Metabolic phenotypes of obesity influence triglyceride and inflammation homoeostasis

Effects of a vegetarian diet combined with aerobic exercise on glycemic control, insulin resistance, and body composition: a systematic review and meta-analysis

BACKGROUND

Vegetarian diets and aerobic exercise are increasingly accepted as a common way to improve lifestyle. Several studies have shown that vegetarian diets combined with aerobic exercise interventions have a significant effect on preventing and reducing the risk of metabolic diseases.

METHODS

A search of the PubMed, EBSCO, Embase, CENTRAL, and Web of Science databases was conducted for comparative studies of pre- and post-vegetarian diet adoption combined with aerobic exercise interventions on glycemic control and body composition. Qualitative reviews and meta-analyses of fixed and random effects were conducted to pool available data. The results were validated by sensitivity analysis.

RESULTS

A total of 27 studies were selected for meta-analysis. Combining the studies included in the meta-analysis showed a mean difference for homeostasis model assessment of insulin resistance of - 0.75 (- 1.08 to - 0.42), fasting plasma glucose of - 0.27(- 0.30 to - 0.23), waist circumference of - 1.10 (- 5.06 to 2.86) and body mass index of - 0.70 (- 1.38 to - 0.01).

CONCLUSION

In summary, our findings suggest that participants who adopted a vegetarian diet combined with aerobic exercise intervention had significantly lower fasting plasma glucose and insulin levels and improved body composition compared to preintervention participants.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis.

Understanding Carbohydrate Metabolism and Insulin Resistance in Acute Intermittent Porphyria

Porphobilinogen deaminase (PBGD) haploinsufficiency (acute intermittent porphyria, AIP) is characterized by neurovisceral attacks associated with high production, accumulation and urinary excretion of heme precursors, δ-aminolevulinic acid (ALA) and porphobilinogen (PBG). The estimated clinical penetrance for AIP is extremely low (<1%), therefore it is likely that other factors may play an important role in the predisposition to developing attacks. Fasting is a known triggering factor. Given the increased prevalence of insulin resistance in patients and the large urinary loss of succinyl-CoA to produce ALA and PBG, we explore the impact of reduced availability of energy metabolites in the severity of AIP pathophysiology. Classic studies found clinical improvement in patients affected by AIP associated with the administration of glucose and concomitant insulin secretion, or after hyperinsulinemia associated with diabetes. Molecular studies have confirmed that glucose and insulin administration induces a repressive effect on hepatic ALA Synthase, the first and regulatory step of the heme pathway. More recently, the insulin-mimicking α-lipoic acid has been shown to improve glucose metabolism and mitochondrial dysfunction in a hepatocyte cell line transfected with interfering RNA targeting PBGD. In AIP mice, preventive treatment with an experimental fusion protein of insulin and apolipoprotein A-I improved the disease by promoting fat mobilization in adipose tissue, increasing the metabolite bioavailability for the TCA cycle and inducing mitochondrial biogenesis in the liver. In this review, we analyze the possible mechanisms underlying abnormal hepatocellular carbohydrate homeostasis in AIP.

Differences of Regional Fat Distribution Measured by Magnetic Resonance Imaging According to Obese Phenotype in Koreans

Background: Obesity is commonly associated with a high risk of metabolic disorders, and obesity-related metabolic abnormalities are affected by some specific obesity phenotypes, regional fat distribution, and body mass index. However, few studies have investigated the relationship between obesity phenotypes and regional fat distribution in Korean subjects. This study aimed to assess regional fat distribution by gender using magnetic resonance imaging (MRI), and to identify a link between fat distribution and metabolic disorders in Korean subjects. Methods: This study included 35 Korean subjects (20 women, 15 men) who were classified into two groups by gender, and further divided into two groups based on their obesity phenotype: a metabolically abnormal obesity (MAO) and metabolically healthy obesity (MHO) group. Fat distribution was measured using MRI. The blood parameters were measured using a commercially available kit. Results: Women in the MAO group had more risk factors for metabolic abnormalities than those in the MHO group. Serum glucose, triglyceride, and high-density lipoprotein cholesterol (HDL-C) levels were also significantly higher in women with MAO than in those with MHO. The intermuscular adipose tissue (IMAT) of women with MAO was significantly higher than that of women with MHO. Serum HDL-C level was negatively correlated with IMAT, whereas leptin showed a positive correlation with IMAT in all subjects. Conclusions: Metabolic abnormalities according to obesity phenotype posed a higher risk in women than that in men. These findings suggest that an understanding of gender differences in relation to the association between obesity and metabolic risk would be helpful to reduce the prevalence of obesity.

Metabolic phenotypes and risk of colorectal cancer: a systematic review and meta-analysis of cohort studies

BACKGROUND

The association of obesity with colorectal cancer (CRC) may vary depending on metabolic status.

OBJECTIVE

This meta-analysis aimed to investigate the combined impacts of obesity and metabolic status on CRC risk.

METHODS

The Scopus, PubMed, and web of sciences databases were systematically searched up to Jun 2021 to find all eligible publications examining CRC risk in individuals with metabolically unhealthy normal-weight (MUHNW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUHO) phenotypes.

RESULTS

A total of 7 cohort studies with a total of 759,066 participants were included in this meta-analysis. Compared with healthy normal-weight people, MUHNW, MHO, and MUHO individuals indicated an increased risk for CRC with a pooled odds ratio of 1.19 (95% CI = 1.09-1.31) in MUHNW, 1.14 (95% CI = 1.06-1.22) in MHO, and 1.24 (95% CI = 1.19-1.29) in MUHO subjects. When analyses were stratified based on gender, associations remained significant for males. However, the elevated risk of CRC associated with MHO and MUHO was not significant in female participants.

CONCLUSIONS

The individuals with metabolic abnormality, although at a normal weight, have an increased risk for CRC. Moreover, obesity is associated with CRC irrespective of metabolic status.

Evolution of Metabolic Phenotypes of Obesity in Coronary Patients after 5 Years of Dietary Intervention: From the CORDIOPREV Study

Background: Obesity phenotypes with different metabolic status have been described previously. We analyzed metabolic phenotypes in obese coronary patients during a 5-year follow-up, and examined the factors influencing this evolution. Methods: The CORDIOPREV study is a randomized, long-term secondary prevention study with two healthy diets: Mediterranean and low-fat. All obese patients were classified as either metabolically healthy obese (MHO) or metabolically unhealthy obese (MUO). We evaluated the changes in the metabolic phenotypes and related variables after 5 years of dietary intervention. Results: Initially, 562 out of the 1002 CORDIOPREV patients were obese. After 5 years, 476 obese patients maintained their clinical and dietary visits; 71.8% of MHO patients changed to unhealthy phenotypes (MHO-Progressors), whereas the MHO patients who maintained healthy phenotypes (MHO-Non-Progressors) lost more in terms of their body mass index (BMI) and had a lower fatty liver index (FLI-score) (p < 0.05). Most of the MUO (92%) patients maintained unhealthy phenotypes (MUO-Non-Responders), but 8% became metabolically healthy (MUO-Responders) after a significant decrease in their BMI and FLI-score, with improvement in all metabolic criteria. No differences were found among dietary groups. Conclusions: A greater loss of weight and liver fat is associated with a lower progression of the MHO phenotype to unhealthy phenotypes. Likewise, a marked improvement in these parameters is associated with regression from MUO to healthy phenotypes.

Postprandial triglyceridaemia is modulated by insulin resistance but not by grade of obesity in abdominal and morbid obese subjects

BACKGROUND

Obesity is associated with high cardiovascular risk. Postprandial lipidaemia has been associated with cardiovascular disease risk. Our aim was to identify whether anthropometric parameters, insulin resistance (IR) and/or fasting plasma triglycerides may determine postprandial changes in lipoprotein concentrations in abdominal and morbid obese subjects.

