Insulin secretion in metabolically obese, but normal weight, and in metabolically healthy but obese individuals

Frequency of prediabetes in individuals with increased adiposity and metabolically healthy or unhealthy phenotypes

AIMS

To utilize the estimated glucose disposal rate (eGDR) index of insulin sensitivity, which is based on readily available clinical variables, namely, waist circumference, hypertension and glycated haemoglobin, to discriminate between metabolically healthy and unhealthy phenotypes, and to determine the prevalence of prediabetic conditions.

METHODS

Non-diabetic individuals (n = 2201) were stratified into quartiles of insulin sensitivity based on eGDR index. Individuals in the upper quartiles of eGDR were defined as having metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW) or metabolically healthy obesity (MHO) according to their body mass index, while those in the lower quartiles were classified as having metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW) and metabolically unhealthy obesity (MUO), respectively.

RESULTS

The frequency of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and IFG + IGT status was comparable among the MHNW, MHOW and MHO groups, while it increased from those with MUNW status towards those with MUOW and MUO status. As compared with participants with MHNW, the odds ratio of having IFG, IGT, or IFG + IGT was significantly higher in participants with MUOW and MUO but not in those with MUNW, MHOW and MHO, respectively.

CONCLUSIONS

A metabolically healthy phenotype is associated with lower frequency of IFG, IGT, and IFG + IGT status across all body weight categories.

The expression of NFAT family genes in subcutaneous adipose tissue before and after weight loss in obese individuals

BACKGROUND AND AIMS

Adipose tissue (AT) serves as a vital energy storage site and plays a pivotal role in metabolic regulation, exhibiting a high response to insulin. Impairment in this response may closely associate with obesity, and NFAT (nuclear factor of activated T cells) family genes may be involved in the process. However, human data linking NFAT and AT remains elusive. The aim of this study was to assess the expression of NFAT family genes and markers of adipogenesis in subcutaneous adipose tissue (SAT) among normal-weight and overweight/obese individuals before and after weight loss, in relation to insulin sensitivity.

METHODS AND RESULTS

The study included 45 participants, 15 normal-weight (control group) and 30 overweight or obese, who underwent a 12-week dietary intervention (DI) program. Before and after the program hyperinsulinemic-euglycemic clamp and SAT biopsy were conducted. Before DI, a positive correlations was observed in the expression of NFATc1, NFATc4, and NFAT5 with insulin sensitivity. The expression of NFAT family genes and markers of adipogenesis in SAT was lower in individuals with overweight or obesity compared to normal-weight. Additionally, a positive correlation was noted between NFAT family genes and adipogenesis markers both before and after weight loss. Following the DI program, there was an increase in the expression of NFATc3, NFATc4, and NFAT5 in SAT.

CONCLUSION

Decreased SAT expression of NFAT genes in obesity is partly reversed in response to weight loss. NFAT genes in SAT are associated with insulin sensitivity and adipogenesis. Registration number for clinical trial: NCT01393210.

Transcriptomic meta-analysis characterizes molecular commonalities between psoriasis and obesity

Despite the abundance of epidemiological evidence for the high comorbid rate between psoriasis and obesity, systematic approaches to common inflammatory mechanisms have not been adequately explored. We performed a meta-analysis of publicly available RNA-sequencing datasets to unveil putative mechanisms that are postulated to exacerbate both diseases, utilizing both late-stage, disease-specific meta-analyses and consensus gene co-expression network (cWGCNA). Single-gene meta-analyses reported several common inflammatory mechanisms fostered by the perturbed expression profile of inflammatory cells. Assessment of gene overlaps between both diseases revealed significant overlaps between up- (n = 170, P value = 6.07 × 10-65) and down-regulated (n = 49, P value = 7.1 × 10-7) genes, associated with increased T cell response and activated transcription factors. Our cWGCNA approach disentangled 48 consensus modules, associated with either the differentiation of leukocytes or metabolic pathways with similar correlation signals in both diseases. Notably, all our analyses confirmed the association of the perturbed T helper (Th)17 differentiation pathway in both diseases. Our novel findings through whole transcriptomic analyses characterize the inflammatory commonalities between psoriasis and obesity implying the assessment of several expression profiles that could serve as putative comorbid disease progression biomarkers and therapeutic interventions.

The triglycerides and glucose index is more strongly associated with metabolically healthy obesity phenotype than the lipid and obesity indices

PURPOSE

The triglycerides and glucose (TyG) index is a reliable biomarker for estimating insulin resistance; however, evidence regarding the use of the TyG index in individuals with metabolically healthy obesity (MHO) is scarce. Thus, we examined the association between the TyG index and the MHO phenotype.

METHODS

Apparently healthy men and women aged 18 years or more with obesity (body mass index [BMI] ≥ 30 kg/m2) were allocated into the following groups: MHO and metabolically unhealthy obesity (MUO). The MHO phenotype was defined by obesity and the absence of the following metabolic disorders: elevated triglyceride concentrations, elevated glucose levels, elevated blood pressure, and low HDL-C. The MUO was defined by individuals with obesity and at least one of the aforementioned cardiovascular risk factors.

RESULTS

A total 827 individuals, 605 (73.1%) women and 222 (26.9%) men were enrolled and allocated into the MHO (n = 104) and MUO (n = 723) groups. The adjusted regression analysis by age, sex, BMI, and waist circumference showed that fasting glucose (OR = 0.90; 95% CI: 0.88-0.93), and triglycerides (OR = 0.97; 95% CI: 0.96-0.98), as well as the triglycerides/HDL-C (OR = 0.18; 95% CI: 0.13-0.26), lipid accumulation product (OR = 0.95; 95% CI: 0.93-0.96), visceral adipose index (OR = 0.38; 95% CI: 0.31-0.46), and TyG index (OR = 0.001; 95% CI: 0.000-0.004) are inversely associated with the MHO, while the HDL-C (OR = 1.10; 95% CI: 1.07-1.12) had a direct association.

CONCLUSIONS

Our results show that the TyG index is more strongly associated with the MHO phenotype than the lipid and obesity indices.

Nonalcoholic Fatty Liver Disease and Associated Risk Factors in Obese Nigerians: A Cross-Sectional Study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is now adjudged the most common liver disease in the world, contributing to the rising incidence of hepatocellular carcinoma worldwide. However, the true prevalence of nonalcoholic fatty liver disease among obese individuals and its contribution to the burden of liver disease in Nigeria is unknown.

AIM

To determine the prevalence of nonalcoholic fatty liver disease and associated risk factors in obese subjects.

METHODS

This was a cross-sectional analytical study of 280 obese subjects and 280 nonobese age and sex-matched controls seen at our health facility. Data collection was done using an interviewer-administered questionnaire and anthropometric parameters were obtained. Fasting blood samples were collected for blood glucose, lipid profile, and liver biochemistry. Abdominal ultrasound was used to screen for NAFLD. The results were subjected to relevant statistical analysis using SPSS version 20.

RESULTS

A higher prevalence of NAFLD was found in obese subjects, compared with nonobese controls (36.4% versus 0.4% P < 0.001). The degree of obesity, transaminases, total cholesterol, diastolic hypertension, fasting blood glucose, and waist circumference was significantly associated with a higher prevalence of NAFLD. However, using multivariate logistic regression analysis, diabetes mellitus and hypertension were significant associations for NAFLD. Individuals with NAFLD had a significantly higher prevalence of metabolic syndrome 65.9%, compared with 34.1% in obese individuals without NAFLD (P < 0.001).

CONCLUSION

The prevalence of NAFLD in obese subjects was significant. NAFLD in obese subjects was associated with degree of obesity, hyperlipidemia, hypertension, and diabetes mellitus.

Phenotyping obesity: A focus on metabolically healthy obesity and metabolically unhealthy normal weight

Over the past 4 decades, research has shown that having a normal body weight does not automatically imply preserved metabolic health and a considerable number of lean individuals harbour metabolic abnormalities typically associated with obesity. Conversely, excess adiposity does not always equate with an abnormal metabolic profile. In fact, evidence exists for the presence of a metabolically unhealthy normal weight (MUHNW) and a metabolically healthy obese (MHO) phenotype. It has become increasingly recognised that different fat depots exert different effects on the metabolic profile of each individual by virtue of their location, structure and function, giving rise to these different body composition phenotypes. Furthermore, other factors have been implicated in the aetiopathogenesis of the body composition phenotypes, including genetics, ethnicity, age and lifestyle/behavioural factors. Even though to date both MHO and MUHNW have been widely investigated and documented in the literature, studies report different outcomes on long-term cardiometabolic morbidity and mortality. Future large-scale, observational and population-based studies are required for better profiling of these phenotypes as well as to further elucidate the pathophysiological role of the adipocyte in the onset of metabolic disorders to allow for better risk stratification and a personalised treatment paradigm.

