Association between body fat distribution and age at menarche: a two sample Mendelian randomization study

Background

Numerous studies have examined the association between obesity and age at menarche (AAM), with most focusing on traditional obesity indicators such as body mass index. However, there are limited studies that explored the connection between body fat distribution and AAM, as well as a scarcity of Mendelian randomization (MR) studies.

Methods

In this study, we conducted a two-sample MR study to evaluate the causal effects of eight body fat distribution indicators on AAM. Inverse variance weighted (IVW) method was used for primary analysis, while supplementary approaches such as MR-Egger and weighted median were also utilized. Considering that the eight exposures were highly correlated, we performed an MR Bayesian model averaging (MR-BMA) analysis to prioritize the effect of major exposure on AAM. A series of sensitivity analyses were also performed.

Results

From a range of 82-105 single nucleotide polymorphisms (SNPs) were utilized as genetic instrumental variables for each of the exposure factors. After Bonferroni correction, we found that whole body fat mass (β: -0.17; 95% CI: -0.24, -0.11), left leg fat percentage (β: -0.14; 95% CI: -0.21, -0.07), left leg fat mass (β: -0.20; 95% CI: -0.27, -0.12), left arm fat percentage (β: -0.18; 95% CI: -0.26, -0.11) and left arm fat mass (β: -0.18; 95%CI: -0.26, -0.10) were associated with decreased AAM using random effects IVW method. And the beta coefficients for all MR evaluation methods exhibited consistent trends. MR-BMA method validated that left arm fat percentage plays a dominant role in AAM.

Conclusions

Our MR study suggested that body fat has broad impacts on AAM. Obtaining more information on body measurements would greatly enhance our comprehension of pubertal development.

Association of three single nucleotide polymorphisms in the LPIN1 gene with milk production traits in cows of the Yaroslavl breed

Lipin-1 is a member of the evolutionarily conserved family of proteins and is expressed predominantly in adipose tissue and skeletal muscle. On the one hand, lipin-1 is an enzyme that catalyzes the dephosphorylation of phosphatidic acid to diacylglycerol (DAG) and thus participates in the metabolic pathways of biosynthesis of storage lipids in the cell, membrane phospholipids, and intracellular signaling molecules. On the other hand, lipin-1 is able to be transported from the cytoplasm to the nucleus and is a coactivator of lipid metabolism gene transcription. It was shown, using the analysis of single nucleotide polymorphism (SNP) associations, that the lipin-1 coding gene (LPIN1) is a promising candidate gene for milk production traits in Holstein and Brown Swiss cows. However, it is unclear how much of its effect depends on the breed. The Yaroslavl dairy cattle breed was created in the 18-19 centuries in Russia by breeding northern Great Russian cattle, which were short and poor productive, but well adapted to local climatic conditions and bad food base. It was shown by whole genome genotyping and sequencing that the Yaroslavl breed has unique genetics compared to Russian and other cattle breeds. The aim of the study was to assess the frequency of alleles and genotypes of three SNPs in the LPIN1 gene and to study the association of these SNPs with milk production traits in Yaroslavl cows. Blood samples from 142 cows of the Yaroslavl breed were obtained from two farms in the Yaroslavl region. Genotyping of SNPs was carried out by polymerase chain reaction-restriction fragment length polymorphism method. Associations of SNPs with 305-day milk yield, fat yield, fat percentages, protein yield, and protein percentages were studied from the first to the fourth lactation. Statistical tests were carried out using a mixed linear model, taking into account the relationship between individuals. We identified three SNPs - rs110871255, rs207681322 and rs109039955 with a frequency of a rare allele of 0.042-0.261 in Yaroslavl cows. SNP rs110871255 was associated with fat yield during the third and fourth lactations. SNP rs207681322 was associated with milk yield for the second, third and fourth lactations, as well as protein yield for the third lactation. Thus, we identified significant associations of SNPs rs207681322 and rs110871255 in the LPIN1 gene with a number of milk production traits during several lactations in Yaroslavl cows.

Holstein Cows

A genome-wide association study (GWAS) of fat percentage (FPC) using 1,231,898 first lactation cows and 75,198 SNPs confirmed a previous result that a Chr14 region about 9.38 Mb in size (0.14-9.52 Mb) had significant inter-chromosome additive × additive (A×A) effects with all chromosomes and revealed many new such effects. This study divides this 9.38 Mb region into two sub-regions, Chr14a at 0.14-0.88 Mb (0.74 Mb in size) with 78% and Chr14b at 2.21-9.52 Mb (7.31 Mb in size) with 22% of the 2761 significant A×A effects. These two sub-regions were separated by a 1.3 Mb gap at 0.9-2.2 Mb without significant inter-chromosome A×A effects. The PPP1R16A-FOXH1-CYHR1-TONSL (PFCT) region of Chr14a (29 Kb in size) with four SNPs had the largest number of inter-chromosome A×A effects (1141 pairs) with all chromosomes, including the most significant inter-chromosome A×A effects. The SLC4A4-GC-NPFFR2 (SGN) region of Chr06, known to have highly significant additive effects for some production, fertility and health traits, specifically interacted with the PFCT region and a Chr14a region with CPSF1, ADCK5, SLC52A2, DGAT1, SMPD5 and PARP10 (CASDSP) known to have highly significant additive effects for milk production traits. The most significant effects were between an SNP in SGN and four SNPs in PFCT. The CASDSP region mostly interacted with the SGN region. In the Chr14b region, the 2.28-2.42 Mb region (138.46 Kb in size) lacking coding genes had the largest cluster of A×A effects, interacting with seventeen chromosomes. The results from this study provide high-confidence evidence towards the understanding of the genetic mechanism of FPC in Holstein cows.

