Cardiovascular autonomic nervous function in children conceived by assisted reproductive technology with frozen or fresh embryo transfer

As a result of epigenetic changes, children conceived by assisted reproduction may be at risk of premature cardiovascular aging with notably increased blood pressures. Their cardiovascular autonomic nervous function is unknown. Therefore, this study investigated the cardiovascular autonomic nervous function in 8-12-yr-old children (51% girls) conceived naturally (n = 33) or by assisted reproduction with frozen (n = 34) or fresh (n = 38) embryo transfer by evaluating heart rate variability, during rest; from provocation maneuvers; and from baroreflex function. Heart rate and blood pressure response to provocation maneuvers and baroreflex function were comparable between children conceived naturally or by assisted reproduction. The mean RR-interval and high-frequency component of heart rate variability were lower in children conceived by assisted reproduction than in children conceived naturally. Children conceived by fresh embryo transfer had ∼17% lower heart rate-corrected standard deviation of normal-to-normal R-R intervals; ∼22% lower heart rate-corrected square root of the mean of the squared difference between successive R-R intervals; and ∼37% higher low-frequency/high-frequency ratio than naturally conceived children. Children conceived by assisted reproduction still had lower heart rate variability and vagal modulation than naturally conceived children after adjustment for confounders. Thus, these results raise the possibility of sympathetic predominance in children conceived by assisted reproduction. Therefore, it is important to reproduce these results in larger and older cohorts as sympathetic predominance relates with cardiovascular and metabolic diseases.NEW & NOTEWORTHY We observed that children conceived by assisted reproductive technology (both frozen and fresh embryo transfer) had lowered heart rate variability during rest as compared with children conceived naturally. During physiological stress maneuvers, however, the cardiovascular autonomic nervous regulation was comparable between children conceived by assisted reproductive technologies and naturally. Our findings highlight the potential that lowered heart rate variability during rest in children conceived by assisted reproductive technologies may precede premature hypertension.

Genetics of Plasma Bilirubin and Associations between Bilirubin and Cardiometabolic Risk Profiles in Danish Children and Adolescents

Bilirubin is the end product of heme catabolism, mainly produced by the breakdown of mature red blood cells. Due to its anti-inflammatory, antioxidant, antidiabetic, and antilipemic properties, circulating bilirubin concentrations are inversely associated with the risk of cardiovascular disease, type 2 diabetes, and all-cause mortality in adults. Some genetic loci associated with circulating bilirubin concentrations have been identified by genome-wide association studies in adults. We aimed to examine the relationship between circulating bilirubin, cardiometabolic risk factors, and inflammation in children and adolescents and the genetic architecture of plasma bilirubin concentrations. We measured fasting plasma bilirubin, cardiometabolic risk factors, and inflammatory markers in a sample of Danish children and adolescents with overweight or obesity (n = 1530) and in a population-based sample (n = 1820) of Danish children and adolescents. Linear and logistic regression analyses were performed to analyze the associations between bilirubin, cardiometabolic risk factors, and inflammatory markers. A genome-wide association study (GWAS) of fasting plasma concentrations of bilirubin was performed in children and adolescents with overweight or obesity and in a population-based sample. Bilirubin is associated inversely and significantly with a number of cardiometabolic risk factors, including body mass index (BMI) standard deviation scores (SDS), waist circumference, high-sensitivity C-reactive protein (hs-CRP), homeostatic model assessment for insulin resistance (HOMA-IR), hemoglobin A1c (HbA1c), low-density lipoprotein cholesterol (LDL-C), triglycerides, and the majority of measured inflammatory markers. In contrast, bilirubin was positively associated with fasting plasma concentrations of alanine transaminase (ALT), high-density lipoprotein cholesterol (HDL-C), systolic blood pressure (SDS), and the inflammatory markers GH, PTX3, THBS2, TNFRSF9, PGF, PAPPA, GT, CCL23, CX3CL1, SCF, and TRANCE. The GWAS showed that two loci were positively associated with plasma bilirubin concentrations at a p-value threshold of <5 × 10-8 (rs76999922: β = -0.65 SD; p = 4.3 × 10-8, and rs887829: β = 0.78 SD; p = 2.9 × 10-247). Approximately 25% of the variance in plasma bilirubin concentration was explained by rs887829. The rs887829 was not significantly associated with any of the mentioned cardiometabolic risk factors except for hs-CRP. Our findings suggest that plasma concentrations of bilirubin non-causally associates with cardiometabolic risk factors in children and adolescents.

An adult-based genetic risk score for liver fat associates with liver and plasma lipid traits in children and adolescents

BACKGROUND & AIMS

Genome-wide association studies have identified steatogenic variants that also showed pleiotropic effects on cardiometabolic traits in adults. We investigated the effect of eight previously reported genome-wide significant steatogenic variants, individually and combined in a weighted genetic risk score (GRS), on liver and cardiometabolic traits, and the predictive ability of the GRS for hepatic steatosis in children and adolescents.

