Metabolically healthy obesity: the low-hanging fruit in obesity treatment?

Relevance of Leptin and Other Adipokines in Obesity-Associated Cardiovascular Risk

Obesity, which is a worldwide epidemic, confers increased risk for multiple serious conditions including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Adipose tissue is considered one of the largest endocrine organs in the body as well as an active tissue for cellular reactions and metabolic homeostasis rather than an inert tissue only for energy storage. The functional pleiotropism of adipose tissue relies on its ability to synthesize and release a large number of hormones, cytokines, extracellular matrix proteins, and growth and vasoactive factors, which are collectively called adipokines known to influence a variety of physiological and pathophysiological processes. In the obese state, excessive visceral fat accumulation causes adipose tissue dysfunctionality that strongly contributes to the onset of obesity-related comorbidities. The mechanisms underlying adipose tissue dysfunction include adipocyte hypertrophy and hyperplasia, increased inflammation, impaired extracellular matrix remodeling, and fibrosis together with an altered secretion of adipokines. This review describes the relevance of specific adipokines in the obesity-associated cardiovascular disease.

Physical Activity and Risk of Metabolic Phenotypes of Obesity: A Prospective Taiwanese Cohort Study in More Than 200,000 Adults

OBJECTIVE

To examine the association between physical activity (PA) and the risk for metabolically unhealthy obesity (MUO) or metabolically healthy obesity (MHO) in Asian adults.

PATIENTS AND METHODS

Data were obtained from 205,745 healthy individuals 18 years or older. Individuals were classified as inactive, lower or upper insufficiently active, active, and high active. Metabolically unhealthy was defined as having 1 or more of the metabolic syndrome criteria, excluding the abdominal obesity criterion.

RESULTS

The percentages of metabolically healthy normal-weight (MHNW), metabolically healthy overweight (MHOW), MHO, and MUO in our cohort were 30.8% (63,408 of 205,745), 5.8% (12,002 of 205,745), 4.1% (8329 of 205,745), and 20.7% (42,564 of 205,745), respectively. During a mean follow-up of 6 (range, 0.5-19) years, among 63,408 MHNW participants, 1890 (3.0%) and 1174 (1.9%) developed MUO and MHO, respectively. Among 12,002 MHOW participants, 3404 (28.4%) developed MUO and 2734 (22.8%) developed MHO. A total of 5506 of 8329 (66.1%) participants moved from MHO to MUO, and 5675 of 42,564 (13.3%) moved from MUO to MHO. Compared with being inactive, MHNW individuals who were active or high active showed lower risk for MUO. Among those with MHOW, being high active was associated with reduced risk for MUO and MHO. Although among MHO participants, PA was not associated with incident MUO, being active or high active was linked to a greater likelihood of moving from MUO to MHO.

CONCLUSION

PA may prevent the development of both MHO and MUO. PA also helps increase the transition from MUO to MHO, which may contribute to reduce the subsequent development of type 2 diabetes mellitus and major cardiovascular disease complications.

Metabolically healthy obesity and risk of cardiovascular disease, cancer, and all-cause and cause-specific mortality: a protocol for a systematic review and meta-analysis of prospective studies

INTRODUCTION

Metabolically healthy obese phenotype (MHO) refers to obese individuals with an adequate metabolic profile and absence of metabolic syndrome. Many prospective studies have reported the benign condition relating the MHO phenotype and its potential role in reducing risk of cardiovascular disease, total cancer, and all-cause and cause-specific mortality. However, inconsistent results were found and the question remains controversial. We aim to conduct a systematic review and meta-analysis to clarify the associations these associations from relevant prospective studies.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols 2015 statement was used to prepare this protocol. MEDLINE, Web of Science databases, EMBASE and Cochrane Database will be used for literature search from their inception up to December 2019 with restriction of published studies in English. Published prospective studies reporting adjusted relative risk (RR) estimates for the association between MHO phenotype and cardiovascular disease, total cancer, all-cause or cause-specific mortality will be included. The process of study screening, selection and data extraction will be performed independently by two reviewers, and the risk of bias for the studies included will be assessed using the Newcastle-Ottawa Quality Assessment Scale. HRs or RRs for disease events and mortality with 95% CIs will be considered as primary outcomes, and summary HRs/RRs will be pooled using random-effects models. The Cochrane's Q and the I2 statistics will be used to assess and quantify heterogeneity, respectively. Subgroup analysis will also be carried out according to study characteristics to investigate potential sources of heterogeneity.

ETHICS AND DISSEMINATION

As this meta-analysis is performed based on the published studies, no ethical approval and patient safety considerations are required. The findings of the study will be reported and submitted to a peer-reviewed journals for publication.

PROSPERO REGISTRATION NUMBER

CRD42019121766.

Effectiveness of the Diabetes Prevention Program for Obesity Treatment in Real World Clinical Practice in a Middle-Income Country in Latin America

The Diabetes Prevention Program (DPP) is effective for the prevention of type 2 diabetes by weight loss with diet and physical activity. However, there is little evidence as to whether this program could be translated into real-world clinical practice in Latin American countries. The objective of this work was to evaluate the effectiveness of the DPP for the management of overweightness and obesity at 6 and 12 months in clinical practice in Mexico. This was a non-controlled intervention study implemented in five public clinics in northern Mexico. Two hundred and thirty-seven adults aged 45.7 ± 9.9 years with a Body Mass Index (BMI) of 34.4 ± 5.4 kg/m² received group sessions with an adaptation of the DPP, in addition to nutrition counseling. One hundred and thirty-three (56%) participants concluded the 6 month phase. They showed a significant weight loss, ranging from 2.76 ± 4.76 to 7.92 ± 6.85 kg (p ≤ 0.01) in the clinics. The intention-to-treat analysis showed a more conservative weight loss. Participant retention at the end of 12 months was low (40%). The implementation of the DPP in different public clinics in Mexico was effective in the management of obesity in the short term, but better strategies are required to improve participant retention in the long term.

Metabolically healthy and unhealthy obesity in erectile dysfunction and male infertility

Introduction: Metabolically unhealthy obesity (MUHO) is the most important preventable cardiovascular (CV) risk factor. Recently, the significance of metabolically healthy obesity (MHO) as a CV risk factor has raised increasing interest. MUHO is a known risk factor for erectile dysfunction (ED); however, the effect of MHO on ED has barely been investigated. This review aims at summarizing the evidence supporting the relation of MUHO and MHO to male sexual functioning and fertility. Areas covered: An extensive Medline search on obesity and ED or male infertility was conducted to summarize the role of MUHO or MHO on male sexual dysfunction and infertility. Expert opinion: Longitudinal studies have demonstrated that MHO causes vascular damage, which is consistent with the impairment in penile blood flows found in ED subjects. In this population, MHO is a predictor of CV events. The relationship between male infertility and MUHO is currently debated and data on MHO are almost completely lacking. The only available study did not find an association between obesity classes and semen parameters. Although the andrological correlates of MHO must be better assessed, in the current state, evidence suggests that MHO does not represent a benign condition and measures for improving lifestyle are mandatory.

Metabolically healthy obesity: what's in a name?

