Homocysteine and cysteine levels in prepubertal children: association with waist circumference and lipid profile

Amino acid profile in overweight and obese prepubertal children - can simple biochemical tests help in the early prevention of associated comorbidities?

Background

It is accepted that plasma branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) are closely related to metabolic risk. Arterial hypertension, metabolic syndrome, endothelial dysfunction, inflammation, and metabolic dysfunction-associated fatty liver disease (MAFLD) are frequently seen in obese patients. Many attempts have been made to find biochemical indicators for the early detection of metabolic complications in children. It is not known if different amino acid profiles and BCAA and AA concentrations in overweight and obese children correlate with chemerin, proinflammatory, and simple biochemical markers. Thus, the study aimed to find out the early markers of cardiovascular disease and MAFLD in overweight and obese children.

Materials and methods

The study included 20 overweight and obese children (M/F 12/8; mean age 7.7 ± 2.3 years; BMI 26.8 ± 5.0 kg/m2) and 12 non-obese children (control group) (M/F 4/8; mean age 6.5 ± 2.2 years; BMI 14.8 ± 1.5 kg/m2). The following plasma amino acids were measured: aspartic acid, glutamic acid, serine, asparagine, glycine, glutamine, taurine, histidine, citrulline, threonine, alanine, arginine, proline, tyrosine, methionine, valine, isoleucine, leucine, phenylalanine, tryptophan, ornithine, and lysine. Chemerin, high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and basic biochemistry parameters were measured.

Results

The mean plasma levels of leucine, isoleucine, valine, phenylalanine, tyrosine, glutamic acid, and alanine were significantly higher in overweight and obese children than in the control group (p<0.03-p<0.0004). Conversely, the mean values of serine, asparagine, glutamine, and citrulline were significantly lower in overweight and obese children than in the control group (p<0.03-p<0.0007). Isoleucine, leucine, valine (BCAAs) tyrosine, and phenylalanine (AAAs) levels showed a positive correlation with uric acid, ALT, hs-CRP, and chemerin (r=0.80-0.36; p<0.05-p<0.00001), but not with IL-6. The mean values of glucose, IL-6, hs-CRP, chemerin, uric acid, and ALT were significantly higher in overweight and obese children than in the control group (p<0.03-p<0.00002). In contrast, the lipid profile did not differ between groups.

Conclusion

An abnormal amino acid profile in overweight and obese pre-pubertal children, accompanied by elevated ALT and UA observed in the studied cohort, may suggest early metabolic disturbances that can potentially lead to metabolic syndrome, or MAFLD, and increased cardiovascular risk.

Association of low-level blood lead with plasma homocysteine in US children and adolescents

Although research in adults has revealed a positive relationship between blood lead levels (BLLs) and homocysteine (Hcy) levels in adults, few studies have investigated this relationship in children and adolescents. We evaluated the relationship between lowlevel blood lead and Hcy levels in US children and adolescents. A total of 8,313 children and adolescents aged 8-19 participated in this study via the National Health and Nutrition Examination Survey 1999-2006. Multivariable linear regression analyses were performed to examine the association between continuous BLLs and Hcy levels. The dose-dependent relationship between continuous BLLs and Hcy levels was analyzed using smooth curve fitting. The average age of participants was 14.1 ± 3.3 years (50.3% male). The mean values of BLLs and Hcy levels were 1.45 μg/dL and 5.77 μmol/L, respectively. In a multivariable adjusted model, an increase in 1.0 μg/dL of BLLs was associated with an elevation of 0.06 μmol/L in Hcy levels (β = 0.06, 95%CI:0.02-0.10, P = 0.001). A linear relationship between BLLs and Hcy levels was discovered using smooth curve fitting (P non-linearity = 0.464). The relationship between low-level blood lead and Hcy levels was stronger on participants with lower serum folate levels (P for interaction = 0.002). Low BLLs were positively associated with plasma Hcy levels in children and adolescents, which varies depending on the levels of folate, vitamin B, and dietary supplements involved in Hcy metabolism.

Total cholesterol and low-density lipoprotein alterations in children and adolescents from Brazil: a prevalence meta-analysis

Objective

The aim of the present study was to evaluate the prevalence of total cholesterol (TC) and low-density lipoprotein (LDL) alterations in children and adolescents in Brazil.