APPROACH & RESULTS

Children and adolescents with overweight (including obesity) from an obesity clinic group (n = 1768) and a population-based group (n = 1890) were included. Cardiometabolic risk outcomes and genotypes were obtained. Liver fat was quantified using 1 H-MRS in a subset of 727 participants. Variants in PNPLA3, TM6SF2, GPAM and TRIB1 were associated with higher liver fat (p < .05) and with distinct patterns of plasma lipids. The GRS was associated with higher liver fat content, plasma concentrations of alanine transaminase (ALT), aspartate aminotransferase (AST) and favourable plasma lipid levels. The GRS was associated with higher prevalence of hepatic steatosis (defined as liver fat ≥5.0%) (odds ratio per 1-SD unit: 2.17, p = 9.7E-10). A prediction model for hepatic steatosis including GRS alone yielded an area under the curve (AUC) of 0.78 (95% CI 0.76-0.81). Combining the GRS with clinical measures (waist-to-height ratio [WHtR] SDS, ALT, and HOMA-IR) increased the AUC up to 0.86 (95% CI 0.84-0.88).

CONCLUSIONS

The genetic predisposition for liver fat accumulation conferred risk of hepatic steatosis in children and adolescents. The liver fat GRS has potential clinical utility for risk stratification.

High Plasma Levels of Soluble Lectin-like Oxidized Low-Density Lipoprotein Receptor-1 Are Associated With Inflammation and Cardiometabolic Risk Profiles in Pediatric Overweight and Obesity

Background Lectin-like oxidized low-density lipoprotein (ox-LDL) receptor-1 is a scavenger receptor for oxidized low-density lipoprotein. In adults, higher soluble lectin-like ox-LDL receptor-1 (sLOX-1) levels are associated with cardiovascular disease, type 2 diabetes, and obesity, but a similar link in pediatric overweight/obesity remains uncertain. Methods and Results Analyses were based on the cross-sectional HOLBAEK Study, including 4- to 19-year-olds from an obesity clinic group with body mass index >90th percentile (n=1815) and from a population-based group (n=2039). Fasting plasma levels of sLOX-1 and inflammatory markers were quantified, cardiometabolic risk profiles were assessed, and linear and logistic regression analyses were performed. Pubertal/postpubertal children and adolescents from the obesity clinic group exhibited higher sLOX-1 levels compared with the population (P<0.001). sLOX-1 positively associated with proinflammatory cytokines, matrix metalloproteinases, body mass index SD score, waist SD score, body fat %, plasma alanine aminotransferase, serum high-sensitivity C-reactive protein, plasma low-density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure SD score, and inversely associated with plasma high-density lipoprotein cholesterol (all P<0.05). sLOX-1 positively associated with high alanine aminotransferase (odds ratio [OR], 1.16, P=4.1 E-04), insulin resistance (OR, 1.16, P=8.6 E-04), dyslipidemia (OR, 1.25, P=1.8 E-07), and hypertension (OR, 1.12, P=0.02). Conclusions sLOX-1 levels were elevated during and after puberty in children and adolescents with overweight/obesity compared with population-based peers and associated with inflammatory markers and worsened cardiometabolic risk profiles. sLOX-1 may serve as an early marker of cardiometabolic risk and inflammation in pediatric overweight/obesity. Registration The HOLBAEK Study, formerly known as The Danish Childhood Obesity Biobank, ClinicalTrials.gov identifier number NCT00928473, https://clinicaltrials.gov/ct2/show/NCT00928473 (registered June 2009).

Cardiovascular autonomic nervous function in 7–12 years old children conceived naturally or by ART with frozen and fresh embryo transfer

Background

Cardiovascular autonomic nervous functions (CANF) exert important homeostatic mechanisms to prevent major arterial blood pressure fluctuations by adjusting heart rate (HR), cardiac contractility, and peripheral vascular tone. Children conceived by assisted reproductive technologies (ART) are at risk of increased carotid intima-media thickness, insulin resistance, arterial stiffness, and hypertension. CANF is impaired in children with obesity and diabetes mellitus, and conductance artery stiffness is documented to influence CANF. CANF may therefore be hypothetized to be impaired in children conceived by ART.

Purpose

This is the first study to investigate whether children conceived by ART have impaired CANF as compared to naturally conceived children.

Method

CANF was studied in 105 singletons aged 7–12 years conceived naturally (NC, N=33) or by ART (frozen embryo transfer (FET, N=34) and fresh embryo transfer (Fresh ET, N=38)). CANF was evaluated with continuous non-invasive hemodynamic measurements (Finapres®) by the HR and blood pressure changes seen relative to rest during active standing, deep breathing and Valsalva, respectively.

