Sex-dependent relationship of polymorphisms in CLOCK and REV-ERBα genes with body mass index and lipid levels in children.

Circadian rhythms, which are governed by a circadian clock, regulate important biological processes associated with obesity. SNPs in circadian clock genes have been linked to energy and lipid homeostasis. The aim of our study was to evaluate the associations of CLOCK and REV-ERBα SNPs with BMI and plasma lipid levels in pre-pubertal boys and girls. The study sample population comprised 1268 children aged 6-8 years. Information regarding anthropometric parameters and plasma lipid concentrations was available. Genotyping of CLOCK SNPs rs1801260, rs4580704, rs3749474, rs3736544 and rs4864548 and REV-ERBα SNPs rs2017427, rs20711570 and rs2314339 was performed by RT-PCR. The CLOCK SNPs rs3749474 and rs4864548 were significantly associated with BMI in girls but no in boys. Female carriers of the minor alleles for these SNPs presented lower BMI compared to non-carriers. A significant association of the REV-ERBα SNP rs2071570 with plasma total cholesterol, LDL-cholesterol and Apo B in males was also observed. Male AA carriers showed lower plasma levels of total cholesterol, LDL-cholesterol and Apo B levels as compared with carriers of the C allele. No significant associations between any of the studied REV-ERBα SNPs and plasma lipid levels were observed in females. In summary, CLOCK and REV-ERBα SNPs were associated with BMI and plasma lipid levels respectively in a sex-dependent manner. Our findings suggest that sex-related factors may interact with Clock genes SNPs conditioning the effects of these polymorphisms on circadian alterations.

Methylation analysis by targeted bisulfite sequencing in large for gestational age (LGA) newborns: the LARGAN cohort.

BACKGROUND: In 1990, David Barker proposed that prenatal nutrition is directly linked to adult cardiovascular disease. Since then, the relationship between adult cardiovascular risk, metabolic syndrome and birth weight has been widely documented. Here, we used the TruSeq Methyl Capture EPIC platform to compare the methylation patterns in cord blood from large for gestational age (LGA) vs adequate for gestational age (AGA) newborns from the LARGAN cohort. RESULTS: We found 1672 differentially methylated CpGs (DMCs) with a nominal p < 0.05 and 48 differentially methylated regions (DMRs) with a corrected p < 0.05 between the LGA and AGA groups. A systems biology approach identified several biological processes significantly enriched with genes in association with DMCs with FDR < 0.05, including regulation of transcription, regulation of epinephrine secretion, norepinephrine biosynthesis, receptor transactivation, forebrain regionalization and several terms related to kidney and cardiovascular development. Gene ontology analysis of the genes in association with the 48 DMRs identified several significantly enriched biological processes related to kidney development, including mesonephric duct development and nephron tubule development. Furthermore, our dataset identified several DNA methylation markers enriched in gene networks involved in biological pathways and rare diseases of the cardiovascular system, kidneys, and metabolism. CONCLUSIONS: Our study identified several DMCs/DMRs in association with fetal overgrowth. The use of cord blood as a material for the identification of DNA methylation biomarkers gives us the possibility to perform follow-up studies on the same patients as they grow. These studies will not only help us understand how the methylome responds to continuum postnatal growth but also link early alterations of the DNA methylome with later clinical markers of growth and metabolic fitness.

Relationship between eating habits, sleep patterns and physical activity and the degree of obesity in children and adolescents.

INTRODUCTION: Childhood obesity is an extremely prevalent pathology and, in order to be able to address it, it is necessary to understand the factors that influence on its genesis and maintenance. We hypothesise that the timing of meals and sleep, the regularity of these throughout the week and a sedentary lifestyle influence the degree of obesity. MATERIAL AND METHODS: We included children and adolescents with obesity who attended a first check-up visit at the Childhood Obesity Unit between January 2018 and February 2020. The data were obtained from a questionnaire on food (36-h intake, frequency of consumption, eating times and habits) and sleep. RESULTS: The degree of obesity was influenced to a greater extent by later meal times and the distribution of calories throughout the day (less at breakfast, more at dinner) than by the total number of calories ingested. In addition, a lower consumption of vegetables was related to a higher degree of obesity. The difference between the hours of sleep at weekends and on weekdays correlated positively with a higher degree of obesity. Finally, the anthropometric data correlated negatively with the number of hours of physical activity. Almost half of the children did not exercise after school. CONCLUSION: In the approach to childhood obesity, it is necessary to include recommendations on the regularity of meal and sleep times, as well as the distribution of calories throughout the day. Additionally, it is necessary to encourage the practice of physical exercise.