Subjects and methods

A systematic review and meta-analysis of prevalence. The search for articles was carried out in the databases: Medline (PubMed), Embase, Scientific Electronic Library Online (SciELO), Latin American and Caribbean Literature in Health Sciences (Lilacs). The meta-analysis was performed using the random effects model. The I² test was used to identify heterogeneity.

Results

The present metanalysis revealed a significant prevalence of altered lipid profile in children and adolescents in Brazil. Regarding lipoprotein fractions, the prevalence of altered TC level was 27.47% (95% CI 24.36-30.82), and a smaller prevalence was observed for LDL cholesterol (19.29% - 95% CI 15.21-24.16). The models revealed high heterogeneity (I² = 99%; p < 0.01), however the precise source of it was not identified; although type of school, age group, year and the region of Brazil appeared to influence the estimations of altered lipid profiles.

Conclusion

An important prevalence of lipid alterations was observed among Brazilian children and adolescents. Those results reinforce the importance of knowing the lipid profile of children and adolescents to perform early interventions for this public.

Differential expression of cystathionine beta synthase in adolescents with Down syndrome: impact on adiposity

Purpose

Obesity is more prevalent among people with Down Syndrome (DS) compared to general population. In this pilot study, we investigated the effect of cystathionine beta-synthase (CBS) overdosage on the regulation of transsulfuration pathway and the obesity phenotype in fifty adolescents (25 obese/overweight and 25 lean) with trisomy 21.

Methods

The transcriptional levels of CBS in leukocytes and its translational levels in plasma were quantified using real time polymerase chain reaction and enzyme-linked immunosorbent assay respectively. Meanwhile, ultra performance liquid chromatography tandem mass spectrometry was used to determine the plasma concentrations of methionine, homocysteine, cystathionine and cysteine. Fasting plasma lipid profiles were assessed by colorimetric assays. The anthropometric measurements and indices of all subjects were recorded.

Results

Both DS groups had comparable levels of CBS transcripts (p = 0.2734). The plasma levels of the enzyme were significantly higher in the lean DS cases (p = 0.0174) compared to the obese/overweight participants. Total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, methionine, homocysteine, cystathionine and cysteine showed similar plasma levels in both groups. However, the plasma cysteine levels exceeded the normal range in all DS cases. We reported a statistically significant inverse association between CBS enzyme levels and weight (r= - 0.3498, p = 0.0128), hip circumference (r= - 0.3584, p = 0.0106), body mass index (r= - 0.3719, p = 0.0078) and body adiposity index (r= - 0.3183, p = 0.0243).

Conclusions

Our data suggests that the high concentrations of CBS enzyme together with cysteine modulate the DS obesity presumably through increased hydrogen sulfide production which has recently showed anti-adiposity effects.

The association between vitamin B12, folate, homocysteine levels, and carotid intima-media thickness in children with obesity: a cross-sectional study

OBJECTIVES

We aimed to evaluate the association between vitamin B12, folate, homocysteine levels, and carotid intima-media thickness (CIMT) among children with obesity in whom vitamin deficiencies are more frequent.

METHODS

Herein, 100 children with obesity (58 girls) were included (age, 5-18 years). Height, weight, body mass index (BMI), waist circumference (WC), puberty stage, blood pressure, and biochemical values were collected from medical records; standard deviations (SDS) and percentiles were calculated. Obesity was defined as BMI SDS of >+2SDS. Vitamin B12 and folate levels of <300 pg/mL and <4.8 ng/mL, respectively, were considered deficient. A radiologist quantified measurements from the carotid artery.

RESULTS

Mean patient age was 12.52 ± 3.63 years. The mean weight SDS, BMI SDS, and WC/height were +3.37 ± 0.93, +2.93 ± 0.55, and 0.65 ± 0.05, respectively. In pubertal cases, insulin (p<0.001), the homeostatic model assessment for insulin resistance (HOMA-IR) (p=0.001) and homocysteine (p=0.002) levels were higher; vitamin B12 (p<0.001) and folate (p<0.001) levels were lower than those in prepubertal ones. WC and HOMA-IR correlated with CIMT; however, homocysteine levels were not correlated with CIMT.

CONCLUSIONS

In our study, pubertal cases had lower vitamin B12 and folate levels as well as higher homocysteine levels. Although no correlation was identified between homocysteine levels and CIMT, this condition may be related to our study group comprising children, who had a shorter duration of obesity than those in adults. As CIMT was higher in children/adolescents with increased WC, it is proposed that they need central obesity more frequently and carefully follow-up.

