Metabolite ratios as potential biomarkers for type 2 diabetes: a DIRECT study.

AIMS/HYPOTHESIS: Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes. METHODS: We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case-control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders. RESULTS: There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p < 9.2 × 10-7). These associations were significantly stronger compared with the individual metabolite components. One of the ratios, valine to phosphatidylcholine acyl-alkyl C32:2 (PC ae C32:2), in addition showed a directionally consistent positive association with OGTT-derived measures of insulin secretion and resistance (p ≤ 5.4 × 10-3) and prevalent type 2 diabetes (ORVal_PC ae C32:2 2.64 [ß 0.97 ± 0.09], p = 1.0 × 10-27). Furthermore, Val_PC ae C32:2 predicted incident diabetes independent of established risk factors in two epidemiological cohort studies (HRVal_PC ae C32:2 1.57 [ß 0.45 ± 0.06]; p = 1.3 × 10-15), leading to modest improvements in the receiver operating characteristics when added to a model containing a set of established risk factors in both cohorts (increases from 0.780 to 0.801 and from 0.862 to 0.865 respectively, when added to the model containing traditional risk factors + glucose). CONCLUSIONS/INTERPRETATION: In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors.

Longitudinal sonographic assessment of abdominal fat distribution from 2 to 5 years of age.

BACKGROUND: To better understand children's adipose tissue (AT) development and distribution, longitudinal data from direct assessment methods are valuable. Previously, we reported sonographic data on abdominal subcutaneous and preperitoneal fat areas ≤1 year of age. METHODS: Sonographic measurements were annually pursued to assess the development of fat compartments in 2-5 year-old children. The effect of sex and correlations with comprehensive anthropometry (e.g., BMI percentiles, skinfold thickness (SFT) measurements, and waist circumference) are presented. RESULTS: Subcutaneous fat areas increased modestly and were significantly greater in females at each time point investigated. Preperitoneal fat area increased significantly over time (all P values < 0.001) with greater area in females from 3 years onward (e.g., at 3 years estimated mean difference -4.8 mm2; 95% CI: -8.6, -0.9; P = 0.016). The strongest correlations for subcutaneous fat area were consistently observed for SFT measurements. Preperitoneal fat area showed rather weak to moderate correlations, with greater correlation coefficients for SFT measurements compared to waist circumference. CONCLUSION: For the first time, longitudinal ultrasound data on abdominal body fat covering preschool age are presented. Evaluation revealed a differential development of fat compartments, depending on children's age and sex with SFT measurements as the best predictor for both fat depots.

Cord blood and child plasma adiponectin levels in relation to childhood obesity risk and fat distribution up to 5 y.

BACKGROUND: Few human studies have explored the role of adiponectin in early life on growth and adipose tissue development. METHODS: High molecular weight (HMW) and total adiponectin levels from 141 cord blood samples and plasma blood samples from 40 3-y-old children were analyzed. Associations between adiponectin levels in cord blood and child plasma, and infant/child growth and fat mass measurements up to the age of 5 y were assessed using linear regression models. RESULTS: HMW cord blood adiponectin was positively associated with weight, BMI percentiles, and lean body mass at birth only. At 3 and 4 y, positive associations were found with cord blood adiponectin and sum of four skinfold thickness measures and percentage of body fat following adjustment for maternal and child covariates, but did not persist at 5 y. There was no significant evidence of an association between child plasma HMW adiponectin and growth or body composition characteristics at 3-5 y. CONCLUSION: Our results do not support the hypothesis that HMW cord blood adiponectin is a useful biomarker for the prediction of adiposity at the age of 5 y. Additionally, there is no evidence that plasma HMW adiponectin levels predict body fat distribution between 3-5 y.

Lactation is associated with altered metabolomic signatures in women with gestational diabetes.