Results

The descriptive data showed no difference in CANF measurements between our study groups (Table 1). In the multivariate analysis, only the Valsalva HR-ratio to rest was significantly higher in children conceived by FET as compared to NC children after adjustments for age, sex, BMI and maternal age at delivery (Figure 1). For all meaures, the effect size (Hedges d) ranged from 0.02 to 0.48.

Conclusion

In this study only the Valsalva HR-response between FET and NC groups were statistically significant after adjustment for confounders, and in general effect sizes were small. Our study suggests that children conceived by ART do not have a significantly impaired cardiovascular autonomic nervous function as compared to naturally conceived children.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation

Aortic distensibility is equal in prepubertal girls and boys and increases with puberty in girls

Windkessel function is governed by conductance artery compliance that is associated with cardiovascular disease in adults independently of other risk factors. Sex-related differences in conductance artery compliance partly explain the sex-related differences in risk of cardiovascular disease. Studies on sex-related differences in conductance artery function in prepubertal children are few and inconclusive. This study determined conductance artery compliance and cardiac function by magnetic resonance imaging in 150 healthy children (75 girls) aged 7-10 years. Any sex-related difference in conductance artery function was determined with correction for other potential predictors in multivariable linear regression models. Our data showed that ascending (crude mean difference 1.11 95% CI (0.22; 2.01)) and descending (crude mean difference 1.10 95% CI (0.09; 1.91)) aortic distensibility were higher in girls, but differences disappeared after adjustment for pubertal status and other identified potential predictors. Systolic and diastolic blood pressure, cardiac output, left ventricle (LV) systolic function, and total peripheral resistance did not differ between the sexes. In girls, heart rate was 7 bpm higher, whereas pulse pressure (by 2 mmHg), and LV end-diastolic volume index (by 7 mL) and stroke volume (by 5 mL) were lower. LV peak filling rate indexed to LV end-diastolic volume was 0.5 s^-1 higher in girls. In conclusion, prepubertal girls and boys have equal conductance artery function. Thus, the well-known sex difference in adult conductance artery function seems to develop after the onset of puberty with girls initially increasing aortic distensibility.

Hyperglucagonemia in Pediatric Adiposity Associates With Cardiometabolic Risk Factors but Not Hyperglycemia

CONTEXT

In adults, hyperglucagonemia is associated with type 2 diabetes, impaired glucose tolerance, and obesity. The role of glucagon in pediatric overweight/obesity remains unclear.

OBJECTIVE

We examined whether fasting concentrations of glucagon are elevated in youth with overweight/obesity and whether this associates with cardiometabolic risk profiles.

METHODS

Analyses were based on the cross-sectional HOLBAEK study, including children and adolescents 6 to 19 years of age, with overweight/obesity from an obesity clinic group (n = 2154) and with normal weight from a population-based group (n = 1858). Fasting concentrations of plasma glucagon and cardiometabolic risk outcomes were assessed, and multiple linear and logistic regressions models were performed.

RESULTS

The obesity clinic group had higher glucagon concentrations than the population-based group (P < 0.001). Glucagon positively associated with body mass index (BMI) standard deviation score (SDS), waist, body fat %, liver fat %, alanine transaminase (ALT), high-sensitivity C-reactive protein, homeostasis model assessment of insulin resistance, insulin, C-peptide, LDL-C, triglycerides, SDS of diastolic and systolic blood pressure, and was inversely associated with fasting glucose. The inverse relationship between glucagon and glucose was attenuated in individuals with high BMI SDS and high fasting insulin. Glucagon was associated with a higher prevalence of insulin resistance, increased ALT, dyslipidemia, and hypertension, but not with hyperglycemia. Glucagon was positively associated with fasting total glucagon-like peptide-1.

CONCLUSION

Compared with normal weight peers, children and adolescents with overweight/obesity had elevated concentrations of fasting glucagon, which corresponded to worsened cardiometabolic risk outcomes, except for hyperglycemia. This suggests hyperglucagonemia in youth may precede impairments in glucose regulation.

Cardiovascular function in 8- to 9-year-old singletons born after ART with frozen and fresh embryo transfer

STUDY QUESTION

Do 8- to 9-year-old singletons conceived after frozen embryo transfer (FET) or fresh embryo transfer (Fresh-ET) have increased arterial stiffness compared to naturally conceived (NC) children?

SUMMARY ANSWER

The process of FET or Fresh-ET is not associated with altered cardiovascular function in 8- to 9-year-old singletons, including arterial stiffness, as compared to NC children.