The Association and Joint Effect of Adipocyte Fatty Acid Binding Protein and Obesity Phenotype With Cardiovascular Events

CONTEXT

There is little evidence regarding the joint effect of serum adipocyte fatty acid binding protein (A-FABP) levels and obesity phenotype on the risk of cardiovascular events.

OBJECTIVE

To explore the association between serum A-FABP levels and obesity phenotype defined by fat percentage (fat%) and visceral fat area (VFA), and their joint impact on incident cardiovascular events.

METHODS

A total of 1345 residents (579 men and 766 women) without previous cardiovascular diseases at baseline, with body composition and serum A-FABP data available, were included. A bioelectrical impedance analyzer and magnetic resonance imaging were used to assess fat% and VFA, respectively.

RESULTS

During a mean follow-up of 7.6 years, 136 cases of cardiovascular events (13.9 per 1000 person-years) occurred. Per 1-unit increase in loge-transformed A-FABP levels was associated with an increase in cardiovascular events risk (hazard ratio [HR] 1.87, 95% CI 1.33-2.63). The highest tertiles of fat% and VFA levels were related to higher risks of cardiovascular events (fat%: HR 2.38, 95% CI 1.49-3.81; VFA: HR 1.79, 95% CI 1.09-2.93). The association between A-FABP levels and cardiovascular events was more pronounced in participants with low fat%, regardless of VFA levels. The joint effect of high A-FABP levels and obesity resulted in a greater risk of cardiovascular events.

CONCLUSION

Serum A-FABP levels were significantly associated with the risk of cardiovascular events, and this pattern of association was more prominent among the population with low fat%, which was independent of VFA.

Low Muscle and High Fat Percentages Are Associated with Low Natural Killer Cell Activity: A Cross-Sectional Study

This study aimed to investigate whether body fat and muscle percentages are associated with natural killer cell activity (NKA). This was a cross-sectional study, conducted on 8058 subjects in a medical center in Korea. The association between the muscle and fat percentage tertiles and a low NKA, defined as an interferon-gamma level lower than 500 pg/mL, was assessed. In both men and women, the muscle mass and muscle percentage were significantly low in participants with a low NKA, whereas the fat percentage, white blood cell count, and C-reactive protein (CRP) level were significantly high in those with a low NKA. Compared with the lowest muscle percentage tertile as a reference, the fully adjusted odd ratios (ORs) (95% confidence intervals (CIs)) for a low NKA were significantly lower in T2 (OR: 0.69; 95% CI: 0.55-0.86) and T3 (OR: 0.74; 95% CI: 0.57-0.95) of men, and T3 (OR: 0.76; 95% CI: 0.59-0.99) of women. Compared with the lowest fat percentage tertile as a reference, the fully adjusted OR was significantly higher in T3 of men (OR: 1.31; 95% CI: 1.01-1.69). A high muscle percentage was significantly inversely associated with a low NKA in men and women, whereas a high fat percentage was significantly associated with a low NKA in men.

Adherence to the Mediterranean Diet Is Associated with Health-Related Quality of Life and Anthropometric Measurements in University Professors

The main objective of this study was to assess the relationship between Mediterranean diet (MD) adherence and health-related quality of life (HRQOL) according to the anthropometric measurements of teaching and research staff (TRS) at the University of Granada (UGR), Spain. This diagnostic, non-experimental, cross-sectional, and observational study was performed on university lecturers (65 women and 62 men) using a correlational descriptive methodology. The lecturers' anthropometric measurements were taken, while MD adherence was determined using the PREvention with MEDiterranean diet (PREDIMED) questionnaire. The Short Form Health Survey (SF-36) was used for measuring HRQOL. Better results for body composition were associated with improvements in the physical and mental dimensions and MD adherence. Statistically significant differences were found between sexes, with men showing higher values for weight, height, waist circumference, BMI, waist/hip ratio (WHR), muscle mass, and systolic and diastolic pressure than women. Similarly, MD adherence was positively correlated with vitality (r = 0.233; p = 0.009), social functioning (r = 0.229; p = 0.008), and the mental component summary (r = 0.205; p = 0.021). The regression model determined that the mental component summary (β = 0.239, p = 0.041), diastolic pressure (PD) (β = -0.473, p < 0.000), fat percentage (FP) (β = -0.241, p = 0.004), and age (β = -0.231, p = 0.022) significantly predicted MD adherence. The results obtained in this study suggest that healthy dietary patterns such as the MD and an optimum body composition contribute to an improved HRQOL.