Association of High-Sensitivity C-Reactive Protein and Lipoprotein-Associated Phospholipase A2 with Metabolically Unhealthy Phenotype: A Cross Sectional Study

Objective

Whether the combination of high-sensitivity C-reactive protein (hs-CRP) and Lipoprotein-associated Phospholipase A2 (Lp-PLA2) was an independent risk factor for metabolic unhealthy is unknown. This study aimed to evaluate the association between combining hs-CRP and Lp-PLA2 and metabolic unhealthy.

Methods

A total of 3198 participants who underwent routine health check-up examinations. The participants completed inflammation indicators (hs-CRP and Lp-PLA2) examination and physical assessments. Four phenotypes were determined according to obesity and metabolic health status. Meanwhile, the participants were divided into four groups according to the level of hs-CRP and Lp-PLA2. The cross-sectional association between hs-CRP, Lp-PLA2 and metabolic unhealthy was tested by logistic regression analysis.

Results

About 30.48%, 17.35%, 17.32% and 34.83% had MHNO, MUNO, MHO, and MUO, respectively. The combination of the hs-CRP and Lp-PLA2 levels was significantly correlated with metabolic unhealthy in non-obese subjects. However, in obese subjects, only hs-CRP level was significantly correlated with metabolic unhealthy.

Conclusion

The hs-CRP and Lp-PLA2 together were significantly associated with metabolic unhealthy in non-obese subjects. hs-CRP level was significantly correlated with metabolic unhealthy in obese subjects.

Metabolic syndrome is associated with similar long-term prognosis in those living with and without obesity: an analysis of 45 615 patients from the nationwide LIPIDOGRAM 2004-2015 studies

AIMS

We aimed to evaluate the association between metabolic syndrome (MetS) and long-term all-cause mortality.

METHODS AND RESULTS

The LIPIDOGRAM studies were carried out in the primary care in Poland in 2004, 2006, and 2015. MetS was diagnosed based on the National Cholesterol Education Program, Adult Treatment Panel III (NCEP/ATP III), and Joint Interim Statement (JIS) criteria. The cohort was divided into four groups: non-obese patients without MetS, obese patients without MetS, non-obese patients with MetS, and obese patients with MetS. Differences in all-cause mortality were analysed using Kaplan-Meier and Cox regression analyses. A total of 45 615 participants were enrolled (mean age 56.3, standard deviation: 11.8 years; 61.7% female). MetS was diagnosed in 14 202 (31%) by NCEP/ATP III criteria and 17 216 (37.7%) by JIS criteria. Follow-up was available for 44 620 (97.8%, median duration 15.3 years) patients. MetS was associated with increased mortality risk among the obese {hazard ratio, HR: 1.88 [95% confidence interval (CI) 1.79-1.99] and HR: 1.93 [95% CI 1.82-2.04], according to NCEP/ATP III and JIS criteria, respectively} and non-obese individuals [HR: 2.11 (95% CI 1.85-2.40) and 1.7 (95% CI 1.56-1.85) according to NCEP/ATP III and JIS criteria, respectively]. Obese patients without MetS had a higher mortality risk than non-obese patients without MetS [HR: 1.16 (95% CI 1.10-1.23) and HR: 1.22 (95% CI 1.15-1.30), respectively in subgroups with NCEP/ATP III and JIS criteria applied].

CONCLUSIONS

MetS is associated with increased all-cause mortality risk in non-obese and obese patients. In patients without MetS, obesity remains significantly associated with mortality. The concept of metabolically healthy obesity should be revised.

Lipid metabolism in non-alcoholic fatty liver disease in patients with different body weights in mid-mountain conditions

Aim. To study the peculiarities of lipid metabolism disorders in non-alcoholic fatty liver disease in lean and obese patients in medium altitude conditions. Materials and methods. The study was carried out within the framework of the project Etiopathogenetic features and rates of development of non-alcoholic fatty liver disease (NAFLD) in the conditions of Kyrgyzstan (№ of state registration MHN/TZ-2020-3). An open comparative study of patients with two forms of NAFLD: fatty liver and non-alcoholic steatohepatitis (n=236) living in low mountains (Bishkek, altitude above sea level 750800 m; n=111) and middle mountains (At-Bashy district , Naryn region, height above sea level 20462300 m; n=125) Kyrgyzstan. The average age of the patients was 55.70.95 years. Given that genetic factors may play a role in the development of NAFLD, we analyzed a population represented only by ethnic Kyrgyz. Patients in each group were divided into lean (BMI23) and obese (BMI23) groups. To determine physical activity, a physical activity questionnaire was used, which was compiled on the basis of the materials of the International Physical Activity Prevalence Study www.ipaq.ki.se. Physical examination included measurement of anthropometric parameters (height, body weight, waist circumference), calculation of body mass index (BMI), skeletal muscle mass index (SMM), percentage of body fat. According to the grades of the WHO, the degree of obesity was assessed by BMI for Asians. Blood samples were taken for research in the morning on an empty stomach after at least 12 hours of fasting. The following indicators were determined: glucose, lipid spectrum (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides), alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels. The BARD scale was used as a predictor for assessing the development of liver fibrosis in patients with NAFLD. The scoring system included three variables: BMI, AST/ALT, and the presence of DM 2. The diagnosis of NAFLD made on the basis of history, laboratory tests, ultrasound examination of the liver, and exclusion of other liver diseases. The results were analyzed using the SPSS 16.0 statistical software package for Windows. A p-value0.05 was considered statistically significant at the 95% confidence level. Results. It was found that the inhabitants of the middle mountains with NAFLD are represented by a lower BMI relative to the inhabitants of the low mountains. In women, the levels of SMM and the percentage of fat are significantly and statistically significantly correlated (r=-0.971; p0.001), while in men these two indicators are not related. Men showed a trend towards higher percentages of fat, regardless of body weight and region of residence. For women, this indicator was within acceptable limits and did not exceed 31%. There was found a statistically significant difference in total cholesterol levels between low and middle mountain people in the group of obese patients (p0.001) suffering from NAFLD. Statistically significant low ALT indices were revealed in the group of obese patients living in mid-mountain conditions. Conclusion. Taken together, our results suggest that chronic mid-mountain hypoxia may slow down the course of overweight-induced NAFLD.

Depression status and insulin resistance in adults with obesity: A cross-sectional study

OBJECTIVE

Insulin resistance (IR) frequently co-occurs with depression, but inconsistent associations between IR and depression have been reported, and less is known about the association in obesity, a major risk factor for both IR and depression. Thus the association between depression status and IR in a nationally representative sample of the US adults with obesity was evaluated.

METHODS

This cross-sectional study involved 3507 adults with obesity from National Health and Nutrition Examination Survey from 2005 to 2016. The homeostasis model assessment of insulin resistance (HOMA-IR) was used, where IR was defined as a HOMA-IR value greater than its 75^th percentile. The Patient Health Questionnaire 9 was used to assess the depression status. Multivariate logistic regression model was applied to evaluate the association between depression status and IR.

RESULTS

The cut-off value of HOMA-IR in adults with obesity was 5.5, and the prevalence of IR was 26.3% in men, 19.8% in women. The association of depression status with IR depended upon gender (P for depression status by gender interaction = 0.04). Depression status was positively associated with IR in women (P = 0.01), where the ORs (95% CIs) for the risk of IR in the mild, moderate, severe depression status were 1.79 (1.21-2.64), 1.95 (1.10-3.45), and 2.21 (1.04-4.71), respectively (P for trend = 0.002). No association was found in men (P = 0.91).

CONCLUSION

Positive association between IR and depression status was identified in women with obesity, where the risk of IR increased with the level of depression status, while no association was found in men with obesity.

Future risk of diabetes among Indians with metabolic and phenotypic obesity: Results from the 10-year follow-up of the Chennai Urban Rural Epidemiology Study (CURES-158)

AIM

To investigate the risk of type 2 diabetes (T2DM) among the combinations of BMI categories and metabolic syndrome in Asian Indians.

MATERIALS AND METHODS

Individuals from the Chennai Urban Rural Epidemiology Study cohort (n = 1,368), free of diabetes at baseline were stratified by BMI and metabolic health as metabolically healthy non-obese (MHNO), metabolically healthy obese (MHO), metabolically obese non-obese (MONO) and metabolically obese obese (MOO). Phenotypic obesity was defined as BMI ≥ 25 kg/m² and metabolic obesity as presence of any two of the metabolic abnormalities: hyperglycemia, high blood pressure, high triglyceridemia or low HDL cholesterol. Hazard ratios for progression to diabetes were estimated using Cox proportional hazard regression.