Metabolically healthy obesity refers to an obesity phenotype with no or little evidence of metabolic dysfunction. Lower liver fat content and visceral adipose tissue, greater insulin sensitivity and secretion, greater cardiorespiratory fitness, and a predominantly lower body (i.e., leg) fat deposition are key physiological traits of a metabolically healthy phenotype. About 35% of all subjects with obesity are metabolically healthy. These individuals have approximately half the risk of developing type 2 diabetes and cardiovascular disease compared with metabolically unhealthy subjects with obesity, but they still have a significantly greater risk (by 50-300%) compared with metabolically healthy lean subjects. Therefore, absence of metabolic risk factors in people with obesity should not be a contraindication for weight-loss treatment. Metabolically healthy obesity needs to be treated, and this need is reinforced by the fact that this phenotype is not stable over time, as ∼50% of these subjects will cease being metabolically healthy within ∼10 y. Intervening early is therefore important. Weight loss dose-dependently decreases visceral adipose tissue and liver fat content, and it improves multiorgan insulin sensitivity and β-cell function (i.e., it beneficially affects many of the physiological traits of a metabolically healthy phenotype); however, weight loss is very difficult to maintain. This typically results in disappointment among patients and hinders adherence, which is likely critical for the limited success of most weight-loss treatments in the long term. On the other hand, using ≥1 metabolic health targets in a non-weight-loss-centered treatment paradigm that includes prudent dietary changes and increased physical activity can serve as an appropriate first goal that can help motivate patients toward the long-term goals of obesity treatment.

The Relationship between Metabolically Healthy Obesity and the Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVD) risk in individuals with metabolically healthy obesity (MHO) is unclear. We searched databases from inception to May 2019. Data were pooled using a random effects model. Newcastle-Ottawa Scale assessment was performed. Primary and secondary outcomes were CVD risk and all-cause mortality. Forty-three studies involving 4,822,205 cases were included. The median percentage of females, age and duration of follow-up was 52%, 49.9 years and 10.6 years, respectively. The mean Newcastle-Ottawa Scale score of the articles was 7.9 ± 1.0. Compared to individuals with a metabolically healthy normal weight, individuals with MHO had higher adjusted risk of CVD and all-cause mortality. We identified a significant linear dose-response relationship between body mass index (BMI) and CVD risk among metabolically healthy individuals (p < 0.001); every unit increase in BMI increased the CVD risk. Multivariate meta-regression analysis showed that an increased proportion of women and age resulted in the risk of CVD affected by MHO reduction (p = 0.014, p = 0.030, respectively). Age and sex explained the observed heterogeneity and reported the adjusted R². MHO resulted in a significantly increased risk for CVD; therefore, long-term weight loss should be encouraged.

Type 2 diabetes and obesity in midlife and breast cancer risk in the Reykjavik cohort

PURPOSE

As obesity and type 2 diabetes (T2D) have been increasing worldwide, we investigated their association with breast cancer incidence in the Reykjavik Study.

METHODS

During 1968-1996, approximately 10,000 women (mean age = 53 ± 9 years) completed questionnaires and donated blood samples. T2D status was classified according to self-report (n = 140) and glucose levels (n  = 154) at cohort entry. A linkage with the Icelandic Cancer Registry provided breast cancer incidence through 2015. Cox regression with age as time metric and adjusted for known confounders was applied to obtain hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Of 9,606 participants, 294 (3.1%) were classified as T2D cases at cohort entry while 728 (7.8%) women were diagnosed with breast cancer during 28.4 ± 11.6 years of follow-up. No significant association of T2D (HR 0.95; 95% CI 0.56-1.53) with breast cancer incidence was detected except among the small number of women with advanced breast cancer (HR 3.30; 95% CI 1.13-9.62). Breast cancer incidence was elevated among overweight/obese women without (HR 1.18; 95% CI 1.01-1.37) and with T2D (HR 1.35; 95% CI 0.79-2.31). Height also predicted higher breast cancer incidence (HR 1.03; 95% CI 1.02-1.05). All findings were confirmed in women of the AGES-Reykjavik sub-cohort (n  = 3,103) who returned for an exam during 2002-2006. With a 10% T2D prevalence and 93 incident breast cancer cases, the HR for T2D was 1.18 (95% CI 0.62-2.27).

CONCLUSIONS

These findings in a population with low T2D incidence suggest that the presence of T2D does not confer additional breast cancer risk and confirm the importance of height and excess body weight as breast cancer risk factors.

Association Between Nonalcoholic Fatty Liver Disease and Future Deterioration of Metabolic Health: A Cohort Study

OBJECTIVE

It was hypothesized that the presence of nonalcoholic fatty liver disease (NAFLD) at baseline predicts future conversion from the metabolically healthy (MH) to the metabolically unhealthy (MU) phenotype according to body fat mass.

METHODS

A total of 22,551 Korean participants (13,601 men and 8,950 women) aged 18 to 78 years in the Kangbuk Samsung Health Study cohort were enrolled from 2007 to 2013.

RESULTS

During a median of 5.1 years of follow-up (interquartile range 2.1-9.8 years), 23.5% (n = 5,298) of MH individuals converted to the MU phenotype. NAFLD at baseline predicted conversion independent of age, sex, BMI, lifestyle factors, individual components of metabolic syndrome, and insulin resistance (HR, 1.29; 95% CI: 1.19-1.39; P < 0.0001). In participants with lower BMI and fat mass, NAFLD was strongly associated with conversion; however, as BMI and fat mass increased, the risk decreased, and there was no association in participants with higher BMI and fat mass (P < 0.0001 for trend).

CONCLUSIONS

NAFLD at baseline was independently associated with future conversion from the MH to the MU phenotype.

Do worse baseline risk factors explain the association of healthy obesity with increased mortality risk? Whitehall II Study

OBJECTIVE

To describe 20-year risk factor trajectories according to initial weight/health status and investigate the extent to which baseline differences explain greater mortality among metabolically healthy obese (MHO) individuals than healthy non-obese individuals.

METHODS

The sample comprised 6529 participants in the Whitehall II study who were measured serially between 1991-1994 and 2012-2013. Baseline weight (non-obese or obese; body mass index (BMI) ≥30 kg/m2) and health status (healthy or unhealthy; two or more of hypertension, low high-density lipoprotein cholesterol (HDL-C), high triglycerides, high glucose, and high homeostatic model assessment of insulin resistance (HOMA-IR)) were defined. The relationships of baseline weight/health status with 20-year trajectories summarizing ~25,000 observations of systolic and diastolic blood pressures, HDL-C, triglycerides, glucose, and HOMA-IR were investigated using multilevel models. Relationships of baseline weight/health status with all-cause mortality up until July 2015 were investigated using Cox proportional hazards regression.

RESULTS

Trajectories tended to be consistently worse for the MHO group compared to the healthy non-obese group (e.g., glucose by 0.21 (95% CI 0.09, 0.33; p < 0.001) mmol/L at 20-years of follow-up). Consequently, the MHO group had a greater risk of mortality (hazard ratio 2.11 (1.24, 3.58; p = 0.006)) when the referent group comprised a random sample of healthy non-obese individuals. This estimate, however, attenuated (1.34 (0.85, 2.13; p = 0.209)) when the referent group was matched to the MHO group on baseline risk factors.

CONCLUSIONS

Worse baseline risk factors may explain any difference in mortality risk between obese and non-obese groups both labelled as healthy, further challenging the concept of MHO.

Implications of the dynamic nature of metabolic health status and obesity on risk of incident cardiovascular events and mortality: a nationwide population-based cohort study

AIMS

We hypothesized that transitions in metabolic health status and obesity affect the cardiovascular (CV) risk and mortality in population with metabolically healthy obesity (MHO).

METHODS

This study enrolled 514,866 participants from the Korean National Health Insurance Service-National Sample Cohort. Changes in metabolic health status and obesity from the baseline examination in 2009-2010 to the next biannual health examination in 2011-2012 were determined. Study participants were categorized into four groups: (1) metabolically healthy, non-obese (MHNO), defined as BMI < 25 kg/m² and no or one metabolic risk factor; (2) metabolically unhealthy, non-obese (MUNO), defined as BMI < 25 kg/m² and ≥2 metabolic risk factors; (3) MHO, defined as BMI ≥ 25 kg/m² and no or one metabolic risk factor; and (4) metabolically unhealthy, obese (MUO), defined as BMI ≥ 25 kg/m² and ≥2 metabolic risk factors. The study subjects were followed-up from 2011 to 2015 for cardiovascular events, CV mortality and all-cause mortality.

