Faculty Bibliography

Abstract Background: Although disparities in child obesity exist during infancy, the underlying mechanisms are unclear. Assessing dissimilarities in feeding practices, styles, and beliefs may provide a better understanding of these mechanisms. This study sought to identify modifiable maternal-infant feeding behaviors that may contribute to disparities in early child obesity. Methods: This study is a cross-sectional analysis comparing mothers with infants (2 weeks to 6 months old) in a low-risk group of high-income white mothers to a high-risk group of low-income Hispanic mothers. Regression analysis was used to explore relationships between each group and (1) infant feeding practices, including breastfeeding, giving juice, and adding cereal to bottles, (2) controlling feeding styles, (3) beliefs about infant hunger and satiety, and (4) infant weight status. Results: The sample included 412 mothers (low-risk group, n=208; high-risk group, n=204). The high-risk group was less likely to exclusively breastfeed (adjusted odds ratio [AOR], 0.43; 95% confidence interval [CI], 0.22-0.83), more likely to introduce juice (AOR, 12.25; 95% CI, 3.44-43.62), and add cereal to the bottle (AOR, 10.61; 95% CI, 2.74-41.0). The high-risk group exhibited greater restrictive and pressuring feeding styles and was more likely to believe that mothers can recognize infant hunger and satiety and less likely to believe that infants know their own hunger and satiety. High-risk infants were more likely to have a weight-for-length percentile >85th percentile (AOR, 2.66; 95% CI, 1.10-6.45). Conclusions: Differences in infant feeding behaviors may contribute to disparities in early child obesity. Longitudinal studies are needed to determine the effect of these differences on child obesity.

Glucose obtained from unprocessed blood samples can decrease by 5%-7% per hour due to glycolysis. This study compared the impact of glucose degradation on measured glucose values by examining two different collection methods. For the first method, blood samples were collected in tubes containing sodium fluoride (NaF), a glycolysis inhibitor. For the second method, blood samples were collected in tubes containing a clot activator and serum gel separator and were centrifuged to separate the serum and plasma 20 minutes after sample collection. The samples used in the two methods were collected during the same blood draw and were assayed by the clinical laboratory 2-4 hours after the samples were obtained. A total of 256 pairs of samples were analyzed. The average glucose reading for the centrifuged tubes was significantly higher than the NaF tubes by 0.196 +/- 0.159 mmol/L (P < 0.01) or 4.2%. This study demonstrates the important role collection methods play in accurately assessing glucose levels of blood samples collected in the field, where working environment may be suboptimal. Therefore, blood samples collected in the field should be promptly centrifuged before being transported to clinical labs to ensure accurate glucose level measurements.

OBJECTIVES: To determine the point prevalences of metabolic syndrome (MetS) and its components among healthy weight, overweight, and obese inner-city public high school students, to compare the prevalences of MetS when using 2 different definitions (one with the impaired fasting glucose [IFG] level and the other with a homeostasis model assessment of insulin resistance [HOMA-IR] of 3.99 or higher to define the glucose regulation component), and to compare the degree to which HOMA-IR and fasting glucose level are associated with the other MetS components. DESIGN: Cross-sectional analysis. SETTING: Two New York City public high schools, from April 2008 through August 2011. PARTICIPANTS: Convenience sample of 1185 high school youth, comprising predominantly Hispanic and African American students from low-income households, participating in The Banishing Obesity and Diabetes in Youth Project, a medical screening and education program. MAIN OUTCOME MEASURES: Prevalences of the following individual MetS components: IFG threshold, HOMA-IR, hypertension, central adiposity, hypertriglyceridemia, and low high-density lipoprotein cholesterol. Rates of MetSIFG and MetSHOMA-IR were also assessed. RESULTS: MetSIFG and MetSHOMA-IR point prevalences were both 0.3% in the healthy weight group; they were 2.6% and 5.9%, respectively, in the overweight group and were 22.9% and 35.1%, respectively, in the obese group (P < .05 for both). An IFG threshold of 100 mg/dL or higher was found in 1.0% of participants, whereas a HOMA-IR of 3.99 or higher was found in 19.5% of participants. CONCLUSIONS: An elevated HOMA-IR is much more sensitive than an IFG threshold in identifying adolescents with metabolic dysregulation. Using a HOMA-IR threshold of 3.99 identifies more youth with MetS than using an IFG threshold of 100 mg/dL. In addition to increasing the sensitivity of MetS detection, HOMA-IR has a much higher association with the other MetS components than the IFG threshold and may better reflect a unified underlying pathologic process useful to identify youth at risk for disease.

OBJECTIVES: We explored the relationship between household food insecurity and maternal feeding styles, infant feeding practices, and perceptions and attitudes about infant weight in low-income mothers. METHODS: Mothers participating in the Special Supplemental Food Program for Women, Infants, and Children with infants aged between 2 weeks and 6 months were interviewed. By using regression analyses, the following relationships were examined between food insecurity and: (1) controlling feeding styles (restrictive and pressuring); (2) infant feeding practices, including breastfeeding, juice consumption, and adding cereal to the bottle; and (3) perceptions and attitudes about infant weight. Path analysis was used to determine if perceptions and attitudes about infant weight mediated the relationships between food insecurity and controlling feeding styles. RESULTS: The sample included 201 mother-infant pairs, with 35% reporting household food insecurity. Food-insecure mothers were more likely to exhibit restrictive (B [SE]: 0.18 [0.08]; 95% confidence interval [CI]: 0.02-0.34) and pressuring (B [SE]: 0.11 [0.06]; 95% CI: 0.001-0.22) feeding styles compared with food-secure mothers. No associations were found with feeding practices. Concern for their infant becoming overweight in the future was associated with food insecurity (adjusted odds ratio: 2.11 [95% CI: 1.02-4.38]). This concern mediated the relationship between food insecurity and both restrictive (P = .009) and pressuring (P = .01) feeding styles. CONCLUSIONS: Increased concern about future overweight and controlling feeding styles represent potential mechanisms by which food insecurity could be related to obesity. Obesity prevention should aim to decrease food insecurity and to reduce controlling feeding styles in families who remain food insecure.

Type 2 diabetes (T2DM) and cardiovascular disease (CVD) are rising dramatically in adolescents in parallel with excess weight. The Banishing Obesity and Diabetes in Youth (BODY) Project, is a school-based intervention that medically screens overweight and obese high school students, provides personalized feedback, and connects to appropriate healthcare. Body mass index (BMI) was determined for 1,526 students in one New York City public high school with a school-based health center (SBHC). Overweight and obese students (n = 640) were invited to complete a medical evaluation that included a survey, blood pressure and blood tests. 328/640 (51%) eligible students returned signed parental consent and participated. All participants received a personalized report detailing their results along with specific recommendations on how to improve their health. Parents of participants with results outside healthy ranges (82%; 270/328) were called and mailed referral letters to connect with healthcare services. Project staff reached by telephone 74% (199/270) of those families and 29% (58/199) stated that the report led them to make arrangements to see a healthcare provider. Most students (83%; 273/328) were registered at the SBHC, and we shared their medical results with them so they could follow-up with the students. The BODY Project is a feasible program for urban schools with a SBHC. This may allow effective prevention of T2DM, and CVD from dyslipidemia and hypertension.