WHAT IS KNOWN ALREADY

ART has been suggested to influence cardiovascular risk factors (i.e. endothelial dysfunction, increased arterial blood pressure and insulin resistance). It is not known if ART procedures alter arterial stiffness in singletons.

STUDY DESIGN, SIZE, DURATION

A cohort study was carried out, including 8- to 9-year-old singletons conceived after FET, Fresh-ET and NC children (50 children in each group). This study was conducted between November 2018 and August 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total, 150 singletons were identified through the Danish IVF Registry and the Medical Birth Registry. They underwent cardiac magnetic resonance imaging (CMR) and anthropometric measurements. Parental data were collected using questionnaires. NC children were matched by sex and birth year with FET/Fresh-ET children. Exclusion criteria were congenital heart disease, maternal gestational diabetes or maternal diabetes mellitus. Our primary outcome was arterial stiffness, which is assessed from noninvasive arterial blood pressure and aortic ascendens distensibility. The secondary outcome was the pulse wave velocity of total aorta and exploratory outcomes were left ventricular ejection fraction, mean arterial pressure, cardiac output and total peripheral resistance. Measurements and analyses were performed blinded to the child group.

MAIN RESULTS AND THE ROLE OF CHANCE

Aortic ascendens distensibility of children conceived after FET and Fresh-ET did not differ from NC children (mean (SD): FET 11.1 (3.6) 10-3 mmHg-1, Fresh-ET 11.8 (3.0) 10-3 mmHg-1, NC 11.4 (2.8) 10-3 mmHg-1, P > 0.05). Multivariate linear regression was performed to adjust for potential confounders (i.e. child sex and age, maternal BMI at early pregnancy and maternal educational level). Data showed no statistically significant differences between study groups and aortic ascendens distensibility. However, the fully adjusted model showed a non-significant tendency of lowered aortic ascendens distensibility in children born after FET compared to Fresh-ET (β estimate (95% CI): -0.99 10-3 mmHg-1 (-2.20; 0.21)) and NC children (β estimate (95% CI): -0.77 10-3 mmHg-1 (-1.98; 0.44)). Lastly, secondary and exploratory outcomes did not differ between the groups. Primary and secondary outcomes showed good intra-rater reliability.

LIMITATIONS, REASONS FOR CAUTION

This study is possibly limited by potential selection bias as the participation rate was higher in the ART compared to the NC group. Also, in some variables, the study groups differed slightly from the non-participant population. The non-participant population (n = 1770) included those who were excluded, not invited to CMR scan, or declined to participate in this study.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings indicate that children born after FET or Fresh-ET do not have altered cardiovascular function, including arterial stiffness. This is reassuring for the future use of ART.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Novo Nordisk Foundation (grant reference number: NNF19OC0054340) and The Research Foundation of Rigshospitalet. All authors declared no conflict of interests.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT03719703.

Vascular stiffness in children born after frozen or fresh embryo transfer. A cardiac magnetic resonance imaging study of 8 to 9 year old children

Background

Vascular stiffness increases during childhood, and increased vascular stiffness is associated with symptomatic cardiovascular disease in adults with metabolic syndrome. In comparison with naturally conceived children (NC), children conceived after in-vitro fertilization by frozen (FET) or fresh embryo transfer (Fresh ET) are at risk of being large- and small-for-gestational-age, respectively. Epigenetic modulation during assisted reproductive technologies (ART) is suggested to influence cardiovascular risk factors, and recent literature suggests that children conceived after ART are at increased risk of insulin resistance, endothelial dysfunction and arterial hypertension. Such changes may be associated with increased vascular stiffness, but it is not yet been examined directly.

Purpose

We investigated if ART children are at increased risk of aortic distensibility and pulse-wave velocity.

Methods

150 children aged 8–9 years conceived after FET (n=50), Fresh ET (n=50) or by natural conception (NC, n=50) were studied with magnetic resonance imaging. Conductance artery stiffness was determined from aortic distensibility and aortic pulse-wave velocity (PWV). Data were analyzed with blinding according to treatment group. Based on a conservative estimate for the common SD for the difference between groups of 1.5 mm2/mmHg, 36 children were required in each group to detect a difference in aortic distensibility of 10%, which corresponds to a 5 year age difference, with an alpha of 0.05 (double-sided) and a beta of 0.80. We aimed for 50 children in each group to allow for dropouts and non-analyzable scans, and to allow for further determinations. The effects of potential confounders on the effect of conception method on ascending aorta distensibility and total aortic PWV were tested stepwise in four linear regression models (Figure 1).