RESULTS

During median 9.1 years of follow-up, incident cases of diabetes were highest among MOO-45.1%, followed by MONO-41.3%, MHO-27.1% and MHNO-15.9%. Incidence rates of diabetes among MOO, MONO, MHO and MHNO were 57.8, 50.9, 30.4 and 18.1 per 1000 person years, respectively. Hazard ratio for diabetes development were 1.71 in MHO, 2.87 in MONO, and 3.39 in MOO compared with MHNO.

CONCLUSIONS

Increased BMI and metabolic risk factor clustering independently contribute to the increased risk of T2DM in obese individuals. Screening for metabolic abnormalities should be performed routinely in clinic to identify high-risk individuals and institute appropriate preventive measures.

Differences in body composition between metabolically healthy and unhealthy midlife women with respect to obesity status

Body composition (BC) characteristics across metabolic health-by-body mass index categories were examined. Metabolic health (MH) was defined by five biomarkers: waist circumference, blood pressure, levels of triglycerides, high density lipoprotein cholesterol, and fasting glucose. Potential differences in BC characteristics between metabolically healthy obese (MH-O) and metabolically unhealthy obese (MUH-O) women, and between MH normal weight (MH-NW) and MUH normal weight (MUH-NW) women were explored in 276 Slovak midlife women (39-65 years). Body composition parameters were measured with bioimpedance analyzer (BIA 101, Akern, S. r. l.). A simple comparison of the BC data between the subgroups showed significant differences in resistance (Rz, ohm) (p=0.035), muscle mass (MM, kg) (p=0.044), and total body water (TBW, kg) (p=0.047) between MH-O and MUH-O women. However, we did not observe any significant differences in BC characteristics between MH-NW and MUHNW. Specific logistic regression models were used to determine differences in BC characteristics between various obesity phenotypes, with controlling for age, menopausal status, smoking status and sport activity. Our results indicated that increasing age and decreasing Rz were statistically significantly associated with an increased likelihood of exhibiting MUH-O (p=0.031 for age; p=0.032 for Rz). Moreover, other logistic models which included age, menopausal status, biochemical variables and life style factors such as covariates, showed that increasing alanine aminotransferase (ALT) and uric acid (UA) were statistically significantly associated with an increased likelihood of exhibiting MUH-O (p=0.023 for ALT, p=0.010 for UA). In conclusion, MUH-O and MH-O cardiometabolic profiles are characterized by differences in the value of resistance and plasma levels of ALT and UA.

Associations of Metabolic/Obesity Phenotypes with Insulin Resistance and C-Reactive Protein: Results from the CNTR Study

BACKGROUND

Obesity is a heterogeneous condition in terms of metabolic status. Different obesity phenotypes have various health risks. The aim of this work was to define different subtypes of obesity and investigate their relationship with inflammatory-cardiometabolic abnormalities among Chinese adult twins.

METHODS

The analyses used data from 1113 adult twins in 4 provinces (Shandong, Zhejiang, Jiangsu and Sichuan) from Chinese National Twin Registry (CNTR) which collected detailed information. We defined those with 0 or 1 metabolic syndrome (MetS) components excluding waist circumference as metabolically healthy, and those with waist circumference ≥90 cm (for men) and ≥85 cm (for women) as obese. The two-category obesity status and metabolic states are combined to generate four metabolic/obesity phenotypes. High sensitivity C reactive protein (hsCRP) was measured to assess underlying inflammation and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as surrogate measure of insulin resistance. Mixed-effect linear regression models and fixed-effect linear regression models were used to analyse the correlation between HOMA-IR, hsCRP and different metabolic/obesity phenotypes.

RESULTS

In cross-sectional analyses of 1113 individuals (mean [SD] age, 46.6 [12.9] years; 463 obese [41.6%]), 20.3% obese twins were metabolic healthy and 64.2% non-obese twins were metabolic unhealthy. Serum HOMA-IR level was higher in metabolically unhealthy non-obesity (MUNO) (β=0.42, 95% CI: 0.21-0.64), metabolically healthy obesity (MHO) (β=0.68, 95% CI: 0.36-1.00) and metabolically unhealthy obesity (MUO) (β=0.69, 95% CI: 0.46-0.91) twins, compared with their metabolically healthy non-obesity (MHNO) counterparts. HsCRP was similar between MHO and MUO, which differed significantly to metabolic healthy non-obesity (MHNO).

CONCLUSION

MHO and MUNO phenotypes were common in Chinese twin population. Both phenotypes were associated with elevated IR and hsCRP which may not be benign and need to be concerned.

Prevalence and characteristics of the metabolically healthy obese phenotype in children and adolescents in a Mexican state

OBJECTIVES

To determine the prevalence of the Metabolically Healthy Obesity (MHO), and Metabolically Obese Normal-Weight (MONW) phenotypes in a sample of children and adolescents. To evaluate which clinical and laboratory variables are related to the MONW and MHO phenotypes.

METHODS

A cross-sectional study was carried out in children and adolescents aged 6-18 years old, presumably healthy. Somatometry, glucose, insulin, triglycerides, HDL-cholesterol, LDL-cholesterol, HOMA-IR, triglycerides/HDL ratio, triglycerides and glucose index, and leptin/adiponectin, were determined.

RESULTS

Data from 620 children and adolescents were included (50.65% were males); the median age was 11 years. The prevalence of the MONW phenotype was 22.85% (95%CI 16.85%-29.79%), and the MHO phenotype 27.61% (95%CI 22.60%-33.06%). The variables that significantly explained the possibility of presenting the MONW and MHO phenotype were triglycerides/HDL ratio, and product of triglycerides and glucose. Insulin and HOMA-IR were significantly associated with the MHO phenotype but not with the MONW phenotype.

CONCLUSIONS

Prevalence of metabolically healthy obese phenotype is lower in the Mexican population compared to European studies; thus, future studies should determine if this difference relies upon genetic profile or lifestyle. The indices to assess the action of insulin based on lipids can help identify children and adolescents with the MHO and MONW phenotypes.

Oleic acid to stearic acid ratio might be a potential marker for insulin resistance in non-obese Japanese

Results from a recent study indicate that a higher level of oleic acid/stearic acid ratio was associated with metabolically unhealthy obesity. This was further validated in cross-sectional and interventional studies; however, this was not extensively studied in a non-obese population. We recruited 260 Japanese subjects with serum free fatty acid profiles undergoing anti-aging health examinations. The determinants for oleic acid/stearic acid ratio were investigated using multiple regression analyses. To compare different markers, the subjects were classified based on oleic acid/stearic acid ratio and the combination of oleic acid/stearic acid ratio and triglyceride levels. The oleic acid/stearic acid ratio exhibited a positive correlation with the logmatic transformed triglyceride/high-density lipoprotein cholesterol ratio and the fasting triglycerides-glucose index, both of which were used as markers for insulin resistance. Multiple regression analyses revealed that the triglyceride/high-density lipoprotein cholesterol ratio and fasting triglyceride-glucose index were positively associated with the oleic acid/stearic acid ratio. Most markers were the worst in the highest triglyceride group in both oleic acid/stearic acid groups. In addition, most markers were worse in high oleic acid/stearic acid ratio group than low group. In conclusion, oleic acid/stearic acid ratio might be a useful marker for insulin resistance in non-obese Japanese subjects.

The association between metabolically healthy obesity and risk of cancer: A systematic review and meta-analysis of prospective cohort studies

The risk of cancer among adults with metabolically healthy obesity (MHO) has not yet been established. We systematically searched from inception to 15 March 2020. We included prospective cohort studies that compared participants with MHO and participants with metabolically healthy non-obesity (MHNO) for incidence of any type of cancer. Benign tumors, cancer mortality or cancer prognosis were not in the scope of our analysis. The Newcastle-Ottawa Scale was used for quality assessment. Ultimately, eight studies with a total of 12 542 390 participants were included. The pooled meta-analysis using random effect model showed participants with MHO demonstrated a significantly increased risk of developing cancer (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.05 to 1.23; and I² = 39%) than those with MHNO. The subgroup analysis revealed a higher pooled estimate (OR, 1.17; 95% CI, 1.01-1.35; and I² = 56%) in comparison with metabolically healthy normal weight. No evidence of effect modification by age, sex, ethnicity, smoking, sample size or length of follow-up was found. In conclusion, the present study reports a positive association between MHO and cancer incidence. All individuals with obesity, even in the absence of metabolic dysfunction, should be encouraged to lose weight.

Metabolically healthy obesity: facts and fantasies

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

Increased Oxidized High-Density Lipoprotein/High-Density Lipoprotein-Cholesterol Ratio as a Potential Indicator of Disturbed Metabolic Health in Overweight and Obese Individuals

BACKGROUND

We evaluated the qualitative characteristics of high-density lipoprotein (HDL) particles in metabolically healthy and unhealthy overweight and obese subjects.

