A DRD4 gene by maternal sensitivity interaction predicts risk for overweight or obesity in two independent cohorts of preschool children.

BACKGROUND: Recent evidence suggests that early exposure to low maternal sensitivity is a risk factor for obesity in children and adolescents. A separate line of study shows that the seven-repeat (7R) allele of the dopamine-4 receptor gene (DRD4) increases susceptibility to environmental factors including maternal sensitivity. The current study integrates these lines of work by examining whether preschoolers carrying the 7R allele are more vulnerable to low maternal sensitivity as it relates to overweight/obesity risk. METHOD: The Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) project in Canada was used as the discovery cohort (N = 203), while the Generation R study in the Netherlands was used as a replication sample (N = 270). Regression models to predict both continuous BMI z-scores and membership in any higher BMI category based on established World Health Organization (WHO) cutoffs for 48 months of age were completed. RESULTS: In both cohorts, there was a significant maternal sensitivity by DRD4 by sex interaction predicting higher body mass indices and/or obesity risk. As hypothesized, post hoc testing revealed an inverse relationship between maternal sensitivity and body mass indices in 7R allele carriers relative to noncarriers. This finding was strongest in girls in the Canadian cohort and in boys in the Dutch cohort. CONCLUSIONS: Many children who carry the 7R allele of DRD4 appear to be more influenced by maternal sensitivity as it relates to overweight/obesity risk, consistent with a plasticity effect. Given the relatively small sample sizes available for these analyses, further replications will be needed to confirm and extend these results.

Low maternal sensitivity at 6 months of age predicts higher BMI in 48 month old girls but not boys.

BACKGROUND: Large population-based studies suggest that systematic measures of maternal sensitivity predict later risk for overweight and obesity. More work is needed to establish the developmental timing and potential moderators of this association. The current study examined the association between maternal sensitivity at 6 months of age and BMI z score measures at 48 months of age, and whether sex moderated this association. DESIGN: Longitudinal Canadian cohort of children from birth (the MAVAN project). METHODS: This analysis was based on a dataset of 223 children (115 boys, 108 girls) who had structured assessments of maternal sensitivity at 6 months of age and 48-month BMI data available. Mother-child interactions were videotaped and systematically scored using the Maternal Behaviour Q-Sort (MBQS)-25 items, a standardized measure of maternal sensitivity. Linear mixed-effects models and logistic regression examined whether MBQS scores at 6 months predicted BMI at 48 months, controlling for other covariates. RESULTS: After controlling for weight-relevant covariates, there was a significant sex by MBQS interaction (P=0.015) in predicting 48 month BMI z. Further analysis revealed a strong negative association between MBQS scores and BMI in girls (P=0.01) but not boys (P=0.72). Logistic regression confirmed that in girls only, low maternal sensitivity was associated with the higher BMI categories as defined by the WHO (i.e. "at risk for overweight" or above). CONCLUSIONS: A significant association between low maternal sensitivity at 6 months of age and high body mass indices was found in girls but not boys at 48 months of age. These data suggest for the first time that the link between low maternal sensitivity and early BMI z may differ between boys and girls.

Novel "thrifty" models of increased eating behaviour.

The thrifty genotype and phenotype hypotheses were developed to explain the rapid increase in diabetes and obesity in developed countries around the world. Most subsequent "thrifty" research has focused on the early developmental origins of the metabolic syndrome and cardio-metabolic disease. The goal of this manuscript is to review an emerging line of research that uses a similar thrifty framework to understand the early developmental origins of eating-related phenotypes that have primary relevance to many psychiatric disorders. Given the important role of environmental adversity in various psychiatric disorders that involve overeating, and their early age of onset, it is likely that several thrifty mechanisms are relevant in this regard. Understanding the early origins of increased eating behaviour based on a thrifty model might point the way to highly targeted preventative interventions during critical periods of development, and provide a new way of addressing these common and difficult to treat disorders.

Adequacy of nutritional intake in a Canadian population of patients with Crohn's disease.

