Sexual Dimorphism in Body Weight Loss, Improvements in Cardiometabolic Risk Factors and Maintenance of Beneficial Effects 6 Months after a Low-Calorie Diet: Results from the Randomized Controlled DiOGenes Trial

Comparison of the impact of longitudinal body mass index changes on cardiac arrest risk between normal and overweight populations

BACKGROUND

Being overweight is a key modifiable risk factor for cardiovascular disease. However, the impact of longitudinal changes in body mass index (BMI) on the risk of out-of-hospital cardiac arrests (OHCA) remains unclear, especially among overweight populations.

METHODS

This nested case-control study utilized data from the Korean National Health Information Database between 2009 and 2018. A total of 23 453 OHCA patients, who underwent national health check-ups within 1 and 2-4 years before OHCA occurrence, and 31 686 controls, who underwent similar national health check-ups, were included. The study population was matched for sex, age and survival status. Conditional logistic regression was employed to analyse the odds ratios (ORs) and 95% confidence intervals (CIs) of each BMI per cent change in assessing the risk of OHCA occurrence within 1 year.

RESULTS

A reverse J-shaped association between BMI per cent change and OHCA risk was observed, even among overweight populations. Among the overweight populations, weight loss significantly increased OHCA risk, with ORs (95% CI) of 4.10 (3.23-5.20) for severe weight loss (BMI decrease > 15%), 2.72 (2.33-3.17) for moderate weight loss (BMI decrease 10-15%) and 1.46 (1.35-1.59) for mild weight loss (BMI decrease 5-10%). Conversely, mild weight gain (BMI increase 5-10%) did not significantly increase OHCA risk. The impact of weight changes on the occurrence of OHCA differed by sex, being more prominent in males.

CONCLUSIONS

Significant weight changes within a 4-year period increase the risk of OHCA with a reverse J-shaped association, even among overweight and obese individuals. Maintaining a stable weight could be a reliable public health strategy irrespective of the weight status, particularly for males.

Association Between the Postprandial Response to an Oral Glucose Tolerance Test and Anthropometric Changes After an 8-Week Low-Calorie Formula Diet - Results From the Lifestyle Intervention (LION) Study

SCOPE

Interindividual variations in postprandial metabolism and weight loss outcomes have been reported. The literature suggests links between postprandial metabolism and weight regulation. Therefore, the study aims to evaluate if postprandial glucose metabolism after a glucose load predicts anthropometric outcomes of a weight loss intervention.

METHODS AND RESULTS

Anthropometric data from adults with obesity (18-65 years, body mass index [BMI] 30.0-39.9 kg m-2) are collected pre- and post an 8-week formula-based weight loss intervention. An oral glucose tolerance test (OGTT) is performed at baseline, from which postprandial parameters are derived from glucose and insulin concentrations. Linear regression models explored associations between these parameters and anthropometric changes (∆) postintervention. A random forest model is applied to identify predictive parameters for anthropometric outcomes after intervention. Postprandial parameters after an OGTT of 158 participants (63.3% women, age 45 ± 12, BMI 34.9 ± 2.9 kg m-2) reveal nonsignificant associations with changes in anthropometric parameters after weight loss (p > 0.05). Baseline fat-free mass (FFM) and sex are primary predictors for ∆ FFM [kg].

CONCLUSION

Postprandial glucose metabolism after a glucose load does not predict anthropometric outcomes after short-term weight loss via a formula-based low-calorie diet in adults with obesity.

Intermittent fasting as a dietary intervention with potential sexually dimorphic health benefits

Intermittent fasting (IF) has proven to be a feasible dietary intervention for the wider population. The recent increase in IF clinical trials highlights its potential effects on health, including changes in body composition, cardiometabolic status, and aging. Although IF may have clinical applications in different populations, studies suggest there may be sex-specific responses in parameters such as body composition or glucose and lipid metabolism. Here, the existing literature on IF clinical trials is summarized, the application of IF in both disease prevention and management is discussed, and potential disparities in response to this type of diet between men and women are assessed. Moreover, the potential mechanisms that may be contributing to the sexually dimorphic response, such as age, body composition, tissue distribution, or sex hormones are investigated. This review underscores the need to further study these sex-specific responses to IF to define the most effective time frames and length of fasting periods for men and women. Tailoring IF to specific populations with a personalized approach may help achieve its full potential as a lifestyle intervention with clinical benefits.

