Louise A. Kelly

Fundamental movement skills and habitual physical activity in young children.

PURPOSE To test for relationships between objectively measured habitual physical activity and fundamental movement skills in a relatively large and representative sample of preschool children. METHODS Physical activity was measured over 6 d using the Computer Science and Applications (CSA) accelerometer in 394 boys and girls (mean age 4.2, SD 0.5 yr). Children were scored on 15 fundamental movement skills, based on the Movement Assessment Battery, by a single observer. RESULTS Total physical activity (r=0.10, P<0.05) and percent time spent in moderate to vigorous physical activity (MVPA) (r=0.18, P<0.001) were significantly correlated with total movement skills score. Time spent in light-intensity physical activity was not significantly correlated with motor skills score (r=0.02, P>0.05). CONCLUSIONS In this sample and setting, fundamental movement skills were significantly associated with habitual physical activity, but the association between the two variables was weak. The present study questions whether the widely assumed relationships between motor skills and habitual physical activity actually exist in young children.

Effect of socioeconomic status on objectively measured physical activity

Background: A socioeconomic gradient in childhood obesity is known to be present by the age of school entry in the UK. The origin of this gradient is unclear at present, but must lie in socioeconomic differences in habitual physical activity, sedentary behaviour, or dietary intake. Aims: To test the hypothesis that habitual physical activity and/or sedentary behaviour are associated with socioeconomic status (SES) in young Scottish children. Methods: Observational study of 339 children (mean age 4.2 years, SD 0.3) in which habitual physical activity and sedentary behaviour were measured by accelerometry over six days (study 1). In a second study, 39 pairs of children of distinctly different SES (mean age 5.6 years, SD 0.3) were tested for differences in habitual physical activity and sedentary behaviour by accelerometry over seven days. Results: In study 1, SES was not a significant factor in explaining the amount of time spent in physical activity or sedentary behaviour once gender and month of measurement were taken into account. In study 2, there were no significant differences in time spent in physical activity or sedentary behaviour between affluent and deprived groups. Conclusion: Results do not support the hypothesis that low SES in young Scottish children is associated with lower habitual physical activity or higher engagement in sedentary behaviour.

Randomized control trial to improve adiposity and insulin resistance in overweight Latino adolescents.

Few randomized trials attempt to improve insulin sensitivity and associated metabolic risks in overweight Latino youth. The purpose of this study is to examine the effects of a modified carbohydrate nutrition program combined with strength training on insulin sensitivity, adiposity, and other type 2 diabetes risk factors in overweight Latino adolescents. In a 16‐week randomized trial, 54 overweight Latino adolescents (15.5 ± 1.0 years) were randomly assigned to: (i) Control (C; n = 16), (ii) Nutrition (N; n = 21), or (iii) Nutrition + Strength training (N+ST; n = 17). The N group received modified carbohydrate nutrition classes (once per week), while the N+ST received the same nutrition classes plus strength training (twice per week). The following were measured at pre‐ and postintervention: strength by 1‐repetition maximum, dietary intake by 3‐day records, body composition by dual‐energy X‐ray absorptiometry, glucose/insulin indices by oral glucose tolerance test (OGTT) and intravenous glucose tolerance test with minimal modeling. Across intervention group effects were tested using analysis of covariance with post hoc pairwise comparisons. A significant overall intervention effect was found for improvement in bench press (P < 0.001) and reductions in energy (P = 0.05), carbohydrate (P = 0.04) and fat intake (P = 0.03). There were no significant intervention effects on insulin sensitivity, body composition, or most glucose/insulin indices with the exception of glucose incremental area under the curve (IAUC) (P = 0.05), which decreased in the N and N+ST group by 18 and 6.3% compared to a 32% increase in the C group. In conclusion, this intense, culturally tailored intervention resulted in no significant intervention effects on measured risk factors with the exception of a beneficial effect on glycemic response to oral glucose.

