ABSTRACT
BACKGROUND: Young children can regulate energy precisely in the short term, showing the potential for an innate compensation mechanism of eating behavior. However, data suggest that precise compensation is attenuated as a function of increasing adiposity, parental feeding style, and age. Common variation in candidate obesity genes may account for some of the individual variation observed in short-term energy compensation. Polymorphisms in the peroxisome proliferator-activated receptor gamma (PPARG) and beta-adrenergic receptor (ADRB3) genes have been linked to increased body mass index (BMI; in kg/m(2)), obesity, and more recently dietary nutrients and preferences. In addition, common variation in ADRB3 interacts with PPARG to modulate adult body weight. OBJECTIVE: This study investigated whether variants in these genes were associated with measurable effects on child eating behavior. DESIGN: Children (n=84) aged 4-10 y were prospectively selected for variants of the PPARG locus (Pro12Ala, C1431T). Heights and weights were measured. Energy intake from a test meal was measured 90 min after ingestion of a no-energy (NE), low-energy (LE), or high-energy (HE) preload, and the compensation index (COMPX) was calculated. RESULTS: BMI differed significantly by gene model, whereby Pro12Ala was associated with a lower BMI. Poor COMPX was associated with the PPARG T1431 allele (P=0.009). There was a significant interaction between COMPX and the ADRB3 Trp64Arg variant in modulating compensation (P=0.003), whereas the Arg64 allele was associated with good compensation (P=0.001). CONCLUSIONS: This is the first study to suggest that a genetic interaction involving ADRB3 and PPARG variants influences eating behavior in children.
Subject(s)
Energy Intake/physiology , Feeding Behavior/physiology , PPAR gamma/genetics , Receptors, Adrenergic, beta/genetics , Alleles , Body Mass Index , Child , Child, Preschool , Cohort Studies , DNA/chemistry , DNA/genetics , Eating/physiology , Female , Genetic Variation , Genotype , Humans , Male , Obesity/genetics , Obesity/metabolism , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , Prospective StudiesABSTRACT
OBJECTIVES: Our purpose with this work was to assess the contribution of glutathione S-transferase gene variants to asthma susceptibility and pulmonary function in relation to tobacco smoke exposure in the home. METHODS: Young individuals with asthma (age: 3-21 years; n = 504) were recruited through primary and secondary care throughout Tayside, Scotland (BREATHE Study). Spirometry was obtained on 407 individuals. Binary logistic regression and general linear modeling were used to explore phenotypic characteristics by genotype and tobacco smoke exposure status in younger children (3-12 years; n = 384) and teenagers and young adults (13-21 years; n = 120). RESULTS: Three- to 12-year-olds with asthma, null for the GSTM1 gene or homozygous for the GSTP1Val105 allele, were overrepresented in the group exposed to environmental tobacco smoke. No differences in lung function values could be detected in this group. In contrast, 13- to 21-year-olds with the GSTM1-null genotype or homozygous for the GSTP1Val105 allele from smoking households were more likely to have a substantially lower percentage of predicted peak expiratory flow rates than those from nonsmoking households (83% vs 98%). CONCLUSIONS: Three- to 12-year-olds who are null for GSTM1 or homozygous for the GSTP1Val105 allele are more susceptible to asthma associated with environmental tobacco smoke exposure than those with more intact glutathione S-transferase status. In the 13- to 21-year-olds, GSTM1-null status interacts with environmental tobacco smoke exposure to substantially reduce peak expiratory flow rate. The environmental tobacco smoke effect in GSTM1-null children with asthma could be cumulative over time, resulting in detrimental effects on peak expiratory flow rate in 13- to 21-year-olds with asthma.
Subject(s)
Asthma/genetics , Glutathione S-Transferase pi/physiology , Glutathione Transferase/physiology , Peak Expiratory Flow Rate , Tobacco Smoke Pollution/adverse effects , Adolescent , Adult , Age Factors , Alleles , Asthma/etiology , Asthma/physiopathology , Child , Child, Preschool , Forced Expiratory Volume , Gene Deletion , Genetic Predisposition to Disease , Genotype , Glutathione S-Transferase pi/deficiency , Glutathione S-Transferase pi/genetics , Glutathione Transferase/deficiency , Glutathione Transferase/genetics , Humans , Phenotype , Point Mutation , Scotland , Vital CapacityABSTRACT
BACKGROUND: Young children accurately compensate for energy-dense preloads consumed before test meals. The accuracy of compensation seems to deteriorate as a function of age. OBJECTIVE: The hypothesis that accurate energy compensation varies by age, body mass index, and individual characteristics of children and their mothers was tested. DESIGN: Energy intake (EI) from a test meal was measured in 74 children aged 6-9 y 90 min after the ingestion of no-energy (NE), low-energy (LE), or high-energy (HE) preload snacks. The NE preload consisted of 250 mL water, the LE preload consisted of a 56-g muffin + a 250-mL orange drink (783 kJ), and the HE preload consisted of a 56-g muffin + a 250-mL orange drink (1628 kJ). RESULTS: A significant dose-related reduction in EI was found after the preloads; younger children adjusted more effectively than did older children, although total EI (including preload energy) indicated that the adjustment was not accurate. The compensation index (COMPX) differed by preload and age group; COMPX scores were higher between the NE and LE preloads (younger children: 44.4 +/- 9.3%; older children: 57.0 +/- 11.6%) than between the NE and HE preloads (39.6 +/- 4.9%; 31.3 +/- 6.2%) and the LE and HE preloads (35.2 +/- 7.8%; 7.4 +/- 9.8%). This finding indicates a more consistent response across preloads and a greater sensitivity to energy load by younger than by older children. High interindividual variation and low intraindividual variation in COMPX was found. The tendency to over- or undereat in response to the preloads (deviation from perfect) correlated directly and positively with maternal concerns about child overweight, not with actual BMI. CONCLUSIONS: The children adjusted their EIs in response to different preloads, and the younger children did so more effectively than did the older children. Poor short-term energy compensation may constitute a behavioral marker for positive energy balance.
Subject(s)
Energy Intake , Feeding Behavior , Age Factors , Body Mass Index , Child , Energy Metabolism , Female , Humans , MaleABSTRACT
OBJECTIVE: Evaluation of the effects of supplementation of n-3 and n-6 fatty acids on vascular tone and endothelial function in healthy men and women aged 40 to 65 years. METHODS: In a double-blind, randomised, placebo controlled study, 173 healthy volunteers took one of six oil supplements for 8 months. Supplements were placebo, oleic acid rich sunflower oil, evening primrose oil, soya bean oil, tuna fish oil, and tuna/evening primrose oil mix. Endothelium-dependent and independent vascular responses were measured in the forearm skin using laser Doppler imaging following iontophoretic applications of acetylcholine and sodium nitroprusside, respectively. RESULTS: Acetylcholine, but not sodium nitroprusside responses were significantly improved after tuna oil supplementation (P=0.02). Additionally, there were significant positive correlations between acetylcholine responses and n-3 fatty acid levels in the plasma and erythrocyte membrane phospholipids after tuna oil supplementation. No significant changes in vascular response were seen after supplementation with any of the other oils. CONCLUSIONS: Fish oil supplementation has a beneficial effect on endothelial function, even in normal healthy subjects. Modification of the diet by an increase of 6% in eicosapentaenoic acid and 27% in docosahexaenoic acid (equivalent to eating oily fish 2-3 times/week) might have significant beneficial effects on cardiovascular function and health.