Body Composition in Fussy-Eating Children, with and without Neurodevelopmental Disorders, and Their Parents, Following a Taste Education Intervention

Fussy eaters may have an increased risk of becoming overweight or obese as adolescents, with fussy eating and weight status also correlating with neurodevelopmental disorders (NDs) such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Further, maternal and children's weight status relationships are well-established. In this study, we analyzed the body composition of parent-child dyads using bioelectrical impedance analysis (BIA). Fifty-one children aged 8-12 years, with an ND (n = 18) and without (n = 33), and their parents, participated in a 7-week food-based Taste Education intervention with 6-month follow-up. The paired t-test was used to compare differences in body composition based on children's ND status. In logistic regression analysis, odds of children being in the overweight/obese or overfat/obese categories increased by a factor of 9.1 and 10.6, respectively, when having NDs, adjusting for parents' BMI (body mass index) or fat percentage (FAT%). Children with NDs and their parents had significantly higher mean BMI-SDS (BMI standard deviation score) and FAT% at pre-intervention than children without NDs and their parents. Mean BMI-SDS and FAT% lowered significantly between time points for children with NDs and their parents but not for children without NDs or their parents. The findings underline the need for additional exploration into the relationships between children's and parents' body composition based on children's ND status.

Stressor-Induced Temporal Cortisol Deficiency as a Primary Trigger for Adaptation to Stress

BACKGROUND

Inconsistencies in measurements of cortisol response to stress have caused disagreements in the direction of the change in cortisol concentrations immediately after the onset of stress. Researchers typically observe increased cortisol levels in response to a stressor, perceiving occasional decreases as a sign of possible disorders. Reports indicate the relative ease of standardizing a physical stressor compared with a mental stressor, and cross-stressor adaptation is observable only in elite athletes.

METHODS

We investigated the cortisol response to top-intensity physical exertion by analyzing the course of the cortisol response, the changes in this response resulting from adaptation to intense exercise, and the possible convergence between the cortisol changes and body fat content. We examined 16 male athletes, members of the Polish National Rowing Team, competing in the World Rowing Championships, in top form, of an average training experience of seven years. The measurements were performed before and after the training camp preparatory to the Championships. We performed the measurements before and after the training camp preparatory to the Championships.

RESULTS

Before the camp, the athletes consistently reacted to the exertion test with a decrease in cortisol concentration and elevated cortisol levels after rest compared with baseline. After the camp, the post-exertion cortisol decrease as well as the post-rest cortisol elevation was much smaller and less consistent.

CONCLUSIONS

The transient decrease in cortisol concentration at the onset of stress thus represents a physiological reaction, and the stress response counteracts the resulting cortisol deficiency to support cortisol availability during stress. Adaptation to stress enhanced this counteracting effect by (1) increasing the baseline cortisol concentration and (2) speeding up the response to its decline. This enhanced effect was boosted by adipose tissue.

Effects of exercise training on obesity-related parameters in people with intellectual disabilities: systematic review and meta-analysis

BACKGROUND

Efforts to synthesise existing knowledge concerning the effects of exercise interventions on obesity (i.e. changes in body weight and composition) have been made, but scientific evidence in this matter is still limited. This systematic review and meta-analysis aims to identify and critically analyse the best available evidence regarding the use of physical exercise as a strategy to attenuate obesity through its effects on adiposity-related anthropometric parameters in people with intellectual disability (ID).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a literature search was performed using PubMed, Scopus, SPORTDiscus, CINAHL and the Cochrane Library through specific keywords up to July 2020. The search adhered to the population, intervention, comparison and outcome strategy. Randomised controlled trials addressing the effects of the exercise intervention on adiposity-related anthropometric parameters (body mass index, waist circumference, waist-hip ratio, fat percentage or body weight) in children, adolescents and adults with ID were included. The methodological quality of the studies found was evaluated through the PEDro scale.

RESULTS

A total of nine investigations with children and/or adolescents (10-19 years) and 10 investigations with adults (18-70 years) were selected, mostly experiencing mild and moderate ID. Methodological quality was fair in 13 of these publications, good in five and excellent in one. Seventeen trials reported comparable baseline and post-intervention data for the intervention and control groups and were included in the meta-analysis. In nine studies, the intervention group performed a cardiovascular training programme. Five papers described a combined training programme. Two trials executed whole-body vibration training programmes, and one publication proposed balance training as the primary intervention. According to the meta-analysis results, the reviewed studies proposed exercise modalities that, in comparison with the activities performed by the participants' in the respective control groups, did not have a greater impact on the variables assessed.

CONCLUSIONS

While physical exercise can contribute to adiposity-related anthropometric parameters in people with mild and moderate ID, these findings show that exercise alone is not sufficient to manage obesity in this population. Multicomponent interventions appear to be the best choice when they incorporate dietary deficit, physical activity increase and behaviour change strategies. Finding the most effective modality of physical exercise can only aid weight loss interventions. Future research would benefit from comparing the effects of different exercise modalities within the framework of a multicomponent weight management intervention.