Cardiovascular Risk Factors in Children with Obesity, Preventive Diagnostics and Possible Interventions

The increasing burden of obesity plays an essential role in increased cardiovascular morbidity and mortality. The effects of obesity on the cardiovascular system have also been demonstrated in childhood, where prevention is even more important. Obesity is associated with hormonal changes and vascular dysfunction, which eventually lead to hypertension, hyperinsulinemia, chronic kidney disease, dyslipidemia and cardiac dysfunction—all associated with increased cardiovascular risk, leading to potential cardiovascular events in early adulthood. Several preventive strategies are being implemented to reduce the cardiovascular burden in children. This paper presents a comprehensive review of obesity-associated cardiovascular morbidity with the preventive diagnostic workup at our hospital and possible interventions in children.

Homocysteine levels and cardiovascular risk factors in children and adolescents: systematic review and meta-analysis

CONTEXT

Studies have indicated that homocysteine levels are nontraditional markers for cardiovascular disease. The onset of atherosclerotic disease begins in childhood and adolescence; thus, prevention of its risk factors should occur early.

OBJECTIVE

This systematic review and meta-analysis was conducted to summarize the association between high homocysteine levels and traditional cardiovascular risk factors in children and adolescents.

DATA SOURCES

This systematic review and meta-analysis were developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the protocol was submitted to PROSPERO. Only observational studies in children and adolescents with homocysteine levels as an exposure variable and cardiovascular risk factors as outcome variables were included and searched in the following electronic bibliographic databases: PubMed/MEDLINE, Web of Science, Embase, Latin American and Caribbean Literature in Health Sciences, Ovid and Scopus.

DATA EXTRACTION

Two authors independently extracted data from eligible studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale.

DATA ANALYSIS

Seven studies were included in the systematic review; they were published from 1999 to 2017, predominantly were of a cross-sectional design, and mainly evaluated adolescents. In the meta-analysis (n = 6), cross-sectional studies (n = 3) identified that high homocysteine levels were positive and weakly correlated with overweight in children and adolescents (odds ratio, 1.08; 95%CI, 1.04-1.11).

CONCLUSION

High homocysteine levels were weakly associated with overweight in children and adolescents in the reviewed cross-sectional studies. However, for the other traditional cardiovascular risk factors, the findings, although important, were inconclusive. Additional robust longitudinal studies are recommended to be conducted to better identify these associations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018086252.

B-vitamins and metabolic syndrome in Mesoamerican children and their adult parents

OBJECTIVE

To examine the associations between vitamins of the methionine-homocysteine (Hcys) cycle (B6, B12 and folate) and Hcys with metabolic syndrome (MetS) among Mesoamerican children and their adult parents.

DESIGN

We conducted a cross-sectional study. Exposures were plasma vitamins B6 and B12 concentrations, erythrocyte folate and plasma Hcys. In children, the outcome was a continuous metabolic risk score calculated through sex- and age standardisation of waist circumference, the homoeostatic model assessment for insulin resistance, mean arterial pressure (MAP), serum HDL-cholesterol and serum TAG. In parents, the outcome was the prevalence of MetS according to the Adult Treatment Panel III Criteria. We estimated mean differences in the metabolic risk score and prevalence ratios of MetS between quartiles of the exposures using multivariable-adjusted linear and Poisson regression models, respectively.

SETTING

Capital cities of Belize, Guatemala, El Salvador, the Dominican Republic, Honduras, Nicaragua, Panama, Costa Rica and Chiapas State in Mexico.

PARTICIPANTS

In total, 237 school-aged children and 524 parents.

RESULTS

Among children, vitamin B12 was inversely associated with the metabolic risk score (quartiles 4-1 adjusted difference = -0·13; 95 % CI: -0·21, -0·04; Ptrend = 0·008) through MAP, HDL-cholesterol and TAG. In contrast, folate was positively associated with the metabolic risk score (quartiles 4-1 adjusted difference = 0·11; 95 % CI: 0·01, 0·20; Ptrend = 0·02). In adults, vitamin B6 was inversely associated with MetS prevalence, whereas vitamin B12 and folate were positively related to this outcome.

CONCLUSIONS

Vitamins of the methionine-Hcys cycle are associated with MetS in different directions. The associations differ between children and adults.