Dietary regulation of intestinal stem cells in health and disease

Diet is a critical regulator for physiological metabolism and tissue homeostasis, with a close relation to health and disease. As an important organ for digestion and absorption, the intestine comes into direct contact with many dietary components. The rapid renewal of its mucosal epithelium depends on the continuous proliferation and differentiation of intestinal stem cells (ISCs). The function and metabolism of ISCs can be controlled by a variety of dietary patterns including calorie restriction, fasting, high-fat, ketogenic, and high-sugar diets, as well as different nutrients including vitamins, amino acids, dietary fibre, and probiotics. Therefore, dietary interventions targeting ISCs may make it possible to prevent and treat intestinal disorders such as colon cancer, inflammatory bowel disease, and radiation enteritis. This review summarised recent research on the role and mechanism of diet in regulating ISCs, and discussed the potential of dietary modulation for intestinal diseases.

Precision nutrition for targeting pathophysiology of cardiometabolic phenotypes

Obesity is a heterogenous disease accompanied by a broad spectrum of cardiometabolic risk profiles. Traditional paradigms for dietary weight management do not address biological heterogeneity between individuals and have catastrophically failed to combat the global pandemic of obesity-related diseases. Nutritional strategies that extend beyond basic weight management to instead target patient-specific pathophysiology are warranted. In this narrative review, we provide an overview of the tissue-level pathophysiological processes that drive patient heterogeneity to shape distinct cardiometabolic phenotypes in obesity. Specifically, we discuss how divergent physiology and postprandial phenotypes can reveal key metabolic defects within adipose, liver, or skeletal muscle, as well as the integrative involvement of the gut microbiome and the innate immune system. Finally, we highlight potential precision nutritional approaches to target these pathways and discuss recent translational evidence concerning the efficacy of such tailored dietary interventions for different obesity phenotypes, to optimise cardiometabolic benefits.

Relationship between Atherogenic Dyslipidaemia and Lipid Triad and Scales That Assess Insulin Resistance

BACKGROUND

Atherogenic dyslipidaemia (AD) and lipid triad (LT) are characterised by high triglyceride levels together with low HDL and normal or high LDL cholesterol and are favoured by a persistent state of insulin resistance (IR), which increases the release of free fatty acids from abdominal adipose tissue. This alteration in the lipid profile favours the accelerated development of atherosclerosis, which is the most important cause of morbidity and mortality in all countries in the developed and developing world. One of the elements that plays a major role in the genesis of AD is IR. The aim of this study was to determine the relationship between variables that assess atherogenic risk (AD and LT) and scales that assess the risk of presenting insulin resistance.

METHODS

A descriptive cross-sectional study of 418,343 workers was conducted to evaluate atherogenic dyslipidaemia and lipid triad; a relationship with three insulin resistance risk scales (Triglycerides/HDL, TyG index, METS-IR) was established. The usefulness of IR risk scales for predicting AD and LT was calculated by applying ROC curves, obtaining the area under the curve (AUC) and cut-off points with their sensitivity, specificity, and Youden index. Multivariate analysis was performed by binary logistic regression.

RESULTS

The prevalence of high-risk values for insulin resistance with all of the scales is much higher in people with AD and LT compared to those without. The ROC curves present us with an AUC with the three insulin resistance risk scales for the two dyslipidaemias studied with figures ranging between 0.856 and 0.991, which implies that the results are good/very good.

CONCLUSIONS

A relationship between atherogenic dyslipidaemia and the three insulin resistance risk scales assessed is revealed, with higher IR mean values and prevalence in people with atherogenic dyslipidaemia and lipid triad. The three scales make it possible to adequately classify the presence of AD and LT. The highest AUC is presented by the triglycerides/HDL scale, with a result close to 1. METS-IR is the most recommended formula to estimate insulin resistance.

Effects of very low-calorie ketogenic diet on hypothalamic-pituitary-adrenal axis and renin-angiotensin-aldosterone system

BACKGROUND

The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system involved in controlling stress responses in humans under physiological and pathological conditions; cortisol is the main hormone produced by the HPA axis. It is known that calorie restriction acts as a stressor and can lead to an increase in cortisol production. Renin-angiotensin-aldosterone system (RAAS) is a complex endocrine network regulating blood pressure and hydrosaline metabolism, whose final hormonal effector is aldosterone. RAAS activation is linked to cardiometabolic diseases, such as heart failure and obesity. Obesity has become a leading worldwide pandemic, associated with serious health outcomes. Calorie restriction represents a pivotal strategy to tackle obesity. On the other hand, it is well known that an increased activity of the HPA may favour visceral adipose tissue expansion, which may jeopardize a successful diet-induced weight loss. Very low-calorie ketogenic diet (VLCKD) is a normoprotein diet with a drastic reduction of the carbohydrate content and total calorie intake. Thanks to its sustained protein content, VLCKD is extremely effective to reduce adipose tissue while preserving lean body mass and resting metabolic rate.

