across the HOMA-IR quartiles ( P < .05), and a Pearson correlation analysis showed that VAI was positively related to the HOMA-IR ( P < .001) in males and females. After adjusting for the other covariates, VAI was independently correlated with the HOMA-IR. A logistic regression analysis indicated that VAI elevation was the main risk factor for the increased HOMA-IR in both genders. Overall, the VAI was closely correlated with the HOMA-IR in a population without central obesity.

Are all metabolically healthy individuals with obesity at the same risk of diabetes onset?

OBJECTIVE

To examine the risk of diabetes and the development of an unhealthy status according to metabolic health. To assess the effect of changes in metabolic health among participants with metabolically healthy obesity (MHO) on the risk of diabetes.

METHODS

A total of 4,340 subjects were included. Unhealthy metabolic status was defined as having three or more risk factors of the Adult Treatment Panel-III criteria. A Cox proportional-hazard analysis was conducted to estimate the hazard ratio (HR) of developing diabetes across the change in the metabolic status of subjects with MHO.

RESULTS

After 40,622 person-years of follow-up, the risk of becoming unhealthy was 1.53 times higher for participants with MHO, compared with lean or overweight healthy subjects. A greater risk of diabetes was found in MHO, but it was attributable to those who progressed to an unhealthier status over time: HR of 4.78 (95% CI: 3.38-6.78). The combination of being metabolically unhealthy and obesity heightened the risk of diabetes: HR of 10.09 (95% CI: 4.82-21.55).

CONCLUSIONS

The increased risk of diabetes in MHO is attributed to the progression to an unhealthier state. "Healthy obesity" is not a permanent situation but a transitory state.

Obesity Severity and Duration Are Associated With Incident Metabolic Syndrome: Evidence Against Metabolically Healthy Obesity From the Multi-Ethnic Study of Atherosclerosis

CONTEXT

Although the health risks of obesity compared to normal weight have been well studied, the cumulative risk associated with chronic obesity remains unknown. Specifically, debate continues about the importance of recommending weight loss for those with metabolically healthy obesity.

OBJECTIVE

We hypothesized that relatively greater severity and longer duration of obesity are associated with greater incident metabolic syndrome. Design, Setting, Participants, and Measures: Using repeated measures logistic regression with random effects, we investigated the association of time-varying obesity severity and duration with incident metabolic syndrome in 2,748 Multi-Ethnic Study of Atherosclerosis participants with obesity (body mass index ≥30 kg/m²) at any visit. Obesity duration was defined as the cumulative number of visits with measured obesity and obesity severity by the World Health Organization levels I-III based on body mass index. Metabolic syndrome was defined using Adult Treatment Panel III criteria modified to exclude waist circumference.

RESULTS

Higher obesity severity (level II odds ratio [OR], 1.32 [95% confidence interval, 1.09-1.60]; level III OR, 1.63 [1.25-2.14] vs level I) and duration (by number of visits: two visits OR, 4.43 [3.54-5.53]; three visits OR, 5.29 [4.21-6.63]; four visits OR, 5.73 [4.52-7.27]; five visits OR, 6.15 [4.19-9.03] vs one visit duration of obesity) were both associated with a higher odds of incident metabolic syndrome.

CONCLUSION

Both duration and severity of obesity are positively associated with incident metabolic syndrome, suggesting that metabolically healthy obesity is a transient state in the pathway to cardiometabolic disease. Weight loss should be recommended to all individuals with obesity, including those who are currently defined as metabolically healthy.

Relationship between body weight and the increment in serum brain-derived neurotrophic factor after oral glucose challenge in men with obesity and metabolic syndrome: A prospective study

Brain-derived neurotrophic factor (BDNF) plays a role in energy homeostasis. However, the postprandial BDNF change has not been well investigated. We hypothesized that the BDNF increment after oral glucose challenge is associated with body weight.To address this possibility, man adults with obesity in conjunction with metabolic syndrome were compared with normal weight controls at baseline in the initial cross-sectional protocol. The obese subjects then underwent a 12-week program for body-weight reduction in the prospective protocol. The area under the curve (AUC) of serum BDNF was recorded during a 75 g oral glucose tolerant test and the BDNF AUC index was defined as [(AUC of BDNF) - (fasting BDNF2 hours)]/(fasting BDNF2 hours).A total of 25 controls and 36 obese subjects completed the study assessments. In the cross-sectional protocol, the BDNF AUC index was significantly higher in the obese subjects than in the controls (9.0 ± 16.5% vs. - 8.0 ± 22.5%, P = 0.001). After weight reduction (from 97.0 ± 12.5 kg to 88.6 ± 12.9 kg, P < 0.001), the percentage change of body weight was significantly associated with the BDNF AUC index after the study (95% CI between 0.21 and 1.82, P = 0.015). Using 6% weight reduction as a cut-off value, a larger weight reduction was able to reliably predict a negative BDNF AUC index.In conclusion, a high BDNF AUC index was observed for obese men in this study, whereas the index value significantly decreased after body-weight reduction. These findings suggest that postprandial BDNF increment may be associated with obesity.