Muscle-to-Fat Ratio for Predicting Metabolic Syndrome Components in Children with Overweight and Obesity

Background: Pediatric obesity has been linked to the components of metabolic syndrome (MetS: abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, and insulin resistance). Data on the role of muscle mass in the development of MetS are sparse. We explored the interaction between the muscle-to-fat ratio (MFR) and MetS components in children with overweight or obesity. Methods: An observational study of 210 pediatric subjects (88 boys, mean age [±standard deviation (SD)] 11.9 ± 3.1 years, BMI z-score range 1.036-3.140) from January 2018 to January 2021. Body composition was measured by bioelectrical impedance analysis (Tanita MC-780 MA and GMON Professional Software), and MFR z-scores were calculated. Results: The 148 subjects (70%) who had MetS components were older (p = 0.008), had lower socioeconomic positions, higher triglyceride/high-density lipoprotein-cholesterol ratios, fat percentages (FATP), truncal FATPs (TRFATPs), and lower MFR z-scores (p < 0.001 for all parameters) than those without MetS components. The correlation between the MFR z-score and the BMI z-score was stronger in subjects with obesity than in subjects with overweight (r = -0.556 vs. r = -0.440, p < 0.001 for both). The risk for MetS components increased by 1.4 for every 3% increase in FATP or TRFATP [odds ratio (OR) = 1.4, confidence interval ([CI] 1.20, 1.64), p < 0.001]. The risk for MetS components was tripled for every 1 SD decrease in MFR z-scores [OR = 3.3, CI (1.74, 6.27), p < 0.001]. Conclusions: Given the strong predictive value of the MFR z-score in the development of early-onset MetS components, preventive strategies should apply interventions for improving the body composition parameters of both adiposity and muscle.

Body composition in children and adolescents with non-classic congenital adrenal hyperplasia and the risk for components of metabolic syndrome: An observational study

BACKGROUND

Treated or untreated non-classic congenital adrenal hyperplasia (NCCAH) diagnosed in childhood could pose an increased risk of obesity and metabolic derangements in adolescence and early adulthood. We aimed to explore the interaction between muscle-to-fat ratio (MFR) and components of metabolic syndrome in pediatric subjects with NCCAH.

METHODS

This retrospective observational study was conducted in the Tel Aviv Medical Center from January 2018 to January 2022. The study group comprised 75 subjects (26 males) with NCCAH (61 hydrocortisone-treated [21 males] and 14 untreated [5 males]) and 134 healthy sex- and age-matched subjects (41 males) with normal puberty served as controls. Body composition was measured by bioelectrical impedance analysis (BIA) and muscle-to-fat ratio (MFR) z-scores were calculated. Stepwise linear regression models were applied to evaluate explanatory variables for MFR z-scores, blood pressure percentiles, lipid profiles, and glucose metabolism.

RESULTS

The median age [interquartile range] was 7.5 years [5.3, 8.8] at NCCAH diagnosis and 12.3 years [8.9, 15.4] at BIA. The median cumulative hydrocortisone dose was 7620 mg/m² [2547, 12903]. Subjects with NCCAH had higher mean BMI z-scores and lower median MFR z-scores compared to controls [(0.47 ± 0.97 vs. -0.19 ± 1.04, p<0.001) and (-0.74 [-1.06, -0.14] vs.-0.37 [-0.99, 0.15], p=0.045), respectively]. The linear regression models dependent variables and their explanatory variables were: MFR z-score (R²= 0.253, p<0.001) - socioeconomic position index (β=0.348, p=0.003), birthweight z-score (β=-0.258, p=0.013), and duration of hydrocortisone treatment in years (β=0.048, p=0.023); systolic blood pressure percentile (R² = 0.166, p<0.001) - MFR z-score (β=-9.75, p<0.001); TG/HDL ratio (R² = 0.116, p=0.024) - MFR z-score (β=-0.300, p=0.024). No significant variables were found for glucose.

CONCLUSIONS

Children and adolescents with NCCAH have a body composition characterized by an imbalance between muscle and fat tissues, which may place them at increased risk for early-onset cardiometabolic derangements. It is reassuring that glucocorticoid therapy aimed to alleviate androgen overproduction does not appear to adversely affect their body composition.

Anthropometric and Body Composition Measurements Related to Osteoporosis in Geriatric Population

Objective:

This study aimed to evaluate different anthropometric and body composition measurements, including weight, body mass index (BMI), body fat percentage (fat%), skeletal muscle index (SMI), a body shape index (ABSI), waist circumference (WC), and hip circumference (HC), in relation to bone mineral density.

Methods:

This is a cross-sectional study of a total of 482 patients who consulted the geriatric outpatient clinic between 2018 and 2019. Patients were evaluated with dual-energy X-ray absorptiometry. Anthropometric measurements (HC, WC, weight, BMI, and ABSI), as well as body composition analysis (fat% and SMI) by bioimpedance analysis system, were performed. The patients were evaluated with the rapid Assessment of Physical Activity Index in terms of aerobic exercise habits.