PURPOSE

The purpose of this narrative review is to gain more insights on the effects of VLCKD on the HPA axis and RAAS, in different phases of weight loss and in different clinical settings.

Sex differences in response to lifestyle intervention among children and adolescents: Systematic review and meta-analysis

OBJECTIVE

Little is known about sex differences in response to lifestyle interventions among pediatric populations. The purpose of this analysis was to evaluate sex differences in adiposity following lifestyle interventions among children and adolescents with overweight or obesity aged 6 to 18 years old.

METHODS

Searches were conducted in PubMed, Web of Science, and MEDLINE (from inception to March 2021), and references from included articles were examined. Eligibility criteria included children and adolescents aged 6 to 18 years with overweight or obesity, randomization to a lifestyle intervention versus a control group, and assessment of at least one adiposity measure. Corresponding authors were contacted to obtain summary statistics by sex (n = 14/49).

RESULTS

Of 89 full-text articles reviewed, 49 (55%) were included, of which 33 (67%) reported statistically significant intervention effects on adiposity. Only two studies (4%) evaluated sex differences in response to lifestyle intervention, reporting conflicting results. The results of the meta-regression models demonstrated no significant differences in the treatment effect between male and female youth for weight (beta = -0.05, SE = 0.18, z = -0.28, p = 0.8), BMI (beta = 0.03, SE = 0.14, z = 0.19, p = 0.85), BMI z score (beta = -0.04, SE = 0.18, z = -0.23, p = 0.82), percentage body fat (beta = -0.11, SE = 0.16, z = -0.67, p = 0.51), and waist circumference (beta = -0.30, SE = 0.25, z = -1.18, p = 0.24).

CONCLUSIONS

The meta-analysis revealed that youth with overweight or obesity do not demonstrate a differential response to lifestyle intervention in relation to adiposity-related outcomes.

Sex differences in endocannabinoids during 3 years of Mediterranean diet intervention: Association with insulin resistance and weight loss in a population with metabolic syndrome

Background

Excess circulating endocannabinoids (eCBs) and imbalanced N-acylethanolamines (NAEs) related eCBs abundance could influence dietary weight loss success. We aimed to examine sex differences in the impact of a 3-years Mediterranean diet (MedDiet) intervention on circulating eCBs, NAEs and their precursor fatty acids, and to analyze the interplay between changes in eCBs or NAEs ratios, insulin resistance and the achievement of clinically meaningful weight reductions.

Methods

Prospective cohort study in a subsample of N = 105 participants (54.3% women; 65.6 ± 4.6 years) with overweight or obesity and metabolic syndrome that underwent a 3-years MedDiet intervention (PREDIMED-Plus study). Plasma eCBs and NAEs, including 2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), fatty acids, diet, glycemic homeostasis (including the assessment of insulin resistance-HOMA-IR), and cardiovascular risk markers were monitored (at 0-6-12-36 months).

Results

Mediterranean diet adherence increased in both sexes and remained high during the 3 years of follow-up. Reductions in body weight, glycemic and cardiovascular parameters were larger in men than in women. Women presented higher concentrations of NAEs than men throughout the study. In both sexes, AEA and other NAEs (including OEA, and PEA) decreased after 6 months (for AEA: −4.9%), whereas the ratio OEA/AEA increased after 1 year (+5.8%). Changes in 2-AG (−3.9%) and the ratio OEA/PEA (+8.2%) persisted over the 3 years of follow-up. In women, 6-months changes in AEA (OR = 0.65) and the ratio OEA/AEA (OR = 3.28) were associated with the achievement of 8% weight reductions and correlated with HOMA-IR changes (r = 0.29 and r = −0.34). In men, OEA/PEA changes were associated with 8% weight reductions (OR = 2.62) and correlated with HOMA-IR changes (r = −0.32).

Conclusion

A 3-years MedDiet intervention modulated plasma concentrations of eCBs and NAEs. Changes in AEA and in the relative abundance of NAEs were associated with clinically meaningful weight reductions. However, marked sex differences were identified in eCBs and NAEs, as well as in the efficacy of the intervention in terms of glycemic and cardiovascular parameters, which could be related to post-menopause alterations in glucose metabolism. These findings support a sex-balanced research strategy for a better understanding of the mechanisms underlying the regulation of body weight loss.