AIMS/HYPOTHESIS: Lactation for >3 months in women with gestational diabetes is associated with a reduced risk of type 2 diabetes that persists for up to 15 years postpartum. However, the underlying mechanisms are unknown. We examined whether in women with gestational diabetes lactation for >3 months is associated with altered metabolomic signatures postpartum. METHODS: We enrolled 197 women with gestational diabetes at a median of 3.6 years (interquartile range 0.7-6.5 years) after delivery. Targeted metabolomics profiles (including 156 metabolites) were obtained during a glucose challenge test. Comparisons of metabolite concentrations and ratios between women who lactated for >3 months and women who lactated for ≤3 months or not at all were performed using linear regression with adjustment for age and BMI at the postpartum visit, time since delivery, and maternal education level, and correction for multiple testing. Gaussian graphical modelling was used to generate metabolite networks. RESULTS: Lactation for >3 months was associated with a higher total lysophosphatidylcholine/total phosphatidylcholine ratio; in women with short-term follow-up, it was also associated with lower leucine concentrations and a lower total branched-chain amino acid concentration. Gaussian graphical modelling identified subgroups of closely linked metabolites within phosphatidylcholines and branched-chain amino acids that were affected by lactation for >3 months and have been linked to the pathophysiology of type 2 diabetes in previous studies. CONCLUSIONS/INTERPRETATION: Lactation for >3 months in women with gestational diabetes is associated with changes in the metabolomics profile that have been linked to the early pathogenesis of type 2 diabetes.

Sonographic assessment of abdominal fat distribution during the first year of infancy.

BACKGROUND: Longitudinal data regarding the fat distribution in the early postnatal period is sparse. METHODS: We performed ultrasonography (US) as a noninvasive approach to investigate the development of abdominal subcutaneous (SC) and preperitoneal (PP) fat depots in infants ≤1 y and compared longitudinal US data with skinfold thickness (SFT) measurements and anthropometry in 162 healthy children at 6 wk, 4 mo, and 1 y postpartum. RESULTS: US was found to be a reproducible method for the quantification of abdominal SC and PP adipose tissue (AT) in this age group. Thickness of SC fat layers significantly increased from 6 wk to 4 mo and decreased at 1 y postpartum, whereas PP fat layers continuously increased. Girls had a significantly higher SC fat mass compared to boys, while there was no sex-specific difference in PP fat thickness. SC fat layer was strongly correlated with SFT measurements, while PP fat tissue was only weakly correlated with anthropometric measures. CONCLUSION: US is a feasible and reproducible method for the quantification of abdominal fat mass in infants ≤1 y of age. PP and SC fat depots develop differentially during the first year of life.

Human placental transcriptome shows sexually dimorphic gene expression and responsiveness to maternal dietary n-3 long-chain polyunsaturated fatty acid intervention during pregnancy.

BACKGROUND: Previously we have examined the effect of maternal dietary n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation during pregnancy on offspring fat mass. Considering the involvement of the placenta in fetal programming, we aimed to analyze the sex-specific gene expression in human term placenta and its response to the n-3 LCPUFA intervention, as well as their correlations to offspring adiposity. RESULTS: Placental gene expression was assessed in a control and n-3 LCPUFA intervention group by DNA microarrays, biological pathway analyses and RT-qPCR validation. Expression data were correlated with sex steroid hormone levels in placenta and cord plasma, and offspring anthropometric data. Transcriptome data revealed sexually dimorphic gene expression in control placentas per se, whereas in intervention placentas sex-specific expression changed, and more n-3 LCPUFA-regulated genes were found in female than male placentas. Sexually dimorphic gene expression and n-3 LCPUFA-responsive genes were enriched in the pathway for cell cycle and its associated modulator pathways. Significant mRNA expression changes for CDK6, PCNA, and TGFB1 were confirmed by RT-qPCR. CDK6 and PCNA mRNA levels correlated with offspring birth weight and birth weight percentiles. Significantly reduced placental estradiol-17ß/testosterone ratio upon intervention found in female offspring correlated with mRNA levels for the 'Wnt signaling' genes DVL1 and LRP6. CONCLUSIONS: Overall, human placentas show sexually dimorphic gene expression and responsiveness to maternal n-3 LCPUFA intervention during pregnancy with more pronounced effects in female placentas. The absence of correlations of analyzed placental gene expression with offspring adipose tissue growth in the first year is not mutually exclusive with programming effects, which may manifest later in life, or in other physiological processes.