METHODS

We have studied 20 non-diabetic, normolipidaemic subjects with abdominal obesity, 20 morbid obese subjects and 20 healthy individuals, that have similar age and gender. In all of them a standardised oral fat load test (OFLT) with unsaturated fat was performed.

RESULTS

During the OFLT, the postprandial triglycerides response was significantly higher in subjects with abdominal obesity compared with morbid obese subjects (4 hours triglycerides pick value and AUC of triglycerides). Both obese groups showed significantly higher postprandial triglycerides response compared with healthy subjects. Dividing the obesity group according to the presence of IR, we found that IR was an important factor related with postprandial lipaemia but not BMI or waist circumference. In addition, postprandial glycaemia and insulinaemia significantly decreased in all studied subjects, being the highest decrease in morbid obese subjects and in subjects with IR. Postprandial triglyceridaemia significantly correlated with IR parameters and not with anthropometric parameters in AO and MO subjects.

CONCLUSION

In subjects with AO and MO, postprandial triglycerides values are higher than healthy individuals and independently predicted by fasting IR parameters. Furthermore, unsaturated fat improved IR state.

Dissociation Between Insulin Resistance and Abnormalities in Lipoprotein Particle Concentrations and Sizes in Normal-Weight Chinese Adults

Insulin resistance in obesity coincides with abnormalities in lipid profile and lipoprotein subclass distribution and size even before abnormalities in glucose homeostasis manifest. We aimed to assess this relationship in the absence of obesity. Insulin sensitivity (3-h intravenous glucose tolerance test and minimal modeling) and lipoprotein particle concentrations and sizes (proton nuclear magnetic resonance spectroscopy) were evaluated in 15 insulin-resistant and 15 insulin-sensitive lean Asians of Chinese descent with normal glucose tolerance, matched on age, sex, and body mass index. Despite a ~50% lower insulin sensitivity index (Si) in insulin-resistant than in insulin-sensitive subjects, which was accompanied by significantly greater acute insulin response to glucose (AIRg) and fasting insulin concentration but not different fasting glucose concentration, there were no significant differences between groups in the blood lipid profile (p ≥ 0.44) or the lipoprotein subclass concentrations (p ≥ 0.30) and particle sizes (p ≥ 0.43). We conclude that, contrary to observations in subjects with obesity, insulin resistance is not accompanied by unfavorable changes in the plasma lipid profile and lipoprotein particle concentrations and sizes in lean Asians with normal glucose tolerance. Therefore, insulin resistance at the level of glucose metabolism is mechanistically or temporally dissociated from lipid and lipoprotein metabolism.

Trial Registration:clinicaltrials.gov, NCT03264001.

Effects of Combined Exercise and Low Carbohydrate Ketogenic Diet Interventions on Waist Circumference and Triglycerides in Overweight and Obese Individuals: A Systematic Review and Meta-Analysis

(1) Background: The purpose of this meta-analysis was to investigate the effects of combined exercise and low carbohydrate ketogenic diet interventions (CELCKD) for overweight and obese individuals. (2) Methods: Relevant studies were searched by using the MEDLINE and EMBASE databases up to October 2020. Study Inclusion and Exclusion Criteria: Inclusion criteria were reporting effects of the CELCKD for overweight and obese individuals from randomized controlled trials. Studies that did not match the inclusion criteria were excluded. The methods for CELCKD and outcomes of selected studies were extracted. The effect sizes for interventions that included cardiorespiratory fitness, body composition, fasting glucose, and lipid profiles were calculated by using the standardized mean difference statistic. (3) Results: A total of seven studies and 278 overweight and obese individuals were included. The average intervention of selected studies consisted of moderate to vigorous intensity, 4 times per week for 9.2 weeks. Participating in CELCKD interventions was decreased triglycerides (d = −0.34, CI; −0.68–−0.01, p = 0.04) and waist circumference (d = −0.74, 95% confidence interval [CI]; −1.28–−1.20, p = 0.01), while cardiovascular fitness, body composition, fasting glucose, total cholesterol, high density lipoprotein (HDL) cholesterol, and low density lipoprotein (LDL) cholesterol were not statistically different after the interventions. No adverse side effects were reported. (4) Conclusions: Participation in interventions by overweight and obese individuals had beneficial effects including decreased waist circumference and triglycerides. Longer term intervention studies with homogenous control groups may be needed.

Association of Metabolic Obesity Phenotypes and Total Testosterone in Chinese Male Population

OBJECTIVE

Obesity and metabolic syndrome have been reported to exert an impact on the male reproductive system with decreasing levels of serum total testosterone (TT); however, the effect of different metabolic obesity phenotypes on testosterone has been poorly studied. We aimed to evaluate the association of metabolic obesity phenotypes and total testosterone levels in a Chinese male population.

METHODS

We performed a retrospective study based on an epidemiological investigation, a total of 4,081 male individuals aged from 40-75 years old were recruited. The population was classified as metabolically healthy normal weight (MHNW), metabolically healthy overweight/obese (MHO), metabolically unhealthy normal weight (MUNW), and metabolically unhealthy overweight/obese (MUO) according to normal weight (BMI<25.0) and overweight/obesity (BMI≥25.0) with or without metabolic syndrome.

RESULTS

We collected 563 hypotestosteronemia among 4,081 male individuals. The odds ratios (ORs) (95% CIs) of hypotestosteronemia in obesity and metabolic syndrome were 3.072 (2.414-3.911) and 3.294 (2.631-4.125), respectively, after adjusting for age, luteinizing hormone, smoking status, and alcohol consumption. Compared to the MHNW group, male subjects in MHO, MUNW, and MUO groups had decreased serum TT levels. Additionally, the MUO group had a lowest concentration of serum TT and a highest proportion of hypotestosteronemia. There was no significant difference of TT levels between the MHO and MUNW groups.

CONCLUSION

Obesity and metabolic syndrome are independent risk factors of hypotestosteronemia in Chinese male populations. Our study also suggested that individuals with MHO, MUNW, and MUO have a higher risk of developing hypotestosteronemia.

Short-term effects of a Paleolithic lifestyle intervention in breast cancer patients undergoing radiotherapy: a pilot and feasibility study

Evolutionary principles are rarely considered in clinical oncology. We here aimed to test the feasibility and effects of a dietary and physical activity intervention based on evolutionary considerations in an oncological setting. A total of 13 breast cancer patients referred to our clinic for curative radiotherapy were recruited for this pilot study. The women were supposed to undertake a "Paleolithic lifestyle" (PL) intervention consisting of a Paleolithic diet and daily outdoor activity of at least 30 min duration while undergoing radiotherapy. Body composition was measured weekly by bioimpedance analysis. Blood parameters were assessed before, during, and at the end of radiotherapy. A control group on an unspecified standard diet (SD) was assigned by propensity score matching. A total of eleven patients completed the study. The majority of patients (64%) reported feeling good or very good during the intervention. The intervention group experienced an average decrease of 0.4 kg body weight (p < 0.001) and 0.34 kg (p < 0.001) fat mass per week, but fat-free and skeletal muscle mass were not significantly affected. Vitamin D levels increased slightly from 23.8 (11-37.3) ng/ml to 25.1 (22.6-41.6) ng/ml (p = 0.053). β-hydroxybutyrate levels were significantly increased and triglycerides and free T3 hormone levels significantly reduced by the PL intervention. This pilot study shows that adoption of a PL intervention during curative radiotherapy of breast cancer patients is feasible and able to reduce fat mass. Daily outdoor activity could eliminate vitamin D deficiency (vitamin D < 20 ng/ml). Future studies are needed to confirm these findings.