Results

Child groups were comparable with respect to anthropometric measures (Table 1). No differences were observed in systolic or diastolic blood pressure, cardiac output, total peripheral resistance, or in aortic distensibility (Ascending aorta distensibility: FET, ascending aorta 11.12±3.55 10–3 mm2/mmHg; Fresh ET 11.77±2.97 10–3 mm2/mmHg; NC 11.43±2.82 10–3 mm2/mmHg) (ANOVA-p=0.58) or aortic PWV (PWV of total aorta: FET, 3.69±0.75 m/s; Fresh ET, 3.49±0.31 m/s; NC, 3.59±0.61 m/s) (ANOVA-p=0.26). The effect of ART remained non-significant after adjustment for child sex, maternal BMI at early pregnancy, and maternal educational level (Figure 1).

Conclusion

The effects of ART on aortic distensibility were not statistically significant, but in the direction of the hypothesis of stiffer conductance arteries from frozen embryo transfer. The confidence interval was relatively wide, and the results suggest that the difference between frozen and fresh embryo transfer may in fact correspond to an age difference of more than 5 years.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Novo Nordisk Foundation Table 1Figure 1

P–779 Vascular stiffness in children born after embryo transfer at 8–9 years of age

Study question

Do 8–9-year-old singletons conceived after frozen (FET) or fresh embryo transfer (Fresh ET) have increased vascular stiffness compared to naturally conceived (NC) children?

Summary answer

FET and Fresh ET was not associated with increased vascular stiffness or altered cardiovascular autonomic reflexes as compared to NC children.

What is known already

Normally, vascular stiffness increases during childhood, and in adults with the metabolic syndrome increased vascular stiffness is associated with symptomatic cardiovascular disease. Children conceived after FET and Fresh ET are at risk of being large- and small-for-gestational-age, respectively. Epigenetic modulation during assisted reproductive technologies (ART) has been suggested to influence cardiovascular risk factors, and previous studies have shown that children conceived after ART are at increased risk of insulin resistance, endothelial dysfunction and increased arterial blood pressure. It is not known if ART procedures alter vascular stiffness of children.

Study design, size, duration

In a cohort study including 8–9 years old singletons conceived after FET, Fresh ET and NC (50 in each group), we used cardiac magnetic resonance imaging (CMR) and cardiovascular autonomic reflex testing (CART) to compare arterial stiffness. The study was powered to detect a difference between groups of aortic distensibility from 8.9 to 8.0, comparable to what is seen in a 5-year older cohort of children (beta 0.80, alpha 0.05). Inclusion period 18 months.

Participants/materials, setting, methods

Singletons were identified through the Danish IVF Registry and the Medical Birth Registry. NC children were matched by sex and birth year with FET children. Exclusion criteria were congenital heart disease, maternal preeclampsia, gestational diabetes or diabetes mellitus. Artery stiffness was assessed from blood pressure and aortic distensibility, pulse wave velocity (PWV), cardiac output and total peripheral resistance by CMR. CART was investigated non-invasively in 40 children. Measurements were performed blinded to the child group.

Main results and the role of chance

Maternal age at delivery was higher in the FET (42.5±5.5 years) and Fresh ET (40.5±6.1 years) compared to the NC group (38.2±5.7 years). In the ART groups, mothers were more likely to have a high educational level (FET 50% and Fresh ET 56.2%) compared to mothers in the NC group (30.6%) (both ANOVA-p&lt;0.05). As expected, children conceived after FET had a higher birth weight standard-deviation-score (0.4±1.1+) compared to Fresh ET (–0.1±1.0) and NC (–0.2±1.1). Among study groups, no significant differences were observed in systolic and diastolic blood pressure (FET 109±6/64±6 mmHg; Fresh ET 109±7/65±5 mmHg; NC 108±8/65±5 mmHg; ANOVA-p&gt;0.05). Heart rate was also similar in all study groups (FET 79±12 bpm; Fresh ET 79±9 bpm; NC 78±11 bpm; ANOVA-p&gt;0.05). No significant differences were observed between groups in total aortic PWV (FET 3.69±0.75 m/s; Fresh ET 3.49±0.31 m/s; NC 3.59±0.61 m/s; ANOVA-p&gt;0.05). Aorta ascendens distensibility was similar in study groups (FET 11.12±3.55 10–3mmHg–1; Fresh ET 11.77±2.97 10–3mmHg–1; NC 11.43±2.82 10–3mmHg–1, ANOVA-p&gt; 0.05). Furthermore, distensibility of aorta descendens and aorta abdominalis, PWV of arcus aorta and PWV from aorta descendens to abdominalis, cardiac output, total peripheral resistance and CART were similar in study groups. Outcome variables remained non-significant after adjustment for potential confounders.

Limitations, reasons for caution

The participation rate was higher in the ART groups (FET 40% and Fresh ET 32%) compared to NC (17%) and hence a selection bias is possible. Data from CART should be interpreted cautiously due to lower number of participating children in these tests.