RESULTS

Among the subjects classified as MHO in 2009-2010, 45.6% were classified as MHO in 2011-2012, whereas 11.6%, 6.0%, and 36.8% were classified as MHNO, MUNO, and MUO, respectively. The risk of CV events was higher in baseline MHO group than MHNO group (HR, 1.14; 95% CI, 1.05-1.24). However, in baseline MHO group, CV mortality was not increased (HR, 0.85; 95% CI, 0.69-1.06) and all-cause mortality was even lower than that of MHNO group (HR, 0.86; 95% CI, 0.79-0.93). Compared to the stable MHO subjects, the risk of CV events was significantly higher in the subjects who transitioned from MHO to MUO with multivariate-adjusted HRs of 1.24 (95% CI: 1.00-1.54). When weight loss and progression to metabolic unhealthy phenotype occur simultaneously in the MHO population, the all-cause mortality was increased compared to the stable MHO group (HR, 1.96; 95% CI, 1.45-2.65).

CONCLUSIONS

Subjects with MHO constitute a heterogeneous group. Our finding supports that evolving to a metabolically unhealthy status and losing weight simultaneously is associated with the adverse outcome in the MHO population.

Health Benefits of Resveratrol in Kidney Disease: Evidence from In Vitro and In Vivo Studies

Different diseases and disorders that affect the kidneys include, but are not limited to, glomerulonephritis, diabetic nephropathy, polycystic kidney disease, kidney stones, renal fibrosis, sepsis, and renal cell carcinoma. Kidney disease tends to develop over many years, making it difficult to identify until much later when kidney function is severely impaired and undergoing kidney failure. Although conservative care, symptom management, medication, dialysis, transplantation, and aggressive renal cancer therapy are some of the current strategies/approaches to kidney disease treatment, new preventative targeted therapies are needed. Epidemiological studies have suggested that a diet rich in fruits and vegetables is associated with health benefits including protection against kidney disease and renal cancer. Resveratrol, a polyphenol found in grapes and berries, has been reported to have antioxidant, anti-inflammatory, antidiabetic, hepatoprotective, neuroprotective, and anti-cancer properties. The current review summarizes the existing in vitro and in vivo animal and human studies examining the nephroprotective effects of resveratrol.

Healthy adiposity and extended lifespan in obese mice fed a diet supplemented with a polyphenol-rich plant extract

Obesity may not be consistently associated with metabolic disorders and mortality later in life, prompting exploration of the challenging concept of healthy obesity. Here, the consumption of a high-fat/high-sucrose (HF/HS) diet produces hyperglycaemia and hypercholesterolaemia, increases oxidative stress, increases endotoxaemia, expands adipose tissue (with enlarged adipocytes, enhanced macrophage infiltration and the accumulation of cholesterol and oxysterols), and reduces the median lifespan of obese mice. Despite the persistence of obesity, supplementation with a polyphenol-rich plant extract (PRPE) improves plasma lipid levels and endotoxaemia, prevents macrophage recruitment to adipose tissues, reduces adipose accumulation of cholesterol and cholesterol oxides, and extends the median lifespan. PRPE drives the normalization of the HF/HS-mediated functional enrichment of genes associated with immunity and inflammation (in particular the response to lipopolysaccharides). The long-term limitation of immune cell infiltration in adipose tissue by PRPE increases the lifespan through a mechanism independent of body weight and fat storage and constitutes the hallmark of a healthy adiposity trait.

Cardiometabolic risk factors in Thai individuals with prediabetes treated in a high-risk, prevention clinic: Unexpected relationship between high-density lipoprotein cholesterol and glycemia in men

AIMS/INTRODUCTION

Relationships between cardiometabolic risk and glycemia have rarely been studied in people under clinical evaluation and treatment for cardiometabolic risk and with prediabetes. We investigated relationships between glycemia and cardiometabolic risk factors in clinic participants with prediabetes.

MATERIALS AND METHODS

This was a cross-sectional analysis of data collected at a center in Thailand. Clinic attendees were at high risk of diabetes or cardiovascular disease, with hemoglobin A1c (HbA1c) 39-<48 mmol/mol or fasting plasma glucose (FPG) 5.6-<7.0 mmol/L. The relationships between glycemia and cardiometabolic risk factors were explored.

RESULTS

Of 357 participants, two or more insulin resistance-related metabolic disturbances were present in 84%; 61% took a statin and 75% an antihypertensive agent. Independently of age, sex, adiposity, medication use, possible non-alcoholic fatty liver disease and sex-glycemia interaction, neither FPG nor HbA1c were associated with variation in any other cardiometabolic risk factors. High-density lipoprotein cholesterol decreased with HbA1c in women (female-HbA1c interaction, P = 0.03) but, unexpectedly, increased with FPG in men (male-FPG interaction, P = 0.02).

CONCLUSIONS

Overall, in Thai people treated for high cardiometabolic risk and with prediabetes defined by FPG and/or HbA1c, neither FPG nor HbA1c were associated with other cardiometabolic risk factors. However, according to sex, high-density lipoprotein cholesterol showed the expected relationship with glycemia in women, but the reverse in men.

Is metabolically healthy obesity a useful concept?

Obesity poses significant public health concerns, including Type 2 diabetes mellitus, cardiovascular disease and stroke. Although deleterious metabolic profiles typically accompany individuals with obesity, various epidemiological studies have identified a subset of patients with a favourable metabolic phenotype referred to as the metabolically healthy obese. Metabolically healthy obesity is a novel concept that stratifies obese individuals according to their respective metabolic status. It has important implications for healthcare policies, particularly the efficient allocation of resources in the targeted treatment of obesity and prevention of metabolic ill-health. However, conflicting evidence in the literature regarding its risk profile questions its clinical relevance. In addition, the lack of a unified definition of metabolically healthy obesity and agreement on its progression further impede its utility as a stratification strategy. This review aims to describe current concepts of metabolically healthy obesity within the literature, evidence of this metabolic phenotype, the clinical implications of patient stratification and limitations of the concept.

Hypertension in Obesity: Novel Insights

BACKGROUND

The relationship between obesity and hypertension has been established in both adults and children. The combination of obesity, hypertension and other cardiovascular risk factors significantly increases the likelihood of adverse cardiovascular effects and raises concerns about aggressive treatment strategies.

OBJECTIVE

Despite the impressive elements which indicate an important role for excessive weight gain in increasing blood pressure, not all obese patients are hypertensive. A subgroup of obese people may not develop hypertension. Furthermore, masked hypertension occurs more common among obese patients, and body fat distribution has a major role in the development of hypertension.

METHOD

We conducted a research of the relevant literature regarding obesity-induced hypertension and possible treatment strategies.

RESULTS

Successful weight loss is correlated with blood pressure reduction and requires a multidisciplinary approach that includes personalized dietary interventions combined with regular exercise and cognitive behavioral therapy.

CONCLUSION

Pharmacological therapy may be considered as part of a comprehensive obesity management strategy. More research and new treatment therapies are required in this field.

Impact of Metabolically Healthy Obesity in Patients with Andrological Problems

BACKGROUND

Although the pathogenic role of metabolically complicated obesity (MCO) in erectile dysfunction (ED), major adverse cardiovascular events (MACE), and male infertility has been widely studied, that of metabolically healthy obesity (MHO) has been poorly investigated.

AIM

To assess the role of MHO in the pathogenesis of ED, prediction of MACE, and male reproductive health.