Results:

There was a significant correlation between lumbar spine (LS) T-score and SMI (r=0.36, p=0.000) and between LS T-score and weight (r=0.21, p=0.000), BMI (r=0.10, p=0.045) and WC (r=0.15, p=0.001). There was a statistically significant correlation between femur neck (FN) T-score and fat% (r=0.15, p=0.001), SMI (r=0.15, p=0.010), weight (r=0.22, p=0.000), BMI (r=0.20, p=0.000), WC (r=0.14, p=0.003), and HC (r=0.17, p=0.001). There was no statistically significant correlation between physical activity and LS T-score (n=353, r=0.08, p=0.16) and FN T-score (n=360, r=0.03, p=0.53). In multiple regression analysis, SMI contributes most in predicting FN and LS T-scores.

Conclusions:

Anthropometric measurements should be carefully selected in the geriatric population. Among the measurements, the strongest relationship was found between LS T-score and SMI.

Children with Poor Motor Skills Have Lower Health-Related Fitness Compared to Typically Developing Children

Most of the current empirical evidence regarding the relationship between health-related fitness and level of motor performance is based on children from high-income countries. Yet, children from low-resource areas may have fewer opportunities to develop their fitness skills. The aim of the study was to determine if South African children from both low- and middle-income areas scoring below the 16th percentile on the Movement Assessment Battery for Children-2 (probable-Developmental Coordination Disorder (p-DCD)) have lower health-related fitness levels than typically developing (TD) children. We hypothesized that children with p-DCD would have lower overall health-related fitness than TD children. A sample of 146 participants aged 10 to 11 (10.05 years (SD = 0.41)) was collected from schools in the North West Province of South Africa, on the basis of their poverty classification. Children were tested for anaerobic capacity and strength using the Bruininks-Oseretsky test of motor proficiency second edition (BOT-2) and aerobic capacity using the Progressive Aerobic Cardiovascular Endurance Run (PACER). Body composition was evaluated using body mass index corrected for age and sex (BMI-z), body fat (BF), and waist circumference. The data was analyzed using Spearman correlations and chi-squared tests. Statistically significant differences (p < 0.05) were found between groups for running and agility, strength, and aerobic capacity. No significant differences were found between p-DCD and TD groups in terms of body mass (36.1 kg vs. 33.3 kg), waist circumference (62.2 cm vs. 59.8 cm), BMI-z (19.7 vs. 17.6), and fat percentage (20.2 vs. 18.1%). Overweight and obesity prevalence was 15% in those with low socio-economic status (SES) and 27% in high SES. In conclusion, children with p-DCD had lower muscular strength, aerobic capacity, and endurance than TD children. Although it has been reported that children with p-DCD have a higher risk for overweight/obesity than TD children, this is not (yet) the case in 10-11-year-old children living in rural areas in South Africa (North West Province).

IL-6 Polymorphisms Are Not Related to Obesity Parameters in Physically Active Young Men

Interleukin 6 (IL-6) is a cytokine with both pro- and anti-inflammatory actions, but is also considered as a "metabolic hormone" involved in immune responses, affecting glucose, protein and lipid metabolism. It has been proposed to be related to obesity, but various results have been presented. Thus, in this study, the very homogenous population of young, male military professionals, living in the same conditions involving high physical activity, has been selected to avoid the influence of environmental factors. The subjects were divided into groups depending on the obesity parameters BMI (body mass index) and fat percentage (fat%), and the following IL-6 SNPs (Single Nucleotide Polymorphisms) were analyzed: rs1800795, rs1800796 and rs13306435. No relation was found between obesity parameters and IL-6 polymorphisms rs1800795, rs1800796 and rs13306435. It may be postulated that even if a genetic predisposition involves IL-6 genes, this effect in individuals with obesity of a low grade is minor, or can be avoided or at least markedly reduced by changes in lifestyle.

Improved metabolic fitness, but no cardiovascular health effects, of a low-frequency short-term combined exercise programme in 50-70-year-olds with low fitness: A randomized controlled trial