Breast milk fatty acid profile in relation to infant growth and body composition: results from the INFAT study.

BACKGROUND: There is some evidence that the n-6/n-3 long-chain polyunsaturated fatty acids (LCPUFAs) ratio in early nutrition, and thus in breast milk, could influence infant body composition. METHODS: In an open-label randomized controlled trial (RCT), 208 healthy pregnant women were allocated to a dietary intervention (supplementation with 1,200 mg n-3 LCPUFAs per day and instructions to reduce arachidonic acid (AA) intake) from the 15th wk of gestation until 4 mo of lactation or to follow their habitual diet. Breast milk LCPUFAs at 6 wk and 4 mo postpartum were related to infant body composition assessed by skinfold thickness (SFT) measurements and ultrasonography during the first year of life. RESULTS: Dietary intervention significantly reduced breast milk n-6/n-3 LCPUFAs ratio. In the whole sample, early breast milk docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and n-3 LCPUFAs at 6 wk postpartum were positively related to the sum of four SFT measurements at age 1. Breast milk AA and n-6 LCPUFAs at 6 wk postpartum were negatively associated with weight, BMI, and lean body mass (LBM) up to 4 mo postpartum. CONCLUSION: Breast milk n-3 LCPUFAs appear to stimulate fat mass growth over the first year of life, whereas AA seems to be involved in the regulation of overall growth, especially in the early postpartum period.

Sensory and molecular characterisation of human milk odour profiles after maternal fish oil supplementation during pregnancy and breastfeeding.

The odourant profile of human milk has been proposed to be modulated by the composition of the maternal diet via the transference of specific food aromas to the milk, such that neonates are exposed to these aromas and are prepared for latter acceptance of specific diets. For that reason the aim of the present study was to investigate whether specific fish oil odour constituents translate into human milk. To achieve this goal, human sensory analyses and qualitative and quantitative instrumental determination of fish oil odourants were performed on the fish oil, as well as on human milk obtained from mothers after long-term fish oil supplementation in comparison to a control group. Sensory and analytical data showed that no statistically significant modification occurred from fish oil intervention.

Associations between long-chain PUFAs in maternal blood, cord blood, and breast milk and offspring body composition up to 5 years: follow-up from the INFAT study.

BACKGROUND/OBJECTIVES: Limited research suggests that exposure to long-chain PUFAs (LCPUFAs) during perinatal development can influence adipose tissue expansion later in life. In previous analyses, we observed that maternal LCPUFAs in late gestation promote offspring gestational growth, whereas breast milk n-3 LCPUFAS promote adipogenesis in infants up to 1 year. This follow-up analysis examines these relationships in offspring up to 5 years. SUBJECTS/METHODS: In this observational study of 169 children, relationships between n-3, n-6 LCPUFAs, and the n-6/n-3 LCPUFA ratio in maternal blood at 32 weeks' gestation, cord blood, and breast milk, and anthropometry in offspring from 2 to 5 years were investigated. Body composition was assessed with indirect (i.e., body weight, BMI percentiles, sum of four skinfold thicknesses) and direct (i.e., ultrasonography, magnetic resonance imaging in a subgroup) measurement tools. RESULTS: Maternal and cord blood LCPUFAs were largely not shown to be related to offspring body composition. Breast milk n-3 LCPUFAs were significantly positively related to several measurements of child anthropometry at 2 and 4 y, but only a positive relationship between n-3 LCPUFAs and lean body mass remained statistically significant at 5 y. Breast milk n-6/n-3 LCPUFA ratio was inversely related to weight and BMI percentiles at 2 y, and lean body mass at 4 and 5 y. CONCLUSIONS: Results from this follow-up do not provide sufficient evidence that LCPUFAs in maternal blood, cord blood, and breast milk predict offspring adiposity in children up to 5 years.