METHODS

A consecutive series of 4,945 men (mean age, 50.5 ± 13.5 years) with sexual dysfunction (SD) (cohort 1) and 231 male partners of infertile couples (mean age, 37.9 ± 9.1 years; cohort 2) were studied. A subset of men with SD (n = 1,687) was longitudinally investigated to evaluate MACE. All patients underwent clinical, biochemical, erectile function, and flaccid penile color Doppler ultrasound (PCDU) assessment. Infertile men also underwent scrotal and transrectal ultrasound; semen analysis, including interleukin (IL-) 8; and prostatitis-like symptom assessment. MHO was defined as body mass index >30 kg/m² with high-density lipoprotein cholesterol level >40 mg/dL and absence of diabetes or hypertension. The rest of the obesity sample was defined as MCO. MHO or MCO were compared with the rest of the sample, defined as normal weight (NW) individuals.

OUTCOMES

Clinical, biochemical, erectile, and PCDU assessment in MHO, MCO and NW men in both cohorts; longitudinal MACE incidence assessment in cohort 1.

RESULTS

In cohort 1, 816 men (16.5%) were obese, 181 (3.7%) were MHO, and 635 (12.8%) were MCO. In cohort 2, 68 men (28.4%) were obese, 19 (8.2%) were MHO, and 49 (21.2%) were MCO. After adjusting for confounders, in both samples, the men with MHO and MCO had lower total testosterone levels and worse PCDU parameters compared with the NW men. However, only MCO men had worse erectile function compared with NW men. In the longitudinal study, both MHO and MCO men independently had a higher incidence of MACE compared with NW men (P < .05 for both). In cohort 2, MHO and MCO men had a larger prostate volume, and MCO men also had higher ultrasound and biochemical (IL-8) features of prostatic inflammation compared with NW men, but no differences in prostatitis-like symptoms or seminal parameters.

CLINICAL IMPLICATIONS

MHO men should be considered at high cardiovascular risk like MCO men and followed-up for erectile dysfunction and prostate abnormalities overtime.

STRENGTHS & LIMITATIONS

The study simultaneously examined several endpoints with validated instruments within 2 different male populations, 1 with SD and 1 with infertility. As for limitations, there is no consensus in the scientific community regarding the definition of MHO, and the results are derived from patients with SD or infertility, which could have different characteristics than the general male population.

CONCLUSION

MHO is associated with subclinical ED, increased cardiovascular risk, and prostate enlargement. Lotti F, Rastrelli G, Maseroli E, et al. Impact of Metabolically Healthy Obesity in Patients with Andrological Problems. J Sex Med 2019:16;821-832.

Non-alcoholic fatty liver disease: causes, diagnosis, cardiometabolic consequences, and treatment strategies

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. In some patients with NAFLD, isolated steatosis can progress to advanced stages with non-alcoholic steatohepatitis (NASH) and fibrosis, increasing the risk of cirrhosis and hepatocellular carcinoma. Furthermore, NAFLD is believed to be involved in the pathogenesis of common disorders such as type 2 diabetes and cardiovascular disease. In this Review, we highlight novel concepts related to diagnosis, risk prediction, and treatment of NAFLD. First, because NAFLD is a heterogeneous disease, the advanced stages of which seem to be strongly affected by comorbidities such as insulin resistance and type 2 diabetes, early use of reliable, non-invasive diagnostic tools is needed, particularly in patients with insulin resistance or diabetes, to allow the identification of patients at different disease stages. Second, although the strongest genetic risk alleles for NAFLD (ie, the 148Met allele in PNPLA3 and the 167Lys allele in TM6SF2) are associated with increased liver fat content and progression to NASH and cirrhosis, these alleles are also unexpectedly associated with an apparent protection from cardiovascular disease. If consistent across diverse populations, this discordance in NAFLD-related risk prediction between hepatic and extrahepatic disease might need to be accounted for in the management of NAFLD. Third, drug treatments assessed in NAFLD seem to differ with respect to cardiometabolic and antifibrotic efficacy, suggesting the need to better identify and tailor the most appropriate treatment approach, or to use a combination of approaches. These emerging concepts could contribute to the development of a multidisciplinary approach for endocrinologists and hepatologists working together in the management of NAFLD.

Metabolic health in normal-weight and obese individuals

Cardiovascular complications are commonly associated with obesity. However, a subgroup of obese individuals may not be at an increased risk for cardiovascular complications; these individuals are said to have metabolically healthy obesity (MHO). In contrast, metabolically unhealthy individuals are at high risk of cardiovascular disease (CVD), irrespective of BMI; thus, this group can include individuals within the normal weight category (BMI 18.5-24.9 kg/m²). This review provides a summary of prospective studies on MHO and metabolically unhealthy normal-weight (MUHNW) phenotypes. Notably, there is ongoing dispute surrounding the concept of MHO, including the lack of a uniform definition and the potentially transient nature of metabolic health status. This review highlights the relevance of alternative measures of body fatness, specifically measures of fat distribution, for determining MHO and MUHNW. It also highlights alternative approaches of risk stratification, which account for the continuum of risk in relation to CVD, which is observable for most risk factors. Moreover, studies evaluating the transition from metabolically healthy to unhealthy phenotypes and potential determinants for such conversions are discussed. Finally, the review proposes several strategies for the use of epidemiological research to further inform the current debate on metabolic health and its determination across different stages of body fatness.

Antidiabetic Properties of Naringenin: A Citrus Fruit Polyphenol

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by insulin resistance and hyperglycemia and is associated with personal health and global economic burdens. Current strategies/approaches of insulin resistance and T2DM prevention and treatment are lacking in efficacy resulting in the need for new preventative and targeted therapies. In recent years, epidemiological studies have suggested that diets rich in vegetables and fruits are associated with health benefits including protection against insulin resistance and T2DM. Naringenin, a citrus flavanone, has been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, immunomodulatory and antidiabetic properties. The current review summarizes the existing in vitro and in vivo animal studies examining the anti-diabetic effects of naringenin.

The obesity transition: stages of the global epidemic

The global prevalence of obesity has increased substantially over the past 40 years, from less than 1% in 1975, to 6-8% in 2016, among girls and boys, and from 3% to 11% among men and from 6% to 15% among women over the same time period. Our aim was to consolidate the evidence on the epidemiology of obesity into a conceptual model of the so-called obesity transition. We used illustrative examples from the 30 most populous countries, representing 77·5% of the world's population to propose a four stage model. Stage 1 of the obesity transition is characterised by a higher prevalence of obesity in women than in men, in those with higher socioeconomic status than in those with lower socioeconomic status, and in adults than in children. Many countries in south Asia and sub-Saharan Africa are presently in this stage. In countries in stage 2 of the transition, there has been a large increase in the prevalence among adults, a smaller increase among children, and a narrowing of the gap between sexes and in socioeconomic differences among women. Many Latin American and Middle Eastern countries are presently at this stage. High-income east Asian countries are also at this stage, albeit with a much lower prevalence of obesity. In stage 3 of the transition, the prevalence of obesity among those with lower socioeconomic status surpasses that of those with higher socioeconomic status, and plateaus in prevalence can be observed in women with high socioeconomic status and in children. Most European countries are presently at this stage. There are too few signs of countries entering into the proposed fourth stage of the transition, during which obesity prevalence declines, to establish demographic patterns. This conceptual model is intended to provide guidance to researchers and policy makers in identifying the current stage of the obesity transition in a population, anticipating subpopulations that will develop obesity in the future, and enacting proactive measures to attenuate the transition, taking into consideration local contextual factors.