METHODS

The study involved 115 subject individuals classified as metabolically healthy and unhealthy, as in overweight and obese groups. Commercial enzyme-linked immunosorbent assay (ELISA) kits were used to measure oxidized HDL (OxHDL) and serum amyloid A (SAA) concentrations. Lipoprotein subfractions were separated using nondenaturing gradient gel electrophoresis.

RESULTS

An independent association was shown between increased OxHDL/HDL-cholesterol ratio and the occurrence of metabolically unhealthy phenotype in the overweight and obese groups. The OxHDL/HDL-cholesterol ratio showed excellent and acceptable diagnostic accuracy in determination of metabolic health phenotypes (overweight group, AUC = 0.881; obese group, AUC = 0.765). Accumulation of smaller HDL particles in metabolically unhealthy subjects was verified by lipoprotein subfraction analysis. SAA concentrations did not differ significantly between phenotypes.

CONCLUSIONS

Increased OxHDL/HDL-cholesterol ratio may be a potential indicator of disturbed metabolic health in overweight and obese individuals.

Physiological and Lifestyle Traits of Metabolic Dysfunction in the Absence of Obesity

PURPOSE OF REVIEW

Individuals with metabolically unhealthy normal weight (MUNW) have an adverse cardiometabolic risk factor profile in the absence of excess body weight, and increased risk for diabetes and heart disease. We critically review some physiological traits and lifestyle characteristics of the MUNW phenotype.

RECENT FINDINGS

The prevalence of MUNW varies considerably around the world and among ethnicities, partly because of different definitions; on average, this phenotype affects about ~ 30% of normal weight persons globally. Most studies have recruited MUNW subjects who, although within the normal weight range, are significantly "more obese" than their metabolically healthy lean peers (greater body mass index or total body fat); hence one cannot ascertain whether observed differences are true traits of the MUNW phenotype of simply secondary to greater relative adiposity within the normal range. Carefully matched studies have indicated that MUNW can exist in the absence of excess total body fat. These subjects have a preferential accumulation of fat in the upper body (abdominal subcutaneous and visceral adipose tissues) and the liver, but not skeletal muscle; perhaps surprisingly, this predominantly "android" fat distribution does not translate into increased waist circumference. The MUNW phenotype is associated with lower aerobic fitness and muscle mass and strength, but whether this is simply due to inadequate regular physical activity is not entirely clear. Likewise, no consistent associations have been found between any dietary factors and the development of MUNW phenotype, but diet-induced modest weight loss facilitates its resolution. Delineating the mechanisms leading to metabolic dysfunction in the absence of increased body weight and body fat will likely reveal important targets for improving metabolic health and eventually for reducing the burden of cardiometabolic disease, not only in individuals with normal body weight but also in people with obesity.

Obesity and Body Composition in Man and Woman: Associated Diseases and the New Role of Gut Microbiota

BACKGROUND

Obesity is now recognized as a worldwide health issue and has reached epidemic proportions, affecting both developed and developing countries. The World Obesity Federation stated that "Obesity is a chronic relapsing disease process": as a result, obesity has been recognized internationally as a chronic disease. The primary cause of the metabolic syndrome and increase of the cardiovascular risk have been identified in "sick fat", a condition then defined as adiposopathy. Heart attacks, strokes and renal failures are pathologies that have mid-risk factors such as dyslipidemia, hypertension and diabetes, which in turn are caused by obesity, whose primary risk factor is represented by the diet. The aim of the present review is to consider the importance of body composition, together with chronic inflammation and a new gut microbiota data that may turn out to be crucial elements of some target treatment of human obesity.

METHODS

In this review, we performed research using PubMed database reviewing the evidence in the literature of evidence information regarding the link between obesity and body composition in the development of metabolic disease via inflammation markers and in particular, the new role exerted by gut microbiota.

RESULTS

Several papers were evaluated searching for differences in fat mass and disease risk. We also identified the same papers dealing with differences in body composition and metabolic syndrome. Our attention focuses also on a new frontier of gut microbiota composition in the body weight decrease and anti-inflammatory effects.

CONCLUSION

To the saving of lean mass, for the prevention of cardiometabolic diseases, also considering the relationship with obesity, it is necessary to reduce the inflammatory state, acting on the gut-microbiota and on the intestinal permeability. To improve the health of the intestinal flora, we propose a 4P medicine and treatment with probiotics, prebiotics, postbiotics, and polyphenols.

Adipose Tissue Distribution, Inflammation and Its Metabolic Consequences, Including Diabetes and Cardiovascular Disease

Adipose tissue plays essential roles in maintaining lipid and glucose homeostasis. To date several types of adipose tissue have been identified, namely white, brown, and beige, that reside in various specific anatomical locations throughout the body. The cellular composition, secretome, and location of these adipose depots define their function in health and metabolic disease. In obesity, adipose tissue becomes dysfunctional, promoting a pro-inflammatory, hyperlipidemic and insulin resistant environment that contributes to type 2 diabetes mellitus (T2DM). Concurrently, similar features that result from adipose tissue dysfunction also promote cardiovascular disease (CVD) by mechanisms that can be augmented by T2DM. The mechanisms by which dysfunctional adipose tissue simultaneously promote T2DM and CVD, focusing on adipose tissue depot-specific adipokines, inflammatory profiles, and metabolism, will be the focus of this review. The impact that various T2DM and CVD treatment strategies have on adipose tissue function and body weight also will be discussed.

Different Patterns of Left Ventricular Hypertrophy in Metabolically Healthy and Insulin-Resistant Obese Subjects

Obese subjects showed different cardiovascular risk depending by different insulin sensitivity status. We investigated the difference in left ventricular mass and geometry between metabolically healthy (MHO) and unhealthy (MUHO) obese subjects. From a cohort of 876 obese subjects (48.3 ± 14.1 years) without cardio-metabolic disease and stratified according to increasing values of Matsuda index after 75 g oral glucose tolerance test, we defined MHO (n = 292) those in the upper tertile and MUHO (n = 292) those in the lower tertile. All participants underwent echocardiographic measurements. Left ventricular mass was calculated by Devereux equation and normalized by height^2,7 and left ventricular hypertrophy (LVH) was defined by values >44 g/m^2.7 for females and >48 g/m^2.7 for males. Left ventricular geometric pattern was defined as concentric or eccentric if relative wall thickness was higher or lower than 0.42, respectively. MHO developed more commonly a concentric remodeling (19.9 vs. 9.9%; p = 0.001) and had a reduced risk for LVH (OR 0.46; p < 0.0001) than MUHO, in which the eccentric type was more prevalent (40.4 vs. 5.1%; p < 0.0001). We demonstrated that obese subjects-matched for age, gender and BMI-have different left ventricular mass and geometry due to different insulin sensitivity status, suggesting that diverse metabolic phenotypes lead to alternative myocardial adaptation.

Risk of type 2 diabetes in metabolically healthy people in different categories of body mass index: an updated network meta-analysis of prospective cohort studies

Introduction: Risk of diabetes mellitus type 2 (T2DM) is variable between individuals due to different metabolic phenotypes. In present network meta-analysis, we aimed to evaluate the risk of T2DM related with current definitions of metabolic health in different body mass index (BMI) categories.

Methods: Relevant articles were collected by systematically searching PubMed and Scopus databases up to 20 March 2018 and for analyses we used a random-effects model. Nineteen prospective cohort studies were included in the analyses and metabolically healthy normal weight (MHNW) was considered as the reference group in direct comparison for calculating indirect comparisons in difference type of BMI categories.

Results: Total of 199403 participants and 10388 cases from 19 cohort studies, were included in our network meta-analysis. Metabolically unhealthy obesity (MUHO) group poses highest risk for T2DM development with 10 times higher risk when is compared with MHNW (10.46 95% CI; 8.30, 13.18) and after that Metabolically unhealthy overweight (MUOW) individuals were at highest risk of T2DM with 7 times higher risk comparing with MHNW (7.25, 95% CI; 5.49, 9.57). Metabolically healthy overweight and obese (MHOW/MHO) individuals have (1.77, 95% CI; 1.33, 2.35) and (3.00, 95% CI; 2.33, 3.85) risk ratio for T2DM development in comparison with MHNW respectively.

Conclusion: In conclusion we found that being classified as overweight and obese increased the risk of T2DM in comparison with normal weight. In addition, metabolically unhealthy (MUH) individuals are at higher risk of T2DM in all categories of BMI compared with metabolically healthy individuals.

Association of proinflammatory genes expression with serum interleukin 1β and free fatty acids in metabolically healthy and unhealthy abdominally obese individuals: a case-control study

Background

Proinflammatory genes are highly expressed in several metabolic disorders associated with obesity. But it is not clarified whether gene expression levels and downstream inflammatory markers are related to the metabolic state or the presence of obesity. Hence, the present study aimed to compare Toll-Like Receptor 2 (TLR2), Myeloid Differentiation Factor 88 (MyD88), and NFĸB mRNA expression levels between metabolically healthy abdominally obese (MHAO) and metabolically unhealthy abdominally obese (MUAO) individuals.