PPARα and PPARβ/δ are negatively correlated with proinflammatory markers in leukocytes of an obese pediatric population

BACKGROUND

Obesity configures a pathophysiological profile that predisposes the development of metabolic and cardiovascular diseases, critically impacting public health. The chronic dysregulation of immuno-metabolic components triggered by pediatric obesity is a common but scarcely understood aspect of the disease. Peroxisome proliferator-activated receptors (PPARs) are a group of transcription factors essential for energy and immune homeostasis of different tissues. Besides, the glucagon-like peptide-1 receptor (GLP-1R) activation influences insulin secretion, but also regulates the cytokine profile possibly mediated through a PPAR isotype. However, the role of PPARs and GLP-1R in leukocytes from obese pediatric patients remains unclear. Therefore, we examined the expression of PPARs isotypes and GLP-1R in leukocytes, and its correlation with metabolic, hormonal, inflammatory, and anthropometric markers in an obese pediatric population.

RESULTS

Obese children and adolescents presented a significant increase in anthropometric and body composition parameters, TG, VLDL, TG/HDL, android fat (%)/gynoid fat (%) (A/G%) index, and HOMA score when compared with the control group. Obese participants exhibited a pro-inflammatory profile with an augment of IL-8 (p = 0,0081), IL-6 (p = 0,0005), TNF-α (p = 0,0004), IFN-γ (p = 0,0110), MCP-1 (p = 0,0452), and adipsin (p = 0,0397), whereas displayed a reduction of adiponectin (p = 0,0452). The expression of PPARα and GLP-1R was lower in the leukocytes from obese participants than in lean subjects. Furthermore, PPARα correlates negatively with TNF-α (p = 0,0383), while GLP-1R did not show correlation with any inflammatory variable. However, both receptors correlate negatively with the abdominal skinfold. Although PPARβ/δ expression was similar between groups, it was negatively associated with IL-8 levels (p = 0,0085).

CONCLUSIONS

PPARα and PPARβ/δ expression are negatively correlated with the proinflammatory markers TNF-α and IL-8, respectively, suggesting participation in the regulation of inflammation which was observed to be altered in pediatric obesity. Furthermore, PPARα and GLP-1R are downregulated in leukocytes from obese participants. The low expression of both receptors is correlated with an increase in abdominal skinfold, suggesting a role in fat distribution that could indirectly affect cytokine secretion from different immune and adipose cells, likely triggering an inflammatory profile as a consequence of obesity. Altogether, these findings may impact the understanding and implementation of PPARα or GLP-1R agonists in the clinic.

Effects of total fat intake on body fatness in adults

BACKGROUND

The ideal proportion of energy from fat in our food and its relation to body weight is not clear. In order to prevent overweight and obesity in the general population, we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population.

OBJECTIVES

To assess the effects of proportion of energy intake from fat on measures of body fatness (including body weight, waist circumference, percentage body fat and body mass index) in people not aiming to lose weight, using all appropriate randomised controlled trials (RCTs) of at least six months duration.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) to October 2019. We did not limit the search by language.

SELECTION CRITERIA

Trials fulfilled the following criteria: 1) randomised intervention trial, 2) included adults aged at least 18 years, 3) randomised to a lower fat versus higher fat diet, without the intention to reduce weight in any participants, 4) not multifactorial and 5) assessed a measure of weight or body fatness after at least six months. We duplicated inclusion decisions and resolved disagreement by discussion or referral to a third party.

DATA COLLECTION AND ANALYSIS

We extracted data on the population, intervention, control and outcome measures in duplicate. We extracted measures of body fatness (body weight, BMI, percentage body fat and waist circumference) independently in duplicate at all available time points. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity, funnel plot analyses and GRADE assessment.

MAIN RESULTS

We included 37 RCTs (57,079 participants). There is consistent high-quality evidence from RCTs that reducing total fat intake results in small reductions in body fatness; this was seen in almost all included studies and was highly resistant to sensitivity analyses (GRADE high-consistency evidence, not downgraded). The effect of eating less fat (compared with higher fat intake) is a mean body weight reduction of 1.4 kg (95% confidence interval (CI) -1.7 to -1.1 kg, in 53,875 participants from 26 RCTs, I² = 75%). The heterogeneity was explained in subgrouping and meta-regression. These suggested that greater weight loss results from greater fat reductions in people with lower fat intake at baseline, and people with higher body mass index (BMI) at baseline. The size of the effect on weight does not alter over time and is mirrored by reductions in BMI (MD -0.5 kg/m², 95% CI -0.6 to -0.3, 46,539 participants in 14 trials, I² = 21%), waist circumference (MD -0.5 cm, 95% CI -0.7 to -0.2, 16,620 participants in 3 trials; I² = 21%), and percentage body fat (MD -0.3% body fat, 95% CI -0.6 to 0.00, P = 0.05, in 2350 participants in 2 trials; I² = 0%). There was no suggestion of harms associated with low fat diets that might mitigate any benefits on body fatness. The reduction in body weight was reflected in small reductions in LDL (-0.13 mmol/L, 95% CI -0.21 to -0.05), and total cholesterol (-0.23 mmol/L, 95% CI -0.32 to -0.14), with little or no effect on HDL cholesterol (-0.02 mmol/L, 95% CI -0.03 to 0.00), triglycerides (0.01 mmol/L, 95% CI -0.05 to 0.07), systolic (-0.75 mmHg, 95% CI -1.42 to -0.07) or diastolic blood pressure(-0.52 mmHg, 95% CI -0.95 to -0.09), all GRADE high-consistency evidence or quality of life (0.04, 95% CI 0.01 to 0.07, on a scale of 0 to 10, GRADE low-consistency evidence).

AUTHORS' CONCLUSIONS

Trials where participants were randomised to a lower fat intake versus a higher fat intake, but with no intention to reduce weight, showed a consistent, stable but small effect of low fat intake on body fatness: slightly lower weight, BMI, waist circumference and percentage body fat compared with higher fat arms. Greater fat reduction, lower baseline fat intake and higher baseline BMI were all associated with greater reductions in weight. There was no evidence of harm to serum lipids, blood pressure or quality of life, but rather of small benefits or no effect.

Postprandial Hypertriglyceridaemia Revisited in the Era of Non-Fasting Lipid Profile Testing: A 2019 Expert Panel Statement, Main Text

Residual vascular risk exists despite the aggressive lowering of Low-Density Lipoprotein Cholesterol (LDL-C). A contributor to this residual risk may be elevated fasting, or non-fasting, levels of Triglyceride (TG)-rich lipoproteins. Therefore, there is a need to establish whethe a standardised Oral Fat Tolerance Test (OFTT) can improve atherosclerotic Cardiovascular (CV) Disease (ASCVD) risk prediction in addition to a fasting or non-fasting lipid profile. An expert panel considered the role of postprandial hypertriglyceridaemia (as represented by an OFTT) in predicting ASCVD. The panel updated its 2011 statement by considering new studies and various patient categories. The recommendations are based on expert opinion since no strict endpoint trials have been performed. Individuals with fasting TG concentration <1 mmol/L (89 mg/dL) commonly do not have an abnormal response to an OFTT. In contrast, those with fasting TG concentration ≥2 mmol/L (175 mg/dL) or nonfasting ≥2.3 mmol/L (200 mg/dL) will usually have an abnormal response. We recommend considering postprandial hypertriglyceridaemia testing when fasting TG concentrations and non-fasting TG concentrations are 1-2 mmol/L (89-175 mg/dL) and 1.3-2.3 mmol/L (115-200 mg/dL), respectively as an additional investigation for metabolic risk prediction along with other risk factors (obesity, current tobacco abuse, metabolic syndrome, hypertension, and diabetes mellitus). The panel proposes that an abnormal TG response to an OFTT (consisting of 75 g fat, 25 g carbohydrate and 10 g proteins) is >2.5 mmol/L (220 mg/dL). Postprandial hypertriglyceridaemia is an emerging factor that may contribute to residual CV risk. This possibility requires further research. A standardised OFTT will allow comparisons between investigational studies. We acknowledge that the OFTT will be mainly used for research to further clarify the role of TG in relation to CV risk. For routine practice, there is a considerable support for the use of a single non-fasting sample.