Obesity and cardiovascular disease: revisiting an old relationship

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

Visceral Adiposity Index as an Independent Marker of Subclinical Atherosclerosis in Individuals Prone to Diabetes Mellitus

Aims: The visceral adiposity index (VAI) has been proposed as an estimate of visceral adipose tissue (VAT) mass and as an indicator of VAT dysfunction. Both parameters are associated with cardiometabolic risk, including insulin resistance. In this study, we investigated whether VAI is associated with subclinical atherosclerosis in subjects who were free of cardiovascular disease but were at risk of developing diabetes mellitus.

Methods: A total of 731 adults with a median age of 47 years old without diabetes mellitus were included in this cross-sectional study. The anthropometric data, blood pressure, and lipid profiles of 398 women and 333 men were measured. All subjects underwent an oral glucose tolerance test, and carotid intima–media thickness (cIMT) was evaluated by ultrasound. Insulin resistance was estimated using the homeostatic model assessment of insulin resistance (HOMA-IR).

Results: VAI and HOMA-IR (β_st = 0.44, p < 0.0001), VAI and cIMT (β_st = 0.17, p < 0.0001), and HOMA-IR and cIMT (β_st = 0.09, p = 0.0127) were correlated with each other. After adjusting for cofounding variables, VAI is still correlated with HOMA-IR (β_st = 0.42, p < 0.0001). Furthermore, VAI (β_st = 0.07, p = 0.0392) but not HOMA-IR (β_st = 0.03, p = 0.37) was correlated with cIMT independently of other established cardiovascular risk factors.

Conclusion: The calculation of VAI may provide a better estimation of subclinical atherosclerosis than the calculation of HOMA-IR.

Dietary Niacin Intake Predicts the Decrease of Liver Fat Content During a Lifestyle Intervention

Niacin inhibits fatty acid flux from adipose tissue to liver, reduces hepatic triglyceride synthesis and increases hepatic lipid oxidation. Thus, niacin may have a role in the regulation of liver fat content in humans. We tested if dietary intake of niacin predicts change of liver fat content during a lifestyle intervention. To this end, we estimated the composition of diet from diaries of 202 healthy subjects at risk of type 2 diabetes undergoing lifestyle intervention comprising physical activity and diet counselling. Total-, subcutaneous- and visceral adipose tissue mass were measured by magnetic resonance (MR) tomography and liver fat content by ¹H-MR spectroscopy at baseline and after 9 months of follow-up. Among fat compartments, liver fat content showed the largest decrease (-32%, p < 0.0001). High baseline niacin intake predicted a larger decrease of liver fat (p = 0.004). Subjects in the highest quartile of niacin intake at baseline also had the largest decrease of liver fat (1^st:-10%; 2^nd:-27%; 3^rd:-35%; 4^th:-37%). Among 58 subjects with nonalcoholic fatty liver disease (NAFLD) at baseline, NAFLD resolved in 23 subjects during the lifestyle intervention. For one standard deviation increase in niacin intake, the odds ratio for resolution of NAFLD was 1.77 (95% CI, 1.00-3.43). High dietary niacin intake may have a favorable effect on the reduction of liver fat during lifestyle intervention.

Potential effects of reduced red meat compared with increased fiber intake on glucose metabolism and liver fat content: a randomized and controlled dietary intervention study

Background

Epidemiological studies suggest that an increased red meat intake is associated with a higher risk of type 2 diabetes, whereas an increased fiber intake is associated with a lower risk.

Objectives

We conducted an intervention study to investigate the effects of these nutritional factors on glucose and lipid metabolism, body-fat distribution, and liver fat content in subjects at increased risk of type 2 diabetes.

Methods

This prospective, randomized, and controlled dietary intervention study was performed over 6 mo. All groups decreased their daily caloric intake by 400 kcal. The "control" group (N = 40) only had this requirement. The "no red meat" group (N = 48) in addition aimed to avoid the intake of red meat, and the "fiber" group (N = 44) increased intake of fibers to 40 g/d. Anthropometric parameters and frequently sampled oral glucose tolerance tests were performed before and after intervention. Body-fat mass and distribution, liver fat, and liver iron content were assessed by MRI and single voxel proton magnetic resonance spectroscopy.

Results

Participants in all groups lost weight (mean 3.3 ± 0.5 kg, P < 0.0001). Glucose tolerance and insulin sensitivity improved (P < 0.001), and body and visceral fat mass decreased in all groups (P < 0.001). These changes did not differ between groups. Liver fat content decreased significantly (P < 0.001) with no differences between the groups. The decrease in liver fat correlated with the decrease in ferritin during intervention (r2 = 0.08, P = 0.0021). This association was confirmed in an independent lifestyle intervention study (Tuebingen Lifestyle Intervention Program, N = 229, P = 0.0084).

Conclusions

Our data indicate that caloric restriction leads to a marked improvement in glucose metabolism and body-fat composition, including liver-fat content. The marked reduction in liver fat might be mediated via changes in ferritin levels. In the context of caloric restriction, there seems to be no additional beneficial impact of reduced red meat intake and increased fiber intake on the improvement in cardiometabolic risk parameters. This trial was registered at clinicaltrials.gov as NCT03231839.

Obesity and the Risk of Gastrointestinal Cancers

Obesity is a risk factor for all major gastrointestinal cancers. With the rapid increase in the prevalence of obesity worldwide, this link could lead to an elevated burden of cancers of the digestive system. Currently, three main mechanisms explaining the link between excess adiposity and gastrointestinal cancer risk are being considered, including altered insulin signaling, obesity-associated chronic low-grade inflammation, and altered sex hormone metabolism, although new potential mechanisms emerge. This review is aimed to present our current knowledge on biological mechanisms involved in adiposity-related gastrointestinal carcinogenesis supported by results collected in epidemiological studies.

Children With Metabolically Healthy Obesity: A Review

Children with "metabolically healthy obesity" (MHO) are a distinct subgroup of youth with obesity, who are less prone to the clustering of cardiometabolic risk factors. Although this phenotype, frequently defined by the absence of metabolic syndrome components or insulin resistance, was first described during the early 1980s, a consensus-based definition of pediatric MHO was introduced only recently, in 2018. The purpose of this review was to concisely summarize current knowledge regarding the MHO phenomenon in youth. The prevalence of MHO in children varies from 3 to 87%, depending on the definition used and the parameters evaluated, as well as the ethnicity and the pubertal status of the sample. The most consistent predictors of MHO in youth include younger age, lower body mass index, lower waist circumference, and lower body fat measurements. Various hypotheses have been proposed to elucidate the underlying factors maintaining the favorable MHO phenotype. While preserved insulin sensitivity and lack of inflammation were previously considered to be the main etiological factors, the most recent findings have implicated adipokine levels, the number of inflammatory immune cells in the adipose tissue, and the reduction of visceral adiposity due to adipose tissue expandability. Physical activity and genetic factors also contribute to the MHO phenotype. Obesity constitutes a continuum-increased risk for cardiometabolic complications, which is less evident in children with MHO. However, some findings have highlighted the emergence of hepatic steatosis, increased carotid intima-media thickness and inflammatory biomarkers in the MHO group compared to peers without obesity. Screening should be directed at those more likely to develop clustering of cardiometabolic risk factors. Lifestyle modifications should include behavioral changes focusing on sleep duration, screen time, diet, physical activity, and tobacco smoke exposure. Weight loss has also been associated with the improvement of insulin sensitivity and inflammation. Further investigative efforts are needed in order to elucidate the mechanisms which protect against the clustering of cardiometabolic risk factors in pediatric obesity, to provide more efficient, targeted treatment approaches for children with obesity, and to identify the protective factors preserving the MHO profile, avoiding the crossover of MHO to the phenotype with metabolically unhealthy obesity.