Changes in feeding habits promoted the differentiation of the composition and function of gut microbiotas between domestic dogs (Canis lupus familiaris) and gray wolves (Canis lupus)

Wolves (Canis lupus) and their domesticated and close relatives, dogs (Canis lupus familiaris), have great differences in their diets and living environments. To the best of our knowledge, the fundamental question of how the abundance and function of the gut microbiota of domestic dogs evolved to adapt to the changes in host feeding habits has yet to be addressed. In this study, our comparative analyses of gut metagenomes showed that the abundance of gut microbiota between the two species have some significant differences. Furthermore, a number of taxa observed in higher numbers in domestic dogs are related to carbohydrate metabolism, which may be because that there were more complicated polysaccharides in dogs diets than that in wolves diets. A significant difference in the abundance of genes encoding glycosyltransferase family 34 (GT34), carbohydrate-binding module family 25 (CBM25), and glycoside hydrolase family 13 (GH13) between the gut microbiota metagenomes of domestic dogs and gray wolves also supported this observation. Furthermore, the domestic dog gut microbiota has greater valine, leucine and isoleucine biosynthesis and nitrogen metabolism. This result showed that compared with wolves, the domestic dog diet contains a smaller amount of animal protein, which is consistent with the dietary composition of wolves and dogs. Our results indicate that the function and abundance of gut microbiota of domestic dogs has been adapted to domestication, which is of great significance for the ability of domestic dogs to adapt to changes in food composition.

Adipocyte-derived Lysophosphatidylcholine Activates Adipocyte and Adipose Tissue Macrophage Nod-Like Receptor Protein 3 Inflammasomes Mediating Homocysteine-Induced Insulin Resistance

The adipose Nod-like receptor protein 3 (NLRP3) inflammasome senses danger-associated molecular patterns (DAMPs) and initiates insulin resistance, but the mechanisms of adipose inflammasome activation remains elusive. In this study, Homocysteine (Hcy) is revealed to be a DAMP that activates adipocyte NLRP3 inflammasomes, participating in insulin resistance. Hcy-induced activation of NLRP3 inflammasomes were observed in both adipocytes and adipose tissue macrophages (ATMs) and mediated insulin resistance. Lysophosphatidylcholine (lyso-PC) acted as a second signal activator, mediating Hcy-induced adipocyte NLRP3 inflammasome activation. Hcy elevated adipocyte lyso-PC generation in a hypoxia-inducible factor 1 (HIF1)-phospholipase A2 group 16 (PLA2G16) axis-dependent manner. Lyso-PC derived from the Hcy-induced adipocyte also activated ATM NLRP3 inflammasomes in a paracrine manner. This study demonstrated that Hcy activates adipose NLRP3 inflammasomes in an adipocyte lyso-PC-dependent manner and highlights the importance of the adipocyte NLRP3 inflammasome in insulin resistance.

Altered gene expression and metabolism in fetal umbilical cord mesenchymal stem cells correspond with differences in 5-month-old infant adiposity gain

The intrauterine period is a critical time wherein developmental exposure can influence risk for chronic disease including childhood obesity. Using umbilical cord-derived mesenchymal stem cells (uMSC) from offspring born to normal-weight and obese mothers, we tested the hypothesis that changes in infant body composition over the first 5 months of life correspond with differences in cellular metabolism and transcriptomic profiles at birth. Higher long-chain acylcarnitine concentrations, lipid transport gene expression, and indicators of oxidative stress in uMSC-adipocytes were related to higher adiposity at 5 months of age. In uMSC-myocytes, lower amino acid concentrations and global differential gene expression for myocyte growth, amino acid biosynthesis, and oxidative stress were related to lower infant percent fat-free mass at 5 months of age, particularly in offspring of obese mothers. This is the first evidence of human infant adipocyte- or myocyte-related alterations in cellular metabolic pathways that correspond with increased adiposity and lower fat-free mass in early infancy. These pathways might reflect the effects of an adverse maternal metabolic environment on the fetal metabolome and genome. Our findings suggest that programmed differences in infant stem cell metabolism correspond with differences in body composition in early life, a known contributor to obesity risk.

Serum Homocysteine and Cysteine Levels and Anthropometric Changes: A Longitudinal Study among Brazilian Children and Adolescents

OBJECTIVE

This article aimed to identify the influence of high serum homocysteine (Hcy) and cysteine (Cys) levels, alone or in conjunction, on changes in anthropometric parameters in children and adolescents over a 12-month follow-up period.