Leptin Concentrations Determine the Association between High-Sensitivity C-Reactive Protein Levels and Body Mass Index in Prepubertal Children.

Obesity is associated with the presence of low-grade inflammation even during childhood. The dysregulation in the secretion of adipokines, such as leptin, which occurs in obesity states, could be associated with an increase in inflammatory factors already at an early age. In this cross-sectional study, we aimed to investigate the role of leptin levels in the association between body mass index (BMI) and high-sensitivity C-reactive protein (hs-CRP) in healthy schoolchildren. Leptin and hs-CRP levels were analyzed in two pediatric cohorts comprising 684 prepubertal children and 763 adolescents. hs-CRP concentrations correlated significantly with BMI and leptin levels in prepubertal males and females as well as in adolescents. However, after adjusting for leptin concentration, no significant correlation was observed between hs-CRP and BMI in prepubertal children, while the correlations remained significant in adolescents. The same differences were observed when analyzed BMI according to hs-CRP tertile after adjusting for leptin; mean BMI was not significantly different between hs-CRP tertile in prepubertal children but was significantly different in adolescents. In conclusion, the fact that leptin concentrations determine the association of BMI with hs-CRP levels in prepubertal children, but not in adolescents, suggests a role for leptin in low-grade inflammation at early ages, while other factors seem to contribute to hs-CRP levels later in life.

Sex-Dependent Mediation of Leptin in the Association of Perilipin Polymorphisms with BMI and Plasma Lipid Levels in Children.

Variations in the perilipin (PLIN) gene have been suggested to be associated with obesity and its related alterations, but a different nutritional status seems to contribute to differences in these associations. In our study, we examined the association of several polymorphisms at the PLIN locus with obesity and lipid profile in children, and then analyzed the mediation of plasma leptin levels on these associations. The single-nucleotide polymorphisms (SNPs) rs894160, rs1052700, and rs2304795 in PLIN1, and rs35568725 in PLIN2, were analyzed by RT-PCR in 1264 children aged 6-8 years. Our results showed a contrasting association of PLIN1 rs1052700 with apolipoprotein (Apo) A-I levels in boys and girls, with genotype TT carriers showing significantly higher Apo A-I levels in boys and significantly lower Apo A-I levels in girls. Significant associations of the SNP PLIN2 rs35568725 with high-density lipoprotein cholesterol (HDL-cholesterol), Apo A-I, and non-esterified fatty acids (NEFA) were observed in boys but not in girls. The associations of the SNPs studied with body mass index (BMI), NEFA, and Apo A-I in boys and girls were different depending on leptin concentration. In conclusion, we describe the mediation of plasma leptin levels in the association of SNPs in PLIN1 and PLIN2 with BMI, Apo A-I, and NEFA. Different leptin levels by sex may contribute to explain the sex-dependent association of the PLIN SNPs with these variables.

Melatonin Rhythm and Its Relation to Sleep and Circadian Parameters in Children and Adolescents With Autism Spectrum Disorder.

Introduction: Sleep problems are prevalent among individuals with autism spectrum disorder (ASD), and a role has been attributed to melatonin in this multifactorial comorbidity. Methods: A cross-sectional study was conducted on 41 autistic children and adolescents (9.9 ± 3.02) and 24 children and adolescents with a normal intellectual function (8.42 ± 2.43) were used as controls. Subjects were matched for sex, body mass index, and pubertal stage, and all were drug-naive. Circadian and sleep parameters were studied using an ambulatory circadian monitoring (ACM) device, and saliva samples were collected around the onset of sleep to determine dim light melatonin onset (DLMO). Results: Prepubertal individuals with ASD presented later DLMO and an earlier decline in melatonin during adolescence. A relationship was found between melatonin and both sleep and circadian parameters. Participants and controls with later DLMOs were more likely to have delayed sleep onset times. In the ASD group, subjects with the later daytime midpoint of temperature had a later DLMO. Later melatonin peak time and DLMO time were related to lower general motor activity and lower stability of its rhythms. Conclusion: The melatonin secretion pattern was different in individuals with ASD, and it showed a relationship with sleep and circadian parameters. Alterations in DLMO have not been previously reported in ASD with the exception of more variable DLMO timing; however, high variability in the study design and sample characteristics prevents direct comparison. The ACM device enabled the measurement of circadian rhythm, a scarcely described parameter in autistic children. When studied in combination with other measures such as melatonin, ACM can offer further knowledge on sleep problems in ASD.