Results

We compared mRNA expression levels of the genes as well as serum FFAs and IL-1β in MUAO (n = 36) and MHAO (n = 34) groups. Serum FBS, TG, and HDL-C in addition to systolic and diastolic blood pressure were significantly higher in MUAO than MHAO groups (p < 0.05). The odds of MUAO was significantly decreased with high HDL-C (OR = 0.22, 95%CI: 0.08–0.63) and increased with high FBS (OR = 7.04, 95%CI: 1.42–34.69) and TG (OR = 30.55, 95%CI: 7.48–60.67). There were no significant differences in proinflammatory genes as well as serum FFAs and IL-1β between the two groups. No associations were found between the genes expression and serum markers. However, NFĸB expression was significantly correlated with TLR2 and MyD88 (r = 0.747; p < 0.001). Significant correlations were also noticed between TLR2 and MyD88 expression as well as between serum FFAs and IL-1β in each group (p < 0.001).

Conclusion

Serum concentration of IL-1β, FFAs, and mRNA expression levels of TLR2, MyD88, and NFĸB may be resulted from abdominal obesity and not be related to the presence or absence of metabolic health.

Body composition, dual-energy X-ray absorptiometry and obesity: the paradigm of fat (re)distribution

Objective

The amount of lean and fat tissues in different body compartments is likely to drive the cardiovascular risk. The longitudinal effects of changes of lean and fat mass, particularly following weight loss programs, cannot be reliably identified by the sole measurement of anthropometry. We discuss this problem on the basis of data collected in obese females with the use of dual-energy X-ray absorptiometry (DXA), anthropometry and laboratory.

Methods

We present longitudinal data in six obese females (three pairs-weight stable, weight loss, weight increase) assigned to a medical treatment. All patients underwent whole-body scan (Lunar iDXA, GE Healthcare, WI) and laboratory analysis (blood fasting glucose, total low-density lipoprotein and high-density lipoprotein cholesterol, triglycerides) before treatment and after 12 months. Fat mass and non-bone lean mass were assessed at whole-body and regional levels. Android visceral adipose tissue was estimated by a recently validated software.

Results

The most common anthropometric measures (body mass index, waist circumference) were totally ineffective in documenting the changes in body composition in 12 month follow-up, whereas DXA could detect regional changes, which were paralleled in part by changes in biochemical indices.

Conclusion

Serial DXA measurements could provide a comprehensive assessment of body compartments, independent of changes in classic anthropometry (body mass index and waist circumference), identifying a significant redistribution of lean and fat mass and providing clues to explain changes in cardiovascular risk profile.

Is normal body mass index a good indicator of metabolic health in Azar cohort population?

Introduction: Metabolic syndrome (Mets) has become most important public health problem in the world. We examined the association between Mets and different cardiometabolic phenotype in Azar cohort population. Methods: In the present study, the data of 13099 subjects who participated in Azar cohort study were cross-sectionally analyzed. Mets was defined according to the National Cholesterol Education Program's Adult Treatment Panel III report (ATPIII) criteria. Participants were categorized into four cardiometabolic phenotypes including metabolically healthy Lean (MHL), metabolically unhealthy lean (MUHL), metabolically healthy Obese (MHO), metabolically unhealthy obese (MUHO) according to BMI cut-off point (25 kg/m2 ), and the presence of Mets. Results: Totally, the prevalence of Mets was 33.20% with the higher prevalence in women (40.1%). About 46.7% of participants were MHO and 1.6% of them were MHL. In both genders, MUHL had the highest prevalence of hyperglycemia, hypertrigliceridemia, hypo-HDL-cholestrolemia and Frahmingham 10-year CVD risk. In both MUHL and MUHO phenotypes, hypertriglyceridemia (OR: 31.97 [95% CI: 22.31, 45.81] and OR: 20.28 [95% CI: 17.32, 23.75]) and hypo-HDL cholestrolemia (OR:27.97 [95% CI: 17.35, 45.09] and OR:11.0 [95% CI: 9.62, 12.58]) are the strongest predictor of incidence of Mets. Also, the results of multinominal regression analyses indicated that in all cardiometabolic phenotypes, Framingham 10- year CVD risks had the lowest power for predicting of Mets incidence. Conclusion: Based on the results, in addition to obese individuals, multiple metabolic abnormalities were seen in normal weight individuals and these subjects are even at higher risk of developing Mets compared with metabolically obese individuals. So, it seems that decision on initiation of lifestyle interventions should not be only based on the BMI; rather metabolic status seems to be even more important.

Contribution of Adipose Tissue Inflammation to the Development of Type 2 Diabetes Mellitus

The objective of this comprehensive review is to summarize and discuss the available evidence of how adipose tissue inflammation affects insulin sensitivity and glucose tolerance. Low-grade, chronic adipose tissue inflammation is characterized by infiltration of macrophages and other immune cell populations into adipose tissue, and a shift toward more proinflammatory subtypes of leukocytes. The infiltration of proinflammatory cells in adipose tissue is associated with an increased production of key chemokines such as C-C motif chemokine ligand 2, proinflammatory cytokines including tumor necrosis factor α and interleukins 1β and 6 as well as reduced expression of the key insulin-sensitizing adipokine, adiponectin. In both rodent models and humans, adipose tissue inflammation is consistently associated with excess fat mass and insulin resistance. In humans, associations with insulin resistance are stronger and more consistent for inflammation in visceral as opposed to subcutaneous fat. Further, genetic alterations in mouse models of obesity that reduce adipose tissue inflammation are-almost without exception-associated with improved insulin sensitivity. However, a dissociation between adipose tissue inflammation and insulin resistance can be observed in very few rodent models of obesity as well as in humans following bariatric surgery- or low-calorie-diet-induced weight loss, illustrating that the etiology of insulin resistance is multifactorial. Taken together, adipose tissue inflammation is a key factor in the development of insulin resistance and type 2 diabetes in obesity, along with other factors that likely include inflammation and fat accumulation in other metabolically active tissues. © 2019 American Physiological Society. Compr Physiol 9:1-58, 2019.

The Pathophysiology of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a serious pregnancy complication, in which women without previously diagnosed diabetes develop chronic hyperglycemia during gestation. In most cases, this hyperglycemia is the result of impaired glucose tolerance due to pancreatic β-cell dysfunction on a background of chronic insulin resistance. Risk factors for GDM include overweight and obesity, advanced maternal age, and a family history or any form of diabetes. Consequences of GDM include increased risk of maternal cardiovascular disease and type 2 diabetes and macrosomia and birth complications in the infant. There is also a longer-term risk of obesity, type 2 diabetes, and cardiovascular disease in the child. GDM affects approximately 16.5% of pregnancies worldwide, and this number is set to increase with the escalating obesity epidemic. While several management strategies exist-including insulin and lifestyle interventions-there is not yet a cure or an efficacious prevention strategy. One reason for this is that the molecular mechanisms underlying GDM are poorly defined. This review discusses what is known about the pathophysiology of GDM, and where there are gaps in the literature that warrant further exploration.

Subcutaneous adipose tissue accumulation protects systemic glucose tolerance and muscle metabolism

The protective effects of lower body subcutaneous adiposity are linked to the depot functioning as a "metabolic sink" receiving and sequestering excess lipid. This postulate, however, is based on indirect evidence. Mechanisms that mediate this protection are unknown. Here we directly examined this with progressive subcutaneous adipose tissue removal. Ad libitum chow fed mice underwent sham surgery, unilateral or bilateral removal of inguinal adipose tissue or bilateral removal of both inguinal and dorsal adipose tissue. Subsequently mice were separated into 5 week chow or 5 or 13 week HFD groups (N = 10 per group). Primary outcome measures included adipocyte distribution, muscle and liver triglycerides, glucose tolerance, circulating adipocytokines and muscle insulin sensitivity. Subcutaneous adipose tissue removal caused lipid accumulation in femoral muscle proximal to excision, however, lipid accumulation was not proportionally inverse to adipose tissue quantity excised. Accumulative adipose removal was associated with an incremental reduction in systemic glucose tolerance in 13 week HFD mice. Although insulin-stimulated pAkt/Akt did not progressively decrease among surgery groups following 13 weeks of HFD, there was a suppressed pAkt/Akt response in the non-insulin stimulated (saline-injected) 13 week HFD mice. Hence, increases in lower body subcutaneous adipose removal resulted in incremental decreases in the effectiveness of basal insulin sensitivity of femoral muscle. The current data supports that the subcutaneous depot protects systemic glucose homeostasis while also protecting proximal muscle from metabolic dysregulation and lipid accumulation. Removal of the "metabolic sink" likely leads to glucose intolerance because of decreased storage space for glucose and/or lipids.

