What is the role of cardiorespiratory fitness and sedentary behavior in relationship between the genetic predisposition to obesity and cardiometabolic risk score?

Physiology of sedentary behavior

Sedentary behaviors (SB) are characterized by low energy expenditure while in a sitting or reclining posture. Evidence relevant to understanding the physiology of SB can be derived from studies employing several experimental models: bed rest, immobilization, reduced step count, and reducing/interrupting prolonged SB. We examine the relevant physiological evidence relating to body weight and energy balance, intermediary metabolism, cardiovascular and respiratory systems, the musculoskeletal system, the central nervous system, and immunity and inflammatory responses. Excessive and prolonged SB can lead to insulin resistance, vascular dysfunction, shift in substrate use toward carbohydrate oxidation, shift in muscle fiber from oxidative to glycolytic type, reduced cardiorespiratory fitness, loss of muscle mass and strength and bone mass, and increased total body fat mass and visceral fat depot, blood lipid concentrations, and inflammation. Despite marked differences across individual studies, longer term interventions aimed at reducing/interrupting SB have resulted in small, albeit marginally clinically meaningful, benefits on body weight, waist circumference, percent body fat, fasting glucose, insulin, HbA1c and HDL concentrations, systolic blood pressure, and vascular function in adults and older adults. There is more limited evidence for other health-related outcomes and physiological systems and for children and adolescents. Future research should focus on the investigation of molecular and cellular mechanisms underpinning adaptations to increasing and reducing/interrupting SB and the necessary changes in SB and physical activity to impact physiological systems and overall health in diverse population groups.

Polymorphisms of Fat Mass and Obesity-Associated Gene in the Pathogenesis of Child and Adolescent Metabolic Syndrome

Childhood metabolic syndrome (MetS) is prevalent around the world and is associated with a high likelihood of suffering from severe diseases such as cardiovascular disease later in adulthood. MetS is associated with genetic susceptibility that involves gene polymorphisms. The fat mass and obesity-associated gene (FTO) encodes an RNA N6-methyladenosine demethylase that regulates RNA stability and molecular functions. Human FTO contains genetic variants that significantly contribute to the early onset of MetS in children and adolescents. Emerging evidence has also uncovered that FTO polymorphisms in intron 1, such as rs9939609 and rs9930506 polymorphisms, are significantly associated with the development of MetS in children and adolescents. Mechanistic studies reported that FTO polymorphisms lead to aberrant expressions of FTO and the adjacent genes that promote adipogenesis and appetite and reduce steatolysis, satiety, and energy expenditure in the carriers. The present review highlights the recent observations on the key FTO polymorphisms that are associated with child and adolescent MetS with an exploration of the molecular mechanisms underlying the development of increased waist circumference, hypertension, and hyperlipidemia in child and adolescent MetS.

Interactions between genetic and lifestyle factors on cardiometabolic disease-related outcomes in Latin American and Caribbean populations: A systematic review

Introduction

The prevalence of cardiometabolic diseases has increased in Latin American and the Caribbean populations (LACP). To identify gene-lifestyle interactions that modify the risk of cardiometabolic diseases in LACP, a systematic search using 11 search engines was conducted up to May 2022.

Methods

Eligible studies were observational and interventional studies in either English, Spanish, or Portuguese. A total of 26,171 publications were screened for title and abstract; of these, 101 potential studies were evaluated for eligibility, and 74 articles were included in this study following full-text screening and risk of bias assessment. The Appraisal tool for Cross-Sectional Studies (AXIS) and the Risk Of Bias In Non-Randomized Studies-of Interventions (ROBINS-I) assessment tool were used to assess the methodological quality and risk of bias of the included studies.

Results

We identified 122 significant interactions between genetic and lifestyle factors on cardiometabolic traits and the vast majority of studies come from Brazil (29), Mexico (15) and Costa Rica (12) with FTO, APOE, and TCF7L2 being the most studied genes. The results of the gene-lifestyle interactions suggest effects which are population-, gender-, and ethnic-specific. Most of the gene-lifestyle interactions were conducted once, necessitating replication to reinforce these results.

Discussion

The findings of this review indicate that 27 out of 33 LACP have not conducted gene-lifestyle interaction studies and only five studies have been undertaken in low-socioeconomic settings. Most of the studies were cross-sectional, indicating a need for longitudinal/prospective studies. Future gene-lifestyle interaction studies will need to replicate primary research of already studied genetic variants to enable comparison, and to explore the interactions between genetic and other lifestyle factors such as those conditioned by socioeconomic factors and the built environment. The protocol has been registered on PROSPERO, number CRD42022308488.

Systematic review registration

https://clinicaltrials.gov, identifier CRD420223 08488.

Prevalence of Metabolic Syndrome and Association with Physical Activity and Frailty Status in Spanish Older Adults with Decreased Functional Capacity: A Cross-Sectional Study

Metabolic syndrome (MetS) is a cluster of medical conditions associated with several health disorders. MetS and frailty can be related to prolonged physical deconditioning. There is a need to know whether there is concordance between the different ways of diagnosing it and to know their prevalence in Spanish older adults. Thus, the aims of this study were to describe the prevalence of MetS; to analyse the concordance between different definitions to diagnose MetS; and to study the associations between MetS, frailty status, and physical activity (PA) in older adults with decreased functional capacity. This report is a cross-sectional study involving 110 Spanish older adults of ages ≥65 years with decreased functional capacity. Clinical criteria to diagnose MetS was defined by different expert groups. Anthropometric measurements, blood biochemical analysis, frailty status, functional capacity, and PA were assessed. The Kappa statistic was used to determine the agreement between the five MetS definitions used. Student’s t-test and the Pearson chi-square test were used to examine differences between sex, frailty, and PA groups. The sex-adjusted prevalence of MetS assessed by the National Cholesterol Education Program—Third Adult Treatment Panel was 39.4% in men and 32.5% in women. The International Diabetes Federation and the Harmonized definitions had the best agreement (k = 1.000). The highest odds ratios (ORs) of cardiometabolic risk factors to develop MetS were elevated triglycerides (37.5) and reduced high-density lipoprotein cholesterol (27.3). Central obesity and hypertension prevalence were significantly higher in the non-active group (70.7% and 26.8%, respectively), compared to the active group (50.0% and 7.7%, respectively). Moreover, the active group (OR = 0.85, 95% CI = 0.35, 2.04) and active women group (OR = 0.77, 95% CI = 0.27, 2.20) appeared to show a lower risk of developing this syndrome. MetS is highly prevalent in this sample and changes according to the definition used. It seems that sex and frailty do not influence the development of MetS. However, PA appears to decrease central obesity, hypertension, and the risk of developing MetS.