Age-dependent effect of metabolic phenotypes on carotid atherosclerotic disease in coronary heart disease patients (CORDIOPREV study)

Background

Aging is associated with a high risk for cardiovascular disease. The relation of obesity and risk of cardiovascular events appears to be more closely linked to certain clinical or metabolic phenotypes than to obesity itself. Our aim was to establish whether aging influenced the metabolic phenotypes regarding to cardiovascular risk, evaluated by changes in the intima media thickness-common carotid (IMT-CC), in coronary heart disease (CHD) patients.

Methods

In this cross-sectional study, 1002 CHD patients were studied at entry from the CORDIOPREV study. We performed carotid ultrasound assessment to obtain their IMT-CC values. Carotid atherosclerosis was considered to exist if IMT-CC > 0.7 mm.

Results

Age determined a higher IMT-CC, regardless metabolic phenotype (all p < 0.05). Metabolically healthy non-obese (MHNO) aged< 60 showed a lesser prevalence for carotid atherosclerotic disease than metabolically sick non-obese (MSNO) and obese (MSO), while MHNO aged≥60 only showed less prevalence for the disease than the MSO. Carotid atherosclerosis associated with age, sex, impaired fasting glucose (IFG), hypertension and high sensitivity C-reactive protein (hsCRP). However, in patients aged< 60, it associated with sex and IFG and in the age ≥ 60 group, with hypertension and hsCRP.

Conclusions

Our results suggest that CHD patients aged≥60 are less metabolic flexible compared to patients aged< 60. Thus, MHO patients aged≥60 show the same risk of suffering carotid atherosclerosis as those with metabolic disease, while MHO patients aged< 60 show lower risk than MSO. This fact indicates the need to focus on therapeutic strategies in order to modify those parameters related to obesity and metabolic inflexibility in patients with CHD before entering old age.

Nuclear factor-kB and nitric oxide synthases in red blood cells: good or bad in obesity? A preliminary study

Emerging evidence suggests that red blood cells (RBCs) are involved in many functions essential for life. Nuclear factor-kB (NF-kB), nitric oxide synthases (inducible nitric oxide synthase -iNOS-, endothelial nitric oxide synthase -eNOS-) and interleukin-1β (-IL-1β-) are all proteins that have been identified in RBCs. In nucleated cells, such as white blood cells (WBCs), these proteins have well investigated roles, linked to stress and inflammation. It is not the same in erythrocytes, for this reason, we considered obese patients for studying the morphology of RBCs. We studied a possible correlation between their morphological changes and several protein expressions. Moreover, we compared the results about the aforementioned proteins and antioxidant markers with those obtained in WBCs from healthy and obese patients before and after omega-3 polyunsaturated fatty acid supplementation. This latter scientific point is important in order to determine whether there are differences in the expression of nucleated and anucleated cells. The morphology of RBCs changed in obese patients, but it is significantly restored after six weeks of supplementation. The expression of antioxidant enzymes changed in RBCs and WBCs in obesity but all proteins restore their positivity after supplementation. We found that: the presence of NF-kB, antioxidant enzymes and eNOS in healthy RBCs could indicate a role of these proteins as regulators of cellular metabolism; obese WBCs showed a higher NF-kB, iNOS and IL-1β positivity, whereas eNOS presence did not significantly change in these cells. We tried to explain the different positivity of NF-kB, proposing a dual role for this protein, as prolifespan and as proinflammatory processes, depending on examined cells. In conclusion, we have considered the literature that focuses on the omega-6/omega-3 ratio. The ratio changed from the past, especially in people whose diet is strongly westernized worsening the state of health of the patient and leading to an higher incidence of obesity. Our study hypothesizes that the supplementation could help to restore the correct ratio.

Th17 and Treg Balance in Children With Obesity and Metabolically Altered Status

Background: Chronic low-grade inflammation and activation of the immune system are hallmark pathogenic mechanisms involved in metabolic dysfunction and are related to obesity. In particular, the involvement of regulatory and pro-inflammatory lymphocyte subpopulations has been reported in adults. We evaluated the Th17/Treg lymphocyte balance in obese and normal weight children, in relation with their metabolic status. Methods: We enrolled 50 pediatric patients. According to metabolic status, subjects were classified into: metabolically healthy (MH) and metabolically unhealthy (MU) groups. MU phenotype was defined as the presence of at least one of the following risk factors: blood pressure >90th percentile, glycemia>100 mg/dl, HDL cholesterol <40 mg/dl, triglycerides>100 mg/dl (<10 years) or >130 mg/dl (>10 years), impaired insulin sensitivity with HOMA-IR>97.5th percentile. Patient Treg and Th17 profiles were also evaluated. Results: Based on the presence of metabolic and/or cardiovascular pathological parameters, we classified 15 MU (30%) and 35 MH (70%) children; all MU children were obese. Analyzing the correlations between lymphocyte subpopulations and metabolic data, we noted a correlation between Th17 percentage and systolic hypertension (p = 0.01, r = -0.37); Treg/Th17 ratio and HOMA-IR (p = 0.02, r = 0.32) and systolic hypertension (p = 0.05, r = 0.30). Conclusion: Children with obesity have a high risk of developing metabolic and cardiovascular complications. The Th17/Treg lymphocyte balance appears to be involved in glycemic homeostasis and blood pressure control. Careful and early monitoring of the immune system would facilitate new early preventive strategies in pediatric metabolic diseases.

New diet trials and cardiovascular risk

PURPOSE OF REVIEW

The prevalence of cardiovascular disease (CVD) is increasing to epidemic proportions and current management centred on treatment with drugs is not enough to stop this pandemic. CVD prevention is of paramount importance. In this context, diet and behavioural intervention programs are the first step and have the advantage of lesser cost and side effects than pharmacological approaches. In this review, we will examine the most recent evidence related to dietary prevention of CVD risk.

RECENT FINDINGS

Healthy dietary patterns such as the dietary approaches to stop hypertension, the vegetarian, the low-fat high carbohydrates and mainly the Mediterranean diet have substantial evidence to be recommended for CVD prevention.

SUMMARY

The evidence in this area needs to be adequately communicated to health professionals and the general public. Diet is the cornerstone of CVD prevention as well as overall health promotion.