Perilipin 1 (Plin1) deficiency promotes inflammatory responses in lean adipose tissue through lipid dysregulation

Lipid droplets are specialized cellular organelles that contain neutral lipid metabolites and play dynamic roles in energy homeostasis. Perilipin 1 (Plin1), one of the major lipid droplet-binding proteins, is highly expressed in adipocytes. In mice, Plin1 deficiency impairs peripheral insulin sensitivity, accompanied with reduced fat mass. However, the mechanisms underlying insulin resistance in lean Plin1 knockout (Plin1^-/-) mice are largely unknown. The current study demonstrates that Plin1 deficiency promotes inflammatory responses and lipolysis in adipose tissue, resulting in insulin resistance. M1-type adipose tissue macrophages (ATMs) were higher in Plin1^-/- than in Plin1^+/+ mice on normal chow diet. Moreover, using lipidomics analysis, we discovered that Plin1^-/- adipocytes promoted secretion of pro-inflammatory lipid metabolites such as prostaglandins, which potentiated monocyte migration. In lean Plin1^-/- mice, insulin resistance was relieved by macrophage depletion with clodronate, implying that elevated pro-inflammatory ATMs might be attributable for insulin resistance under Plin1 deficiency. Together, these data suggest that Plin1 is required to restrain fat loss and pro-inflammatory responses in adipose tissue by reducing futile lipolysis to maintain metabolic homeostasis.

Effects of Physical Exercise on Adiponectin, Leptin, and Inflammatory Markers in Childhood Obesity: Systematic Review and Meta-Analysis

BACKGROUND

New findings on adipose tissue physiology and obesity-associated inflammation status suggest that modification of the adipokine level can be relevant for the long-term prevention of obesity-associated chronic disease.

OBJECTIVES

The scope of the present study was to investigate the effectiveness of physical exercise in reducing the systemic inflammation related to obesity in children.

METHODS

We conducted a systematic review with meta-analysis of controlled randomized trials, identified through electronic database search, which investigated the effect of physical exercise, without concomitant dietary intervention, on adiponectin, leptin, and/or other inflammatory markers in children up to age 18 years with a body mass index greater than the 95th percentile for age and sex.

RESULTS

Seven trials were included in the meta-analysis, with a total of 250 participants. Compared with the control group without any lifestyle modification, the physical exercise resulted in a reduction in leptin [standardized mean difference (SMD) -1.13; 95% confidence interval (95%CI): -1.89 to -0.37; I² = 79.9%] and interleukin-6 (SMD -0.84; 95%CI: -1.45 to -0.23, I² = 0.9%) and an increase in adiponectin plasma concentration (SMD 0.69; 95%CI: 0.02-1.35; I² = 74.3%).

CONCLUSIONS

These results indicate that physical exercise improved the inflammatory state in children with obesity. It is unclear whether this effect can reduce the risk of cardiovascular and metabolic disease in adulthood. Clinical trials with a uniform intervention protocol and outcome measurements are required to put our knowledge on adipose tissue biology into a clinical perspective.

Moderate Weight Loss Improves Body Composition and Metabolic Function in Metabolically Unhealthy Lean Subjects

OBJECTIVE

Individuals who have "metabolically obese normal weight" (MONW) have an increased risk for cardiometabolic disease. Moderate weight loss has multiple benefits in people with obesity, but its effects in lean people are unknown. Thus, the effects of diet-induced 5% weight loss on body composition and metabolic function in MONW subjects were evaluated.

METHODS

Total body fat, visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAT) volumes, intrahepatic and intramyocellular lipid contents, insulin sensitivity (hyperinsulinemic-euglycemic clamp), glucose tolerance, and postprandial insulin secretion and clearance rates (mixed meal with minimal modeling) were measured before and after 4.8% ± 0.5% weight loss in 11 MONW Asians (48 ± 3 years old, six men and five women, BMI 22.7 ± 0.4 kg/m² ).

RESULTS

Weight loss decreased total fat mass by ∼9%, VAT and SAT volumes by ∼11% and ∼17%, respectively, and intrahepatic fat by ∼50% (all P < 0.05). Fasting plasma insulin, triglyceride, and total low- and high-density lipoprotein cholesterol concentrations were also reduced (P < 0.05). Insulin sensitivity indexes (M-value and M/I ratio) increased by 21% to 26% (both P < 0.05); β-cell responsivity and postprandial insulin secretion rate did not change, but insulin clearance rate increased by 16% (P < 0.05).

CONCLUSIONS

Diet-induced moderate weight loss improves body composition, lipid profile, and insulin sensitivity and thereby reduces cardiometabolic risk in MONW Asians.

The relationship between obesity and the severity of non-alcoholic fatty liver disease: systematic review and meta-analysis

A number of researches have explored the association between obesity and nonalcoholic fatty liver disease (NAFLD) liver function, histopathology, complications, genetic factors and prognosis, but the results were conflicting and inconclusive. Areas covered: In this meta-analysis, the liver function, histopathology, metabolic complications, patatin-like phospholipase domain-containing protein 3 (PNPLA3) genetic polymorphism and prognosis were compared between non-obese and obese NAFLD. Pubmed, EMBASE, Cochrane databases were searched to identify eligible studies. The odds ratio (OR) or standardized mean difference (SMD) with 95% confidence intervals (CI) were pooled using fixed- or random-effects models. Expert commentary: This meta-analysis indicated that for NAFLD patients, obesity (according to ethnic-specific BMI cut-off points to define obesity) could predict a worse long-term prognosis. However, obesity may not be an independent factor for the development of NASH or advanced fibrosis in NAFLD patients and NAFLD should be considered as potential population for pharmacologic treatment regardless of obesity. In addition, PNPLA3 rs738409 may be more relevant to the progression of non-obese NAFLD when compared to obese NAFLD. Importantly, large-sample, long-term follow-up cohort studies based on liver biopsy are highly needed due to limited liver pathology and long-term follow-up data at present.

Regulation of glucose metabolism in nondiabetic, metabolically obese normal-weight Asians

Type 2 diabetes in Asia occurs largely in the absence of obesity. The metabolically obese normal-weight (MONW) phenotype refers to lean subjects with metabolic dysfunction that is typically observed in people with obesity and is associated with increased risk for diabetes. Previous studies evaluated MONW subjects who had greater body mass index (BMI) or total body fat than respective control groups, making interpretation of the results difficult. We evaluated insulin sensitivity (hyperinsulinemic-euglycemic clamp); insulin secretion (mixed meal with oral minimal modeling); intra-abdominal, muscle, and liver fat contents (magnetic resonance); and fasting and postprandial glucose and insulin concentrations in 18 MONW subjects and 18 metabolically healthy controls matched for age (43 ± 3 and 40 ± 3 yr; P = 0.52), BMI (both 22 ± 1 kg/m²; P = 0.69), total body fat (17 ± 1 and 16 ± 1 kg; P = 0.33), and sex (9 men and 9 women in each group). Compared with controls, MONW subjects had an approximately twofold greater visceral adipose tissue volume and an approximately fourfold greater intrahepatic fat content (but similar muscle fat), 20-30% lower glucose disposal rates and insulin sensitivity, and 30-40% greater insulin secretion rates (all P < 0.05). The disposition index, fasting glucose, and HbA1c concentrations were not different between groups, whereas postprandial glucose and insulin concentrations were ~15% and ~65% greater, respectively, in MONW than control subjects (both P < 0.05). We conclude that the MONW phenotype is associated with accumulation of fat in the intra-abdominal area and the liver, profound insulin resistance, but also a robust β-cell insulin secretion response that compensates for insulin resistance and helps maintain glucose homeostasis.

Biochemical and clinical characterization of metabolic phenotypes: a cross-sectional study from Maracaibo city, Venezuela

Background: In 1980, Reuben Andresen observed that in certain individuals, obesity did not increase mortality, introducing an atypical phenotype called "healthy obese". Other studies reported that 10-15 % of lean individuals presented insulin resistance, hyperglycemia and dyslipidemia. The objective of this study was to evaluate biochemical and clinical characteristics of metabolic phenotypes in Maracaibo city. Methods: A descriptive, cross-sectional sub-analysis of The Maracaibo City Metabolic Syndrome Prevalence Study, with a randomized multistage sampling was performed including 1226 non diabetic individuals from both sexes. For phenotype definition, the subjects were first classified according to their BMI into Normal-Weight, Overweight and Obese; then divided in metabolically healthy and unhealthy using a two-step analysis cluster being predictive variables: HOMA2-IR, HOMA2-βcell, triglycerides. To evaluate the relationship with coronary risk, a multiple logistic regression model was performed. Results: In the studied population, 43.9% (n=538) were healthy normal weight, 5.2% (n=64) unhealthy normal weight, 17.4% (n=217) healthy obese and 33.5% (n=411) unhealthy obese subjects. Atypical phenotypes, Metabolically Unhealthy Normal-Weight (MUNW) was more frequent in males (56.3%), whereas Metabolically Unhealthy Obese (MUO) was more frequent in females (51.3%). This phenotypes had a higher coronary event risk, especially for obese individuals (MHO: OR=1.85 CI95%: 1.11-3.09; p=0.02 and MUO: OR=2.09 CI95%: 1.34-3.28; p<0.01). Conclusion: Individuals with atypical metabolic phenotypes are common in Maracaibo city. Related factors may include insulin resistance, basal glucose, and triglycerides levels. Lastly, obese subjects show a higher coronary event risk even those with normal metabolic status.

