Abdominal Adiposity, Not Cardiorespiratory Fitness, Mediates the Exercise-Induced Change in Insulin Sensitivity in Older Adults

Role of the N6-methyladenosine regulatory factor in reducing the risk of cardiovascular disease: subtype diagnosis following aerobic exercise-assisted weight loss

OBJECTIVES

This study aimed to construct a model based on different N6-methyladenosine (m6A) regulatory factors involved in reducing the risk of the development of cardiovascular diseases under conditions of aerobic exercise.

METHODS

We screened for significantly different expressions of m6A regulators from the GSE66175 dataset. Five candidate m6A regulators were identified using the random forest model to predict aerobic exercise-mediated fat loss and reduction of the risk of cardiovascular disease. A nomogram model was established for analysis, and the consensus clustering method was used to distinguish between the two m6A clusters (clusters A and B). The single-sample gene set-enrichment analysis method was used to assess the abundance of immune cells in the samples related to cardiovascular anomalies. We determined the relationship between the functions of 29 immune cells and m6A clusters.

RESULTS

Twelve significantly and differentially expressed m6A regulators in the control and aerobic exercise groups were screened out, and it was observed that METTL13 correlated positively with the expression levels of the YTH domain containing 1 (YTHDC1), YTH N (6)-methyl adenosine RNA binding protein 1, and leucine-rich pentatricopeptide repeat-containing. The fat mass and obesity-associated gene negatively correlated with YTHDC1 and the fragile X mental retardation 1 protein. The random forest and support vector machine models were used to screen the ELAV-like RNA binding protein 1 (ELAVL1), RNA binding motif protein 15B (RBM15B), insulin-like growth factor binding protein 1 (IGFBP1), Wilms tumor 1-associated protein (WTAP), and zinc finger CCCH-type containing 13 (ZC3H13) genes. Analysis of the line graph model and the results obtained using decision curve analysis revealed the efficiency of the model. Gene ontology enrichment analysis was used to analyze the m6A regulatory gene model, and the results suggested that it was associated with RNA splicing. The results obtained using the Kyoto Encyclopedia of Genes and Genomes enrichment analysis method suggests that the genes were associated with Alzheimer's disease and neurodegeneration pathways associated with multiple diseases. The m6A regulatory gene model was associated with most of the immune cells infiltrating tumors and was also closely related to genes associated with lipid metabolism.

CONCLUSIONS

The m6A regulatory factor plays an important role in reducing the risk of cardiovascular disease under conditions of aerobic exercise-assisted weight loss. It is also associated with the metabolic pathways of low-density lipoprotein, high-density lipoprotein, and triglyceride.

Cardiovascular Risk Factors and Physical Activity for the Prevention of Cardiovascular Diseases in the Elderly

Cardiovascular diseases create an important burden on the public health systems, especially in the elderly, mostly because this group of patients frequently suffer from multiple comorbidities. Accumulating cardiovascular risk factors during their lifetime has a detrimental effect on an older adult's health status. The modifiable and non-modifiable cardiovascular risk factors are very diverse, and are frequently in a close relationship with the metabolic comorbidities of the elderly, mainly obesity and Diabetes Mellitus. In this review, we aim to present the most important cardiovascular risk factors which link aging and cardiovascular diseases, starting from the pathophysiological links between these factors and the aging process. Next, we will further review the main interconnections between obesity and Diabetes Mellitus and cardiovascular diseases of the elderly. Lastly, we consider the most important aspects related to prevention through lifestyle changes and physical activity on the occurrence of cardiovascular diseases in the elderly.

Anthropometric variables as mediators of the association of changes in diet and physical activity with inflammatory profile

BACKGROUND

Mechanisms underlying the associations of high levels of physical activity (PA) and adherence to the Mediterranean Diet (MedDiet) with a better inflammatory profile remain unclear. Our objective was to assess the mediating role of changes in body mass index (BMI) and waist circumference (WC), as markers of body fat in the association of changes in PA and adherence to the MedDiet, with changes in the inflammatory profile.

METHODS

This study included 489 adults, aged 55 to 75 years, from the PREDIMED-Plus multi-centre lifestyle intervention trial. An inflammatory score was calculated, based on 8 blood biomarkers: high-sensitivity C-reactive protein, interleukin 6, interleukin 8, interleukin 18, monocyte chemo-attractant protein-1, C-peptide, leptin, and regulated on activation, normal T-cell expressed and secreted chemokine (RANTES). Biomarkers, levels of PA, score of MedDiet adherence, BMI and WC were measured at baseline and at one-year follow-up. Linear regression models were fitted according to the Baron and Kenny framework for mediation analysis.