Postprandial activation of leukocyte-endothelium interaction by fatty acids in the visceral adipose tissue microcirculation

High-fat diet (HFD)-induced obesity is associated with accumulation of inflammatory cells predominantly in visceral adipose depots [visceral adipose tissue (VAT)] rather than in subcutaneous ones [subcutaneous adipose tissue (SAT)]. The cellular and molecular mechanisms responsible for this phenotypic difference remain poorly understood. Controversy also exists on the overall impact that adipose tissue inflammation has on metabolic health in diet-induced obesity. The endothelium of the microcirculation regulates both the transport of lipids and the trafficking of leukocytes into organ tissue. We hypothesized that the VAT and SAT microcirculations respond differently to postprandial processing of dietary fat. We also tested whether inhibition of endothelial postprandial responses to high-fat meals (HFMs) preserves metabolic health in chronic obesity. We demonstrate that administration of a single HFM or ad libitum access to a HFD for 24 h quickly induces a transient P-selectin-dependent inflammatory phenotype in the VAT but not the SAT microcirculation of lean wild-type mice. Studies in P-selectin-deficient mice confirmed a mechanistic role for P-selectin in the initiation of leukocyte trafficking, myeloperoxidase accumulation, and acute reduction in adiponectin mRNA expression by HFMs. Despite reduced VAT inflammation in response to HFMs, P-selectin-deficient mice still developed glucose intolerance and insulin resistance when chronically fed an HFD. Our data uncover a novel nutrient-sensing role of the vascular endothelium that instigates postprandial VAT inflammation. They also demonstrate that inhibition of this transient postprandial inflammatory response fails to correct metabolic dysfunction in diet-induced obesity.-Preston, K. J., Rom, I., Vrakas, C., Landesberg, G., Etwebe, Z., Muraoka, S., Autieri, M., Eguchi, S., Scalia, R. Postprandial activation of leukocyte-endothelium interaction by fatty acids in the visceral adipose tissue microcirculation.

Metabolic phenotypes of obese, overweight, and normal weight individuals and risk of chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

Chronic kidney disease (CKD) risk is inconsistent in the normal-weight, overweight, and obese individuals due to the heterogeneity of metabolic status. This meta-analysis aimed to examine the combined effects of body mass index (BMI) and metabolic status on CKD risk.

MATERIALS AND METHODS

The MEDLINE, EMBASE, and Web of Knowledge databases were systematically searched up to March 2019 to identify all eligible studies investigating the CKD risk (defined as GFR < 60 mL/min per 1.73 m2 and/or microalbuminuria or proteinuria) associated with the body size phenotypes which are known as metabolically unhealthy normal-weight (MUNW), metabolically healthy overweight (MHOW), metabolically unhealthy overweight, metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO). The classification of subjects in included studies as metabolically unhealthy was based on the presence of three components of metabolic syndrome. BMI categorization was based on the criteria of included studies. The risk estimates and 95% confidence intervals (CIs) were extracted and pooled using random effects analysis.

RESULTS

A total of 9 prospective cohort studies with 128773 participants and 4797 incident cases were included in the meta-analysis. Compared with healthy normal-weight individuals as reference, MUNW and MHO subjects showed an increased risk for CKD events with a pooled RR of 1.58 (95% CI = 1.28-1.96) in MUNW and 1.55 (95% CI = 1.34-1.79) in MHO persons. Also, MHOW was at increased risk for CKD (RR = 1.34, 95% CI = 1.20-1.51). MUHO individuals were at the highest risk for the development of CKD (RR = 2.13, 95% CI = 1.66-2.72).

CONCLUSIONS

Individuals with metabolic abnormality, although at normal-weight, have an increased risk for CKD. Healthy overweight and obese individuals had higher risk; refuting the notion that metabolically healthy overweight and obese phenotypes are benign conditions.

Gray matter reduction related to decreased serum creatinine and increased triglyceride, Hemoglobin A1C, and low-density lipoprotein in subjects with obesity

PURPOSE

Altered brain volume and metabolic variables have been found in subjects with obesity. However, the role of metabolic parameters in gray matter volume (GMV) has been poorly investigated. This study aimed to investigate the relationship between the metabolic parameters and brain volume in subjects with obesity.

METHODS

Thirty-seven subjects with obesity and 39 age and sex matched normal-weight controls were included in this study. Eighteen of the 37 participants who underwent sleeve gastrectomy were included in the longitudinal analysis. Blood samples and high-resolution 3T T1-weighted magnetic resonance images were collected. Metabolic parameters in plasma and GMV were measured.

RESULTS

Multiple linear regression analysis showed that gray matter reduction in several cognition-related cortices including right angular gyrus, superior occipital cortex, superior parietal cortex, and cerebellum was related to decreased creatinine, as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity. Weight loss after the surgery induced significant recovery of altered metabolic parameters and decreased gray matter volume. Furthermore, changes in the four metabolic parameters before and after the surgery were associated with changes in gray matter volume.

CONCLUSION

Our results suggest that the gray matter reduction is related to decreased creatinine as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity.

Associations between Macronutrient Intakes and Obesity/Metabolic Risk Phenotypes: Findings of the Korean National Health and Nutrition Examination Survey

Obesity is a risk factor for many health issues, as are metabolic abnormalities. However, few studies have addressed the associations between obesity/metabolic risk phenotypes and dietary macronutrient intakes (carbohydrate, protein, and fat). Therefore, this study examined the associations between macronutrient intakes and obesity/metabolic risk phenotypes in a Korean population. We used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted in 2014 and 2016, and data on a total of 7374 participants were analyzed. Macronutrient intakes were defined as the proportions of energy derived from carbohydrate, protein, and fat. Those exhibiting obesity/metabolic risk phenotypes (or not) were divided into four groups: normal weight without metabolic abnormalities; obese without metabolic abnormalities; normal weight with metabolic abnormalities; and obese with metabolic abnormalities. After adjusting for age, smoking status, alcohol consumption, extent of physical activity, household income, and daily fiber intake, no association was found between the proportions of carbohydrate, protein, or fat intakes and obesity/metabolic risk phenotypes except for a positive association between metabolically healthy but obese status and low protein intake in females. Further studies are required to evaluate the effects of macronutrient intakes on obesity/metabolic risk phenotypes and associated health outcomes.

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

OBJECTIVE

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Design and implementation of a cross-sectional nutritional phenotyping study in healthy US adults

Background

Metabolic imbalance is a key determinant of risk of chronic diseases. Metabolic health cannot be assessed solely by body mass calculations or by static, fasted state biochemical readouts. Although previous studies have described temporal responses to dietary challenges, these studies fail to assess the environmental factors associated with certain metabolic phenotypes and therefore, provide little scientific rationale for potentially effective intervention strategies.

Methods/design

In this phenotyping study of healthy US adults, we are evaluating lifestyle, biological and environmental factors in addition to metabolic parameters to determine the factors associated with variations in metabolic health. A series of practical fitness, dietary, and emotional challenges are introduced and temporal responses in various areas of specialization, including immunology, metabolomics, and endocrinology, are monitored. We expect that this study will identify key factors related to healthy or unhealthy metabolic phenotypes (metabotypes) that may be modifiable targets for the prevention of chronic diseases in an individual.

Discussion

This study will provide novel insights into metabolic variability among healthy adults in balanced strata defined by sex, age and body mass index. Usual dietary intake and physical activity will be evaluated across these strata to determine how diet is associated with health status defined using many indicators including immune function, metabolism, body composition, physiology, response to exercise andmeal challenges and neuroendocrine assessment. A principal study goal is to identify dietary and other personal factors that will differentiate different levels of "health" among study participants.

Trial registration

ClinicalTrials.gov NCT02367287.

Oral spore-based probiotic supplementation was associated with reduced incidence of post-prandial dietary endotoxin, triglycerides, and disease risk biomarkers

AIM

To determine if 30-d of oral spore-based probiotic supplementation could reduce dietary endotoxemia.

METHODS

Apparently healthy men and women (n = 75) were screened for post-prandial dietary endotoxemia. Subjects whose serum endotoxin concentration increased by at least 5-fold from pre-meal levels at 5-h post-prandial were considered “responders” and were randomized to receive either placebo (rice flour) or a commercial spore-based probiotic supplement [Bacillus indicus (HU36), Bacillus subtilis (HU58), Bacillus coagulans, and Bacillus licheniformis, and Bacillus clausii] for 30-d. The dietary endotoxemia test was repeated at the conclusion of the supplementation period. Dietary endotoxin (LAL) and triglycerides (enzymatic) were measured using an automated chemistry analyzer. Serum disease risk biomarkers were measured using bead-based multiplex assays (Luminex and Milliplex) as secondary, exploratory measures.