Leptin in Maternal Plasma and Cord Blood as a Predictor of Offspring Adiposity at 5 Years: A Follow-up Study.

OBJECTIVE: Perinatal leptin exposure may modulate the risk of adiposity in early childhood. In previous analyses, negative associations between maternal (32 weeks' gestation) and cord blood leptin and offspring body composition at 2 years were observed. METHODS: Associations between maternal/cord blood leptin were assessed with indirect (i.e., body weight, BMI percentiles, sum of 4 skinfold thicknesses), and direct (i.e., ultrasonography, magnetic resonance imaging in a subgroup) growth and adipose tissue (AT) measurements in 120 children aged 3 to 5 years. RESULTS: Maternal leptin was not shown to be associated with offspring body composition in univariate analyses. In adjusted analyses, some weak negative associations were observed with weight and BMI percentiles but not with sum of 4 skinfold thicknesses or calculated body fat at 3 to 5 years. Cord blood leptin was inversely related to offspring body composition, but effect sizes were small and not consistently statistically significant. No evidence of associations with direct AT measurements was observed. CONCLUSIONS: Although some negative relationships with indirect measurements of AT mass were observed, the results of this study do not provide sufficient evidence that maternal plasma or cord blood leptin is clinically relevant predictors of obesity or body fat distribution in early childhood.

Impact of Dietary Macronutrient Intake during Early and Late Gestation on Offspring Body Composition at Birth, 1, 3, and 5 Years of Age.

Dietary intake during pregnancy as a possible modifiable risk factor for childhood obesity is poorly explored. In a prospective observational study, two multivariable regression models were therefore used to associate maternal diet at 15 and 32 weeks’ gestation with offsprings’ body composition and fat distribution at birth, 1, 3, and 5 years. Mean energy intake was 2157 ± 375 kcal (n = 186) in early and 2208 ± 460 kcal (n = 167) in late gestation. The partition model showed mostly no significant associations between maternal diet in early pregnancy and offspring body composition. In late pregnancy, higher fat intake was negatively associated with clinical outcomes at birth, 1, and 5 years. Protein intake was negatively associated with BMI z score (zBMI) at 3 and 5 years. A 10 g increase in fiber was associated with an increase of 3.50 mm² abdominal subcutaneous fat at 1, 172.49 g fat mass at 3, and 0.23 zBMI at 5 years. Results were largely comparable in the substitution model. An incremental increase in fat and protein at the expense of carbohydrates in late but not early pregnancy may be associated with lower fat mass up to 5 years. Findings require confirmation by additional prospective studies.

Efficacy of vildagliptin for prevention of postpartum diabetes in women with a recent history of insulin-requiring gestational diabetes: A phase II, randomized, double-blind, placebo-controlled study.

OBJECTIVE: Women with insulin-requiring gestational diabetes mellitus (GDM) are at high risk of developing diabetes within a few years postpartum. We implemented this phase II study to test the hypothesis that vildagliptin, a dipeptidyl peptidase-4 inhibitor, is superior to placebo in terms of reducing the risk of postpartum diabetes. METHODS: Women with insulin-requiring GDM were randomized to either placebo or 50 mg vildagliptin twice daily for 24 months followed by a 12-month observation period (EudraCT: 2007-000634-39). Both groups received lifestyle counseling. The primary efficacy outcomes were the diagnosis of diabetes (American Diabetes Association (ADA) criteria) or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT). RESULTS: Between 2008 and 2015, 113 patients (58 vildagliptin, 55 placebo) were randomized within 2.2-10.4 (median 8.6) months after delivery. At the interim analysis, nine diabetic events and 28 IFG/IGT events had occurred. Fifty-two women withdrew before completing the treatment phase. Because of the low diabetes rate, the study was terminated. Lifestyle adherence was similar in both groups. At 24 months, the cumulative probability of postpartum diabetes was 3% and 5% (hazard ratio: 1.03; 95% confidence interval: 0.15-7.36) and IFG/IGT was 43% and 22% (hazard ratio: 0.55; 95% confidence interval: 0.26-1.19) in the placebo and vildagliptin groups, respectively. Vildagliptin was well tolerated with no unexpected adverse events. CONCLUSIONS: The study did not show significant superiority of vildagliptin over placebo in terms of reducing the risk of postpartum diabetes. However, treatment was safe and suggested some improvements in glycemic control, insulin resistance, and ß-cell function. The study identified critical issues in performing clinical trials in the early postpartum period in women with GDM hampering efficacy assessments. With this knowledge, we have set a basis for which properly powered trials could be performed in women with recent GDM. TRIAL REGISTRATION NUMBER AT CLINICALTRIALS.GOV: NCT01018602.

