Taq1a polymorphism (rs1800497) is associated with obesity-related outcomes and dietary intake in a multi-ethnic sample of children.

BACKGROUND: In adults, the Taq1a polymorphism (rs1800497) near the D2 receptor (DRD2) gene is associated with body mass index and binge eating and is more prevalent among non-Hispanic Blacks (NHB) and Hispanic-Americans (HA) relative to non-Hispanic Whites (NHW). We hypothesize Taq1a polymorphism (rs1800497) risk alleles contribute to paediatric racial/ethnic differences in obesity phenotypes. OBJECTIVES: This study aims to characterize the relationship between the Taq1a polymorphism (rs1800497), diet and adiposity in a multi-ethnic cohort of 286 children (98 NHB, 76 HA and 112 NHW), ages 7-12. METHODS: Dual-energy X-ray absorptiometry, computed tomography scans and two 24-h dietary recalls assessed body composition, fat distribution and dietary intakes, respectively. RESULTS: Children with two Taq1a risk alleles (NHB = 50.0%, HA = 43.3%, NHW = 6.7%) reported a 20% increase in total energy intake (P = 0.0034) and per cent of calories from sugar consumed (P = 0.0077) than did children with less than two risk alleles. Children with two Taq1a risk alleles demonstrated significantly higher total body fat (P = 0.0145), body fat percentage (P = 0.0377), intra-abdominal adiposity (P = 0.0459), subcutaneous abdominal adiposity (P = 0.0213) and total abdominal adiposity (P = 0.0209) than did children with one or no Taq1a risk alleles. CONCLUSIONS: Our results suggest that having two Taq1a risk alleles is associated with an increase in reported calorie and sugar consumption and is a potential risk factor for early development of excess adiposity in multi-ethnic children. These results need to be confirmed in a larger sample.

Characterization of adult obesity in Florida using the OneFlorida clinical research consortium.

INTRODUCTION: With obesity rates and obesity-related healthcare costs increasing, policy makers must understand the scope of obesity across populations. OBJECTIVE: This study sought to characterize adult obesity using electronic health records (EHRs) available from a statewide clinical data research network, the OneFlorida Clinical Research Consortium, which contains claims and EHR data from over 12 million patients in Florida. The primary aim was to compare EHR-based Florida obesity rates with those rates obtained from the Behavioural Risk Factor Surveillance System (BRFSS). METHODS: Body mass index from OneFlorida patient data (2012-2016) was used to characterize obesity among adults 20-79 years old. Obesity rates from both OneFlorida and BRFSS (2013) were reported by demographics and by county. RESULTS: Among the 1,344,015 adults in OneFlorida with EHR data and who met inclusion criteria, the obesity rate was 37.1%. Women had higher obesity rates compared with men. Obesity rates varied within racial/ethnic groups, with the highest rate among African-Americans (45.7%). Obesity rates from OneFlorida were consistently higher than those found in BRFSS (overall 27.8%). CONCLUSIONS: Utilizing clinical big data available through hospital system and health partner collaborations provides an important view of the extent of obesity. Although these data are available only from healthcare users, they are large in scope, directly measured and are available sooner than commonly used national data sources.

Social status and energy intake: a randomized controlled experiment.

While the inverse association between socioeconomic status (SES) and obesity in high gross domestic product countries is well established using observational data, the extent to which the association is due to a true causal effect of SES and, if so, the mechanisms of this effect remain incompletely known. To assess the influence of social status on obesity via energy intake, we randomized individuals to a higher or lower social status and observed subsequent energy intake. College students between the ages of 18 and 25 were randomized to social status and were operationalized as being a leader or follower in a partner activity as purportedly determined by a (bogus) test of leadership ability. Investigators were blinded to treatment assignment. Immediately after being told their leadership assignment, paired participants were provided with platters of food. Energy intake was objectively measured in kilocalories (kcal) consumed, and paired t-tests were used to test for significant differences in intake between leaders and followers. A total of 60 participants were included in the final analysis (males = 28, females = 32). Overall, no difference in energy intake was observed between leaders and followers, consuming an average of 575.3 and 579.8 kcal, respectively (diff = 4.5 kcal, P = 0.94). The null hypothesis of no effect of social status, operationalized as assignment to a leadership position in a small-group activity, on energy intake was not rejected.