RESULTS

Changes in BMI and WC mediated the association of both changes in PA and changes in the MedDiet adherence with the inflammatory score. BMI mediated 26% of the association of changes in total PA with the inflammatory profile, and 27% of the association of changes in the MedDiet, while WC mediated 13% and 12% of these associations, respectively.

CONCLUSION

In older adults at high cardiovascular risk, increasing PA levels and adherence to a MedDiet during 1 year were associated with a lower inflammatory score, which was partly mediated by a reduction in body fat.

Effects of Exercise Interventions on Weight, Body Mass Index, Lean Body Mass and Accumulated Visceral Fat in Overweight and Obese Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

(1) Background: Exercise interventions for overweight and obese individuals help reduce accumulated visceral fat, which is an indicator of cardiometabolic risk, but the effectiveness of these interventions is controversial. The purpose of this meta-analysis was to investigate the effectiveness of exercise interventions in overweight and obese individuals in order to reduce weight, body mass index (BMI), and accumulated visceral fat, and increase lean body mass. (2) Methods: Databases were used to select eligible studies for this meta-analysis. Randomized controlled trials with control and experimental groups were included. The degrees of effectiveness of the exercise interventions were computed to assess the benefits on reducing weight, BMI, and accumulated visceral fat, and increasing lean body mass. (3) Results: Sixteen studies were included in this meta-analysis. Participation in exercise interventions reduced weight (d = −0.58 (95% confidence interval (CI), −0.84–−0.31; p < 0.001; k = 9)), BMI (d = −0.50 (95% CI, −0.78–−0.21; p < 0.001; k = 7)), and accumulated visceral fat (d = −1.08 (95% CI, −1.60–−0.57; p < 0.001; k = 5)), but did not significantly increase lean body mass (d = 0.26 (95% CI, −0.11–0.63; p = 0.17; k = 6)). The average exercise intervention for overweight and obese individuals was of moderate to vigorous intensity, 4 times per week, 50 min per session, and 22 weeks duration. (4) Conclusions: Participating in exercise interventions has favorable effects on weight, BMI, and accumulated visceral fat. Further studies considering different modalities, intensities, durations, and measurements of fatness need to be conducted.

Functional DNA variations associated with Saudi female with low VO2max: a pilot microarray study

The study aims to explore the genetic predispositions and molecular pathways of low cardiorespiratory fitness (VO2max) in young Saudi females (n = 70). Young females were grouped based on the level of VO2max according to the specification of the physical fitness specialist certification as low VO2max (< 28.9; n = 19) and high VO2max (> 33; n = 14) and genotyped for 243345 putative functional exonic variants. The CYFIP2&FNDC9-rs10037485T, C1R-rs75380747G and TOP2A-rs13695C SNPs on chromosome 5, 12 and 17, respectively were found to be the most significant among young Saudi females with low VO2max (P < 8.01 × 10-05). Linkage disequilibrium (LD) analysis among the significant SNPs (P < 0.001) have revealed risk and protective haplotypes with high degree (p-value < 1.0 × 10-4) of LD. The most significant risk haplotypes with the low VO2max in young Saudi females are: Chromosome 1: LOC112268276-rs10800201G; LOC112268276-rs4657537A; rs4657583T (p-value = 2.00 × 10-04); Chromosome 3: rs978979G; CCDC66-rs7637449A; CCDC66-rs111934125T; FAM208A-rs9835332G (p-value = 5.00 × 10-04) and Chromosome 17: STX2-rs13696C; TNS4-rs1901187C (p-value = 1.00 × 10-04). Functional Enrichment Analysis revealed that the genes with SNPs P < 0.001 have significantly involved in the heart rate (P = 0.00442), body weight (P = 0.00629), breath tests (P = 0.0147), proteolysis (P = 0.00623) and cardiac muscle fiber development (P = 0.0263). In conclusion we could say that the identified genetic predispositions and gene-annotation enrichment in low VO2max in young Saudi females revealed that they are at high risk for developing cardiovascular complications.

An Objective Method to Accurately Measure Cardiorespiratory Fitness in Older Adults Who Cannot Satisfy Widely Used Oxygen Consumption Criteria