Reduction of the n-6:n-3 long-chain PUFA ratio during pregnancy and lactation on offspring body composition: follow-up results from a randomized controlled trial up to 5 y of age.

BACKGROUND: It has been hypothesized that the n-6:n-3 (ω-6:ω-3) long-chain polyunsaturated fatty acid (LCPUFA) ratio in the maternal diet during the prenatal and early postnatal phase positively affects the body composition of the offspring. However, only limited data from prospective human intervention studies with long-term follow-up are available. OBJECTIVE: We assessed the long-term effects of a reduced n-6:n-3 LCPUFA ratio in the diets of pregnant and lactating women [1020 mg docosahexaenoic acid (DHA) plus 180 mg eicosapentaenoic acid (EPA)/d together with an arachidonic acid-balanced diet compared with a control diet] on the body weights and compositions of their offspring from 2 to 5 y of age with a focus on the 5-y results. DESIGN: Participants in the randomized controlled trial received follow-up assessments with annual body-composition measurements including skinfold thickness (SFT) measurements (primary outcome), a sonographic assessment of abdominal subcutaneous and preperitoneal fat, and child growth. In addition, abdominal MRI was performed in a subgroup of 5-y-old children. For the statistical analysis, mixed models for repeated measures (MMRMs) were fit with the use of data from each visit since birth (except for MRI). RESULTS: Maternal LCPUFA supplementation did not significantly influence the children's sum of 4 SFTs [means ± SDs at 5 y of age: intervention, 23.9 ± 4.7 mm (n = 57); control, 24.5 ± 5.0 mm (n = 55); adjusted mean difference, -0.5 (95% CI: -2.2, 1.2)], growth, or ultrasonography measures at any time point in the adjusted MMRM model (all P values < 0.05). Results were consistent with abdominal MRI measurements (n = 44) at 5 y of age, which showed no significant differences in subcutaneous and visceral adipose tissue volumes and ratios. CONCLUSION: The current study provides no evidence that a dietary reduction of the n-6:n-3 LCPUFA ratio in the maternal diet during pregnancy and lactation is a useful early preventive strategy against obesity at preschool age. This trial was registered at clinicaltrials.gov as NCT00362089.

Accuracy and reproducibility of adipose tissue measurements in young infants by whole body magnetic resonance imaging.

PURPOSE: MR might be well suited to obtain reproducible and accurate measures of fat tissues in infants. This study evaluates MR-measurements of adipose tissue in young infants in vitro and in vivo. MATERIAL AND METHODS: MR images of ten phantoms simulating subcutaneous fat of an infant's torso were obtained using a 1.5T MR scanner with and without simulated breathing. Scans consisted of a cartesian water-suppression turbo spin echo (wsTSE) sequence, and a PROPELLER wsTSE sequence. Fat volume was quantified directly and by MR imaging using k-means clustering and threshold-based segmentation procedures to calculate accuracy in vitro. Whole body MR was obtained in sleeping young infants (average age 67±30 days). This study was approved by the local review board. All parents gave written informed consent. To obtain reproducibility in vivo, cartesian and PROPELLER wsTSE sequences were repeated in seven and four young infants, respectively. Overall, 21 repetitions were performed for the cartesian sequence and 13 repetitions for the PROPELLER sequence. RESULTS: In vitro accuracy errors depended on the chosen segmentation procedure, ranging from 5.4% to 76%, while the sequence showed no significant influence. Artificial breathing increased the minimal accuracy error to 9.1%. In vivo reproducibility errors for total fat volume of the sleeping infants ranged from 2.6% to 3.4%. Neither segmentation nor sequence significantly influenced reproducibility. CONCLUSION: With both cartesian and PROPELLER sequences an accurate and reproducible measure of body fat was achieved. Adequate segmentation was mandatory for high accuracy.