We evaluated the cardiometabolic effects of a 15-week combined exercise programme, implemented in sports clubs, for 50-70-year-olds with low aerobic fitness. In a randomized controlled trial, 45 participants (26 women) with low fitness were randomly assigned (2:1-ratio) to a training group (TG, n = 30) or inactive control group (CG, n = 15). TG had 15 weeks with one weekly 90-min supervised group-based session in a recreational sports club with combined aerobic exercise and strength training and were encouraged to perform home-based training 30 min/wk. Evaluations of relative VO_2max (mLO₂/min/kg), blood pressure, resting heart rate (HR), echocardiography, peripheral arterial tonometry, body composition, lipid profile and HbA1c were performed at 0 and 15 wks. Average HR during supervised training was 113 ± 13 bpm (68.6 ± 7.0%HR_max), with 4.3 ± 6.6% spent >90%HR_max. At 15-wk follow-up, intention-to-treat analyses revealed no between-group difference for VO_2max/kg (0.4 mLO₂/min/kg, 95%CI -0.8-1.5, P = 0.519; -3 mL/min, 95%CI -123-118, P = 0.966) or other cardiovascular outcomes (all P > 0.05). Compared to CG, total fat mass (-1.9 kg; 95%CI -3.2 to -0.5, P = 0.005), total fat percentage (-1.3%, 95%CI -2.2 to -0.3, P = 0.01) and total/HDL cholesterol ratio (P = 0.032) decreased in TG. Regular adherence to supervised training was high (81%), but 0% for home-based exercise. In conclusion, the group-based supervised training was associated with high adherence and moderate exercise intensity, whereas insufficiently supported home-based training was not feasible. Together, 15 wks of combined exercise training did not improve aerobic fitness or affected cardiovascular function in 50-70-yr-olds with low aerobic fitness, whereas some positive effects were observed in metabolic parameters.HighlightsCombined exercise training implemented in a sports club elicited moderate aerobic intensity in 50-70-year-old untrained individuals.Supervised group-based training had high adherence whereas unsupported home-based training had very low adherence.15 weeks of low-frequency combined moderate intensity exercise training improved lipid profile and fat mass, but had no effect on cardiovascular fitness.

The Physical Characteristics of Elite Female Rugby Union Players

This study explored the anthropometric and body composition characteristics of elite female rugby union players, comparing between and within different playing positions. Thirty elite female rugby union players (25.6 ± 4.3 y, 171.3 ± 7.7 cm, 83.5 ± 13.9 kg) from New Zealand participated in this study. Physical characteristics were assessed using anthropometric (height, body mass, skinfolds) and body composition (dual-energy X-ray absorptiometry) measures. Forwards were significantly taller (p < 0.01; d = 1.34), heavier (p < 0.01; d = 2.19), and possessed greater skinfolds (p < 0.01; d = 1.02) than backs. Forwards also possessed significantly greater total (p < 0.01; d = 1.83–2.25) and regional (p < 0.01; d = 1.50–2.50) body composition measures compared to backs. Healthy bone mineral density values were observed in both forwards and backs, with significantly greater values observed at the arm (p < 0.01; d = 0.92) and femoral neck (p = 0.04; d = 0.77) sites for forwards. Tight-five players were significantly heavier (p = 0.02; d = 1.41) and possessed significantly greater skinfolds (p < 0.01; d = 0.97) than loose-forwards. Tight-five also possessed significantly greater total body composition measures (p < 0.05; d = 0.97–1.77) and significantly greater trunk lean mass (p = 0.04; d = 1.14), trunk fat mass (p < 0.01; d = 1.84), and arm fat mass (p = 0.02; d = 1.35) compared to loose-forwards. Specific programming and monitoring for forwards and backs, particularly within forward positional groups, appear important due to such physical characteristic differences.

Characteristics of Serum Thyroid Hormones in Different Metabolic Phenotypes of Obesity

Aim: Metabolically healthy obese (MHO) individuals have attracted broad attention. We aimed to investigate the characteristics of serum thyroid hormones in different metabolic phenotypes of obesity. Methods: The study included 1,023 community-based euthyroid subjects (age range: 27-81 years), of whom 586 were women. Fat% was detected by a bioelectrical impedance analyzer. Two definitions of obesity were applied as follows: (1) fat% ≥ 25% for men and ≥ 30% for women; (2) body mass index (BMI) ≥ 25 kg/m². According to the diagnostic criteria for metabolic syndrome by the Chinese Diabetes Society, metabolically unhealthy was defined as two or more components of metabolic syndrome, excluding waist circumference. Serum-free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) levels were measured by electrochemiluminescence immunoassay. Results: The proportions of obesity defined by fat% and BMI were 41.3 and 27.1%, respectively. The proportion of metabolically unhealthy was 41.6%. After adjusting for age and gender, regardless of the definitions based on fat% or BMI, FT3 was positively related to both the MHO and the metabolically unhealthy obese (MUO) phenotypes [MHO: odds ratio (OR)s = 1.676 based on fat% and 2.055 based on BMI; MUO: ORs = 1.818 based on fat% and 1.526 based on BMI; all P < 0.05]; FT4 was negatively related to the MUO phenotype (ORs = 0.870 based on fat% and 0.849 based on BMI, all P < 0.05); FT3/FT4 was also positively related to both the MHO and the MUO phenotypes (MHO: ORs = 1.678 based on fat% and 2.825 based on BMI; MUO: ORs = 2.866 based on fat% and 2.883 based on BMI; all P < 0.05); and TSH was positively related to the metabolically unhealthy non-obese phenotype (ORs = 1.329 based on fat% and 1.321 based on BMI, all P < 0.01). Conclusions: In euthyroid population, both the MHO and the MUO phenotypes were characterized by increased FT3 and FT3/FT4 levels.