Wider implications of the findings: Our study did not find any associations between FET or Fresh ET compared to NC children and arterial stiffness. Nor, any associations to CART could be made. Further studies are needed in younger adults to better exclude important long-term effects of ART.

Trial registration number

NCT03719703

Fasting Plasma GLP-1 Is Associated With Overweight/Obesity and Cardiometabolic Risk Factors in Children and Adolescents

CONTEXT

The importance of fasting glucagon-like peptide-1 (GLP-1) in altered metabolic outcomes has been questioned.

OBJECTIVE

This work aimed to assess whether fasting GLP-1 differs in children and adolescents with overweight/obesity compared to a population-based reference, and whether concentrations predict cardiometabolic risk (CMR) factors.

METHODS

Analyses were based on The Danish Childhood Obesity Data- and Biobank, a cross-sectional study including children and adolescents, aged 6 to 19 years, from an obesity clinic group (n = 1978) and from a population-based group (n = 2334). Fasting concentrations of plasma total GLP-1 and quantitative CMR factors were assessed. The effects of GLP-1 as a predictor of CMR risk outcomes were examined by multiple linear and logistic regression modeling.

RESULTS

The obesity clinic group had higher fasting GLP-1 concentrations (median 3.3 pmol/L; interquartile range, 2.3-4.3 pmol/L) than the population-based group (2.8 pmol/L; interquartile range, 2.1-3.8 pmol/L; P < 2.2E-16). Body mass index SD score (SDS), waist circumference, and total body fat percentage were significant predictors of fasting GLP-1 concentrations in boys and girls. Fasting GLP-1 concentrations were positively associated with homeostasis model assessment of insulin resistance, fasting values of insulin, high-sensitivity C-reactive protein, C-peptide, triglycerides, alanine transaminase (ALT), glycated hemoglobin A1c, and SDS of diastolic and systolic blood pressure. A 1-SD increase in fasting GLP-1 was associated with an increased risk of insulin resistance (odds ratio [OR] 1.59), dyslipidemia (OR 1.16), increased ALT (OR 1.14), hyperglycemia (OR 1.12) and hypertension (OR 1.12).

CONCLUSION

Overweight/obesity in children and adolescents is associated with increased fasting plasma total GLP-1 concentrations, which was predictive of higher CMR factors.

Low-grade inflammation independently associates with cardiometabolic risk in children with overweight/obesity

BACKGROUND AND AIMS

Pediatric obesity associates with both low-grade inflammation and cardiometabolic risk on the population level. Yet on an individual patient level, overweight/obesity does not always equal increased cardiometabolic risk. In this study, we examine whether low-grade inflammation associates with cardiometabolic risk in Danish children, independent of degree of adiposity. We further assess the value of integrating multiple inflammation markers to identify children with very-high cardiometabolic risk profiles.

METHOD AND RESULTS

We studied 2192 children and adolescents aged 6-18 years from an obesity clinic cohort and a population-based cohort, in a cross-sectional study design. Anthropometry, blood pressure, pubertal stage and body composition by dual-energy X-ray absorptiometry were assessed, and biomarkers including fasting serum high sensitivity C-reactive protein (hsCRP), white blood cells (WBC), resistin, lipid profile and glucose metabolism were measured. Adjusted correlation analysis and odds ratios were calculated. We found that, independent of degree of adiposity, having high-normal inflammation marker concentrations associated with increased cardiometabolic risk: for girls, hsCRP >0.57-9.98 mg/L (mid/upper tertile) associated with ~2-fold higher odds of dyslipidemia and hepatic steatosis (vs. lower tertile). For both sexes, WBC >7.0-12.4 10⁹/L (upper tertile) associated with 2.5-fold higher odds of insulin resistance. Lastly, children with multiple inflammation markers in the high-normal range exhibited the most severe cardiometabolic risk profile.

CONCLUSION

Low-grade inflammation associates with cardiometabolic risk in children independent of degree of adiposity. The associations vary with sex and inflammation marker measured. Finally, integrating multiple low-grade inflammation markers identifies a very-high-risk subgroup of children with overweight/obesity and may have clinical value.

Urinary markers of nucleic acid oxidation increase with age, obesity and insulin resistance in Danish children and adolescents

PURPOSE

Oxidative stress may play an important role in childhood obesity and increased cardiometabolic risk. 8-oxo-7,8-dihydroguanosine (8-oxoGuo) from oxidation of RNA and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) from oxidation of DNA are excreted into urine and function as biomarkers for oxidative stress reflecting the modification rate of nucleic acids by oxidation. This study investigates the associations between urinary markers of nucleic acid oxidation and Body Mass Index (BMI), age, sex and cardiometabolic risk factors in children and adolescents with and without obesity.