Crohn's disease is frequently associated with nutritional deficiencies, often a result of disease activity and poor oral intake. This study investigated the adequacy of dietary intake, based on the Canadian Dietary Reference Intake, in ambulatory patients with Crohn's disease and a normal body mass index (BMI; calculated as kg/m(2)). This was a cross-sectional study of 74 patients with mean age of 35.7+/-1.4 years and BMI of 23.05+/-0.45. All patients completed a 7-day food record and a diary for the Crohn's Disease Activity Index. Mean Crohn's Disease Activity Index was 138.99+/-11.38. Energy and protein intakes were within the recommended levels of intake, but total carbohydrates, fat, and saturated fat intake exceeded the recommended levels of <55%, <35%, and <10% in 39.2%, 27%, and 59.5% of the patients, respectively. Micronutrient intakes were suboptimal most notably for folate, vitamins C, E, and calcium. There were no substantial differences between patients with active and inactive disease in terms of failure to meet the Dietary Reference Intake. In conclusion, in this population sample, a large number of ambulatory patients with Crohn's disease have suboptimal dietary patterns despite a normal BMI and inactive disease. Dietary counseling and supplementation may be warranted in this patient population.

Malnutrition in institutionalized seniors: the iatrogenic component.

OBJECTIVES: To provide practitioners with benchmarks for micronutrient supplementation policies for older residents of long-term care (LTC) facilities, based upon residents' usual energy intake. DESIGN: Retrospective secondary analysis of nutrient intake and delivery data, obtained from 21 consecutive collection days. SETTING: A fully accredited geriatric teaching facility, affiliated with the University of Toronto's Medical School, that includes a chronic care hospital and a home for the aged, housing more than 800 senior residents. PARTICIPANTS: Twenty-three cognitively impaired residents who retained the ability to feed themselves. MEASUREMENTS: Average daily micronutrient (vitamin and mineral) content of two common diet types--unrestricted diet as tolerated and lactose-free--were evaluated based upon all foods served during a 28-day cycle of menus, providing an estimate of total possible micronutrient intake. Energy intake needed to meet recommended intakes for each of the micronutrients was then determined and compared with actual dietary intakes. RESULTS: Even if entirely consumed, neither diet (providing approximately 2,000 kcal/d) supplied sufficient quantities of vitamins (vitamin E, pantothenic acid) and minerals (calcium, zinc, copper and manganese) to enable residents to meet recommended intakes, making these deficiencies iatrogenic in nature. As projected intake levels fell to reflect ranges more consistently observed in LTC residents (1,000-1,500 kcal/d), the number and severity of risk nutrients increased. Similar predictions, based upon actual intake measurements, were made and confirmed. CONCLUSIONS: The traditional approach of developing LTC menus using resources such as Canada's Food Guide or the Food Guide Pyramid of the United States results in iatrogenic malnutrition. New guidelines are needed that are targeted toward the special needs of older adults who have low food intakes. In the interim, all older LTC residents require full-spectrum vitamin and mineral supplements.

Antioxidant vitamin supplementation in Crohn's disease decreases oxidative stress. a randomized controlled trial.

OBJECTIVE: We showed previously that patients with Crohn's disease (CD) had increased oxidative stress and lower antioxidant vitamins compared with healthy controls. This is despite inactive or mildly active disease and maintenance therapy. The aim of this study was to evaluate in these patients the effects of antioxidant vitamin supplementation on oxidative stress. METHODS: This is a randomized controlled trial where stable but oxidatively stressed CD subjects (n = 57) were supplemented with vitamins E (800 IU) and C (1000 mg) or their placebo for 4 wk. Oxidative stress measured by breath pentane and ethane output, plasma lipid peroxides, and F2-isoprostane was assessed at baseline and at 4 wk. Disease activity was also monitored by measuring CD activity index and plasma orosomucoid. RESULTS: During supplementation, plasma vitamin C and alpha-tocopherol increased and all indices of oxidative stress decreased significantly. Disease activity remained stable. CONCLUSIONS: In this population, vitamin E and C supplementation resulted in a significant reduction in oxidative stress. This suggests that patients with inactive or mildly active CD can be oxidatively stressed and have increased requirement in antioxidant vitamins.