Cardiorespiratory fitness (CRF) is routinely investigated in older adults; however, the most appropriate CRF measure to use for this population has received inadequate attention. This study aimed to 1) evaluate the reliability and validity of the oxygen uptake efficiency slope (OUES) as a sub-maximal measurement of CRF; 2) examine demographic, risk-factor, and exercise testing differences in older adults who satisfied standardized criteria for a peak oxygen consumption (V̇O2peak) test compared to those who did not; and 3) determine the difference between directly measured V̇O2peak values and OUES-predicted V̇O2peak values. One hundred ten enrollees from the Wisconsin Registry for Alzheimer's Prevention participated in this study. Participants performed a graded maximal exercise test and wore an accelerometer for 7 days. For each participant, the OUES was calculated at 75%, 90%, and 100% of exercise duration. V̇O2peak was recorded at peak effort, and one week of physical activity behavior was measured. OUES values calculated at separate relative exercise durations displayed excellent reliability (ICC = 0.995; p < 0.001), and were strongly correlated with V̇O2peak (rrange = 0.801-0.909; p < 0.001). As hypothesized, participants who did not satisfy V̇O2peak criteria were significantly older than those who satisfied criteria (p = 0.049) and attained a directly measured V̇O2peak that was 2.31 mL·kg·min-1 less than the value that was predicted by OUES V̇O2peak (p = 0.003). Older adults are less likely to satisfy V̇O2peak criteria, which results in an underestimation of their CRF. Without adhering to standardized criteria, V̇O2peak measurement error may lead to misinterpretation of CRF and age-related associations. Here, we conclude that OUES is a reliable, valid measurement of CRF which does not require achievement of standardized criteria.

Cardiorespiratory fitness and development of abdominal obesity

Both, cardiorespiratory fitness and abdominal obesity are independently associated with developing cardiovascular disease and its risk factors. However, the relationship between both attributes is unclear. We examine the relationship between cardiorespiratory fitness and the risk of developing abdominal obesity, and secondarily, other adiposity measures. Retrospective observational study of a cohort of 1284 sedentary patients, who had participated in a clinical trial of physical activity promotion carried out in Spain (2003-2007). At baseline, they were free of cardiovascular disease, hypertension, diabetes, dyslipidemia and/or abdominal obesity, with an indirect VO₂max measurement, were 19-80 years old, 62% women, and had completed the two year follow-up. The exposure factor was cardiorespiratory fitness categorized as high, moderate or low, according to tertiles of VO₂max values. The main outcome measure was the risk of developing abdominal obesity, as defined by waist circumference >102 (men) and >88 (women) cm. Secondary outcomes were the risk of developing: general obesity, excess body fat, and their combination ("defined" obesity). At two years, 10.5% of the participants had developed abdominal obesity: 6.1% in the high cardiorespiratory fitness tertile, 9.7% in the moderate tertile (adjusted odds ratio, 1.20; 95% confidence interval 0.68-2.10), and 15.7% in the low tertile (adjusted odds ratio, 2.29; 95% confidence interval 1.34-3.91). Moreover, 2.2% of participants in the high cardiorespiratory fitness tertile developed "defined" obesity as did 5.4% in the low tertile (adjusted odds ratio, 2.90; 95% confidence interval 1.15-7.29). Low cardiorespiratory fitness levels are associated with a higher risk of developing abdominal and "defined" obesity.

Expression of Metabolic Syndrome in Women with Severe Obesity

BACKGROUND

The prevalence of metabolic syndrome (MetS) generally rises with increasing adiposity, but tends to plateau at the highest levels of body mass index (BMI) with some individuals, even with severe obesity, expressing few or no components of MetS. We examined factors associated with the expression of MetS in severely obese women participating in a large observational study.

METHODS

Anthropometrics, including Heath equation-adjusted bioimpedance-determined fat-free mass (FFM) and fat mass (FM), lipids and related laboratory measurements, resting energy expenditure (REE), and respiratory quotient (RQ), were studied in 949 women with severe obesity.

RESULTS

Even though the mean BMI was 45.7 kg/m² and all participants met MetS criteria for increased waist circumference, 30% of subjects did not have MetS. Unadjusted FM (P = 0.0011), FFM (P < 0.0001), and REE (P < 0.0001) were greater in the women with MetS. Surprisingly, in multivariate logistic regression FFM was positively associated with MetS (P = 0.0002), while FM was not (P = 0.89). Moreover, FFM, not FM, was significantly associated with all five components of MetS except for triglyceride levels. REE and RQ were higher in those with MetS, and REE was strongly associated with multiple components of MetS.

CONCLUSIONS

In women with severe obesity, higher FFM and REE were paradoxically associated with increased rather than decreased risk of MetS, while FFM-adjusted FM was unrelated to MetS.

The Role of the Growth Hormone/Insulin-Like Growth Factor System in Visceral Adiposity

There is substantial evidence that the growth hormone (GH)/insulin-like growth factor (IGF) system is involved in the pathophysiology of obesity. Both GH and IGF-I have direct effects on adipocyte proliferation and differentiation, and this system is involved in the cross-talk between adipose tissue, liver, and pituitary. Transgenic animal models have been of importance in identifying mechanisms underlying these interactions. It emerges that this system has key roles in visceral adiposity, and there is a rationale for targeting this system in the treatment of visceral obesity associated with GH deficiency, metabolic syndrome, and lipodystrophies. This evidence is reviewed, gaps in knowledge are highlighted, and recommendations are made for future research.