METHODS

This is a cohort study involving 483 boys and girls 7-15 years of age. The outcome variables were body mass index (BMI)-for-age and waist circumference (WC) and the principal exposure variables were serum Hcy and Cys levels, alone or in conjunction. A generalized estimating equation (GEE) approach was used to identify longitudinal changes in the outcome variables.

RESULTS

Irrespective of age, sex, socioeconomic conditions, dietary intake, or the practice of physical activity, the children and adolescents in the fifth quintile of distribution of Hcy levels had a z-score increase of 0.50 (p < 0.01) and a 3.62 cm increase (p < 0.01) in mean BMI-for-age and WC, respectively, over the period of the study. In individuals with Cys values above the fifth quintile, a z-score increase of 0.59 (p < 0.01) and a 5 cm increase (p < 0.01) were found in BMI-for-age and WC, respectively. When serum Hcy and Cys levels were both above the fifth quintile of distribution, a z-score increase of 0.87 (p < 0.01) and a 6.57 cm increase (p < 0.01) were found in mean BMI-for-age and WC, respectively, over the 12-month follow-up.

CONCLUSION

High serum Hcy and Cys levels contributed to an increase in BMI-for-age and WC in children and adolescents over a 12-month follow-up period, with these increases being even greater when these 2 biochemical parameters were simultaneously high.

Changes in pediatric waist circumference percentiles despite reported pediatric weight stabilization in the United States

BACKGROUND

Obesity is a global health concern but the United States has reported a leveling in obesity rates in the pediatric population.

OBJECTIVE

To provide updated waist circumference (WC) percentile values, identify differences across time and discuss differences within the context of reported weight stabilization in a nationally representative sample of American children.

METHODS

Percentiles for WC in self-identified African Americans (AA), European Americans (EA) and Mexican Americans (MA) were obtained from 2009-2014 National Health and Nutrition Examination Survey data (NHANES2014). Descriptive trends across time in 10th, 25th, 50th, 75th and 90th percentile WC distributions were identified by comparing NHANES2012 with previously reported NHANESIII (1988-1994).

RESULTS

WC increased in a monotonic fashion in AA, EA and MA boys and girls. When compared with NHANESIII data, a clear left shift of percentile categories was observed such that values that used to be in the 90th percentile are now in the 85th percentile. Differences in WC were observed in EA and MA boys during a reported period of weight stabilization.

CONCLUSION AND RELEVANCE

WC has changed in the US pediatric population across time, even during times of reported weight stabilization, particularly among children of diverse racial/ethnic backgrounds.

Leptin concentrations and SCD-1 indices in classical homocystinuria: Evidence for the role of sulfur amino acids in the regulation of lipid metabolism

BACKGROUND

We describe body composition, lipid metabolism and Stearoyl-CoA desaturase-1 (SCD-1) indices in patients with classical homocystinuria (HCU).

METHODS

Eleven treated HCU patients and 16 healthy controls were included. Body composition and bone mineral density were assessed by dual X-ray absorptiometry. Sulfur amino acids (SAA) and their derivatives (total homocysteine, cysteine, methionine, S-adenosylmethionine, S-adenosylhomocysteine, and glutathione), lipids (free fatty acids, acylcarnitines, triglycerides and lipoproteins), glucose, insulin, leptin, adiponectin, and isoprostanes were measured in plasma. Insulin resistance was evaluated by HOMA-IR. To estimate liver SCD-1 activity, SCD-16 [16:1(n-7)/16:0] and SCD-18 [18:1(n-9)/18:0] desaturation indices were determined.

RESULTS

In HCU patients, SCD-16 index was significantly reduced (p=0.03). A trend of an association of SCD-16 index with cysteine was observed (r=0.624, p=0.054). HCU patients displayed lower lean mass (p<0.05), with no differences in fat mass percentage. Leptin and low-density lipoprotein concentrations were lower in HCU patients (p<0.05). Femur bone mineral density Z-scores were correlated with plasma cysteine (r=0.829; p=0.04) and total homocysteine (r=-0.829; p=0.04) in HCU patients.

CONCLUSIONS

We report alterations in leptin and SCD-1 in HCU patients. These results agree with previous findings from epidemiologic and animal studies, and support a role for SAA on lipid homeostasis.