The effects of experimentally manipulated social status on acute eating behavior: A randomized, crossover pilot study.

Both subjective and objectively measured social status has been associated with multiple health outcomes, including weight status, but the mechanism for this relationship remains unclear. Experimental studies may help identify the causal mechanisms underlying low social standing as a pathway for obesity. Our objective was to investigate the effects of experimentally manipulated social status on ad libitum acute dietary intakes and stress-related outcomes as potential mechanisms relating social status and weight. This was a pilot feasibility, randomized, crossover study in Hispanic young adults (n=9; age 19-25; 67% female; BMI ≥18.5 and ≤30kg/m(2)). At visit 1, participants consumed a standardized breakfast and were randomized to a high social status position (HIGH) or low social status position (LOW) in a rigged game of Monopoly™. The rules for the game differed substantially in terms of degree of 'privilege' depending on randomization to HIGH or LOW. Following Monopoly™, participants were given an ad libitum buffet meal and energy intakes (kcal) were estimated by pre- and post-weighing foods consumed. Stress-related markers were measured at baseline, after the game of Monopoly™, and after lunch. Visit 2 used the same standardized protocol; however, participants were exposed to the opposite social status condition. When compared to HIGH, participants in LOW consumed 130 more calories (p=0.07) and a significantly higher proportion of their daily calorie needs in the ad libitum buffet meal (39% in LOW versus 31% in HIGH; p=0.04). In LOW, participants reported decreased feelings of pride and powerfulness following Monopoly™ (p=0.05) and after their lunch meal (p=0.08). Relative to HIGH, participants in LOW demonstrated higher heart rates following Monopoly™ (p=0.06), but this relationship was not significant once lunch was consumed (p=0.31). Our pilot data suggest a possible causal relationship between experimentally manipulated low social status and increased acute energy intakes in Hispanic young adults, potentially influenced by decreased feelings of pride and powerfulness. Increased energy intake over time, resulting in positive energy balance, could contribute to increased risk for obesity, which could partially explain the observed relationship between low social standing and higher weight. Larger and longitudinal studies in a diverse sample need to be conducted to confirm findings, increase generalizability, and assess whether this relationship persists over time.

African genetic admixture is associated with body composition and fat distribution in a cross-sectional study of children.

OBJECTIVE: Although differences in body composition parameters among African American (AA), Hispanic American (HA) and European American (EA) children are well documented, the factors underlying these differences are not completely understood. Environmental and genetic contributors have been evaluated as contributors to observed differences. This study evaluated the extent to which African or European ancestral genetic background influenced body composition and fat distribution in 301 peripubertal AA (n = 107), HA (n = 79) and EA (n = 115) children aged 7-12. DESIGN: Estimates of African admixture (AFADM) and European admixture (EUADM) were obtained for every subject using 142 ancestry informative DNA markers. Dual energy X-ray absorptiometry and computed tomography scanning were used to determine body composition and abdominal fat distribution, respectively. Multiple regression models were conducted to evaluate the contribution of admixture estimates to body composition and fat distribution. RESULTS: Greater AFADM was associated with lower fat mass (P = 0.0163), lower total abdominal adipose tissue (P = 0.0006), lower intra-abdominal adipose tissue (P = 0.0035), lower subcutaneous abdominal adipose tissue (P = 0.0115) and higher bone mineral content (BMC) (P = 0.0253), after adjusting for socio-economic status, sex, age, height, race/ethnicity and pubertal status. Greater EUADM was associated with lower lean mass (LM) (P = 0.0056). CONCLUSION: These results demonstrate that ancestral genetic background contributes to racial/ethnic differences in body composition above and beyond the effects of racial/ethnic classification and suggest a genetic contribution to total body fat accumulation, abdominal adiposity, LM and BMC.