Beneficial effects of breastfeeding in women with gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) increases the future risk of developing type 2 diabetes mellitus (T2DM). There is now a growing evidence that breastfeeding has short- and long-term health benefits for mothers with GDM. Mothers with GDM who breastfeed have improved lipid and glucose metabolic profiles for the first 3 months after birth. However, women with GDM are less likely to breastfeed and, if they do, breastfeeding is usually continued for a shorter duration compared with women without GDM. One long-term prospective study followed women with GDM from delivery for up to 19 years postpartum, and found that breastfeeding for ≥3 months reduced the risk of T2DM and delayed the development of T2DM by a further 10 years compared with breastfeeding for <3 months. However, the physiological mechanisms underlying the protective effects of breastfeeding are still unknown, even though it is important to gain a full understanding of the pathways involved in these effects. Therefore, the purpose of this review is to provide a comprehensive analysis of the recent developments in the field of GDM and breastfeeding. We reviewed data from animal experiments and human studies. We also provide insight into the molecular pathways and describe promising topics for future research.

Effect of reducing the n-6/n-3 fatty acid ratio on the maternal and fetal leptin axis in relation to infant body composition.

OBJECTIVE: To investigate the effect of reducing the n-6/n-3 fatty acid ratio in maternal nutrition on the maternal and cord blood leptin axis and their association with infant body composition up to 2 years. DESIGN AND METHODS: 208 healthy pregnant women were randomized to either a dietary intervention to reduce the n-6/n-3 fatty acid ratio from 15th week of gestation until 4 months postpartum or a control group. Leptin, soluble leptin receptor and free leptin index were determined in maternal and cord plasma and related to infant body composition assessed by skinfold thicknesses up to 2 years. RESULTS: The intervention had no effect on either the maternal or fetal leptin axis. Maternal leptin in late pregnancy was inversely related to infant weight and lean body mass (LBM) up to 2 years, after multiple adjustments. Cord leptin was positively related to weight, body fat, and LBM at birth, and inversely associated with weight, BMI, fat mass, and LBM at 2 years and weight gain up to 2 years. The contribution of cord leptin to infant outcomes was overall stronger compared with maternal leptin. CONCLUSIONS: Both, maternal and fetal leptin were associated with subsequent infant anthropometry with a greater impact of fetal leptin.

Postpartum outcomes in women with gestational diabetes and their offspring: POGO study design and first-year results.

BACKGROUND: Gestational diabetes mellitus (GDM) is a risk factor for mothers to develop type 2 diabetes (T2D) postpartum, and for their children to develop obesity. The aim of the ongoing POGO study is to identify long-lasting changes in the maternal and fetal metabolism and microbiome, after GDM, which contribute to subsequent development of T2D and obesity. METHODS: Women screened for GDM are asked to attend a postpartum study visit together with their offspring. At the visit, demographic, nutritional, and anthropometric data are recorded. Additionally, data about physical activity, metabolism, and genetic susceptibility are collected using accelerometers, breath gas analyses, 75g oral glucose tolerance tests (OGTT), and bio-samples such as blood and stool. RESULTS: To date, 121 women (median follow-up time postpartum: 5.5 years) have been enrolled together with 133 index children. GDM has been diagnosed using OGTT in 105 women (and 117 children). It showed that 47 mothers had abnormal glucose tolerance, including 19 cases of impaired glucose tolerance, 19 of impaired fasting glucose, eight with T2D, and one with type 1 diabetes (T1D). The prevalence of obesity in the offspring of GDM mothers was 5.1%. Of 61 children tested by OGTT, three were diagnosed with impaired glucose tolerance, another three with impaired fasting glucose, and none with T1D or T2D. CONCLUSIONS: The POGO study will contribute to the understanding of the pathogenesis of T2D and obesity after GDM, and will thus help to develop appropriate prevention and intervention strategies. This article presents the first results of the ongoing study, which are looking promising.