Serum homocysteine and cysteine levels and changes in the lipid profile of children and adolescents over a 12-month follow-up period

INTRODUCTION

There is evidence of associations between high serum homocysteine (Hcy) and cysteine (Cys) levels and changes in the lipid profile of adults; however, little information is available with respect to these associations in the pediatric age group.

OBJECTIVE

To identify the effect of high baseline serum Hcy and Cys levels, alone or in conjunction, on the lipid profile of children and adolescents over a 12-month follow-up period.

METHODS

A cohort study involving 540 boys and girls of 7-15 years of age was conducted over 12 months. The outcome variables were the lipid indicators and the principal exposure variable was serum Hcy and Cys levels. A generalized estimating equation (GEE) approach was used to identify the associations of interest.

RESULTS

Irrespective of age, sex, socioeconomic status, diet or anthropometric status, when serum Hcy levels were above the 5th quintile of distribution at baseline, HDL-cholesterol decreased by a mean of 2.91 mg/dl (p < 0.01), while triglyceride levels increased by a mean of 1.58 mg/dl (p < 0.01) over the 12-month follow-up period. In individuals with high baseline Cys levels, there was a reduction of 1.95 mg/dl (p < 0.01) and an increase of 1.76 mg/dl (p < 0.01) in mean serum HDL-cholesterol and triglyceride levels, respectively, over the 12-month period. When serum Hcy and Cys levels were both above the 5th quintile of distribution at baseline, there was a reduction of 3.65 mg/dl (p < 0.01) in mean HDL-cholesterol and an increase of 3.53 mg/dl (p < 0.01) in mean triglyceride levels in the 12 months of follow-up.

CONCLUSIONS

High baseline serum Hcy and Cys levels resulted in a reduction in mean HDL-cholesterol levels and an increase in mean triglycerides levels over the 12 months of follow-up in children and adolescents, with these alterations being greater when these two biochemical parameters were simultaneously high at baseline.

Additive Interaction of MTHFR C677T and MTRR A66G Polymorphisms with Being Overweight/Obesity on the Risk of Type 2 Diabetes

Although both methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms have been associated with type 2 diabetes (T2D), their interactions with being overweight/obesity on T2D risk remain unclear. To evaluate the associations of the two polymorphisms with T2D and their interactions with being overweight/obesity on T2D risk, a case-control study of 180 T2D patients and 350 healthy controls was conducted in northern China. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). After adjustments for age and gender, borderline significant associations of the MTHFR C677T and MTRR A66G polymorphisms with T2D were observed under recessive (OR = 1.43, 95% CI: 0.98-2.10) and dominant (OR = 1.43, 95% CI: 1.00-2.06) models, respectively. There was a significant interaction between the MTHFR 677TT genotype and being overweight/obesity on T2D risk (AP = 0.404, 95% CI: 0.047-0.761), in addition to the MTRR 66AG/GG genotypes (RERI = 1.703, 95% CI: 0.401-3.004; AP = 0.528, 95% CI: 0.223-0.834). Our findings suggest that individuals with the MTHFR 677TT or MTRR 66AG/GG genotypes are more susceptible to the detrimental effect of being overweight/obesity on T2D. Further large-scale studies are still needed to confirm our findings.

Prospective study of serum cysteine and cysteinylglycine and cancer of the head and neck, esophagus, and stomach in a cohort of male smokers

BACKGROUND

The nonessential amino acid cysteine is known to be involved in many antioxidant and anticarcinogenic pathways. Cysteinylglycine is a pro-oxidant metabolite of glutathione and a precursor of cysteine.

OBJECTIVE

To examine the relation between serum cysteine and cysteinylglycine and risk of gastric adenocarcinomas, esophageal squamous cell carcinomas, and head and neck squamous cell carcinomas, we conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention study of male Finnish smokers aged 50-69 y at baseline.

DESIGN

In total, 170 gastric adenocarcinomas, 68 esophageal squamous cell carcinomas, and 270 head and neck squamous cell carcinomas (identified from the Finnish Cancer Registry) were matched one-to-one with cancer-free control subjects on age and the date of serum collection. We calculated ORs and 95% CIs with the use of a multivariate-adjusted conditional logistic regression.