RESULTS

Data were statistically analyzed using repeated measures ANOVA and a P < 0.05. We found that spore-based probiotic supplementation was associated with a 42% reduction in endotoxin (12.9 ± 3.5 vs 6.1 ± 2.6, P = 0.011) and 24% reduction in triglyceride (212 ± 28 vs 138 ± 12, P = 0.004) in the post-prandial period Placebo subjects presented with a 36% increase in endotoxin (10.3 ± 3.4 vs 15.4 ± 4.1, P = 0.011) and 5% decrease in triglycerides (191 ± 24 vs 186 ± 28, P = 0.004) over the same post-prandial period. We also found that spore-based probiotic supplementation was associated with significant post-prandial reductions in IL-12p70 (24.3 ± 2.2 vs 21.5 ± 1.7, P = 0.017) and IL-1β (1.9 ± 0.2 vs 1.6 ± 0.1, P = 0.020). Compared to placebo post supplementation, probiotic subject had less ghrelin (6.8 ± 0.4 vs 8.3 ± 1.1, P = 0.017) compared to placebo subjects.

CONCLUSION

The key findings of the present study is that oral spore-based probiotic supplementation reduced symptoms indicative of “leaky gut syndrome”.

Change in Body Weight from Age 20 Years Is a Powerful Determinant of the Metabolic Syndrome

BACKGROUND

Higher body weight is a well-known determinant of the metabolic syndrome (MetS) and its components. It is however less well studied how the change in weight from age 20 years to middle age or old age affects MetS development.

METHODS

In the community-based EpiHealth (n = 19,000, age range 45 to 75 years, 56% females) and PIVUS (n = 1000, all aged 70 years, 50% females) studies, the participants were asked about their body weight at age 20 years. Data were collected to determine MetS prevalence (NCEP ATP III criteria).

RESULTS

In EpiHealth, the probability of having MetS increased fairly linearly with increasing weight from age 20 in the obese [odds ratios (OR) 1.04 per kg change in weight, 95% confidence interval (CI) 1.03-1.05, P < 0.0001], as well as in the overweight (OR 1.15, 95% CI 1.14-1.17, P < 0.0001) and normal-weight (OR 1.18, 95% CI 1.14-1.21, P < 0.0001), subjects after adjustment for age, sex, body mass index (BMI) at age 20, alcohol intake, smoking, education, and exercise habits. Also in the PIVUS study, the change in weight over 50 years was related to prevalent MetS (OR 1.08 per kg change in weight, 95% CI 1.06-1.10, P < 0.0001). In both studies, self-reported BMI at age 20 was related to prevalent MetS.

CONCLUSION

Self-reported weight gain from age 20 was strongly and independently associated with prevalent MetS both in middle age or old age. Interestingly, this relationship was not restricted only to obese subjects. Our data provide additional support for the importance of maintaining a stable weight throughout life.

Consumption of a high-fat breakfast on consecutive days alters preclinical biomarkers for atherosclerosis

BACKGROUND/OBJECTIVES

Recent research has speculated that the risk of developing atherosclerosis is due to the accumulation of the effects of daily diet choices. The purpose of this study was to examine which of our previously identified preclinical disease risk biomarkers were further elevated when consuming a high-fat (644±50 kcal; 100% recommended dietary allowance for fat), high-calorie (1118±100 kcal; 70% daily caloric needs) breakfast on consecutive days. Young, normal weight females (N=7) participated in this study.

SUBJECTS/METHODS

Blood samples were taken premeal and hourly for 5-h postprandial. Serum biomarkers (C-peptide, eotaxin, gastric inhibitory polypeptide, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), insulin, leptin, monocyte chemoattractant protein 1, pancreatic polypeptide (PPY) and tumor necrosis factor-α), monocyte concentration, and adhesion molecule expression (CD11a, CD18 and CD54) were measured. Area under the curve was calculated for each outcome variable as a function of day and data were analyzed for significance.

RESULTS

We found significant (P<0.05) increases on Day 2 for: GM-CSF (+47%; P=0.041), G-CSF (+31%; P=0.012), PPY (+51%; P=0.049), total monocyte (+110%; P=0.043), pro-inflammatory (PI) monocyte (+60%; P=0.012), PI monocyte CD18 (+960%; P=0.003), PI monocyte CD11a (+230%; P=0.006), and PI monocyte CD54 (+208%; P=0.015).

CONCLUSIONS

To our knowledge, the present study is the first to report changes in selected biomarkers and monocytes following eating a high-fat, high-calorie breakfast on consecutive days in humans. More research is needed to determine how transient the observed changes are and what the long-term implications for disease risk are.

Dyslipidemia: Obese or Not Obese-That Is Not the Question

PURPOSE OF REVIEW

Purpose of review: It is becoming increasingly clear that some obese individuals do not develop dyslipidemia and instead remain healthy, while some normal weight individuals become dyslipidemic and unhealthy.

RECENT FINDINGS

The present review examines the similarities and differences between healthy and unhealthy individuals with and without obesity and discusses putative underlying mechanisms of dyslipidemia. The presence of dyslipidemia and compromised metabolic health in both lean and obese individuals suggests that the obese phenotype per se does not represent a main independent risk factor for the development of dyslipidemia and that dyslipidemia, rather than obesity, may be the driver of metabolic diseases. Notably, adipose tissue dysfunction and ectopic lipid deposition, in particular in the liver, seems a common trait of unhealthy individuals.

Small HDL subclasses become cholesterol-poor during postprandial period after a fat diet intake in subjects with high triglyceridemia increases

BACKGROUND

Postprandial triglyceridemia may transitory affect the structure of HDL subclasses and probably their antiatherogenic properties but little is known in this field. We analyzed the HDL subclasses lipid content along postprandial period.

METHODS

Fifteen metabolic syndrome (MS) patients and 15 healthy controls were enrolled. HDL were isolated from plasma samples obtained at fasting and every 2-h up to 8-h, after a 75-g fat meal. Cholesterol (C), triglycerides (TAG), and phospholipid (Ph) plasma concentrations of five HDL subclasses were determined by densitometry of electrophoresis gels enzymatically stained.

RESULTS

The increase of postprandial triglyceridemia expressed as the incremental area under the curve (iAUC) was twice in MS patients than in controls. Only large HDL2b-TAG were higher in MS than controls at 4, 6 and 8h after meal intake, whereas cholesterol of HDL2a, 3a and 3b were lower at 8h. HDL size distribution shifted towards large HDL and HDL3a-, 3b- and 3c-subclasses had a lower content of cholesterol (estimated by the C-to-Ph ratio) in subjects whose iAUC>289.5mgh/dl (n=15) in comparison with those subjects with iAUC below this cutoff point (n=15), independently of the MS status and fasting TAG. Triglycerides content of HDL subclasses changed only discreetly along the postprandial period, whereas paraoxonase-1 remained unchanged.

CONCLUSIONS

A high postprandial triglyceridemia conditions the shift of HDL size distribution towards large particles and the decrease of cholesterol in HDL3 subclasses. These data demonstrate that postprandial hypertriglyceridemia contributes to a transitory hypoalphalipoproteinemia that may increase the risk of cardiovascular disease.

Interaction of an S100A9 gene variant with saturated fat and carbohydrates to modulate insulin resistance in 3 populations of different ancestries

BACKGROUND

S100 calcium-binding protein A9 (S100A9) has previously been identified as a type 2 diabetes (T2D) gene. However, this finding requires independent validation and more in-depth analyses in other populations and ancestries.