Status and transition of normal-weight central obesity and the risk of cardiovascular diseases: A population-based cohort study in China

BACKGROUND AND AIMS

Cardiovascular disease (CVD) has become a growing public health concern. Normal weight central obesity (NWCO) has emerged as a potential risk factor for cardiometabolic dysregulation. To date, the association between NWCO and new-onset CVDs remains unclear. We aimed to evaluate the associations of NWCO and its longitudinal transitions with cardiovascular risks in middle-aged and older Chinese.

METHODS AND RESULTS

Data were from the China Health and Retirement Longitudinal Study 2011-2018. NWCO was defined as the combination of a body mass index (BMI) of <24.0 kg/m² and a waist circumference (WC) of >85 cm in males or >80 cm in females. CVDs included heart diseases and stroke. Cause-specific hazard models and subdistribution hazard models with all-cause death as the competing event were applied. In 2011, 9856 participants without prior CVDs were included, of whom 1814 developed CVDs during a 7-year follow-up. Compared to normal weight and non-central obesity (NWNCO), NWCO was significantly associated with new-onset CVDs, with cause-specific hazard ratios (cHRs) and 95% confidence intervals (CIs) of 1.21 (1.04-1.41) for heart diseases and 1.40 (1.11-1.76) for stroke. From 2011 to 2013, 571 NWNCO participants developed NWCO who subsequently demonstrated a 45% higher risk of CVDs than those with maintained NWNCO.

CONCLUSION

NWCO and transition from NWNCO to NWCO are associated with higher risks of CVDs. Identification and prevention of NWCO may be useful in the management of CVDs.

Restricted cafeteria feeding and treadmill exercise improved body composition, metabolic profile and exploratory behavior in obese male rats

The aim of this study was to evaluate, in male Long-Evans rats, whether a restricted-cafeteria diet (CAFR), based on a 30% calorie restriction vs continuous ad libitum cafeteria (CAF) fed animals, administered alone or in combination with moderate treadmill exercise (12 m/min, 35 min, 5 days/week for 8 weeks), was able to ameliorate obesity and the associated risk factors induced by CAF feeding for 18 weeks and to examine the changes in circadian locomotor activity, hypothalamic-pituitary-adrenal (HPA) axis functionality, and stress response elicited by this dietary pattern. In addition to the expected increase in body weight and adiposity, and the development of metabolic dysregulations compatible with Metabolic Syndrome, CAF intake resulted in a sedentary profile assessed by the home-cage activity test, reduced baseline HPA axis activity through decreased corticosterone levels, and boosted exploratory behavior. Both CAFR alone and in combination with exercise reduced abdominal adiposity and hypercholesterolemia compared to CAF. Exercise increased baseline locomotor activity in the home-cage in all dietary groups, boosted exploratory behavior in STD and CAF, partially decreased anxiety-like behavior in CAF and CAFR, but did not affect HPA axis-related parameters.

AMPK Activation Is Indispensable for the Protective Effects of Caloric Restriction on Left Ventricular Function in Postinfarct Myocardium

Background: Caloric restriction (CR) extends lifespan in many species, including mammals. CR is cardioprotective in senescent myocardium by correcting pre-existing mitochondrial dysfunction and apoptotic activation. Furthermore, it confers cardioprotection against acute ischemia-reperfusion injury. Here, we investigated the role of AMP-activated protein kinase (AMPK) in mediating the cardioprotective CR effects in failing, postinfarct myocardium. Methods: Ligation of the left coronary artery or sham operation was performed in rats and mice. Four weeks after surgery, left ventricular (LV) function was analyzed by echocardiography, and animals were assigned to different feeding groups (control diet or 40% CR, 8 weeks) as matched pairs. The role of AMPK was investigated with an AMPK inhibitor in rats or the use of alpha 2 AMPK knock-out mice. Results: CR resulted in a significant improvement in LV function, compared to postinfarct animals receiving control diet in both species. The improvement in LV function was accompanied by a reduction in serum BNP, decrease in LV proapoptotic activation, and increase in mitochondrial biogenesis in the LV. Inhibition or loss of AMPK prevented most of these changes. Conclusions: The failing, postischemic heart is protected from progressive loss of LV systolic function by CR. AMPK activation is indispensable for these protective effects.