Dietary Intake and the Metabolic Syndrome in Overweight Latino Children

Little is known about the relationship between diet and metabolic health in Latino children, a population at increased risk for diabetes. The present study evaluates diet composition and the metabolic syndrome in a cross-sectional sample of 109 overweight Latino children aged 10 to 17 years with a family history of type 2 diabetes. Dietary intake was assessed by two 24-hour recalls. Associations between nutrients and features of the metabolic syndrome were examined using multiple linear regression and analysis of covariance. Log cholesterol intake was positively associated with log systolic blood pressure (beta=0.034, P=0.017) and log soluble dietary fiber intake was inversely associated with log waist circumference (beta=-0.069, P=0.036). Log soluble fiber intake was significantly higher in participants with 0 features compared to those with 3+ features of the metabolic syndrome (P=0.046), which translates to 5.2 g vs 4.1 g soluble fiber daily. No other significant associations were found between dietary variables and either the individual features of the metabolic syndrome or the clustering of metabolic syndrome components. Increases in soluble fiber through the daily consumption of fruits, vegetables, and beans may improve metabolic health in Latino children.

Pubertal Changes of Insulin Sensitivity, Acute Insulin Response, and β-Cell Function in Overweight Latino Youth

OBJECTIVE To examine changes in insulin sensitivity (SI), compensatory acute insulin response (AIR), and β-cell function/disposition index (DI) across puberty in overweight Latino boys and girls. STUDY DESIGN Latino children (n = 253) were followed annually for up to 5 years. Longitudinal modeling was used to examine changes in SI, AIR, DI, and fasting and 2-hour glucose and insulin across Tanner stage. RESULTS In boys, SI decreased in early puberty with a recovery by late puberty. The compensatory increase in AIR was appropriate in early maturation, but after Tanner stage 3, AIR declined by more than that predicted from the recovery in SI. For girls, SI decreased in early puberty and across all stages of maturation. In early maturation, there was an appropriate compensatory increase in AIR, but after Tanner stage 3, AIR decreased. Thus, DI deteriorated across puberty in boys and girls. CONCLUSIONS In overweight Hispanic youth, compensatory changes in insulin secretion fails after Tanner stage 3 in both sexes, indicating β-cell deterioration during this critical period of development, thus increasing risk for type 2 diabetes.

Validation of energy intake by 24-hour multiple pass recall: comparison with total energy expenditure in children aged 5-7 years.

Accurate measurement of energy intake (EI) is essential in studies of energy balance in all age groups. Reported values for EI can be validated against total energy expenditure (TEE) measured using doubly labelled water (DLW). Our previous work has indicated that the use of the standardized 24 h multiple pass recall (24 h MPR) method produces slight overestimates of EI in pre-school children which are inaccurate at individual level but acceptable at group level. To extend this work, the current study validated EI by 24 h MPR against TEE by DLW in sixty-three (thirty-two boys) school-aged children (median age 6 years). In both boys and girls, reported EI was higher than TEE, although this difference was only significant in the girls (median difference 420 kJ/d, P=0.05). On analysis of agreement between TEE and EI, the group bias was an overestimation of EI by 250 kJ/d with wide limits of agreement (-2880, 2380 kJ/d). EI was over-reported relative to TEE by 7 % and 0.9 % in girls and boys, respectively. The bias in the current study was lower than in our previous study of pre-school children, suggesting that estimates of EI become less inaccurate as children age. However, the current study suggests that the 24 h MPR is inaccurate at the individual level.

Parental feeding style, energy intake and weight status in young Scottish children

Parental feeding style, as measured by the Child Feeding Questionnaire (CFQ), may be an important influence on child feeding behaviour and weight status in early to mid childhood, but more evidence on parental feeding style is required from samples outside the USA. We aimed to use the CFQ in a sample of 117 Scottish children (boys n 53, girls n 64 mean age 4.6 (SD 0.5) years) to: characterise gender differences and changes over time (in forty of the 117 children studied over 2 years); test associations between parental feeding style, free-living energy intake (measured over 3 days using the multiple pass 24-h recall), and weight status (BMI SD score). No dimensions of parental feeding style changed significantly over 2 years in the longitudinal study (P>0.05 in all cases). No aspects of parental feeding style as measured by the CFQ differed significantly between the sexes (P>0.05 in all cases). Parental perceptions of child weight status were generally significantly positively correlated with child weight status as measured by the BMI SD score. In this sample and setting, measures of parental control over child feeding were generally not associated with child energy intake or weight status.