Association Between Weight Status and Executive Function in Young Adults

Background and objectives: To explore the association between weight status and executive function in young adults. Materials and Methods: Ninety-seven young males (age 17–26 years) underwent adiposity and body composition measurements using body composition analyzer. Inhibitory control and working memory were measured using the Cambridge Neuropsychological Test Battery (CANTAB). Results: Multiple linear regression using both unadjusted and adjusted analyses revealed no association between adiposity and body composition variables with executive tasks, apart from a significant association between skeletal muscle mass (SMM) and mean reaction time on go trial (standardized B = -0.28; p = 0.02). Multivariate analysis of covariance (MANCOVA) revealed that underweight participants presented inferior working memory compared to their normal weight (p = 0.001) or overweight peers (p = 0.008). However, according to the percentage fat quartiles (Q) participants with the highest quartile (Q4) were inferior in inhibitory control than their peers with Q2 (p = 0.04), and participants with the lowest quartile (Q1) were inferior in working memory compared with their peers with Q2 (p = 0.01) or Q3 (p = 0.02). A worse inhibitory control was observed for participants with the highest fat/SMM (Q4) compared to participants in Q3 (p = 0.03), and in contrast worse working memory was observed for participants with the lowest fat/SMM (Q1) compared to participants in Q2 (p = 0.04) or Q3 (p = 0.009). Conclusions: Low adiposity is associated with worse working memory, whereas high adiposity is associated with worse inhibitory control. Therefore, our findings show that normal adiposity, but greater SMM may have a positive impact on executive function in young adults.

Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT)

OBJECTIVES

To compare the effects of interval training and moderate-intensity continuous training (MOD) on body adiposity in humans, and to perform subgroup analyses that consider the type and duration of interval training in different groups.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

English-language, Spanish-language and Portuguese-language searches of the electronic databases PubMed and Scopus were conducted from inception to 11 December 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that met the following criteria were included: (1) original articles, (2) human trials, (3) minimum exercise training duration of 4 weeks, and (4) directly or indirectly compared interval training with MOD as the primary or secondary aim.

RESULTS

Of the 786 studies found, 41 and 36 were included in the qualitative analysis and meta-analysis, respectively. Within-group analyses showed significant reductions in total body fat percentage (%) (interval training: -1.50 [95% CI -2.14 to -0.86, p<0.00001] and MOD: -1.44 [95% CI -2.00 to -0.89, p<0.00001]) and in total absolute fat mass (kg) (interval training: -1.58 [95% CI -2.74 to -0.43, p=0.007] and MOD: -1.13 [95% CI -2.18 to -0.08, p=0.04]), with no significant differences between interval training and MOD for total body fat percentage reduction (-0.23 [95% CI -1.43 to 0.97], p=0.705). However, there was a significant difference between the groups in total absolute fat mass (kg) reduction (-2.28 [95% CI -4.00 to -0.56], p=0.0094). Subgroup analyses comparing sprint interval training (SIT) with MOD protocols favour SIT for loss of total absolute fat mass (kg) (-3.22 [95% CI -5.71 to -0.73], p=0.01). Supervised training, walking/running/jogging, age (<30 years), study quality and intervention duration (<12 weeks) favourably influence the decreases in total absolute fat mass (kg) observed from interval training programmes; however, no significant effect was found on total body fat percentage (%). No effect of sex or body mass index was observed on total absolute fat mass (kg) or total body fat percentage (%).

CONCLUSION

Interval training and MOD both reduce body fat percentage (%). Interval training provided 28.5% greater reductions in total absolute fat mass (kg) than MOD.

TRIAL REGISTRATION NUMBER

CRD42018089427.

Football training improves metabolic and cardiovascular health status in 55- to 70-year-old women and men with prediabetes

We examined the effects of 16 weeks of football training and dietary advice on blood glucose control and health status in 55- to 70-year-old women and men with prediabetes. Fifty participants with prediabetes (age; 61 ± 6 years, BMI; 29.6 ± 4.7; VO_2max 22.3 ± 5.7 mL·min^-1 ·kg^-1 ) were randomized into a football and dietary advice group (F+D; n = 27) and a dietary advice group (D; n = 23). F+D performed football training (twice weekly 30- to 60-minutes sessions) and received dietary advice, while D only received dietary advice. An oral glucose tolerance test (OGTT) was completed pre and post the 16-week period. Body composition, blood pressure, and maximal oxygen uptake (VO_2max ) were additionally measured. Both groups demonstrated a decrement (P < .05) in fasting blood glucose (-0.4 ± 0.5 mmol·L^-1 ) and lowered blood glucose throughout OGTT. F+D displayed lower values than D (P < .05) after 60 minutes (9.0 ± 2.7 vs 10.6 ± 2.9 mmol·L^-1 ) and 120 minutes (5.7 ± 1.6 vs 7.5 ± 2.4 mmol·L^-1 ). VO_2max increased by 14% in F+D, with a higher (P < .05) change score than in D (2%). Mean arterial pressure declined more (P < .05) in F+D than in D (-8 ± 9 vs -4 ± 11 mm Hg). Fat loss was greater (P < .05) in F+D than in D (-3.4 ± 2.8 vs -1.2 ± 2.0 kg), and the increase in lean body mass was also greater (P < .05) in F+D than in D (0.7 ± 1.5 vs -0.3 ± 1.6 kg). In conclusion, football training combined with dietary advice has broad-spectrum effects on metabolic and cardiovascular health profile with greater overall effects than professional dietary advice per se for 55- to 70-year-old women and men with prediabetes.