Association of ACE2 Polymorphisms and Derived Haplotypes With Obesity and Hyperlipidemia in Female Spanish Adolescents.

Background: In the cardiovascular (CV) system, overactivation of the angiotensin converting enzyme (ACE) may trigger deleterious responses derived from angiotensin (Ang)-II, which can be attenuated by stimulation of ACE2 and subsequent Ang-(1-7) metabolite. However, ACE2 exhibits a high degree of genetic polymorphism that may affect its structure and stability, interfering with these cardioprotective actions. The aim of this study was to analyse the relationship of ACE2 polymorphisms with cardiovascular risk factors in children. Methodology: Five ACE2-single nucleotide polymorphisms (SNP), rs4646188, rs2158083, rs233575, rs879922, and rs2074192, previously related to CV risk factors, were analyzed in a representative sample of 12-16-year-old children and tested for their potential association with anthropometric parameters, insulin levels and the lipid profile. Results: Girls (N = 461) exhibited lower rates of overweight, obesity, blood pressure, and glycemia than boys (N = 412), though increased plasma lipids. The triglycerides (TG)/HDL-C ratio was, however, lower in females. Interestingly, only in girls, the occurrence of overweight/obesity was associated with the SNPs rs879922 [OR 1.67 (1.02-2.75)], rs233575 [OR 1.98 (1.21- 3.22)] and rs2158083 [OR 1.67 (1.04-2.68)]. Also, TG levels were linked to the rs879922, rs233575, and rs2158083 SNPs, and the TG/HDL-C ratio was associated with rs879922 and rs233575. Levels of TC and LDL-C were associated with rs2074192 and rs2158083. Furthermore, the established cut-off level for TG ≥ 90 mg/dL was related to rs879922 [OR 1.78 (1.06-2.96)], rs2158083 [OR 1.75 (1.08-2.82)], and rs233575 [OR 1.62 (1.00-2.61)]. The cut-off level for TC ≥ 170 mg/dL was associated with rs2074192 OR 1.54 (1.04-2.28) and rs2158083 [OR 1.53 (1.04-2.25)]. Additionally, the haplotype (C-G-C) derived from rs879922-rs2158083-rs233575 was related to higher prevalence of overweight/obesity and TG elevation. Conclusion: The expression and activity of ACE2 may be essential for CV homeostasis. Interestingly, the ACE2-SNPs rs879922, rs233575, rs2158083 and rs2074192, and the haplotype (C-G-C) of the three former could induce vulnerability to obesity and hyperlipidemia in women. Thus, these SNPs might be used as predictive biomarkers for CV diseases and as molecular targets for CV therapy.

Sex-dependent relationship of C-reactive protein levels with HDL-cholesterol and HDL-phospholipid concentrations in children.

Obesity has been consistently associated with inflammation but the influence of HDL on this association remains under study. Our study analyzes the influence of obesity-related parameters in the relationship of high-sensitivity C-reactive protein (hs-CRP) with HDL-cholesterol and HDL-phospholipid in male and female adolescents. The study sample population comprised 350 males and 401 females aged 12 to 16 years. Information regarding anthropometric parameters, HDL-cholesterol, HDL-phospholipid, adiponectin, leptin, insulin, and hs-CRP concentrations was available. hs-CRP levels were inversely related to HDL-cholesterol and HDL-phospholipid in males but not in females, and were positively related to leptin concentrations in both sexes but were not related to adiponectin levels. In regression analyses, HDL-phospholipid and leptin appeared significantly associated to hs-CRP in males in a model explaining 14.3% of hs-CRP variation. In females, only leptin appeared related to hs-CRP concentrations. After adjusting by leptin and adiponectin, males in the highest hs-CRP tertile showed significantly lower levels of HDL-cholesterol and HDL-phospholipid than those in tertiles 1 and 2, while no significant differences in HDL-cholesterol and HDL-phospholipid concentrations by hs-CRP tertile were observed in females. In summary, high hs-CRP levels were associated with lower plasma HDL-cholesterol and HDL-phospholipid concentrations in male adolescents irrespective of adipokines, while in females, HDL-related parameters are not associated with hs-CRP concentrations.

