Insulin resistance and impaired glucose tolerance in overweight and obese Costa Rican schoolchildren.
BACKGROUND
Worldwide obesity has become an unprecedented public health challenge. In addition, a notable increase in the risk of insulin resistance and type 2 diabetes mellitus has emerged. In Costa Rica, there are no epidemiological data to establish the prevalence of type 2 diabetes in the pediatric population. However, information from the Endocrinology Department of the Children's National Hospital indicates an increased number of cases in the last 2 to 3 years.


OBJECTIVE
To determine the prevalence of insulin resistance and impaired glucose tolerance in overweight and obese schoolchildren.


METHODS
This cross-sectional study was conducted among 214 healthy 8- to 10-year-old children from urban schools of San José, Costa Rica. Anthropometric measurements and blood determinations of glucose, insulin, proinsulin, glycosylated hemoglobin, C-peptide, and leptin were performed. Indexes were calculated to assess insulin resistance. Information on social and lifestyle variables was obtained from questionnaires, and acanthosis nigricans was certified by a physician. Statistical analysis was performed with SPSS software for Windows, version 10.0.


RESULTS
The prevalence of type 2 diabetes mellitus was very low (0.5%) in the studied population. However, hyperinsulinemia and impaired glucose tolerance were present in 20.6% and 6.5% of the subjects, respectively. On the basis of the Fasting Glucose-to-Insulin Resistance Ratio (FGIR), 46.7% of the children showed insulin resistance. Girls and obese children (body mass index > or = 95th percentile) were more likely to have higher serum insulin levels and insulin resistance than boys and overweight children (BMI > or = 85th percentile). Compared with the lowest quintile, children in the highest quintile of body-fat tissue had higher insulin resistance but had similar serum concentrations of glucose, C-peptide, and proinsulin. Positive family histories of type 2 diabetes mellitus and sedentarism (73.7% and 40.7%, respectively) were highly prevalent among overweight and obese children.


CONCLUSIONS
The prevalence of impaired glucose tolerance and insulin resistance in obese children indicates a worrisome trend in the incidence of type 2 diabetes in Costa Rica. Strategies for weight reduction, obesity prevention, and promotion of healthy lifestyles are necessary to prevent the onset of type 2 diabetes during childhood and adolescence.
Holst-Schumacher
Ileana
I
Faculty of Microbiology and Hematological Investigation Center and Related Sicknesses (CIHATA), University of Costa Rica, San José, Costa Rica. iholst@cariari.ucr.ac.cr
Nuñez-Rivas
Hilda
H
Monge-Rojas
Rafael
R
Barrantes-Santamaría
Mauro
M
D000886:Anthropometry; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D003364:Costa Rica / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology / Q000378:metabolism; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006306:Health Surveys; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D008019:Life Style; D008297:Male; D009765:Obesity / Q000097:blood / Q000453:epidemiology / Q000378:metabolism*; D050177:Overweight / Q000097:blood / Q000453:epidemiology / Q000378:metabolism*; D015995:Prevalence; D011795:Surveys and Questionnaires
D001786:Blood Glucose; D007328:Insulin