Predictive Value of Triglyceride Glucose Index for the Risk of Incident Diabetes: A 4-Year Retrospective Longitudinal Study

The Triglyceride Glucose Index (TyG index) is considered a surrogate marker of insulin resistance. The aim of this study is to investigate whether the TyG index has a predictive role in identifying individuals with a high risk of incident diabetes and to compare it with other indicators of metabolic health. A total 2900 non-diabetic adults who attended five consecutive annual health check-ups at Kangbuk Samsung Hospital was divided into four subgroups using three methods: (1) baseline TyG index; (2) obesity status (body mass index ≥25 kg/m2) and cutoff value of TyG index; (3) obesity status and metabolic health, defined as having fewer than two of the five components of high blood pressure, fasting blood glucose, triglyceride, low high-density lipoprotein cholesterol, and highest decile of homeostasis model assessment-insulin resistance. The development of diabetes was assessed annually using self-questionnaire, fasting glucose, and glycated hemoglobin. We compared the risk of incident diabetes using multivariate Cox analysis. During 11623 person-years there were 101 case of incident diabetes. Subjects with high TyG index had a high risk of diabetes. For TyG index quartiles, hazard ratios (HRs) of quartiles 3 and 4 were 4.06 (p = 0.033) and 5.65 (p = 0.006) respectively. When the subjects were divided by obesity status and cutoff value of TyG index of 8.8, the subgroups with TyG index ≥ 8.8 regardless of obesity had a significantly high risk for diabetes (HR 2.40 [p = 0.024] and 2.25 [p = 0.048]). For obesity status and metabolic health, the two metabolically unhealthy subgroups regardless of obesity had a significantly high risk for diabetes (HRs 2.54 [p = 0.024] and 2.73 [p = 0.021]). In conclusion, the TyG index measured at a single time point may be an indicator of the risk for incident diabetes. The predictive value of the TyG index was comparable to that of metabolic health.

Healthy obesity as an intermediate state of risk: a critical review

Obesity is a top public health priority but interventions to reverse the condition have had limited success. About one-in-three obese adults are free of metabolic risk factor clustering and are considered 'healthy', and much attention has focused on the implications of this state for obesity management. Areas covered: We searched for individual studies, systematic reviews, and meta-analyses which examined correlates and outcomes of metabolically healthy obesity. We discuss the key roles of fat distribution and physical activity in determining healthy vs. unhealthy obesity and report a greatly increased risk of incident type 2 diabetes associated with healthy obesity vs. healthy normal weight, among other outcomes. We argue that despite inconsistencies in the definition, patterns across studies clearly show that healthy obesity is a state of intermediate disease risk. Expert commentary: Given the current state of population-level evidence, we conclude that obesity and metabolic dysfunction are inseparable and that healthy obesity is best viewed only as a state of relative health but not of absolute health. We recommend that weight loss through energy restriction be a stand-alone target in addition to increased physical activity for minimising risk of future disease.

Obesity, metabolic health, and mortality in adults: a nationwide population-based study in Korea

BMI, metabolic health status, and their interactions should be considered for estimating mortality risk; however, the data are controversial and unknown in Asians. We aimed to investigate this issue in Korean population. Total 323175 adults were followed-up for 96 (60–120) (median [5–95%]) months in a nationwide population-based cohort study. Participants were classified as “obese” (O) or “non-obese” (NO) using a BMI cut-off of 25 kg/m². People who developed ≥1 metabolic disease component (hypertension, diabetes, dyslipidaemia) in the index year were considered “metabolically unhealthy” (MU), while those with none were considered “metabolically healthy” (MH). The MUNO group had a significantly higher risk of all-cause (hazard ratio, 1.28 [95% CI, 1.21–1.35]) and cardiovascular (1.88 [1.63–2.16]) mortality, whereas the MHO group had a lower mortality risk (all-cause: 0.81 [0.74–0.88]), cardiovascular: 0.73 [0.57–0.95]), compared to the MHNO group. A similar pattern was noted for cancer and other-cause mortality. Metabolically unhealthy status was associated with higher risk of all-cause and cardiovascular mortality regardless of BMI levels, and there was a dose-response relationship between the number of incident metabolic diseases and mortality risk. In conclusion, poor metabolic health status contributed more to mortality than high BMI did, in Korean adults.