OBJECTIVES

We aimed to replicate the associations between an S100A9 variant and insulin resistance and T2D and to initiate an investigation of potential interactions with the habitual diet in several independent populations.

DESIGN

We investigated the association of the S100A9 variant rs3014866 with insulin resistance and T2D risk and its interactions with diet in 3 diverse populations as follows: the CORDIOPREV (Coronary Diet Intervention with Olive Oil and Cardiovascular Prevention; n = 711), which consisted of Spanish white adults; the GOLDN (Genetics of Lipids Lowering Drugs and Diet Network; n = 818), which involved North American non-Hispanic white adults; and Hispanic adults who participated in the BPRHS (Boston Puerto Rican Health Study; n = 1155).

RESULTS

Meta-analysis indicated that T carriers presented a lower risk of T2D than CC carriers (pooled OR: 0.714; 95% CI: 0.584, 0.845; P = 0.002). In all 3 populations (CORDIOPREV, GOLDN, and BPRHS), we showed a significant interaction between the rs3014866 single nucleotide polymorphism and dietary SFA:carbohydrate ratio intake for the homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.028, P = 0.017, and P = 0.026, respectively). CC carriers had a significantly higher HOMA-IR only when SFA:carbohydrate intake was high (P = 0.045 for the CORDIOPREV, P = 0.033 for the GOLDN, and P = 0.046 for the BPRHS) but not when SFA:carbohydrate ratio intake was low.

CONCLUSIONS

The minor allele (T) of the S100A9 variant rs3014866 is associated with lower T2D risk in 3 populations of different ancestries. Note that individuals with the high-risk CC genotype may be more likely to benefit from a low SFA:carbohydrate ratio intake to improve insulin resistance as evaluated with the use of the HOMA-IR. These trials were registered at clinicaltrials.gov as NCT00924937 (CORDIOPREV), NCT00083369 (GOLDN), and NCT01231958 (BPRHS).

CORonary Diet Intervention with Olive oil and cardiovascular PREVention study (the CORDIOPREV study): Rationale, methods, and baseline characteristics: A clinical trial comparing the efficacy of a Mediterranean diet rich in olive oil versus a low-fat diet on cardiovascular disease in coronary patients

Coronary heart disease (CHD) represents a major global health burden. However, despite the well-known influence that dietary habits exert over the progression of this disease, there are no well-established and scientifically sound dietary approaches to prevent the onset of clinical outcomes in secondary prevention. The objective of the CORonary Diet Intervention with Olive oil and cardiovascular PREVention study (CORDIOPREV study, clinical trials number NCT00924937) is to compare the ability of a Mediterranean diet rich in virgin olive oil versus a low-fat diet to influence the composite incidence of cardiovascular events after 7 years in subjects with documented CHD at baseline. For this purpose, we enrolled 1,002 coronary patients from Spain. Baseline assessment (2009-2012) included detailed interviews and measurements to assess dietary, social, and biological variables. Results of baseline characteristics: The CORDIOPREV study in Spain describes a population with a high body mass index (37.2% overweight and 56.3% obesity) and with a median of low-density lipoprotein cholesterol of 88.5 mg/dL (70.6% of the patients having <100 mg/dL and 20.3% patients <70 mg/dL). A total of 9.6% of the participants were active smokers, and 64.4% were former smokers. Metabolic syndrome was present in 58% of this population. To sum up, we describe here the rationale, methods, and baseline characteristics of the CORDIOPREV study, which will test for the first time the efficacy of a Mediterranean diet rich in extra virgin olive oil as compared with a low-fat diet on the incidence of CHD recurrence in a long-term follow-up study.

Red Blood Cells from Individuals with Abdominal Obesity or Metabolic Abnormalities Exhibit Less Deformability upon Entering a Constriction

Abdominal obesity and metabolic syndrome (MS) are multifactorial conditions associated with increased risk of cardiovascular disease and type II diabetes mellitus. Previous work has demonstrated that the hemorheological profile is altered in patients with abdominal obesity and MS, as evidenced for example by increased whole blood viscosity. To date, however, no studies have examined red blood cell (RBC) deformability of blood from individuals with obesity or metabolic abnormalities under typical physiological flow conditions. In this study, we pumped RBCs through a constriction in a microfluidic device and used high speed video to visualize and track the mechanical behavior of ~8,000 RBCs obtained from either healthy individuals (n = 5) or obese participants with metabolic abnormalities (OMA) (n = 4). We demonstrate that the OMA+ cells stretched on average about 25% less than the healthy controls. Furthermore, we examined the effects of ingesting a high-fat meal on RBC mechanical dynamics, and found that the postprandial period has only a weak effect on the stretching dynamics exhibited by OMA+ cells. The results suggest that chronic rigidification of RBCs plays a key role in the increased blood pressure and increased whole blood viscosity observed in OMA individuals and was independent of an acute response triggered by consumption of a high-fat meal.

Assessment of postprandial triglycerides in clinical practice: Validation in a general population and coronary heart disease patients

BACKGROUND

Previous studies have suggested that for clinical purposes, subjects with fasting triglycerides (TGs) between 89-180 mg/dl (1-2 mmol/l) would benefit from postprandial TGs testing.

OBJECTIVE

To determine the postprandial TG response in 2 independent studies and validate who should benefit diagnostically from an oral-fat tolerance test (OFTT) in clinical practice.

METHODS

A population of 1002 patients with coronary heart disease (CHD) from the CORDIOPREV clinical trial and 1115 white US subjects from the GOLDN study underwent OFTTs. Subjects were classified into 3 groups according to fasting cut points of TGs to predict the usefulness of OFTT: (1) TG < 89 mg/dl (<1 mmol/l); (2) TG, 89-180 mg/dl (1-2 mmol/l); and (3) TG > 180 mg/dl (>2 mmol/l). Postprandial TG concentration at any point > 220 mg/dl (>2.5 mmol/l) has been pre-established as an undesirable postprandial response.

RESULTS

Of the total, 49% patients with CHD and 42% from the general population showed an undesirable response after the OFTT. The prevalence of undesirable postprandial TG in the CORDIOPREV clinical trial was 12.8, 50.3, and 89.7%, in group 1, 2, and 3, respectively (P < .001) and 11.2, 58.1, and 97.5% in group 1, 2, and 3, respectively (P < .001) in the GOLDN study.

CONCLUSIONS

These two studies validate the predictive values reported in a previous consensus. Moreover, the findings of the CORDIOPREV and GOLDN studies show that an OFTT is useful to identify postprandial hyperlipidemia in subjects with fasting TG between 1-2 mmol/l (89-180 mg/dL), because approximately half of them have hidden postprandial hyperlipidemia, which may influence treatment. An OFTT does not provide additional information regarding postprandial hyperlipidemia in subjects with low TG (<1 mmol/l, <89 mg/dL) or increased TG (>2 mmol/l, >180 mg/dl).