Broad-spectrum health improvements with one year of soccer training in inactive mildly hypertensive middle-aged women

The study tested the hypothesis that long-term soccer training has positive impact on cardiovascular profile, body composition, bone health, and physical capacity in inactive, pre-menopausal women with mild hypertension. The study applied a randomized controlled design in which physically inactive middle-aged women were separated into a soccer training group (n=19; SOC) and a control group (n=12; CON). SOC performed 128±29 (±SD) one-h small-sided soccer training sessions over one year. Blood pressure, body composition, blood lipid profile, and fitness level were determined pre- and post-intervention. Over one year, mean arterial pressure decreased more in SOC than in CON (-5±7 vs +4±5 mmHg; P<.05). Total-body fat mass decreased more (P<.05) in SOC than in CON (-2.5±2.5 vs +0.6±3.2 kg; P<.05), while the change scores for lean body mass were not significantly different in SOC (2.6±2.7 kg) compared to CON (1.1±1.9 kg, P=.09). Over one year, change scores in whole-body bone mineral density (0.004±0.032 vs -0.019±0.026 g·cm² ) as well as bone mineral content (30±70 vs -39±113 g) were positive in SOC compared to CON (P<.05). Post-intervention plasma triglycerides decreased more (-0.1±0.7 vs +0.2±0.2 mmol·L^-1 ) and HDL cholesterol increased more (0.2±0.7 vs -0.2±0.2 mmol·L^-1 ) in SOC than in CON (P<.05). Yo-Yo intermittent endurance level 1 (122±105 vs 2±21%) and 20-m sprint performance (6±6 vs -1±2%) increased more (P<.05) in SOC than in CON. In conclusion, long-term soccer training resulted in broad-spectrum improvements in the health profile of untrained, pre-menopausal women with mild hypertension, including cardiovascular, metabolic, and musculo-skeletal benefits.

Age plays an important role in the relationship between smoking status and obesity risk: a large scale cross-sectional study of Chinese adults

OBJECTIVE

To study the role of age plays in the relationship between smoking status and obesity in both Chinese men and women.

METHODS

From Chinese Physical and Psychological Database, participants were divided into non-smokers, current smokers, and former smokers. Body mass index (BMI), waist circumference (WC), fat percentage, fat mass, and fat free mass were measured. The mean, standard deviation and frequency of these indicators were calculated for each age bracket. One-way ANOVA and post-hoc test analyses were used to detect the difference among these three groups.

RESULTS

In men, from 19 to 24 years old, BMI, WC and fat free mass of current smokers were higher than that of non-smokers (P<0.01). However, fat mass and fat percentage of current smokers were lower than that of non-smokers but higher than that of former smokers (P<0.01). From 25 to 34 years old, BMI and fat mass of former smokers were higher than non-smokers and current smokers (P<0.01). In addition, WC and fat free mass of non-smokers were lower than that of current smokers and former smokers (P<0.01). From 45 to older, BMI, WC, fat mass, fat free mass and fat percentage of former smokers were higher than that of current smokers (P<0.01). From 55 to older, BMI, WC, fat mass, fat free mass and fat percentage of current smokers were lower than that of non-smokers (P<0.01). In women, smoking status might not be significantly related to obesity (P>0.05).

CONCLUSION

For young men, smoking might have an effect on increasing fat free mass, BMI and WC, and decreasing fat mass and fat percentage. For middle and older men, smoking might have an effect on decreasing fat free mass, fat mass, BMI, WC, and fat percentage. Obesity risk should be paid more attention in smoking cessation programs for those former smokers.

Genetic variants in leptin: Determinants of obesity and leptin levels in South Indian population

The revelation of leptin action mechanisms has led to various attempts to establish the association of polymorphisms in the leptin gene with obesity-related phenotypes. But, outcomes have been contradicting, which made the information on the role of the leptin gene in regulating the mechanism of pathophysiology of obesity inexplicable. Moreover, none of the studies are known to have similar implications on the Indian population. To address such contradictions, our study aims to evaluate the association of leptin gene polymorphism with obesity and leptin levels in a South Indian Population. A total of 304 cases (BMI≥27.5) and 309 controls (BMI≤23) from local inhabitants of Mysore, Karnataka were recruited for the study. The leptin gene variants rs7799039, rs2167270 and rs4731426 independently, as well as in 4 haplotype combinations, were found to be significantly associated with the risk of obesity. An increasing trend in BMI and leptin levels was observed with every addition of A and C minor alleles of exonic variant (rs2167270) and intronic variant (rs4731426) respectively. However, only AA genotype of SNP rs7799039 was positively associated with BMI. None of the SNPs were associated with fat percentage and waist to hip ratio. On a whole, this data suggests that the common polymorphisms in the leptin gene are strong predictors of obesity and leptin levels in South Indians.