PPARγ2 Pro12Ala Polymorphism is Associated in Children With Traits Related to Susceptibility to Type 2 Diabetes.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated nuclear receptor that regulates glucose and lipid metabolism. Pharmacological activators of PPARγ are being used as a treatment of obesity related disorders such as dyslipidaemia and type 2 diabetes, but questions remain open regarding the effects of PPARγ on traits related to the development of type 2 diabetes. In our study, we have analyzed the relationship of the common variant Pro12Ala in the human PPARγ2 gene with the presence of obesity and with insulin, HOMA and lipid profile in a representative sample of 6-to 8-year-old children free from the confounding factors associated with adults. We found that Ala12Ala genotype was significantly more frequent in females with obesity than in those without obesity, with Ala12Ala carriers having significantly higher weight and body mass index (BMI), however the association disappeared when adjusting by leptin concentrations. The Ala12Ala genotype was associated with significantly higher HDL-cholesterol and apoA-I levels in males but not in females, independently of BMI. In a recessive model, in females, leptin levels appeared higher in Ala12Ala carriers. Although no apparent differences were observed in any sex when analyzing insulin levels and HOMA among genotypes without adjusting, lower insulin levels and lower HOMA appeared associated with Ala12Ala carriers when adjusting for BMI and leptin levels. In summary, our data showed that leptin seems to be having an effect on the association between the PPARγ2 Pro12Ala and BMI. Besides, after controlling for BMI and leptin, a protective effect of the Ala12Ala variant of the PPARγ2 Pro12Ala polymorphism on insulin sensitivity is evident already in prepubertal children.

Sex steroid hormones, leptin, and high-sensitivity C-reactive protein levels in adolescents.

BACKGROUND: The association of sex hormones with C-reactive protein (CRP) levels has been reported. However, this association remains unexplored in children in whom important anthropometric and hormonal changes are taking place. OBJECTIVES: To analyze the association between high-sensitivity CRP (hs-CRP) and testosterone, estradiol and sex hormone-binding globulin (SHBG) levels in a population-based sample of adolescents, and to evaluate the influence of leptin levels on this association. MATERIALS AND METHODS: The sample population of this cross-sectional study was comprised of 338 male and 385 female adolescents, aged 12-16 years. Information on anthropometric variables, hormone, leptin, and hs-CRP levels was available. RESULTS: In male adolescents in our study, higher age is significantly associated with higher testosterone levels and with lower leptin and SHBG concentrations across the range of age studied. No significant changes in leptin and SHBG levels by age are observed in females. In males, leptin correlates negatively with testosterone levels (-0.263, p < 0.001), showing a stronger correlation after adjusting by body mass index (BMI) (-0.424, p < 0.001). A significant correlation between hs-CRP and testosterone levels is observed in males after adjusting by BMI, but the correlation disappears after adjusting by leptin. No association between testosterone and hs-CRP was observed in females. The negative association between hs-CRP levels and SHBG remains significant after adjusting by leptin in both sexes but disappears in males after adjusting by BMI. CONCLUSION: The negative association between hs-CRP and testosterone concentrations observed in 12- to 16-year-old males seems to be related to leptin levels which are closely negatively related to testosterone levels in males independently of BMI.

Leptin Concentration, Obesity, and Plasma Non-esterified Fatty Acid Levels in Children.

The association between obesity and higher non-esterified fatty acid (NEFA) levels has been established in adults. In contrast, lower NEFA levels have been described in children with obesity although the reason behind this association remains unclear. Leptin, which regulates body weight and plays a role in lipolysis, could be involved in this relationship. We evaluated the influence of leptin in the association between obesity and NEFA concentrations in children, analyzing two cohorts including 684 6- to 8-year-olds and 836 12- to 16-year-old children, respectively. After adjusting by leptin, insulin levels remained significantly higher in adolescents with obesity as compared with levels in those without obesity. However, insulin levels showed no differences between prepubertal children with and without obesity. The significantly lower NEFA concentrations observed in 6- to 8-year-old girls with obesity disappeared when comparing NEFA levels between girls with and without obesity after adjusting by leptin. We report an influence of leptin levels on the association between obesity and insulin and NEFA in young children that is not observed in adolescents. Our findings add information about factors that may contribute to explain the lower NEFA levels described in prepubertal children with obesity.

Children with type 1 diabetes have elevated high-sensitivity C-reactive protein compared with a control group.