METHODS

We studied 543 children and adolescents from an obesity clinic cohort (n = 418) and a population-based cohort (n = 125), all aged 6-18 years. Anthropometrics, urine and blood samples were collected. A validated liquid chromatography-tandem mass spectrometry method was used to measure the nucleic acid oxidation markers.

RESULTS

Compared with the population-based cohort, children and adolescents in the obesity clinic cohort had higher calculated 24-h excretion of 8-oxoGuo (p = 0.045) and 8-oxodG (p = 0.014) adjusted for basal metabolic rate. Both oxidation markers were positively associated with age and female sex (all p < 0.002). In the obesity clinic cohort the RNA oxidation marker 8-oxoGuo correlated with serum insulin (rho = 0.18, p = <.001) and insulin resistance (rho = 0.19, p = <.001).

CONCLUSIONS

Childhood obesity associate with higher urinary excretion of nucleic acid oxidation biomarkers, and increase with age throughout childhood, mirroring the obesity- and age-related increase shown in adults. Finally, children with obesity and insulin resistance had higher RNA oxidation markers than children with obesity and no insulin resistance, supporting a possible link between oxidative stress and the pathogenesis of cardiometabolic risk including type 2 diabetes.

Disturbed eating behaviours do not impact treatment response in a paediatric obesity chronic care treatment programme

AIM

This study investigates the prevalence of disturbed eating behaviours in children and adolescents initiating obesity treatment, and how the prevalence varies with age, sex and body mass index (BMI) standard deviation score (SDS). Secondly, it examines whether the presence of disturbed eating behaviours at enrolment is associated with the degree of weight loss after 12 months of treatment.

METHODS

A total of 3621 patients aged 3-18 years enrolled in a multidisciplinary obesity treatment programme were studied. Follow-up data after a median of 12.4 months were available for 2055 patients. Upon entry, patients were assessed for the following disturbed eating behaviours: meal skipping, emotional eating, overeating and rapid eating. Height and weight were measured at baseline and follow-up.

RESULTS

At enrolment, median age was 11.4 years, median BMI SDS was 2.87, and 82.2% of patients exhibited one or more disturbed eating behaviours. The prevalence of meal skipping, emotional eating and rapid eating increased with age (P < 0.01). Patients who reported overeating or rapid eating exhibited a 0.06-0.11 higher BMI SDS at enrolment than patients without these disturbed eating behaviours (P < 0.02). After 1 year of treatment, BMI SDS was reduced in 75.7% of patients, and the median reduction was 0.24 (95% confidence interval: 0.22-0.27). Overeating was associated with a higher degree of weight loss, while meal skipping, emotional eating and rapid eating did not associate with the degree of weight loss at follow-up.

CONCLUSIONS

Disturbed eating behaviours were highly prevalent in children and adolescents with overweight or obesity, and varied with age and sex. After 1 year of treatment, the degree of obesity improved, regardless of the presence of disturbed eating behaviours at treatment initiation.

Leptin, adiponectin, and their ratio as markers of insulin resistance and cardiometabolic risk in childhood obesity

BACKGROUND

It is imperative to develop markers for risk stratification and detection of cardiometabolic comorbidities in children with obesity. The adipokines leptin and adiponectin are both involved in fat mass regulation and the development of obesity-related disorders; furthermore, their ratio (leptin/adiponectin ratio) is suggested to be associated with insulin resistance and cardiometabolic risk.

OBJECTIVE

To evaluate associations between fasting serum concentrations of the adipokines (total leptin and adiponectin as well as the L/A ratio) and cardiometabolic comorbidities in children with overweight/obesity.

METHODS

A total of 2258 children with overweight/obesity or normal weight aged 6 to 18 years were studied. Differences in anthropometrics and adipokine concentrations were tested using Wilcoxon rank-sum test. Associations between the adipokines and cardiometabolic risk were tested using Spearman's correlation and logistic regression, adjusted for age and body mass index SD score (BMI-SDS).

RESULTS

Compared to normal weight children; children with overweight/obesity exhibited higher leptin concentrations, lower adiponectin concentrations, and higher L/A ratios. After adjusting for age and degree of obesity, girls with overweight/obesity in the upper quartile range for the L/A ratio, when compared with girls in the lower quartile range, were more likely to have insulin resistance (odds ratio [OR]: 7.78 [95% confidence interval [CI], 3.78-16.65]), dysglycemia (OR: 3.08 [95% CI, 1.35-7.31]), and dyslipidemia (OR: 2.53 [95% CI, 1.18-5.59]); while boys were more likely to have insulin resistance (OR: 4.45 [95% CI, 2.03-10.10]).

CONCLUSIONS

Independent of the degree of obesity, leptin, adiponectin, and the L/A ratio were associated with insulin resistance and other cardiometabolic comorbidities in children with overweight/obesity, but the L/A ratio exhibited stronger associations than the respective adipokines.