Environmental risk factors and nonpharmacological and nonsurgical interventions for obesity: An umbrella review of meta-analyses of cohort studies and randomized controlled trials

BACKGROUND

Multiple environmental factors have been implicated in obesity, and multiple interventions, besides drugs and surgery, have been assessed in obese patients. Results are scattered across many studies and meta-analyses, and they often mix obese and overweight individuals.

MATERIALS AND METHODS

PubMed and Cochrane Database of Systematic Reviews were searched through 21 January 2017 for meta-analyses of cohort studies assessing environmental risk factors for obesity, and randomized controlled trials investigating nonpharmacological and nonsurgical therapeutic interventions for obesity. We excluded data on overweight participants. Evidence from observational studies was graded according to criteria that included the statistical significance of the random-effects summary estimate and of the largest study in a meta-analysis, the number of obesity cases, heterogeneity between studies, 95% prediction intervals, small-study effects and excess significance. The evidence of intervention studies for obesity was assessed with the GRADE framework.

RESULTS

Fifty-four articles met eligibility criteria, including 26 meta-analyses of environmental risk factors (166 studies) and 46 meta-analyses of nondrug, nonsurgical interventions (206 trials). In adults, the only risk factor with convincing evidence was depression, and childhood obesity, adolescent obesity, childhood abuse and short sleep duration had highly suggestive evidence. Infancy weight gain during the first year of life, depression and low maternal education had convincing evidence for association with paediatric obesity. All interventions had low or very-low-quality evidence with one exception of moderate-quality evidence for one comparison (no differences in efficacy between brief lifestyle primary care interventions and other interventions for paediatric obesity). Summary effect sizes were mostly small across compared interventions (maximum 5.1 kg in adults and 1.78 kg in children) and even these estimates may be inflated.

CONCLUSIONS

Depression, obesity in earlier age groups, short sleep duration, childhood abuse and low maternal education have the strongest support among proposed risk factors for obesity. Furthermore, there is no high-quality evidence to recommend treating obesity with a specific nonpharmacological and nonsurgical intervention among many available, and whatever benefits in terms of magnitude of weight loss appear small.

Adiposity predicts low cardiorespiratory fitness in individuals with metabolic diseases

Cardiorespiratory fitness (CRF) is impaired in those with metabolic diseases and strongly predicts mortality. We found that adiposity, not glycaemic control or disease type, is the strongest predictor of low CRF in those with metabolic diseases. We discuss how adiposity and metabolic health may relate to outcomes in obesity.

Glucose tolerance and insulin sensitivity define adipocyte transcriptional programs in human obesity

OBJECTIVE

Although debated, metabolic health characterizes 10-25% of obese individuals and reduces risk of developing life-threatening co-morbidities. Adipose tissue is a recognized endocrine organ important for the maintenance of whole-body metabolic health. Adipocyte transcriptional signatures of healthy and unhealthy obesity are largely unknown.

METHODS

Here, we used a small cohort of highly characterized obese individuals discordant for metabolic health, characterized their adipocytes transcriptional signatures, and cross-referenced them to mouse phenotypic and human GWAs databases.

RESULTS AND CONCLUSIONS

Our study showed that glucose intolerance and insulin resistance co-operate to remodel adipocyte transcriptome. We also identified the Nuclear Export Mediator Factor (NEMF) and the Ectoderm-Neural Cortex 1 (ENC1) as novel potential targets in the management of metabolic health in human obesity.

Gender differences of visceral fat area for predicting incident type 2 diabetes in Koreans

AIMS

Visceral fat accumulation is known to be an independent risk factor for type 2 diabetes. We aimed to determine the optimal cutoff values of visceral fat area (VFA) for predicting incident type 2 diabetes in Koreans.

METHODS

Our study population consisted of 13,004 individuals initially free of type 2 diabetes the ages between 20 and 69 years, who underwent routine health examinations between January 2012 and December 2012 and returned for follow-up examinations between January 2016 and December 2016. VFA values were derived from bioelectrical impedance analysis (BIA) at baseline.

RESULTS

During a median follow-up of 4.02 years, a total of 481 (4.6% for men and 2.3% for women) incident cases of type 2 diabetes were identified. According to the receiver operating characteristic (ROC) curve, the optimal VFA cutoff values for predicting incident type 2 diabetes were 118.8 cm² in men and 82.6 cm² in women, respectively. In a multivariable-adjusted model including obesity and glycemic status, the odds ratios (ORs) of VFA over 120 cm² in men and 80 cm² in women were 1.72 and 3.56, respectively.

CONCLUSIONS

Higher VFA at baseline was an independent risk factor for developing type 2 diabetes and the optimal VFA cutoff values were markedly different between men and women. Therefore, sex-specific reference values for visceral fat obesity such that men with a VFA ≥120 cm² and women with a VFA ≥80 cm² should be considered to predict incident type 2 diabetes.

An Experimental Test of the Effects of a Target Person's Body Weight and Engagement with Health Behaviours on Perceptions of Overall Health

BACKGROUND

Public health campaigns commonly emphasise the association between excess weight and poor health. The present study aimed to examine the effect of information about weight and engagement with health behaviours on judgements of a person's health.

METHOD

In two experimental studies, participants were asked to evaluate a target person's health and to make recommendations about that person's health-related behaviours. In Study 1 (n = 306), we manipulated the target's behaviours (healthy, unhealthy) and body weight (normal, overweight, obese); in Study 2 (n = 192), we manipulated the behaviour of an overweight target (healthy, unhealthy).

RESULTS

Study 1 found that the obese target was consistently rated as less healthy than the normal-weight target, whereas the overweight target was only rated as less healthy when her behaviours were unhealthy. Study 2 found that the overweight target's weight was viewed as being more harmful to her health when she engaged in unhealthy behaviours. Recommendations to lose weight were most common for the obese targets (with healthy or unhealthy behaviours), and for the overweight target with unhealthy behaviours.

CONCLUSIONS

Whereas obesity appears to be viewed as harmful to health independent of health behaviours, the extent to which overweight is perceived as harmful depends on the overweight individual's diet and exercise behaviours.

Obesity and gastrointestinal cancer: the interrelationship of adipose and tumour microenvironments

Increasing recognition of an association between obesity and many cancer types exists, but how the myriad of local and systemic effects of obesity affect key cellular and non-cellular processes within the tumour microenvironment (TME) relevant to carcinogenesis, tumour progression and response to therapies remains poorly understood. The TME is a complex cellular environment in which the tumour exists along with blood vessels, immune cells, fibroblasts, bone marrow-derived inflammatory cells, signalling molecules and the extracellular matrix. Obesity, in particular visceral obesity, might fuel the dysregulation of key pathways relevant to both the adipose microenvironment and the TME, which interact to promote carcinogenesis in at-risk epithelium. The tumour-promoting effects of obesity can occur at the local level as well as systemically via circulating inflammatory, growth factor and metabolic mediators associated with adipose tissue inflammation, as well as paracrine and autocrine effects. This Review explores key pathways linking visceral obesity and gastrointestinal cancer, including inflammation, hypoxia, altered stromal and immune cell function, energy metabolism and angiogenesis.

