Ya-Wen Hsu

CRP Is Related to Higher Leptin Levels in Minority Peripubertal Females Regardless of Adiposity Levels

Overweight is related to higher levels of C‐reactive protein (CRP) and leptin, which have been independently associated with increased risk for diabetes, cardiovascular disease, and the metabolic syndrome. Elevated CRP may trigger leptin resistance by inhibiting the binding of leptin to its receptors. We cross‐sectionally examined the relationship between CRP, leptin, BMI z‐score, percent body fat (%BF) assessed by air plethysmography (BodPod), and insulin sensitivity (SI) and acute insulin response (AIRg) measured by intravenous glucose tolerance test in 51 Latina and African‐American females (77% Latina), mean age 9.2 (±0.9) years, at either Tanner Pubertal Stage (TPS) 1 (n = 25) or TPS 2 (n = 26). Females at TPS 2 had higher BMI z‐scores, %BF (23% ± 10.1 vs. 30% ± 10.0, P = 0.02), AIRg (976.7 ± 735.2 vs. 1555.3 ± 1,223 µIU/ml, P = 0.05), fasting insulin (11.0 ± 10.8 vs. 17.2 ± 13.6 µlU/ml, P = 0.00) and leptin levels (11.0 ± 7.1 vs. 19.6 ± 10.9 ng/ml, P < 0.001) than those at TPS 1. There were no ethnic differences in any of the measured variables. CRP was positively correlated with BMI z‐score (P = 0.001), %BF (P = 0.006), fasting insulin and AIRg (P = 0.02), and fasting leptin (P = 0.00), and negatively correlated with SI (P = 0.05). A linear regression model showed that CRP independently explained 10% (P = 0.00) of the variance in leptin after adjusting %BF, TPS, ethnicity, habitual physical activity and SI. Hence, low‐grade inflammation may contribute to prolonged leptin exposure and leptin resistance, even in healthy children.

The influence of worries on emotional eating, weight concerns, and body mass index in Latina female youth.

PURPOSE To investigate the effect of worries on weight concerns, emotional eating, and body mass index (BMI) percentile in an ethnically diverse sample of female youth. METHODS This study used baseline and follow-up data from a brief school-based physical activity intervention trial involving minority female youth. Partial correlations adjusted for intervention status, age, and ethnicity were used to assess the relationships between emotional eating, weight concerns, and BMI percentile at follow-up. Multilevel modeling was used to analyze the relationships between baseline worries and follow-up emotional eating, weight concerns, and BMI percentile. Additional analysis assessed whether emotional eating mediated and/or moderated the relationship between baseline worries and follow-up BMI. Data were analyzed using SAS version 9.1. RESULTS The sample consisted of 404 minority females (67.1% Latina; mean age = 12.5 ± .6; 60.6% were of normal weight). Weight concerns were positively correlated with emotional eating and BMI percentile (p < .001 for both). At follow-up, baseline worries significantly predicted emotional eating (p = .027) and weight concerns (p < .001) but not BMI percentile (p = .183). Emotional eating did not mediate the relationship between baseline worries and follow-up BMI percentile; however, it did moderate the relationship between baseline worries and follow-up BMI percentile (p = .003). CONCLUSIONS In this sample, worries were associated with psychosocial variables but not with BMI percentile. Reducing worries in those with high emotional eating scores may influence future weight gain among Latina females.

Objectively Measured Physical Activity Is Negatively Associated with Plasma Adiponectin Levels in Minority Female Youth

Objective. To evaluate the relationship between adiponectin and physical activity (PA) in minority female youth. Methods. Plasma adiponectin was measured in 39 females (mean age years; 30 Latina, 9 African-American; 56% overweight). PA was assessed by accelerometry. Mean minutes per day spent in daily PA (DPA) (≥3 metabolic equivalents (METs)), moderate PA (MPA)(4–7 METs), vigorous PA (VPA)(≥7 METs), and moderate-to-vigorous PA (MVPA)(≥4 METs) were calculated. The association between adiponectin and PA, controlling for age, fat weight, lean weight, and insulin sensitivity (SI) was analyzed using linear regression. Results. Adiponectin correlated with fat weight (, ) and SI (, ). Minutes spent in DPA (, ), MPA (, ), or MVPA (, ) were predictors of adiponectin in the adjusted model. Conclusions. Higher PA levels were related to lower adiponectin levels. Potential mechanisms include upregulation of adiponectin receptors or an increase in high-molecular weight adiponectin with increasing PA.