RESULTS

Cysteine had a U-shaped association with gastric adenocarcinomas; a model that included a linear and a squared term had a significant global P-test (P = 0.036). Serum cysteinylglycine was inversely associated with adenocarcinomas of the gastric cardia (OR for above the median compared with below the median: 0.07; 95% CI: 0.01, 0.70; n = 38 cases) but not for other sites. Both cysteine and cysteinylglycine were not associated with esophageal squamous cell carcinoma or head and neck squamous cell carcinoma.

CONCLUSIONS

We observed associations between serum cysteine and cysteinylglycine with upper gastrointestinal cancer risk. Future studies are needed to replicate these findings. This trial was registered at clininicaltrials.gov as NCT00342992.

Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events

Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption.

Dietary Intakes of Folic Acid and Methionine in Early Childhood Are Associated with Body Composition at School Age

BACKGROUND

Deficiency of vitamin B-6, vitamin B-12, folate, folic acid, or methionine may lead to dysregulation of DNA methylation, which might lead to disturbed energy and lipid metabolism.

OBJECTIVE

We aimed to explore whether intakes of vitamin B-6, vitamin B-12, folate, folic acid, and methionine at 1 y are associated with measures of growth and body composition at the age of 6 y.

METHODS

This study was performed in 2922 children participating in The Generation R Study, a population-based prospective cohort study. Dietary intakes of vitamins B-6 and B-12, folate, folic acid, and methionine were assessed at a median age of 12.9 mo by using a validated food-frequency questionnaire. At the age of 6 y, height and weight were measured, and body mass index (BMI; in kg/m(2)) was calculated. Body fat was measured with dual-energy X-ray absorptiometry, and body fat percentage and the ratio of android fat mass to gynoid fat mass (android:gynoid) were calculated.

RESULTS

In models adjusted for maternal and child characteristics, children with folic acid intakes in the highest tertile had a 0.16 SD score (SDS) lower weight (95% CI: -0.31, -0.02 SDS) and a 0.14 SDS lower BMI (95% CI: -0.26, -0.01 SDS) than children in the lowest tertile. Children with vitamin B-12 intakes in the highest tertile had a 0.13 SDS higher android:gynoid (95% CI: 0.00, 0.25 SDS) than children in the lowest tertile. In addition, children with intakes in the highest tertile of methionine had a 0.09 SDS higher BMI (95% CI: 0.01, 0.17) and a 0.12 SDS higher android:gynoid (95% CI: 0.02, 0.22) than children in the lowest tertile. Vitamin B-6 and folate intakes were not associated with any of the body composition outcomes measured.

CONCLUSIONS

In this population of children, early high folic acid intakes were associated with a lower body weight and BMI at the age of 6 y. In contrast, early higher methionine intakes were associated with unfavorable body composition at the age of 6 y. Future studies should investigate long-term consequences of these outcomes on health.

Plasma resistin levels are associated with homocysteine, endothelial activation, and nitrosative stress in obese youths

OBJECTIVE

To evaluate whether serum resistin levels are related to cardiovascular risk in obese children.

DESIGN AND METHODS

Cross-sectional study of 110 children (40 normal weight and 70 severely obese). Clinical and biochemical parameters, including lipid profile, fasting glucose and insulin, and homocysteine, were determined. The levels of adipokines (adiponectin, leptin, and resistin), markers of inflammation (high-sensitivity C-reactive protein (hs-CRP)), endothelial activation (serum concentrations of soluble intercellular and vascular cellular adhesion molecule-1 (sICAM-1, sVCAM-1)), and oxidative/nitrosative stress (malondialdehyde and urinary nitrate/nitrite) were measured.

RESULTS

A partial correlation adjusted by gender, Tanner stage, and body mass index in obese children showed that resistin was significantly related to central obesity (p<0.002), insulin resistance (p<0.005), and homocysteine (p<0.001). No association was found with other metabolic risk factors or hs-CRP levels. Malondialdehyde (p<0.043) and sVCAM-1 (p<0.002) were positively correlated whereas urinary nitrate/nitrite was negatively correlated (p<0.007). In multiple regression analysis homocysteine, sVCAM-1, and urinary nitrate/nitrite remained independent determinants of resistin levels (R(2) adjusted=0.347, p=0.000).

CONCLUSIONS

Resistin could be considered as a promising marker for future cardiovascular disease in obese children.

Molecular nutrition research: the modern way of performing nutritional science

In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.