A reduced M1-like/M2-like ratio of macrophages in healthy adipose tissue expansion during SGLT2 inhibition

The adipose tissue includes various stromal cells, such as preadipocytes, endothelial cells, fibroblasts, and immune cells, which are involved in adipose tissue functions. We previously reported that, in obese mice, the sodium–glucose cotransporter 2 inhibitor ipragliflozin (Ipra) promoted the expansion of the epididymal adipose tissue (Epi) with increase of serum ketone body concentration. The Ipra-induced adipose tissue expansion did not deteriorate adipose inflammation, or systemic glucose/lipid metabolism, referred to as “healthy adipose tissue expansion.” Here we found that Ipra promoted healthy adipose tissue expansion with a reduced ratio of pro-inflammatory M1-like adipose tissue macrophages (ATMs) to anti-inflammatory M2-like ATMs. Ipra downregulated the gene expression of interleukin (IL)−15 (Il15) in stromal cells of Epi. IL-15 inhibited lipogenesis in 3T3-L1 cells associated with downregulation of the lipogenic gene. Ketone body β-hydroxybutyrate suppressed Il15 gene induction in M1-polarized cultured macrophages, and a ketogenic diet reproduced the adipose tissue expansion without deteriorating systemic glucose metabolism in mice. Our data indicate that the phenotypic switch of ATMs could mediate healthy adipose tissue expansion by treatment with Ipra, and it may offer new insights into the pathophysiological mechanisms of adipose tissue expansion.

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.

Transition from metabolic healthy to unhealthy phenotypes and association with cardiovascular disease risk across BMI categories in 90 257 women (the Nurses' Health Study): 30 year follow-up from a prospective cohort study

BACKGROUND

Cardiovascular disease risk among individuals across different categories of BMI might depend on their metabolic health. It remains unclear to what extent metabolic health status changes over time and whether this affects cardiovascular disease risk. In this study, we aimed to examine the association between metabolic health and its change over time and cardiovascular disease risk across BMI categories.

METHODS

Between June and December, 1976, 121 701 female nurses were recruited to the Nurses' Health Study (NHS) of whom 103 298 returned a questionnaire in 1980 used as baseline in this study. After excluding women with a history of cardiovascular disease or cancer, with missing body weight and with underweight. 90 257 women were followed-up from 1980 to 2010 for incident cardiovascular disease. Participants were cross-classified by BMI categories, metabolic health (defined by absence of diabetes, hypertension and hypercholesterolaemia), and change in metabolic health status during follow-up. The cardiovascular component of the NHS is registered with ClinicalTrials.gov, number NCT00005152.

FINDINGS

During 2 127  391 person-years of follow-up with a median follow-up of 24 years, we documented 6306 cases of cardiovascular disease including 3304 myocardial infarction cases and 3080 strokes. Cardiovascular disease risk of women with metabolically healthy obesity was increased compared with women with metabolically healthy normal weight (HR 1·39, 95% CI 1·15-1·68), but risk was considerably higher in women with metabolically unhealthy normal weight (2·43, 2·19-2·68), overweight (2·61, 2·36-2·89) and obesity (3·15, 2·83-3·50). The majority of metabolically healthy women converted to unhealthy phenotypes (2555 [84%] of 3027 women with obesity, 22 215 [68%] of 32 882 women with normal-weight after 20 years). Women who maintained metabolically healthy obesity during follow-up were still at a higher cardiovascular disease risk compared with women with stable healthy normal weight (HR 1·57, 1·03-2·38), yet this risk was lower than for initially metabolically healthy women who converted to an unhealthy phenotype (normal-weight 1·90, 1·66-2·17 vs obesity 2·74, 2·30-3·27). Particularly incident diabetes and hypertension increased the risk among women with initial metabolic health.

INTERPRETATION

Even when metabolic health is maintained during long periods of time, obesity remains a risk factor for cardiovascular disease. However, risks are highest for metabolically unhealthy women across all BMI categories. A large proportion of metabolically healthy women converted to an unhealthy phenotype over time across all BMI categories, which is associated with an increased cardiovascular disease risk.

FUNDING

US National Institutes of Health, German Federal Ministry of Education and Research.

Metabolically Healthy versus Unhealthy Morbidly Obese: Chronic Inflammation, Nitro-Oxidative Stress, and Insulin Resistance

Metabolically heathy obesity is characterised by the presence of obesity in the absence of metabolic disturbances. The aim of our study was to analyse pro-inflammatory, nitro-oxidative stress, and insulin-resistance (IR) markers in metabolically healthy morbidly obese (MHMO) with respect to metabolically unhealthy morbidly obese (MUHMO) with metabolic syndrome (MS) and to identify the potential predictors of MS in the MHMO group. Two groups of MHMO and MUHMO with MS were analysed. We evaluated serum high sensitivity C reactive protein (hsCRP), tumor necrosis factor alpha (TNF-α), chemerin, nitrite and nitrate (NOx), total oxidant status (TOS), total antioxidant response (TAR), fasting blood glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR.) MHMO have similar hsCRP and TNF-α values as the MUHMO with MS, while chemerin was significantly lower in MHMO. NOx was higher in MUHMO with MS patients, while no difference regarding TOS and TAR was found between the two groups. HOMA-IR and insulin values were lower in MHMO as compared to the MUHMO with MS group. Insulin, HOMA-IR, and chemerin were identified predictors of MS in MHMO. In conclusion, MHMO and MUHMO display similarities and differences in terms of chronic inflammation, nitro-oxidative stress, and IR. Markers of IR and chemerin are possible predictors of MS in MHMO.

Individualized Meal Replacement Therapy Improves Clinically Relevant Long-Term Glycemic Control in Poorly Controlled Type 2 Diabetes Patients

Background Formula diets can improve glycemic control or can even induce remission in type 2 diabetes. We hypothesized that especially an individualized intense meal replacement by a low-carbohydrate formula diet with accompanied self-monitoring of blood glucose (SMBG) contributes to long-term improvements in HbA1c, weight, and cardiometabolic risk factors in poorly controlled type 2 diabetes. Methods Type 2 diabetes patients were randomized into either a moderate group (M-group) with two meal replacements/day (n = 160) or a stringent group (S-group) with three meal replacements/day (n = 149) during the first week of intervention (1300⁻1500 kcal/day). Subsequently, both groups reintroduced a low-carbohydrate lunch based on individual adaption due to SMBG in weeks 2⁻4. After week 4, breakfast was reintroduced until week 12. During the follow-up period, all of the participants were asked to continue replacing one meal per day until the 52-weeks follow-up. Additionally, an observational control group (n = 100) remained in routine care. Parameters were compared at baseline, after 12 and 52 weeks within and between all of the groups. Results 321 participants (83%) completed the acute meal replacement phase after 12 weeks and 279 participants (72%) the whole intervention after 52 weeks. Both intervention groups achieved improvements in HbA1c, fasting blood glucose, blood pressure, and weight (all p < 0.001) within 12 weeks. However, these results were not significantly different between both of the intervention groups. The estimated treatment difference in HbA1c reduction was (mean (95% confidence interval [CI]) -0.10% with 95% CI [-0.40; 0.21] also (p > 0.05) (S-group vs. M-group) not statistically different after 12 weeks. However, only the S-group showed a clinically relevant improvement in HbA1c of -0.81% [-1.06; -0.55] (p < 0.001) after 52 weeks of follow-up, whereas HbA1c was not statistically different between the M- and control group. Conclusion Individualized meal replacement with SMBG demonstrated beneficial effects on HbA1c and cardiometabolic parameters in type 2 diabetes. Furthermore, the initiation of a weight loss program with one week of full meal replacement (three meals per day) resulted in a clinically relevant long-term HbA1c reduction, as compared to an observational control group that had standard care.

Edmonton obesity staging system among pediatric patients: a validation and obesogenic risk factor analysis

PURPOSE

The Edmonton Obesity Staging System for Pediatrics (EOSS-P) is a useful tool, delineating different obesity severity tiers associated with distinct treatment barriers. The aim of the study was to apply the EOSS-P on a Greek pediatric cohort and assess risk factors associated with each stage, compared to normal weight controls.