Natural Course of Metabolically Healthy Overweight/Obese Subjects and the Impact of Weight Change

Few studies have described the characteristics of metabolically healthy individuals with excess fat in the Chinese population. This study aimed to prospectively investigate the natural course of metabolically healthy overweight/obese (MH-OW/OB) adults, and to assess the impact of weight change on developing metabolic abnormalities. During 2009–2010, 525 subjects without any metabolic abnormalities or other obesity-related diseases were evaluated and reevaluated after 5 years. The subjects were categorized into two groups of overweight/obese and normal weight based on the criteria of BMI by 24.0 at baseline. At follow-up, the MH-OW/OB subjects had a significantly increased risk of developing metabolically abnormalities compared with metabolically healthy normal-weight (MH-NW) individuals (risk ratio: 1.35, 95% confidence interval: 1.17–1.49, p value < 0.001). In the groups of weight gain and weight maintenance, the MH-OW/OB subjects was associated with a larger increase in fasting glucose, triglycerides, systolic blood pressure, diastolic blood pressure and decrease in high-density lipoprotein cholesterol comparing with MH-NW subjects. In the weight loss group, no significant difference of changes of metabolic parameters was observed between MH-OW/OB and MH-NW adults. This study verifies that MH-OW/OB are different from MH-NW subjects. Weight management is needed for all individuals since weight change has a significant effect on metabolic health without considering the impact of weight change according to weight status.

A panel of free fatty acid ratios to predict the development of metabolic abnormalities in healthy obese individuals

Increasing evidences support that metabolically healthy obese (MHO) is a transient state. However, little is known about the early markers associated with the development of metabolic abnormalities in MHO individuals. Serum free fatty acids (FFAs) profile is highlighted in its association with obesity-related insulin resistance, type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). To examine the association of endogenous fatty acid metabolism with future development of metabolic abnormalities in MHO individuals, we retrospectively analyzed 24 [product FFA]/[precursor FFA] ratios in fasting sera and clinical data from 481 individuals who participated in three independent studies, including 131 metabolic healthy subjects who completed the 10-year longitudinal Shanghai Diabetes Study (SHDS), 312 subjects cross-sectionally sampled from the Shanghai Obesity Study (SHOS), and 38 subjects who completed an 8-week very low carbohydrate diet (VLCD) intervention study. Results showed that higher baseline level of oleic acid/stearic acid (OA/SA), and lower levels of stearic acid/palmitic acid (SA/PA) and arachidonic acid/dihomo-γ-linolenic acid (AA/DGLA) ratios were associated with higher rate of MHO to MUO conversion in the longitudinal SHDS. Further, the finding was validated in the cross-sectional and interventional studies. This panel of FFA ratios could be used for identification and early intervention of at-risk obese individuals.

Fatty liver index is a risk determinant of incident type 2 diabetes in a metabolically healthy population with obesity

OBJECTIVE

This study investigated the effect of fatty liver disease (FLD) on the risk of incident type 2 diabetes in a population with metabolically healthy obesity (MHO).

METHODS

The study population comprised 34,258 Koreans without type 2 diabetes. Participants were stratified by BMI (cutoff value, 25.0 kg/m(2) ) and metabolic health state (using Wildman criteria). FLD was defined by the fatty liver index (FLI), a predictive algorithm to detect FLD. Subjects were classified into low and high FLI groups based on tertile.

RESULTS

At baseline, there were significant differences in FLI between four study groups. During a median follow-up of 36.5 months, 1.7% individuals developed type 2 diabetes. The risk of incident type 2 diabetes varied for the MHO group according to the level of FLI. The risk of type 2 diabetes in the MHO with low FLI was not significantly elevated compared with the metabolically healthy individuals without obesity (MHNO) with low FLI (multivariate-adjusted HR, 1.19 [95% CI 0.66-2.14]). However, the MHO with high FLI had an elevated risk of incident type 2 diabetes (multivariate-adjusted HR, 1.99 [95% CI 1.36-2.92]).

CONCLUSIONS

MHO subjects have a substantially higher risk of incident type 2 diabetes than MHNO subjects. The presence of FLD assessed by FLI partially explains this increased risk.

Obesity or obesities? Controversies on the association between body mass index and premature mortality

Obesity is still defined on the basis of body mass index (BMI) and BMI in itself is generally accepted as a strong predictor of overall early mortality. However, an inverse association between BMI and mortality has been reported in patients with many disease states and in several clinical settings: hemodialysis, cardiovascular diseases, hypertension, stroke, diabetes, chronic obstructive pulmonary disease, surgery, etc. This unexpected phenomenon is usually called obesity-survival paradox (OP). The contiguous concepts of metabolically healthy obesity (MHO, a phenotype having BMI ≥ 30 but not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance, HOMA, <2.5) and metabolically obese normal weight (MONW, normal-weight individuals displaying obesity-related phenotypic characteristics) have received a great deal of attention in recent years. The interactions that link MHO, MONW and OP with body composition, fat distribution, aging and cardiorespiratory fitness are other crucial areas of research. The article is an introductory narrative overview of the origin and current use of the concepts of MHO, MONW and OP. These phenomena are very controversial and appear as a consequence of the frail current diagnostic definition of obesity based only on BMI. A new commonly established characterization and classification of obesities based on a number of variables is needed urgently.