Biochemical and clinical characterization of metabolic phenotypes: a cross-sectional study from Maracaibo city, Venezuela

Background: In 1980, Reuben Andresen observed that in certain individuals, obesity did not increase mortality, introducing an atypical phenotype called "healthy obese". Other studies reported that 10-15 % of lean individuals presented insulin resistance, hyperglycemia and dyslipidemia. The objective of this study was to evaluate biochemical and clinical characteristics of metabolic phenotypes in Maracaibo city. Methods: A descriptive, cross-sectional study with a randomized multistage sampling was performed including 1226 non diabetic individuals from both sexes. For phenotype definition, the subjects were first classified according to their BMI into Normal-Weight, Overweight and Obese; then divided in metabolically healthy and unhealthy using a two-step analysis cluster. To evaluate the relationship with coronary risk, a multiple logistic regression model was performed. Results: In the studied population, 5.2% (n=64) corresponded to unhealthy lean subjects, and 17.4% (n=217) to healthy obese subjects. Metabolically unhealthy normal-weight (MUNW) phenotype was found in males in 53.3% in contrast to 51.3% of metabolically unhealthy obese (MUO) phenotype found in females. An association between metabolically unhealthy phenotypes and a higher risk of a coronary event was found, especially for obese individuals (MHO: OR=1.85 CI95%: 1.11-3.09; p=0.02 and MUO: OR=2.09 CI95%: 1.34-3.28; p<0.01). Conclusion: Individuals with atypical metabolic phenotypes exist in Maracaibo city. Related factors may include insulin resistance, basal glucose levels, and triglycerides levels. Lastly, cardiovascular risk exhibited by healthy obese individuals should be classified in categories of major coronary risk related to lean subjects.

Biochemical and clinical characterization of metabolic phenotypes: a cross-sectional study from Maracaibo city, Venezuela

Background: In 1980, Reuben Andresen observed that in certain individuals, obesity did not increase mortality, introducing an atypical phenotype called "healthy obese". Other studies reported that 10-15 % of lean individuals presented insulin resistance, hyperglycemia and dyslipidemia. The objective of this study was to evaluate biochemical and clinical characteristics of metabolic phenotypes in Maracaibo city. Methods: A descriptive, cross-sectional sub-analysis of The Maracaibo City Metabolic Syndrome Prevalence Study, with a randomized multistage sampling was performed including 1226 non diabetic individuals from both sexes. For phenotype definition, the subjects were first classified according to their BMI into Normal-Weight, Overweight and Obese; then divided in metabolically healthy and unhealthy using a two-step analysis cluster being predictive variables: HOMA2-IR, HOMA2-βcell, triglycerides. To evaluate the relationship with coronary risk, a multiple logistic regression model was performed. Results: In the studied population, 43.9% (n=538) were healthy normal weight, 5.2% (n=64) unhealthy normal weight, 17.4% (n=217) healthy obese and 33.5% (n=411) unhealthy obese subjects. Atypical phenotypes, Metabolically Unhealthy Normal-Weight (MUNW) was more frequent in males (56.3%), whereas Metabolically Unhealthy Obese (MUO) was more frequent in females (51.3%). This phenotypes had a higher coronary event risk, especially for obese individuals (MHO: OR=1.85 CI95%: 1.11-3.09; p=0.02 and MUO: OR=2.09 CI95%: 1.34-3.28; p<0.01). Conclusion: Individuals with atypical metabolic phenotypes are common in Maracaibo city. Related factors may include insulin resistance, basal glucose, and triglycerides levels. Lastly, obese subjects show a higher coronary event risk even those with normal metabolic status.

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.

Non-alcoholic Fatty Liver Disease in Lean Subjects: Characteristics and Implications

Non-alcoholic fatty liver disease (NAFLD) is commonly diagnosed in obese subjects; however, it is not rare among lean individuals. Given the absence of traditional risk factors, it tends to remain under-recognised. The metabolic profiles of lean NAFLD patients are frequently comparable to those of obese NAFLD patients. Though results from several studies have been mixed, it has been generally revealed that lean subjects with NAFLD have minor insulin resistance compared to that in obese NAFLD. Several genetic variants are associated with NAFLD without insulin resistance. Some data suggest that the prevalence of steatohepatitis and advanced fibrosis do not differ significantly between lean and obese NAFLD; however, the former tend to have less severe disease at presentation. The underlying pathophysiology of lean NAFLD may be quite different. Genetic predispositions, fructose- and cholesterol-rich diet, visceral adiposity and dyslipidaemia have potential roles in the pathogenic underpinnings. Lean NAFLD may pose a risk for metabolic disturbances, cardiovascular morbidity or overall mortality. Secondary causes of hepatic steatosis are also needed to be ruled out in lean subjects with NAFLD. The effectiveness of various treatment modalities, such as exercise and pharmacotherapy, on lean NAFLD is not known. Weight loss is expected to help lean NAFLD patients who have visceral obesity. Further investigation is needed for many aspects of lean NAFLD, including mechanistic pathogenesis, risk assessment, natural history and therapeutic approach.

Normal weight obesity among young adults in Trinidad and Tobago: prevalence and associated factors

BACKGROUND

Patients with normal weight obesity (NWO) have a normal body mass index (BMI) but elevated body fat percentage (BF%), thereby increasing their risk of cardiovascular and metabolic disorders. The purpose of this research was to determine the prevalence of NWO and its associated factors in a sample of young adults in Trinidad and Tobago (T&T).

METHODS

A cross sectional study involving a convenience non-voluntary sample of participants with a normal BMI of 18.5-24.9 kg/m2 was conducted. The following information was collected: history, basic anthropometric measurements, including BF% via the Tanita Ironman Body Composition Analyzer (BC554), physical examination and basic blood investigations. Participants were divided into two groups; normal BF% (<23.1% males, <33.3% females) and elevated BF% (≥23.1% males, ≥33.3% females).

RESULTS

Two hundred and thirty-six students participated, F:M (2.1:1), aged 18-28 years [Mean 21.33 (SD 2.5)], mean BMI 21.66 (SD 1.9). A response rate of 80.3%. The prevalence of NWO for this population was 19.9% [95% confidence interval (CI) 15.1-25.7]. Males 14.4% (95% CI 10.3-19.7) and females 5.5% (95% CI 3.1-9.5). Variables with a statistically significant association with NWO included gender, waist circumference, waist-to-hip ratio (WHR), systolic blood pressure (BP), the ratio of total cholesterol (TC) to high density lipoprotein and in females, the presence of polycystic ovarian syndrome (PCOS) (p<0.05). Binary logistic regression revealed that predictors of NWO were male gender and waist circumference.

CONCLUSIONS

One in five of this young adult population was found to have NWO. Long-term studies are recommended to study the full implications of these findings.

Long Distance Metabolic Regulation through Adipose-Derived Circulating Exosomal miRNAs: A Trail for RNA-Based Therapies?

The contribution of non-coding RNAs, such as microRNAs (miRNAs) in regulating physiological and pathological states has been intensively elucidated during last 15 years. The discovery of circulating miRNAs (cir-miRNAs) in variety of body fluids, is, however a recent focus of interest in understanding pathophysiological states of their originating cells/organs. Yet another stimulating debate that takes miRNAs to the next level is their presence in exosomes, and this is truly interesting area of research. Exosomes are cell-derived extracellular vesicles, and are naturally equipped biological vehicles that not only enable functional transfer of miRNAs between cells (horizontal transfer) but also foster inter-organ communication, presumably guided by organ specific receptors—decorated on their surface. However, understandings on inter-organ communication elicited by tissue specific exosomal-miRNA fingerprints remain elusive. Recently, Thomou et al., has discovered that adipose tissue contributes a large fraction of adipose specific exosomal-miRNA fingerprints in blood circulation. Experimental evidence emphasize adipose tissue as major depot of cir-miRNAs that sail through blood flow and reach to distal organs—primarily in the liver, where they regulate gene expression of host tissue and elicit metabolic control. This appears to be a genetic form of adipokines (endocrine factors secreted from adipose tissue). We review such offshore metabolic insults, and make an effort to address few important missing links between miRNAs processing and their incorporation into exosomes. We provide potential perspectives on how this knowledge could be steered towards RNA-based therapeutics for monitoring complex metabolic diseases and beyond.

