Association of changes in body fatness and fatty acid composition of plasma phospholipids during early puberty in Japanese children

Palmitoleic and Dihomo-γ-Linolenic Acids Are Positively Associated With Abdominal Obesity and Increased Metabolic Risk in Children

Background: The impact of abdominal obesity (AO) on plasma fatty acid changes and cardiometabolic risk in children who are obese and overweight has rarely been investigated. This study determined whether plasma fatty acid composition differed between children with AO and those without AO and its relationship with metabolic risk, particularly in the obese and overweight groups. Methods: A total of 181 schoolchildren (aged 7-18 years) were included. Anthropometric and biochemical data and plasma fatty acid profiles were analyzed, and the indices of desaturase activity were estimated. Children were categorized based on their body weight and AO status. A continuous metabolic risk score was calculated using the sum of the z-scores of metabolic variables. A one-way analysis of variance test was used to compare the composition ratio of fatty acids between children with and without AO in the obese and overweight groups and normal-weight controls. Pearson analysis was also used to explore significant fatty acid and desaturase indicators associated with metabolic abnormalities. Results: Children who were obese and overweight (N = 126) displayed higher dihomo-γ-linolenic acid (20:3n-6) and γ-linolenic acid (18:3n-6) proportions than normal-weight controls (N = 55), but lower heptadecanoic acid (17:0) proportion, regardless of the AO status of each individual. Obese and overweight children with AO (N = 89), but not their non-AO counterparts (N = 37), exhibited a significantly higher proportion of palmitoleic acid (16:1n-7) than the remaining study groups. Pearson analysis showed that high proportions of palmitoleic acid and dihomo-γ-linolenic acid, as well as increased stearoyl-coenzyme A desaturase-1(16) and delta-6 desaturase and decreased delta-5 desaturase activities, are strongly correlated with weight-height ratio, homeostasis model of assessment values for insulin resistance, hypertriglyceridemia, and continuous metabolic risk scores. Conclusion: Higher palmitoleic acid and dihomo-γ-linolenic acid proportions, as well as increased stearoyl-coenzyme A desaturase-1(16) and delta-6 desaturase and decreased delta-5 desaturase activities are associated with AO and increased metabolic risk in children who are obese and overweight.

Serum polyunsaturated fatty acids in infancy are associated with body composition in adolescence

BACKGROUND

Polyunsaturated fatty acids (PUFA) have been related to the development of adiposity. N-3 PUFA appears to be protective against obesity risk, while n-6 PUFA may be associated with greater adiposity. However, most studies have been conducted among adults. The role of PUFA in infancy is unknown.

OBJECTIVE

To examine associations of serum PUFA at age 1 year with age- and sex-adjusted body mass index Z score (BMIZ) change through age 16 years and body composition at 16 years.

METHODS

We quantified serum PUFA in 636 Chilean infants aged 1 year. We measured BMIZ at ages 1, 5, 10 and 16 years, and body composition by dual energy X-ray absorptiometry at 16 years. We estimated differences in 1- to 16-years BMIZ change between PUFA quartiles from multivariable linear mixed models with restricted cubic splines. At 16 years, we estimated differences in total fat mass (ToFM), truncal fat mass (TrFM), total lean mass (TLM), percent total fat mass (%ToFM) and percent truncal fat mass (%TrFM) between PUFA quartiles using linear regression.

RESULTS

PUFA were not associated with BMIZ change. Alpha-linolenic acid (ALA) was positively associated with TrFM (P = .03) and %TrFM (P < .0001) at 16 years while eicosapentaenoic acid (EPA) was inversely associated with %TrFM (P = .001). Docosapentaenoic acid (DPA) was positively associated with ToFM (P = .01), TrFM (P = .009), %ToFM (P = .02) and %TrFM (P = .02). Gamma-linolenic acid (GLA) and the Δ6-desaturase (D6D) activity index were each positively, linearly associated with ToFM, TrFM and %ToFM. The Δ5-desaturase (D5D) activity index was inversely associated with %TrFM (P = .04).

CONCLUSIONS

ALA, DPA, GLA and the D6D index at 1 year of age were positively associated with adiposity at age 16 years, while EPA and the D5D index were inversely associated with central adiposity. Our results related to EPA and desaturase indices are in agreement with limited prior studies.