METHODS

A total of 361 children (2-14 years old), outpatients of an Athenian hospital, participated in this case-control study by forming two groups: the obese (n = 203) and the normoweight controls (n = 158). Anthropometry, blood pressure, blood and biochemical markers, comorbidities and obesogenic lifestyle parameters were recorded and the EOSS-P was applied. Validation of EOSS-P stages was conducted by juxtaposing them with IOTF-defined weight status. Obesogenic risk factors' analysis was conducted by constructing gender-and-age-adjusted (GA) and multivariate logistic models.

RESULTS

The majority of obese children were stratified at stage 1 (46.0%), 17.0% were on stage 0, and 37.0% on stage 2. The validation analysis revealed that EOSS-P stages greater than 0 were associated with diastolic blood pressure and levels of glucose, cholesterol, LDL and ALT. Reduced obesity odds were observed among children playing outdoors and increased odds for every screen time hour, both in the GA and in the multivariate analyses (all P < 0.05). Although participation in sports > 2 times/week was associated with reduced obesity odds in the GA analysis (OR = 0.57, 95% CI = 0.33-0.98, P linear = 0.047), it lost its significance in the multivariate analysis (P linear = 0.145). Analogous results were recorded in the analyses of the abovementioned physical activity risk factors for the EOSS-P stages. Linear relationships were observed for fast-food consumption and IOTF-defined obesity and higher than 0 EOSS-P stages. Parental obesity status was associated with all EOSS-P stages and IOTF-defined obesity status.

CONCLUSIONS

Few outpatients were healthy obese (stage 0), while the majority exhibited several comorbidities. Since each obesity tier entails different impacts to disease management, the study herein highlights modifiable factors facilitating descend to lower stages, and provides insight for designing tailored approaches tackling the high national pediatric obesity rates.

Role of Physical Activity and Fitness in the Characterization and Prognosis of the Metabolically Healthy Obesity Phenotype: A Systematic Review and Meta-analysis

The aims of the present article are to systematically review and meta-analyze the existing evidence on: 1) differences in physical activity (PA), sedentary behavior (SB), cardiorespiratory fitness (CRF) and muscular strength (MST) between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO); and 2) the prognosis of all-cause mortality and cardiovascular disease (CVD) mortality/morbidity in MHO individuals, compared with the best scenario possible, i.e., metabolically healthy normal-weight (MHNW), after adjusting for PA, SB, CRF or MST. Our systematic review identified 67 cross-sectional studies to address aim 1, and 11 longitudinal studies to address aim 2. The major findings and conclusions from the current meta-analysis are: 1) MHO individuals are more active, spend less time in SB, and have a higher level of CRF (yet no differences in MST) than MUO individuals, suggesting that their healthier metabolic profile could be at least partially due to these healthier lifestyle factors and attributes. 2) The meta-analysis of cohort studies which accounted for PA (N = 10 unique cohorts, 100% scored as high-quality) support the notion that MHO individuals have a 24-33% higher risk of all-cause mortality and CVD mortality/morbidity compared to MHNW individuals. This risk was borderline significant/non-significant, independent of the length of the follow-up and lower than that reported in previous meta-analyses in this topic including all type of studies, which could be indicating a modest reduction in the risk estimates as a consequence of accounting for PA. 3) Only one study has examined the role of CRF in the prognosis of MHO individuals. This study suggests that the differences in the risk of all-cause mortality and CVD mortality/morbidity between MHO and MHNW are largely explained by differences in CRF between these two phenotypes.

Psoas and paraspinous muscle index as a predictor of mortality in African American men with type 2 diabetes mellitus

AIM

Recent studies revealed a correlation between skeletal muscle mass index and density with longevity; these studies largely evaluated appendicular skeletal muscles in older Caucasians. This retrospective cohort study assessed the association between axial skeletal muscles size and density with survival in African Americans with type 2 diabetes mellitus.

METHODS

Psoas and paraspinous muscle mass index (cross sectional area/height²) and radiographic density (in Hounsfield Units) were measured using computed tomography in African American-Diabetes Heart Study participants, 314 women and 256 men, with median (25th, 75th quartile) age 55.0(48.0, 62.0) and 57.0(50.0, 64.0) years, respectively. Covariates in fully-adjusted model included age, sex, BMI, smoking, hormone replacement therapy (women), cardiovascular disease, hypertension, coronary artery calcified plaque mass, carotid artery calcified plaque mass, and African ancestry proportion.

RESULTS

After median of 7.1(5.9, 8.2) years follow-up, 30(9.6%) of women and 49(19.1%) of men were deceased. In fully-adjusted models, psoas muscle mass index and paraspinous muscle mass index were inversely associated with mortality in men (psoas muscle mass index, hazard ratio [HR] = 0.61, P = 0.004; paraspinous muscle mass index, HR = 0.64, P = 0.004), but not in women. Psoas and paraspinous muscle densities did not associate with all-cause mortality. A penalized Cox regression that involved all covariates and predictors associated with mortality showed that only paraspinous muscle mass index remained a significant predictor of mortality (HR = 0.65, P = 0.02).

CONCLUSION

Independent from established risk factors for mortality, higher psoas and paraspinous muscle index associate with reduced all-cause mortality in middle-aged African American men with type 2 diabetes mellitus.

Resolution of fatty liver and weight loss: Independent associations with changes in serum lipids and apolipoproteins

BACKGROUND AND AIMS

It is uncertain whether resolution of fatty liver can improve cardiovascular disease risk factors, independently of changes in body mass index (BMI). Our aim was to test whether resolution of fatty liver is associated with improvements in components of the lipid profile, independently of changes in BMI, and to quantify and compare the magnitude of benefit of resolution of liver fat, and decreases in BMI on the lipid profile.

METHODS

36,195 subjects with fatty liver were studied. Persistence/resolution of fatty liver was determined by ultrasound at follow up (mean = 4.93 years). Total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and apolipoproteins were measured at baseline and follow up. Regression modelling was undertaken to test the independence of associations between change in fatty liver status or change in BMI, with any change in lipid profile concentrations between baseline and follow up.

RESULTS

Mean (SD) age was 36.3 ± 6.6 and 39.8 ± 8.7 years (men and women, respectively). Resolution of fatty liver occurred in 7,086, and persisted in 29,109 subjects. Mean ± SD weight change was -3.2 ± 4.3 (∼1 kg/m² decrease in BMI) with resolution of, and +0.5 ± 3.5 kg with persistence of fatty liver, respectively. Both resolution of fatty liver and decrease in BMI were independently associated with improvements in all components of the lipid profile and there was a similar magnitude of benefit associated with resolution of fatty liver, or 1 kg/m² decrease in BMI.

CONCLUSIONS

Resolution of fatty liver improves the lipid profile, independently of weight loss.

Impact of Genetic Variants on the Individual Potential for Body Fat Loss

The past decade has witnessed the discovery of obesity-related genetic variants and their functions through genome-wide association studies. Combinations of risk alleles can influence obesity phenotypes with different degrees of effectiveness across various individuals by interacting with environmental factors. We examined the interaction between genetic variation and changes in dietary habits or exercise that influences body fat loss from a large Korean cohort (n = 8840). Out of 673 obesity-related SNPs, a total of 100 SNPs (37 for carbohydrate intake; 19 for fat intake; 44 for total calories intake; 25 for exercise onset) identified to have gene-environment interaction effect in generalized linear model were used to calculate genetic risk scores (GRS). Based on the GRS distribution, we divided the population into four levels, namely, “very insensitive”, “insensitive”, “sensitive”, and “very sensitive” for each of the four categories, “carbohydrate intake”, “fat intake”, “total calories intake”, and “exercise”. Overall, the mean body fat loss became larger when the sensitivity level was increased. In conclusion, genetic variants influence the effectiveness of dietary regimes for body fat loss. Based on our findings, we suggest a platform for personalized body fat management by providing the most suitable and effective nutrition or activity plan specific to an individual.