INTRODUCTION: Our objective was to compare high-sensitivity C-reactive protein (hsCRP) levels in children with type 1 diabetes, healthy controls, and children with obesity. Additionally, we aimed to analyze the association between hsCRP levels and glycemic control measured by glycohemoglobin A (HbA1c) and anthropometric and biochemical variables. RESEARCH DESIGN AND METHODS: We conducted a non-randomized descriptive study of children with type 1 diabetes matched for sex and age with a control group and group with obesity. We recorded anthropometric parameters and studied variables related to diabetes, blood pressure, lipid profile, and HbA1c. hsCRP was measured by ELISA. RESULTS: We included 49 children with type 1 diabetes, 46 controls, and 40 children with obesity. hsCRP levels were significantly higher in the group with type 1 diabetes compared with controls and nearly significantly lower than in the group comprising children with obesity. We found no correlation between hsCRP and HbA1c and characteristics of type 1 diabetes with the exception of albumin to creatinine ratio. Statistically significant association was found between hsCRP and body mass index (BMI) and waist circumference Z-score. CONCLUSIONS: The higher hsCRP levels observed in children with type 1 diabetes compared with a control group with a similar BMI suggest a basal inflammatory state that could increase cardiovascular risk. The main factors related to hsCRP are BMI and waist circumference, so obesity prevention should be a priority when performing follow-up in children with type 1 diabetes.

Circadian health differs between boys and girls as assessed by non-invasive tools in school-aged children.

BACKGROUND & AIMS: Assessment of circadian health is confined to adults. However, understanding circadian status of school-aged children is necessary due to its health implications. The aim was to develop 1) a protocol to assess circadian function in school-aged children by combining the best non-invasive tools previously validated in adults; 2) a score to capture circadian function in children including food timing. This protocol will allow to explore gender differences and to compare the circadian function of school-aged children with adults from the same Mediterranean area. METHODS: Healthy children (8-12 y) from 3 schools in a Mediterranean area of Spain were recruited (n = 248; 125 males and 123 females). Several non-invasive tools were used: a) 7-day-diaries of food timing and food intake, physical-activity and sleep, b) Munich-chronotype-self-reported-questionnaire; c) cortisol and melatonin saliva determinations; d) 7-day-rhythms of wrist temperature (T), activity (A), position (P) and the integrative variable TAP e) 7-day-light exposure. RESULTS: We have constructed the first school-aged children population for the assessment of circadian function (ONTIME-Jr) and a new circadian score has been developed. Among circadian-related measures, TAP was the most suitable and reliable to determine circadian system characteristics. Circadian function was better in girls than in boys [circadian score (AU) Mean ± SD (girls, 1216 ± 153 vs. 1159 ± 173 boys, P = 0.012)], and also in school-aged children than in adults from the same Mediterranean area (Circadian-Function-Index: children 0.47 ± 0.06 vs. adults 0.45 ± 0.06 P = 0.001). CONCLUSIONS: A new protocol, including TAP and food timing, demonstrated to be reliable in assessing circadian function in children. These non-invasive techniques provide the wherewithal for paediatricians to assess circadian function in clinical practice. TRIAL REGISTRATION: Chronobiology and childhood obesity (ONTIME-Jr: Obesity, Nutrigenetics, Timing and Mediterranean, Junior). ClinicalTrials.gov ID: NCT02895282, October 2014.

Sirt1 protects from K-Ras-driven lung carcinogenesis.

The NAD+-dependent deacetylase SIRT1 can be oncogenic or tumor suppressive depending on the tissue. Little is known about the role of SIRT1 in non-small cell lung carcinoma (NSCLC), one of the deadliest cancers, that is frequently associated with mutated K-RAS Therefore, we investigated the effect of SIRT1 on K-RAS-driven lung carcinogenesis. We report that SIRT1 protein levels are downregulated by oncogenic K-RAS in a MEK and PI3K-dependent manner in mouse embryo fibroblasts (MEFs), and in human lung adenocarcinoma cell lines. Furthermore, Sirt1 overexpression in mice delays the appearance of K-RasG12V-driven lung adenocarcinomas, reducing the number and size of carcinomas at the time of death and extending survival. Consistently, lower levels of SIRT1 are associated with worse prognosis in human NSCLCs. Mechanistically, analysis of mouse Sirt1-Tg pneumocytes, isolated shortly after K-RasG12V activation, reveals that Sirt1 overexpression alters pathways involved in tumor development: proliferation, apoptosis, or extracellular matrix organization. Our work demonstrates a tumor suppressive role of SIRT1 in the development of K-RAS-driven lung adenocarcinomas in mice and humans, suggesting that the SIRT1-K-RAS axis could be a therapeutic target for NSCLCs.