Body Mass Index, Physical Activity, and Body Image in Adolescents

Body image dissatisfaction is a concern for adolescents’ mental and physical well-being, and the role of body mass index (BMI) and physical activity (PA) in it is still unclear. This study investigates the associations of BMI and PA with body image, separately for boys and girls, in a large sample of Finnish adolescents. We also examine the associations of BMI with body image in varying PA levels. A total of 10,496 adolescents (girls 52.6%) were included in the analyses. Body image was assessed using a pictorial tool, and categorized as wishing for a smaller body, being satisfied, and wishing for a bigger body. BMI (kg/m2) was categorized as thin, normal weight, and overweight/obese. Self-reported PA was divided into three similar-sized categories as low, moderate, and high PA levels. Adjusted ordinal regression analyses were conducted. Our results show that adolescents with thinness had higher odds of wishing for a bigger body compared to their normal-weight peers, while adolescents with overweight/obesity had smaller odds of wishing for a bigger body. Adolescents in low and middle PA levels had lower odds of wishing for a bigger body compared to adolescents in the high PA level. Yet, the PA level modified the associations between BMI and body image, especially in adolescents with thinness and more so in girls than in boys. These findings highlight the need to pay attention to healthy weight gain and PA in adolescents to support their body image satisfaction

Body Mass Index, Physical Activity, and Body Image in Adolescents

Body image dissatisfaction is a concern for adolescents’ mental and physical well-being, and the role of body mass index (BMI) and physical activity (PA) in it is still unclear. This study investigates the associations of BMI and PA with body image, separately for boys and girls, in a large sample of Finnish adolescents. We also examine the associations of BMI with body image in varying PA levels. A total of 10,496 adolescents (girls 52.6%) were included in the analyses. Body image was assessed using a pictorial tool, and categorized as wishing for a smaller body, being satisfied, and wishing for a bigger body. BMI (kg/m2) was categorized as thin, normal weight, and overweight/obese. Self-reported PA was divided into three similar-sized categories as low, moderate, and high PA levels. Adjusted ordinal regression analyses were conducted. Our results show that adolescents with thinness had higher odds of wishing for a bigger body compared to their normal-weight peers, while adolescents with overweight/obesity had smaller odds of wishing for a bigger body. Adolescents in low and middle PA levels had lower odds of wishing for a bigger body compared to adolescents in the high PA level. Yet, the PA level modified the associations between BMI and body image, especially in adolescents with thinness and more so in girls than in boys. These findings highlight the need to pay attention to healthy weight gain and PA in adolescents to support their body image satisfaction

Uncovering the complex genetic architecture of human plasma lipidome using machine learning methods

Genetic architecture of plasma lipidome provides insights into regulation of lipid metabolism and related diseases. We applied an unsupervised machine learning method, PGMRA, to discover phenotype-genotype many-to-many relations between genotype and plasma lipidome (phenotype) in order to identify the genetic architecture of plasma lipidome profiled from 1,426 Finnish individuals aged 30-45 years. PGMRA involves biclustering genotype and lipidome data independently followed by their inter-domain integration based on hypergeometric tests of the number of shared individuals. Pathway enrichment analysis was performed on the SNP sets to identify their associated biological processes. We identified 93 statistically significant (hypergeometric p-value \u3c 0.01) lipidome-genotype relations. Genotype biclusters in these 93 relations contained 5977 SNPs across 3164 genes. Twenty nine of the 93 relations contained genotype biclusters with more than 50% unique SNPs and participants, thus representing most distinct subgroups. We identified 30 significantly enriched biological processes among the SNPs involved in 21 of these 29 most distinct genotype-lipidome subgroups through which the identified genetic variants can influence and regulate plasma lipid related metabolism and profiles. This study identified 29 distinct genotype-lipidome subgroups in the studied Finnish population that may have distinct disease trajectories and therefore could be useful in precision medicine research

Frequency of virus-resistant hosts determines experimental community dynamics.

