RESUMO
OBJECTIVES: To examine the relationship between C-reactive protein (CRP) concentration and body mass index (BMI) in children. STUDY DESIGN: With the use of data from 5305 children aged 6 to 18 years in the Third National Health and Nutrition Examination Survey (1988 to 1994), a cross-sectional health survey, we examined whether CRP concentrations were elevated among overweight children. RESULTS: Among children whose BMI was below the age- and sex-specific 15th percentile, 6.6% of boys and 10.7% of girls had an elevated CRP concentration (>2.1 mg/L) compared with 24.2% of boys and 31.9% of girls whose BMI was > or =95th percentile. After adjustment was done for age, sex, race or ethnicity, poverty income ratio, high-density lipoprotein cholesterol concentration, white blood cell count, and history of chronic bronchitis, the adjusted odds of having an elevated CRP concentration were 2.20 (95% CI 1.30, 3.75) for children with a BMI of 85th to <95th percentile and 4.92 (95% CI 3.39, 7.15) for children with a BMI of > or =95th percentile compared with children who had a BMI of 15th to <85th percentile. The associations did not differ significantly by age, sex, or race or ethnicity. CONCLUSIONS: In a large representative sample of US children, CRP concentration was significantly elevated among children with a BMI > or=85th percentile, thus confirming previous findings of this association in children and extending previous research in adults to children. Excess body weight may be associated with a state of chronic low-grade inflammation in children.
Assuntos
Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Obesidade/sangue , Adolescente , Adulto , Criança , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Inflamação/sangue , MasculinoRESUMO
BACKGROUND: Mexican American females have a higher prevalence of iron deficiency than do non-Hispanic white females. OBJECTIVE: The objective was to estimate the prevalence of iron deficiency anemia and examine potential reasons for this difference between Mexican American (n = 1194) and non-Hispanic white (n = 1183) females aged 12-39 y. DESIGN: We used data from the third National Health and Nutrition Examination Survey (1988-1994). Iron deficiency anemia was defined as abnormal results from >/=2 of 3 tests (erythrocyte protoporphyrin, transferrin saturation, and serum ferritin) and a low hemoglobin concentration. We used multiple logistic regression to adjust for factors that were more prevalent in Mexican American females and significantly associated with iron deficiency anemia. RESULTS: The prevalence of iron deficiency anemia was 6.2 +/- 0.8% (f1.gif" BORDER="0"> +/- SE) in Mexican American females and 2.3 +/- 0.4% in non-Hispanic white females. Mean dietary iron intake, mean serum vitamin C concentrations, and the proportion of females using oral contraceptives were similar in the 2 groups. Age <20 y and education were not associated with iron deficiency anemia. After adjustment for poverty level, parity, and iron supplement use, the prevalence of iron deficiency anemia was 2.3 times higher in Mexican American than in non-Hispanic white females (95% CI: 1.4, 3.9). In those with a poverty income ratio (based on household income) >3.0, however, the prevalence of iron deficiency anemia was 2.6 +/- 0.9% in Mexican American and 1.9 +/- 0.6% in non-Hispanic white females (NS). CONCLUSION: Although much of the ethnic disparity in iron deficiency anemia remains unexplained, factors associated with household income may be involved.