Plasma fatty acid metabolic profiling coupled with clinical research reveals the risk factors for atherosclerosis development in type 2 diabetes mellitus

Many publications have reported that the incidence of atherosclerotic cardiovascular diseases is higher in patients with type 2 diabetes mellitus (T2DM) than in the non-diabetic population; however, until now, the reason has been unclear. In this study, 25 males (25/64, 39.06%) and 19 females (19/54, 35.19%) had complications with atherosclerosis after two years. To reveal the risk factors for developing atherosclerosis in patients with T2DM, plasma fatty acid metabolic profiling based on gas chromatography-mass spectrometry was combined with the analysis of clinical biochemical indices. The results of partial least squares-discriminant and canonical correlation analyses suggested that C20:0, C22:6n-3, glycosylated hemoglobin, waist circumference, and waist-to-hip ratio are likely to be closely related to T2DM complicated with atherosclerosis. Metabolomic information is a beneficial supplement to existing clinical indices and is useful in predicting the development of a patient's disease and optimizing the treatment.

Serum Polyunsaturated Fatty Acids in Middle Childhood and Body Mass Index Change Through Adolescence

BACKGROUND

Polyunsaturated fatty acids (PUFA) status in childhood may be associated with adiposity development.

OBJECTIVE

To assess associations of serum PUFA biomarkers in childhood with change in body mass index (BMI)-for-age Z scores (BMIZ) through adolescence.

METHODS

We quantified serum PUFA at ages 5 and 10 years among 418 children from Santiago, Chile. BMI was measured at 5, 10, and 16 years. We compared BMIZ change through age 16 years between quartiles of PUFA at 5 and 10 years and PUFA change 5-10 years by fitting growth curves from mixed effects models.

RESULTS

At age 5 years, serum docosahexaenoic acid was inversely associated with BMIZ change from ages 5 to 16 years. At age 10 years, arachidonic acid (AA) was nonlinearly positively related to BMIZ change from ages 10 to 16 years. Change in AA and the Δ5-desaturase (D5D) activity index between 5 and 10 years were each positively associated with BMIZ change from ages 10 to 16 years. Change in eicosapentaenoic acid was inversely associated with change in BMIZ.

CONCLUSIONS

Serum long-chain n-3 PUFA in middle childhood were associated with less BMI gain through adolescence, whereas AA and D5D activity was related to greater BMI gain.

The role of a FADS1 polymorphism in the association of fatty acid blood levels, BMI and blood pressure in young children-Analyses based on path models

Background

The recent obesity epidemic in children also showed an increase in the prevalence of hypertension. As blood pressure (BP) is associated with (long-chain) polyunsaturated fatty acids (LC PUFA), genetic variation in desaturase enzymes being involved in the synthesis of LC PUFA may be associated with BP. This study aimed to investigate the direct effects (independent of mediating variables) and indirect effects (mediated through intermediate variables) of a common variant in the FADS1 gene, rs174546, known to affect delta-5 desaturase (D5D) activity on PUFA level, body mass index (BMI) and BP.

Methods

A subsample of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) baseline survey including 520 children aged 2 to <10 years from six European countries was included. The association between rs174546 (T<C) and BP z-score as well as the mediating effects of selected key PUFA levels (dihomo-gamma-linolenic acid, DGLA; arachidonic acid, ARA; eicosapentaenoic acid, EPA) or estimated D5D activity (D5D index) and BMI z-score were investigated through path model analyses, adjusting for sex, age, educational level of parents, family history of hypertension, lifestyle factors and blood levels of saturated and monounsaturated fatty acids, triglycerides and low density lipoprotein cholesterol. Whole blood fatty acids were measured by a validated gas chromatographic method and recorded as percentage of weight of all fatty acids detected.

Results

Minor allele carriers of the SNP rs174546 had significantly higher DGLA and lower ARA and EPA levels as well as a lower D5D index. Via ARA and BMI z-score, the polymorphism had an indirect lowering effect on systolic BP z-score for each additional T allele (standardized effect estimate -0.057, p = 0.007). For DGLA, EPA and D5D index, the indirect effects of rs174546 on systolic BP were also negative but did not reach significance. DGLA and EPA had an increasing indirect effect on systolic BP via BMI. Results for diastolic BP were in general similar but effect estimates were lower compared to systolic BP.