Parasites, such as bacterial viruses (phages), can have large effects on host populations both at the ecological and evolutionary levels. In the case of cyanobacteria, phages can reduce primary production and infected hosts release intracellular nutrients influencing planktonic food web structure, community dynamics, and biogeochemical cycles. Cyanophages may be of great importance in aquatic food webs during large cyanobacterial blooms unless the host population becomes resistant to phage infection. The consequences on plankton community dynamics of the evolution of phage resistance in bloom forming cyanobacterial populations are still poorly studied. Here, we examined the effect of different frequencies of a phage-resistant genotype within a filamentous nitrogen-fixing Nodularia spumigena population on an experimental plankton community. Three Nodularia populations with different initial frequencies (0%, 5%, and 50%) of phage-resistant genotypes were inoculated in separate treatments with the phage 2AV2, the green alga Chlorella vulgaris, and the rotifer Brachionus plicatilis, which formed the experimental plankton community subjected to either nitrogen-limited or nitrogen-rich conditions. We found that the frequency of the phage-resistant Nodularia genotype determined experimental community dynamics. Cyanobacterial populations with a high frequency (50%) of the phage-resistant genotype dominated the cultures despite the presence of phages, retaining most of the intracellular nitrogen in the plankton community. In contrast, populations with low frequencies (0% and 5%) of the phage-resistant genotype were lysed and reduced to extinction by the phage, transferring the intracellular nitrogen held by Nodularia to Chlorella and rotifers, and allowing Chlorella to dominate the communities and rotifers to survive. This study shows that even though phages represent minuscule biomass, they can have key effects on community composition and eco-evolutionary feedbacks in plankton communities.Peer reviewe

BMI is positively associated with accelerated epigenetic aging in twin pairs discordant for body mass index

Background Obesity is a heritable complex phenotype that can increase the risk of age-related outcomes. Biological age can be estimated from DNA methylation (DNAm) using various "epigenetic clocks." Previous work suggests individuals with elevated weight also display accelerated aging, but results vary by epigenetic clock and population. Here, we utilize the new epigenetic clock GrimAge, which closely correlates with mortality. Objectives We aimed to assess the cross-sectional association of body mass index (BMI) with age acceleration in twins to limit confounding by genetics and shared environment. Methods and results Participants were from the Finnish Twin Cohort (FTC; n = 1424), including monozygotic (MZ) and dizygotic (DZ) twin pairs, and DNAm was measured using the Illumina 450K array. Multivariate linear mixed effects models including MZ and DZ twins showed an accelerated epigenetic age of 1.02 months (p-value = 6.1 x 10(-12)) per one-unit BMI increase. Additionally, heavier twins in a BMI-discordant MZ twin pair (Delta BMI >3 kg/m(2)) had an epigenetic age 5.2 months older than their lighter cotwin (p-value = 0.0074). We also found a positive association between log (homeostatic model assessment of insulin resistance) and age acceleration, confirmed by a meta-analysis of the FTC and two other Finnish cohorts (overall effect = 0.45 years, p-value = 4.1 x 10(-25)) from adjusted models. Conclusion We identified significant associations of BMI and insulin resistance with age acceleration based on GrimAge, which were not due to genetic effects on BMI and aging. Overall, these results support a role of BMI in aging, potentially in part due to the effects of insulin resistance.Peer reviewe

Immediate effects of deep brain stimulation of anterior thalamic nuclei on executive functions and emotion-attention interaction in humans

BACKGROUND: Deep brain stimulation (DBS) of anterior thalamic nuclei (ANT) is a novel promising therapeutic method for treating refractory epilepsy. Despite reports of subjective memory impairments and mood disturbances in patients with ANT-DBS, little is known of its effects on cognitive and affective processes. HYPOTHESIS: The anterior thalamus has connections to prefrontal and limbic networks important for cognitive control and emotional reactivity. More specifically, anterior cingulate cortex (ACC), linked with ANT, has been assigned roles related to response inhibition and attention allocation to threat. Thus, we hypothesized ANT-DBS to influence executive functions, particularly response inhibition, and modulate emotional reactivity to threat. METHOD: Twelve patients having undergone ANT-DBS for intractable epilepsy participated in the study. Patients performed a computer-based executive reaction time (RT) test—that is, a go/ no-go visual discrimination task with threat-related emotional distractors and rule switching, while the DBS was switched ON (5/5 mA constant current) and OFF every few minutes. RESULTS: ANT-DBS increased the amount of commission errors—that is, errors where subjects failed to withhold from responding. Furthermore, ANT-DBS slowed RTs in context of threat-related distractors. When stimulation was turned off, threat-related distractors had no distinct effect on RTs. CONCLUSION: We found immediate objective effects of ANT-DBS on human cognitive control and emotion-attention interaction. We suggest that ANT-DBS compromised response inhibition and enhanced attention allocation to threat due to altered functioning of neural networks that involve the DBS-target, ANT, and the regions connected to it such as ACC. The results highlight the need to consider affective and cognitive side-effects in addition to the therapeutic effect when adjusting stimulation parameters. Furthermore, this study introduces a novel window into cognitive and affective processes by modulating the associative and limbic networks with direct stimulation of key nodes in the thalamus