Consumption of a high-fat meal containing cheese compared with a vegan alternative lowers postprandial C-reactive protein in overweight and obese individuals with metabolic abnormalities: a randomised controlled cross-over study

Dietary recommendations suggest decreased consumption of SFA to minimise CVD risk; however, not all foods rich in SFA are equivalent. To evaluate the effects of SFA in a dairy food matrix, as Cheddar cheese, v. SFA from a vegan-alternative test meal on postprandial inflammatory markers, a randomised controlled cross-over trial was conducted in twenty overweight or obese adults with metabolic abnormalities. Individuals consumed two isoenergetic high-fat mixed meals separated by a 1- to 2-week washout period. Serum was collected at baseline, and at 1, 3 and 6 h postprandially and analysed for inflammatory markers (IL-6, IL-8, IL-10, IL-17, IL-18, TNFα, monocyte chemotactic protein-1 (MCP-1)), acute-phase proteins C-reactive protein (CRP) and serum amyloid-A (SAA), cellular adhesion molecules and blood lipids, glucose and insulin. Following both high-fat test meals, postprandial TAG concentrations rose steadily (P < 0·05) without a decrease by 6 h. The incremental AUC (iAUC) for CRP was significantly lower (P < 0·05) in response to the cheese compared with the vegan-alternative test meal. A treatment effect was not observed for any other inflammatory markers; however, for both test meals, multiple markers significantly changed from baseline over the 6 h postprandial period (IL-6, IL-8, IL-18, TNFα, MCP-1, SAA). Saturated fat in the form of a cheese matrix reduced the iAUC for CRP compared with a vegan-alternative test meal during the postprandial 6 h period. The study is registered at clinicaltrials.gov under NCT01803633.

The insulin resistance phenotype (muscle or liver) interacts with the type of diet to determine changes in disposition index after 2 years of intervention: the CORDIOPREV-DIAB randomised clinical trial

AIMS/HYPOTHESIS

The aim of the study was to determine whether basal insulin resistance (IR) phenotype (muscle and/or liver) determines the effect of long-term consumption of a Mediterranean diet or a low-fat diet on tissue-specific IR and beta cell function.

METHODS

The study was performed in 642 patients included in The effect of an olive oil rich Mediterranean diet on type 2 diabetes mellitus risk and incidence study (CORDIOPREV-DIAB). A total of 327 patients were randomised to a Mediterranean diet (35% fat; 22% from monounsaturated fatty acids) and 315 to a low-fat diet (<28% fat). At baseline, the patients were classified into four phenotypes according to the type of IR: (1) no IR; (2) muscle IR; (3) liver IR; (4) muscle + liver IR. The hepatic insulin resistance index (HIRI), muscular insulin sensitivity index (MISI) and disposition index were analysed at baseline and after 2 years of follow-up.

RESULTS

At baseline, 322 patients presented no IR, 106 presented muscle IR, 109 presented liver IR, and 105 presented muscle + liver IR. With both dietary interventions, HIRI decreased in all patients (p < 0.001) and MISI increased in muscle IR and muscle + liver IR patients (p < 0.01). Long-term intake of the Mediterranean diet increased the disposition index and insulinogenic index in the muscle IR patients (p = 0.042 and p = 0.044, respectively) and the disposition index in the muscle + liver IR patients (p = 0.048), whereas the low-fat diet increased the disposition index in the liver IR patients (p = 0.017).

CONCLUSIONS/INTERPRETATION

Although both diets improve insulin sensitivity, there are differences based on basal IR phenotypes. Moreover, according to insulinogenic and disposition index data, a low-fat diet might be more beneficial to patients with liver IR, whereas patients with muscle IR and muscle + liver IR might benefit more from a Mediterranean diet. Trial registration ClinicalTrials.gov NCT00924937 FUNDING: The study was supported by the Ministerio de Economia y Competitividad (AGL2012/39615) and by the Ministerio de Ciencia e Innovacion (PIE14/00005 and PI13/00023).

Metabolomics Reveals Metabolically Healthy and Unhealthy Obese Individuals Differ in their Response to a Caloric Challenge

OBJECTIVE

To determine if metabolically healthy obese (MHO) individuals have a different metabolic response to a standardized diet compared to lean healthy (LH) and metabolically unhealthy obese (MUO) individuals.

METHODS

Thirty adults (35-70 yrs) were classified as LH, MHO, and MUO according to anthropometric and clinical measurements. Participants consumed a standardized high calorie meal (~1330 kcal). Blood glucose and insulin were measured at fasting, and 15, 30, 60, 90 and 120 min postprandially. Additional blood samples were collected for the targeted analysis of amino acids (AAs) and derivatives, and fatty acids (FAs).

RESULTS

The postprandial response (i.e., area under the curve, AUC) for serum glucose and insulin were similar between MHO and LH individuals, and significantly lower than MUO individuals (p < 0.05). Minor differences were found in postprandial responses for AAs between MHO and MUO individuals, while three polyunsaturated FAs (linoleic acid, γ-linolenic acid, arachidonic acid) showed smaller changes in serum after the meal in MHO individuals compared to MUO. Fasting levels for various AAs (notably branched-chain AA) and FAs (e.g., saturated myristic and palmitic acids) were found to correlate with glucose and insulin AUC.

CONCLUSION

MHO individuals show preserved insulin sensitivity and a greater ability to adapt to a caloric challenge compared to MUO individuals.

Postprandial triglyceride response in normolipidemic, hyperlipidemic and obese subjects - the influence of polydextrose, a non-digestible carbohydrate

BACKGROUND

Three independent trials were conducted to evaluate postprandial triglyceride (TG) responses in subjects with different lipid metabolism. The effect of polydextrose (PDX), a soluble non-digestible carbohydrate, on postprandial response was also studied using practically relevant, high fat meal interventions.

METHODS

A total of 19 normolipidemic (average BMI 24.1 kg/m(2)), 21 overweight/hyperlipidemic (average BMI 29.6 kg/m(2)) and 18 obese/non-diabetic subjects (average BMI 33.6 kg/m(2)) were included in the study. On two separate occasions all subjects ate two high-fat meals (4293 kJ, 36% from fat), one with PDX (either 12.5 g or 15 g) and one without PDX during placebo-controlled, double-blind, crossover and randomized trials. To obtain the triglyceride measurements venous blood samples were taken before the consumption of the test meal and five times afterwards, up to 6 h post-test meal. The triglyceride responses were modeled using a mixed-effects linear model.

RESULTS

The key variables that explain the variation of the postprandial triglyceride response in the different subject groups were: baseline triglyceride concentration, time point, and PDX vs. placebo treatment (p < 0.05). The maximum postprandial TG concentration was more pronounced in hyperlipidemic group compared to normolipidemic (p < 0.001) or obese groups (p < 0.01). The modeled TG response analysis showed that irrespective of the study population PDX supplementation was one of the factors significantly reducing triglyceride response compared to the placebo treatment (p < 0.05).

CONCLUSIONS

Subjects with elevated fasting triglyceride levels display exaggerated and prolonged postprandial triglyceride responses. PDX, a soluble non-digestible carbohydrate, may offer a dietary concept for reducing the postprandial triglyceride response after the consumption of a meal containing a high concentration of fat.

Adipose tissue as an immunological organ

OBJECTIVE

This review will focus on the immunological aspects of adipose tissue and its potential role in development of chronic inflammation that instigates obesity-associated comorbidities.

METHODS

The review used PubMed searches of current literature to examine adipose tissue leukocytosis.

RESULTS AND CONCLUSIONS

The adipose tissue of obese subjects becomes inflamed and contributes to the development of insulin resistance, type 2 diabetes, and metabolic syndrome. Numerous immune cells including B cells, T cells, macrophages, and neutrophils have been identified in adipose tissue, and obesity influences both the quantity and the nature of immune cell subtypes, which emerges as an active immunological organ capable of modifying whole-body metabolism through paracrine and endocrine mechanisms. Adipose tissue is a large immunologically active organ during obesity and displays hallmarks of both and innate and adaptive immune response. Despite the presence of hematopoietic lineage cells in adipose tissue, it is unclear whether the adipose compartment has a direct role in immune surveillance or host defense. Understanding the interactions between leukocytes and adipocytes may reveal the clinically relevant pathways that control adipose tissue inflammation and is likely to reveal mechanisms by which obesity contributes to increased susceptibility to both metabolic and certain infectious diseases.