Impact of Mediterranean diet on metabolic syndrome, cancer and longevity

Obesity symbolizes a major public health problem. Overweight and obesity are associated to the occurrence of the metabolic syndrome and to adipose tissue dysfunction. The adipose tissue is metabolically active and an endocrine organ, whose dysregulation causes a low-grade inflammatory state and ectopic fat depositions. The Mediterranean Diet represents a possible therapy for metabolic syndrome, preventing adiposopathy or "sick fat" formation.The Mediterranean Diet exerts protective effects in elderly subjects with and without baseline of chronic diseases. Recent studies have demonstrated a relationship between cancer and obesity. In the US, diet represents amount 30-35% of death causes related to cancer. Currently, the cancer is the second cause of death after cardiovascular diseases worldwide. Furthermore, populations living in the Mediterranean area have a decreased incidence of cancer compared with populations living in Northern Europe or the US, likely due to healthier dietary habits. The bioactive food components have a potential preventive action on cancer. The aims of this review are to evaluate the impact of Mediterranean Diet on onset, progression and regression of metabolic syndrome, cancer and on longevity.

Metabolism rather than obesity is associated with ischemic stroke: a cross-sectional study in rural Northeastern China

Little is known about stroke with different obesity phenotype as determined using the Adult Treatment Panel-III criteria with metabolic health or not. This study aimed to investigate the effects of metabolically healthy and unhealthy obesity on ischemic stroke in a general population. A total of 11,150 adults were examined using a multi-stage cluster sampling method to select a representative sample of individuals 35 years or older. Ischemic stroke was defined as history of a cerebrovascular event, as documented by doctors via either cranial CT or MR scan within the past 2 years. All subjects were categorized as having metabolically healthy non-obesity (MHNO), metabolically unhealthy non-obesity (MUNO), metabolically healthy obesity (MHO) or metabolically unhealthy obesity (MUO) using the Adult Treatment Panel-III criteria. Stratified analysis were done based on different body mass index group. For the total population, multiple regression analyses revealed that individuals with MUNO and MUO were more likely to experience ischemic stroke compared with those with MHNO (OR 2.136, 95 % CI 1.677-2.720; OR 2.712, 95 % CI 1.798-4.092; all p < 0.001). The OR for ischemic stroke did not significantly differ between MHO and MHNO. Stratification based on different BMI group showed that, compared with people who were normal weight without Mes, participants who were in Mes with overweight or obesity had significantly higher OR for ischemic stroke(both p < 0.05); participants who were not in Mes with overweight or obesity did not showed OR significantly higher. Ischemic stroke is likely associated with poor metabolic health rather than with obesity itself.

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.

New obesity classification criteria as a tool for bariatric surgery indication

Obesity plays relevant pathophysiological role in the development of health problems, arising as result of complex interaction of genetic, nutritional, and metabolic factors. Due to the role of adipose tissue in lipid and glucose metabolism, and low grade inflammation, it is necessary to classify obesity on the basis of body fat composition and distribution, rather than the simply increase of body weight, and the Body Mass Index. The new term of adiposopathy (‘‘sick fat’’) clearly defines the pathogenic role of adipose tissue. Four phenotypes of obese individuals have been described: (1) normal weight obese (NWO); (2) metabolically obese normal weight; (3) metabolically healthy obese; and (4) metabolically unhealthy obese or “at risk” obese. Moreover, sarcopenic obesity has been related to all the phenotypes. The category of normal weight lean, represented by metabolically healthy normal weight has been classified to distinguish from NWO. It is crucial to recommend a bariatric surgery taking into account adiposopathy and sick fat that occurs with the expansion of fat mass, changing the inflammatory and metabolic profile of the patient. Body fat percentage and genetic polymorphism have to be evaluated to personalize the best bariatric surgery intervention.

Incidence and potential risk factors of obesity among Tehranian adults

AIM

Evaluating the incidence of obesity and its risk factors among Tehranian adults.

MATERIAL & METHODS

In this population-based cohort, non-obese participants, aged ≥20years, were followed for development of obesity (Body Mass Index (BMI) ≥30). Incidence density and cumulative incidence rates of obesity were calculated for each sex. Cox proportional hazard regression was used to determine the association of potential obesity risk factors including: age, BMI, metabolic syndrome, waist circumference (WC), smoking, marital status, education, and physical activity.

RESULT

A total of 7257 participants (3536 men) were followed for a median of 8years. At baseline, mean age, BMI and WC were 41.3±14.6years, 25.1±2.9kg/m(2) (24.9±3kg/m(2) men and 25.2±3kg/m(2) women), and 84.8±9.8cm (87.06±9.2cm men and 82.6±9.9cm women) respectively. During the follow-up, 1345 participants (876 women) developed obesity contributing to cumulative incidences of 31.3% (CI: 29.9%-32.7%), 38.1% (CI: 36.2%-40.1%), and 23.4% (CI: 21.6%-25.3%) for the whole population, women, and men, respectively. Corresponding incidence density rates per 1000 person-year were 25.9 (CI: 24.5-27.3), 33.67 (CI: 31.5-36.0), and 18.0 (CI: 16.5-19.7), respectively. Highest incidence rates were observed during their 40s and 20s for women and men, respectively. Participants with metabolic syndrome, lower educational level, higher BMI and WC, were at higher risk of obesity development in both sexes.

CONCLUSION

High incidence of obesity was observed among Tehranian adults with higher incidence of obesity in women. Different modifiable variables may act as risk factors for obesity development which should be targeted to control the epidemic of obesity.

Serum Zinc and Metabolic Health Status in Siblings of Patients with Type 2 Diabetes Mellitus

INTRODUCTION

There is increasing evidence on the association between lower serum zinc levels and metabolically unhealthy status in normal weight individuals'.

AIM

Our aim was to investigate serum zinc levels in a sample of siblings of patients with type 2 diabetes mellitus and to ascertain its relation with metabolic syndrome components.

MATERIALS AND METHODS

Serum zinc was determined in 331 apparently healthy individuals, 201 were siblings of patients with type 2 diabetes mellitus (type 2 DM) and 130 individuals with negative family history of diabetes (healthy controls), with age range 20-40 years. The association between components of metabolic syndrome and serum zinc levels was examined.

RESULTS

The siblings of patients with type2 DM exhibited significantly lower serum zinc levels than did the healthy controls (94.1±20.8 ug/dl vs. 103.2±15.6 ug/dl, p=0.012). The mean serum zinc levels were lower in siblings exhibited higher levels of waist circumference, fasting blood glucose and triglycerides. Those categorized as metabolically obese, normal weight (MONW) exhibited lower serum zinc levels than did the non-MONW, but the difference was not significant (93.7+20.9 ug/dl vs. 96.2+18.1ug/dl, p=0.059). The correlation between serum zinc levels and fasting blood glucose was inverse among the siblings (r=- 0.233, p=0.001).

CONCLUSION

A low zinc status is present in 13.9% of the siblings of patients with type 2 DM, particularly among MONW individuals. This finding may have clinical implications due to the increased risk of future metabolic disease.

Association of metabolic syndrome components with insulin resistance in normal weight population: the Qazvin Metabolic Diseases study

PURPOSE

Metabolically obese but normal weight (MONW) is associated with higher risk of type 2 diabetes, dyslipidemia, and hypertension. The aim of this study was to evaluate the association of metabolic syndrome components with MONW in each sex in Iranian population.

METHODS

This cross-sectional study was performed on 417 normal weight subjects in Qazvin, Iran between September 2010 and April 2011. MONW was defined by insulin resistance (IR) using the homeostatic model assessment (HOMA). Cut off point for IR was defined as the lower limit of top quintile of HOMA-IR values in normal weight population without any metabolic risk factors. Data were analyzed using T test, Mann-Whitney U test, and multi-variant logistic regression analysis.

RESULTS

Of 417 subjects, 44.3 % were female. The prevalence of MONW was 33.8 % in men and 39.8 % in women. Triglycerides levels were significantly higher in both men and women with MONW. Waist circumference was significantly higher in men with MONW, while high-density lipoprotein cholesterol levels were significantly lower in women with MONW. In logistic regression analysis, hypertriglyceridemia in women (OR 3.398; 95 % CI 1.306-8.846) and waist circumference (per 5 cm increment) in men (OR 1.653; 95 % CI 1.279-2.136) had independent association with MONW.

CONCLUSION

Association of metabolic syndrome components with MONW is different in men and women. Waist circumference had an independent association with IR in men but not in women. IR and its complications should be considered in lean women with hypertriglyceridemia.