The Effect of Overweight and Obesity on Liver Biochemical Markers in Children and Adolescents

BACKGROUND

Elevated plasma concentrations of liver enzymes are routinely used as markers of liver injury in adults and children. Currently, the age- and sex-specific effects of adiposity on pediatric liver enzyme concentrations are unclear.

METHODS

We included participants from 2 cohorts of Danish children and adolescents: 1858 from a population-based cohort and 2155 with overweight or obesity, aged from 6 to 18 years. Age- and sex-specific percentile curves were calculated for fasting plasma concentrations of alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), gamma-glutamyltransferase (GGT), bilirubin, and alkaline phosphatase (ALP) in both cohorts. Hepatic fat content was assessed by proton magnetic resonance spectroscopy in 458 participants.

RESULTS

Concentrations of ALT, AST, LDH, and ALP decreased with age in both girls and boys, while GGT and bilirubin were comparable across age groups in girls and increased slightly with age in boys. Children and adolescents with overweight or obesity exhibited higher concentrations of ALT in all age groups. Concentrations of ALT, and to a lesser degree GGT, increased with age in boys with overweight or obesity. Optimal ALT cut-points for diagnosing hepatic steatosis (liver fat content > 5%) was 24.5 U/L for girls (sensitivity: 55.6%, specificity: 84.0%), and 34.5 U/L for boys (sensitivity: 83.7%, specificity: 68.2%).

CONCLUSIONS

Pediatric normal values of liver enzymes vary with both age and sex. Overweight and obesity is associated with elevated biochemical markers of liver damage. These findings emphasize the need for prevention and treatment of overweight and obesity in children and adolescents. (J Clin Endocrinol Metab XX: 0-0, 2019).

Glucose metabolism in children and adolescents: Population-based reference values and comparisons to children and adolescents enrolled in obesity treatment

BACKGROUND

Alterations in glucose metabolism that lead to the development of metabolic and cardiovascular disease may begin already in childhood.

OBJECTIVE

This study aims to generate pediatric age and sex-specific reference values for fasting concentrations of glucose, hemoglobin A1c (HbA1c), insulin, C-peptide, and homeostasis model assessment: insulin resistance (HOMA-IR) in Danish/North-European white children and adolescents from a population-based cohort and to compare values from children and adolescents with overweight/obesity with this reference.

METHODS

The population- and obesity clinic-based cohorts consisted of 2451 and 1935 children and adolescents between 6 and 18 years of age. Anthropometric measurements and blood samples were obtained and percentile curves were calculated.

RESULTS

In the population-based cohort, glucose, insulin, and HOMA-IR values increased before the expected onset of puberty (P < .05). Thereafter, all variables decreased in girls (P < .05) and HbA1c decreased in boys (P < .05). Concentrations of all measured markers of glucose metabolism were higher in the obesity clinic-based cohort than the population-based cohort (both sexes P < .001). Specifically, insulin and HOMA-IR continued to increase to 18 years in the clinic-based cohort, particularly among boys.

CONCLUSIONS

Fasting glucose, insulin, and HOMA-IR change during childhood, making pediatric reference values essential for timely identification of derangements in glucose metabolism. Children and adolescents with obesity exhibit increased concentrations of these biomarkers.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites-A Randomized Controlled Trial

Cardiac surgery with cardiopulmonary bypass (CPB) causes an acute lung ischemia-reperfusion injury, which can develop to pulmonary dysfunction postoperatively. This sub-study of the Pulmonary Protection Trial aimed to elucidate changes in arterial blood gas analyses, inflammatory protein interleukin-6, and metabolites of 90 chronic obstructive pulmonary disease patients following two lung protective regimens of pulmonary artery perfusion with either hypothermic histidine-tryptophan-ketoglutarate (HTK) solution or normothermic oxygenated blood during CPB, compared to the standard CPB with no pulmonary perfusion. Blood was collected at six time points before, during, and up to 20 h post-CPB. Blood gas analysis, enzyme-linked immunosorbent assay, and nuclear magnetic resonance spectroscopy were used, and multivariate and univariate statistical analyses were performed. All patients had decreased gas exchange, augmented inflammation, and metabolite alteration during and after CPB. While no difference was observed between patients receiving oxygenated blood and standard CPB, patients receiving HTK solution had an excess of metabolites involved in energy production and detoxification of reactive oxygen species. Also, patients receiving HTK suffered a transient isotonic hyponatremia that resolved within 20 h post-CPB. Additional studies are needed to further elucidate how to diminish lung ischemia-reperfusion injury during CPB, and thereby, reduce the risk of developing severe postoperative pulmonary dysfunction.