Effect of reducing the n-6:n-3 long-chain PUFA ratio during pregnancy and lactation on infant adipose tissue growth within the first year of life: an open-label randomized controlled trial.

BACKGROUND: The composition of long-chain PUFAs (LCPUFAs) in the maternal diet may affect obesity risk in the mother's offspring. OBJECTIVE: We hypothesized that a reduction in the n-6 (omega-6):n-3 (omega-3) LCPUFA ratio in the diet of pregnant women and breastfeeding mothers may prevent expansive adipose tissue growth in their infants during the first year of life. DESIGN: In a randomized controlled trial, 208 healthy pregnant women were randomly assigned to an intervention (1200 mg n-3 LCPUFAs as a supplement per day and a concomitant reduction in arachidonic acid intake) or a control diet from the 15th wk of pregnancy to 4 mo of lactation. The primary outcome was infant fat mass estimated by skinfold thickness (SFT) measurements at 4 body sites at 3-5 d, 6 wk, and 4 and 12 mo postpartum. Secondary endpoints included sonographic assessment of abdominal subcutaneous and preperitoneal fat, fat distribution, and child growth. RESULTS: Infants did not differ in the sum of their 4 SFTs at ≤1 y of life [intervention: 24.1 ± 4.4 mm (n = 85); control: 24.1 ± 4.1 mm (n = 80); mean difference: -0.0 mm (95% CI: -1.3, 1.3 mm)] or in growth. Likewise, longitudinal ultrasonography showed no significant differences in abdominal fat mass or fat distribution. CONCLUSIONS: We showed no evidence that supplementation with n-3 fatty acids and instructions to reduce arachidonic acid intake during pregnancy and lactation relevantly affects fat mass in offspring during the first year of life. Prospective long-term studies are needed to explore the efficacy of this dietary approach for primary prevention. This trial was registered at clinicaltrials.gov as NCT00362089.

Influence of different CLA isomers on insulin resistance and adipocytokines in pre-diabetic, middle-aged men with PPARγ2 Pro12Ala polymorphism.

Conjugated linoleic acids (CLAs) are natural PPARγ ligands, which showed conflicting effects on metabolism in humans. We examined metabolic effects of different isomers of CLA in subjects with PPARγ2 Pro12Ala polymorphisms. A total of 35 men underwent four intervention periods in a crossover study design: subjects with either genotypes received c9, t11 CLA or t10, c12 CLA, a commercially available 1:1 mix of both isomers or reference oil (linoleic acid (LA)). Adipocytokines, insulin, glucose and triglycerides were assessed in the fasting state and after a standardized mixed meal. Across all genotypes, there was a significant (p = 0.025) CLA treatment effect upon postprandial (pp) HOMA-IR values, with c9, t11 CLA and CLA isomer mix improving, but t10, c12 CLA isomer worsening. In Ala12Ala subjects, the t10, c12 isomer caused weight gain (p = 0.03) and tended to increase postprandial insulin levels (p = 0.05). In Pro12Pro subjects, t10, c12 resulted in reduction in waist circumference (p = 0.03). The comparison of the different genotype groups revealed statistically different changes in fasting and postprandial insulin, HOMA-IR and leptin after intervention. c9, t11 CLA and the commercial CLA mix showed beneficial effects on insulin sensitivity compared with LA, while t10, c12 CLA adversely affects body weight and insulin sensitivity in different PPAR genotypes. CLA isomers have different effects on metabolism in Ala and Pro carriers.