Conclusion

Genetic variation in FADS1 influences BP via ARA and BMI indicating a favorable effect of the minor allele in SNP rs174546. Thus, polymorphisms with an impact on the D5D activity may play a role for the BP level mediated through PUFA and BMI. Therefore, health effects of dietary n-6 and n-3 PUFA may vary depending on genetic FADS1 variants.

Relationship between Changes in Fatty Acid Composition of the Erythrocyte Membranes and Fatty Acid Intake during Pregnancy in Pregnant Japanese Women

OBJECTIVE

Docosahexaenoic acid (DHA) is an important nutrient required by pregnant women and fetuses. Several studies suggest that fatty acid composition changes during pregnancy. However, the association of longitudinal changes in erythrocyte fatty acid composition and dietary fatty acid intake during pregnancy is not well understood. We assessed the relationship between fatty acid composition of the erythrocyte membranes and fatty acid intake at each trimester in pregnant Japanese women.

METHODS

We conducted a prospective hospital-based cohort study. We investigated fatty acid composition of the erythrocyte membranes and intake of fatty acids during the three trimesters in 178 healthy, pregnant Japanese women.

RESULTS

The eicosapentaenoic acid and arachidonic acid percentage of the erythrocyte membranes significantly decreased. The percentages of linoleic acid and α-linolenic acid significantly increased during pregnancy. The DHA percentage in the erythrocyte membranes decreased from the second to the third trimester. The DHA percentage in the erythrocyte membranes positively correlated with DHA intake in the third trimester.

CONCLUSION

In pregnant Japanese women, the fatty acid composition of the erythrocyte membranes markedly changed throughout pregnancy. The DHA intake in the third trimester may be insufficient to maintain DHA percentage in the maternal erythrocyte membranes.

Desaturase Activity Is Associated With Weight Status and Metabolic Risk Markers in Young Children

CONTEXT

Activity of delta-9, delta-6, and delta-5 desaturases (D9D, D6D, D5D) are associated with obesity, insulin resistance, and dyslipidemia.

OBJECTIVE

To investigate the association of estimated desaturase activities with weight status, insulin resistance, and dyslipidemia in children, cross-sectionally and longitudinally.

DESIGN

The IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) cohort study was used, with examinations at baseline (T0) and after 2 years (T1).

SETTING AND PARTICIPANTS

Children aged 2 to less than 10 years from eight European countries were recruited in kindergartens/primary schools. Children with available data on fatty acids, outcome, and covariate information were included in the analyses.

METHODS

Whole blood fatty acids were analyzed in 2600 children at baseline. D9D (16:1n-7/16:0), D6D (20:3n-6/18:2n-6), and D5D (20:4n-6/20:3n-6) activities were estimated from product-precursor fatty acids ratios. Body mass index (BMI), Homeostatic Model Assessment index, and high-density lipoprotein cholesterol (HDL), and triglycerides (TG) served as outcomes for weight status, insulin resistance, and dyslipidemia, respectively. Linear and logistic regression and repeated measures models were used to assess the cross-sectional and longitudinal associations between desaturase activity and outcomes.

RESULTS

In the cross-sectional analysis, D9D and D6D were positively associated with BMI and TG z-scores and inversely with HDL z-scores. D5D was inversely associated with BMI and TG z-scores (ie, a D5D increase of 1 unit is associated with a BMI z-score decrease of 0.07 and a 28% lower odds ratio for TG ≥ 75th percentile). Longitudinally, similar associations were found for T0 desaturase activities with BMI and for T0 D6D with HDL at follow-up (T1). Baseline D6D and D5D were positively associated with the change of HDL z-score from T0 to T1, and D6D with the change of Homeostatic Model Assessment index z-score.

CONCLUSION

Desaturase activities are associated with metabolic risk markers already in young children and appear to predict the metabolic risk.

Reference values of whole-blood fatty acids by age and sex from European children aged 3-8 years

OBJECTIVES

To establish reference values for fatty acids (FA) especially for n-3 and n-6 long-chain polyunsaturated FAs (LC PUFA) in whole-blood samples from apparently healthy 3-8-year-old European children. The whole-blood FA composition was analysed and the age- and sex-specific distribution of FA was determined.