Randomized Controlled Trial to Improve Adiposity, Inflammation, and Insulin Resistance in Obese African-American and Latino Youth

The purpose of this study was to examine ethnic differences in the metabolic responses to a 16‐week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African‐American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre‐ and postintervention: strength, dietary intake, body composition (dual‐energy X‐ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. −32.3% vs. −6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. −14.2% vs. −13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: −27.3% vs. −4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor‐1 (PAI‐1) (−38.3% vs. +1.0%, P < 0.01) and resistin (−18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2‐h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (Ps < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.

Influence of gender, BMI and Hispanic ethnicity on physical activity in children

OBJECTIVE The purpose of this study was to examine the association between overweight status and physical activity (PA) among gender and ethnic (Hispanic vs. non-Hispanic) sub-groups in elementary school-age children. METHODS PA was assessed over five days using the Actigraph accelerometer in 169 fourth grade students (mean age 9.4 years; 50% female; 63% Hispanic; and 43% overweight, defined as body mass index, BMI > or = 85th percentile for age and gender) from four elementary schools in Los Angeles County, California. RESULTS In the total sample, boys and normal weight students had higher levels of total PA (counts per minute, cpm; p<0.05). Boys spent less time in sedentary PA (p=0.02) and more time in combined moderate to vigorous PA (MVPA, p=0.01). There was a significant gender, ethnicity, and overweight interaction for total PA and MVPA (both p<0.01). MVPA and counts per minute were significantly lower in overweight non-Hispanic girls and Hispanic boys (p<0.05) and marginally lower in overweight non-Hispanic boys (p=0.10) when compared with non-overweight students, while overweight Hispanic girls were more physically active than Hispanic non-overweight girls, though the difference was non-significant (p>0.05). CONCLUSIONS Data from the present study does not consistently support the prevailing hypothesis that overweight subjects engage in less PA. Results show overweight students engage in less PA than non-overweight students, with the exception that non-overweight Hispanic girls do not engage in more PA than their overweight peers. These results suggest the need for further investigation into the role that ethnicity and overweight status plays in PA levels, particularly among ethnic and gender sub-groups.

PARENTAL HISTORY AND RISK OF TYPE 2 DIABETES IN OVERWEIGHT LATINO ADOLESCENTS: A LONGITUDINAL ANALYSIS.

OBJECTIVE— The purpose of this article was to examine metabolic risk factors for type 2 diabetes in children and adolescents as a function of maternal versus paternal family history of type 2 diabetes and to examine whether differences in these risk factors emerge during adolescent growth. RESEARCH DESIGN AND METHODS— A total of 247 overweight Latino children (baseline age = 11.1 ± 1.7 years) with a parental history of type 2 diabetes were followed annually for 5 years (2.2 ± 1.2 observations/child) with measures of insulin sensitivity, acute insulin response to glucose, and disposition index. Longitudinal linear mixed-effects modeling was used to evaluate the influence of maternal versus paternal family history of type 2 diabetes on changes in diabetes risk factors over age. RESULTS— Insulin sensitivity and the disposition index decreased over age (β = −0.052 and β = −0.033, P < 0 0.01). Acute insulin response to glucose and fasting and 2-h glucose increased (β = 0.019, β = 0.002, and β = 0.003, P < 0.01). Declines in insulin sensitivity were significantly greater in participants whose maternal grandmothers had a history of type 2 diabetes (β = −0.03, P = 0.03). Declines in the disposition index (β = −0.02, P = 0.04) and increases in fasting glucose were significantly influenced by a maternal history of type 2 diabetes (β = 0.60, P < 0.05). CONCLUSIONS— Maternal but not paternal family history for diabetes may have a significant impact on insulin dynamics, becoming more pronounced during growth in overweight Latino adolescents. Further research is clearly warranted.