Temporal relationship between insulin sensitivity and the pubertal decline in physical activity in peripubertal Hispanic and African American females.

OBJECTIVE Little attention has been paid to possible intrinsic biological mechanisms for the decline in physical activity that occurs during puberty. This longitudinal observational study examined the association between baseline insulin sensitivity (SI) and declines in physical activity and increases in sedentary behavior in peripubertal minority females over a year. RESEARCH DESIGN AND METHODS Participants were Hispanic and African American girls (n = 55; 76% Hispanic; mean age 9.4 years; 36% obese). SI and other insulin indices were measured at baseline using the frequently sampled intravenous glucose tolerance test. Physical activity was measured on a quarterly basis by accelerometry and self-report. RESULTS Physical activity declined by 25% and time spent in sedentary behaviors increased by ∼13% over 1 year. Lower baseline SI predicted the decline in physical activity measured by accelerometry, whereas higher baseline acute insulin response to glucose predicted the decline in physical activity measured by self-report. Time spent in sedentary behavior increased by ~13% over 1 year, and this was predicted by lower baseline SI. All models controlled for adiposity, age, pubertal stage, and ethnicity. CONCLUSIONS When evaluated using a longitudinal design with strong outcome measures, this study suggests that lower baseline SI predicts a greater decline in physical activity in peripubertal minority females.

Leptin predicts a decline in moderate to vigorous physical activity in minority female children at risk for obesity

What is already known about this subject Physical activity declines as children enter puberty. Leptin is cross‐sectionally associated with physical activity, but there are conflicting findings on the magnitude and direction of this association. Leptin concentrations fluctuate during puberty, and may impact energy balance.

Behavioral Differences Leading to Disparities in Energy Balance and Cancer

The patterns of racial/ethnic, gender, and socio-demographic disparities in cancer incidence patterns are complex. While susceptibility, exposure, environment, access to and attitudes towards screening and medical treatment influence cancer incidence and mortality, there are strong behavioral influences on racial/ethnic and socioeconomic disparities in incidence and mortality by cancer site. These behaviors are intertwined with culture and acculturation. In this chapter, we discuss disparities in four central areas of behavior that are related to both energy balance and cancer. These include dietary intake (broken down by key nutrients), disparities in physical activity and sedentary behavior, disparities in sleep, and disparities in smoking.

Double Jeopardy: Metabolic Syndrome Leads to Increased Sedentary Behavior in Peri-Pubertal Minority Females

While most studies have focused on investigating the preventive effects of physical activity on metabolic risk, the longitudinal impacts of metabolic syndrome (MetS) on activity levels is poorly understood. This study aims to examine the influence of MetS on initial activity levels and the trajectory of activity levels in Latina and African American female children over 12 months (n = 55, 9 ± 1 years). Metabolic measures, including fat and lean tissue mass by BodPod, fasting glucose, lipids, blood pressure, and waist circumference, were collected at baseline. Moderate-to-vigorous physical activity and sedentary behavior by accelerometry were collected on a quarterly basis. There were no significant differences in either initial activity levels by MetS status (Moderate-to-vigorous physical activity: 33 ± 12 mins/day for MetS, 48 ± 28 mins/day for Non-MetS, p = .12; sedentary behavior: 408 ± 57 mins/day for MetS, 421 ± 72 mins/day for Non-MetS, p = .67). Longitudinal declines in moderate-to-vigorous physical activity (p = .038) and increases in sedentary behavior (p = .003) were found. Daily sedentary behavior increased by 82.64 more minutes in youth with MetS than in those without over one year (p = .015). This study yields the first evidence of the adverse effect of MetS on sedentary behavior. Targeted intervention strategies to reduce progressive sedentariness evident in minority youth with MetS are warranted.