DESIGN AND SUBJECTS

Blood samples for FA analysis were taken from 2661 children of the IDEFICS (identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study cohort. Children with obesity (n=454) and other diseases that are known to alter the FA composition (n=450) were excluded leaving 1653 participants in the reference population.

MEASUREMENTS

The FA composition of whole blood was analysed from blood drops by a rapid, validated gas chromatographic method.

RESULTS

Pearson correlation coefficients showed an age-dependent increase of C18:2n-6 and a decrease of C18:1n-9 in a subsample of normal weight boys and girls. Other significant correlations with age were weak and only seen either in boys or in girls, whereas most of the FA did not show any age dependence. For age-dependent n-3 and n-6 PUFA as well as for other FA that are correlated with age (16:0, C18:0 and C18:1n-9) percentiles analysed with the general additive model for location scale and shape are presented. A higher median in boys than in girls was observed for C20:3n-6, C20:4n-6 and C22:4n-6.

CONCLUSIONS

Given the reported associations between FA status and health-related outcome, the provision of FA reference ranges may be useful for the interpretation of the FA status of children in epidemiological and clinical studies.

Associations between estimated desaturase activity and insulin resistance in korean boys

OBJECTIVES

Obesity in childhood increases the risk of obesity in adulthood, and is predictive of the development of metabolic disorders. The fatty acid compositions of various tissues, including blood, are associated with obesity and obesity-associated disorders. Thus, tracking plasma phospholipid (PL) features and metabolic parameters in young individuals may strengthen the utility of fatty acid composition as an early biomarker of future metabolic disorders.

METHODS

Anthropometric and blood biochemical data were obtained from 131 Korean males aged 10.5 ± 0.4 years, and followed up at 2 years. We analyzed the plasma PL fatty acids according to obesity. Obese children were defined as those with a body mass index (BMI) greater than the 85(th) percentile for age and gender, based on Korean child growth standards.

RESULTS

Activities of lipid desaturases, stearyl-CoAD (SCD-16,16:1n-7/16:0), delta-6D (D6D, 20:3n-6/18:2n-6), and delta-5D (D5D, 20:4n-6/20:3n-6), were estimated. Obese individuals had significantly higher proportions of palmitoleic acid (16:1n-7) and dihomo-gamma linolenic acid (DGLA, 20:3n-6) at both baseline and follow-up than did lean individuals. The activities of SCD-16 and D6D were higher in obese than lean boys. The baseline SCD-16 activity level was positively associated with the baseline waist circumference (WC) and the metabolic risk score. The baseline D6D level was positively associated with WC and also with the homeostasis model of assessment of insulin resistance (HOMA-IR), a surrogate marker of insulin resistance (IR), and metabolic risk score at both baseline and follow-up.

CONCLUSION

In young Korean males, higher D6D activity predicts the future development of IR and associated metabolic disorders including dyslipidemia.

Prediction of the presence of insulin resistance using general health checkup data in Japanese employees with metabolic risk factors

AIM

The aim of the current study was to develop a predictive model of insulin resistance using general health checkup data in Japanese employees with one or more metabolic risk factors.

METHODS

We used a database of 846 Japanese employees with one or more metabolic risk factors who underwent general health checkup and a 75-g oral glucose tolerance test (OGTT). Logistic regression models were developed to predict existing insulin resistance evaluated using the Matsuda index. The predictive performance of these models was assessed using the C statistic.

RESULTS

The C statistics of body mass index (BMI), waist circumference and their combined use were 0.743, 0.732 and 0.749, with no significant differences. The multivariate backward selection model, in which BMI, the levels of plasma glucose, high-density lipoprotein (HDL) cholesterol, log-transformed triglycerides and log-transformed alanine aminotransferase and hypertension under treatment remained, had a C statistic of 0.816, with a significant difference compared to the combined use of BMI and waist circumference (p＜0.01). The C statistic was not significantly reduced when the levels of log-transformed triglycerides and log-transformed alanine aminotransferase and hypertension under treatment were simultaneously excluded from the multivariate model (p=0.14). On the other hand, further exclusion of any of the remaining three variables significantly reduced the C statistic (all p＜0.01).

CONCLUSIONS

When predicting the presence of insulin resistance using general health checkup data in Japanese employees with metabolic risk factors, it is important to take into consideration the BMI and fasting plasma glucose and HDL cholesterol levels.