Relationships between reported macronutrient intake and insulin dynamics in a multi-ethnic cohort of early pubertal children.
BACKGROUND
Racial/ethnic differences in the pediatric population in insulin dynamics have been documented. Additionally, girls tend to be more insulin resistant than boys. Although the mechanism driving these differences is unclear, diet may be a contributor.


OBJECTIVE
The objective of this study was to evaluate the contribution of reported macronutrient intake on insulin dynamics and determine if diet composition may account for racial/ethnic and sex differences in insulin response/action.


METHODS
Participants were 250 African- (n=84), European- (n=105), or Hispanic-American (n=61) children 7-12 years, pubertal stage < or =3. An intravenous glucose tolerance test was used to derive the insulin sensitivity index and acute insulin response to glucose (AIRg) diet by two 24 h recalls, and body composition by dual-energy x-ray absorptiometry (DXA).


RESULTS
Reported energy intake from fat was positively related to fasting insulin (P < 0.05) and AIRg (P=0.05). Reported energy from carbohydrate was inversely associated with fasting insulin (P < 0.05), and reported energy from protein was inversely associated with AIRg (P < 0.05). The interaction terms between ethnicity and diet, and sex and diet were not significant for any outcome variables.


CONCLUSIONS
Dietary intake influences insulin dynamics; however, the racial/ethnic and sex differences in insulin dynamics in this population are not accounted for by macronutrient intake. Pubertal status is likely to play a role in the interaction between diet, race/ethnicity, sex and insulin dynamics. Longitudinal studies are needed to determine if the contribution of diet to insulin dynamics strengthens with reproductive maturation.
Casazza
Krista
K
Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL 35294-3360, USA. kristac@uab.edu
Dulin-Keita
Akilah
A
Gower
Barbara A
BA
Fernández
José R
JR
D015502:Absorptiometry, Photon; D001741:Black or African American / Q000706:statistics & numerical data; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004032:Diet / Q000009:adverse effects / Q000208:ethnology*; D002149:Energy Intake; D004734:Energy Metabolism; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D005951:Glucose Tolerance Test; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000208:ethnology*; D016014:Linear Models; D008297:Male; D009752:Nutritional Status; D011627:Puberty / Q000208:ethnology* / Q000378:metabolism*; D013997:Time Factors; D044465:White People / Q000706:statistics & numerical data
D001786:Blood Glucose; D007328:Insulin