VERONA, ITALY — The prevalence of impaired glucose tolerance is far more common among obese and overweight Italian children than was previously thought, Dr. Marco Cappa said.
He reported on a study of 215 overweight and obese Italian children in which the prevalence of impaired glucose tolerance (IGT) was 11%, compared with 4.5% as previously reported among this population (Diabetes Care 2003;26:118–24).
The finding is of concern, but it comes nowhere near the prevalence rate of 23% reported in a multiethnic cohort of 167 obese American children and adolescents (N. Engl. J. Med. 2002; 346:802–10), said Dr. Cappa, who presented the study at a joint meeting of the Italian Association of Clinical Endocrinologists and the American Association of Clinical Endocrinologists.
The increase in IGT may be caused by unknown factors or by inactivity and increased caloric intake, which are often cited for the alarming rate of IGT and obesity among American children, he explained. “Childhood obesity is an increasing problem in Italy, as in other developed countries,” said Dr. Cappa, of the Bambino Gesù Children's Hospital in Rome.
National growth curves of Italian children published in 2006 show a dramatic shift toward obesity. Another recent Italian study (Obesity 2006;14:765–9) indicated that when using the U.S. Centers for Disease Control and Prevention reference charts, the prevalence of overweight and obesity in Italian children is close to that reported in U.S. children (32% vs. 32.7%).
The cross-sectional study also found that the prevalence of overweight and obesity was higher in the southern sampling area of Messina than it was in the northern area of Verona, most likely because of differences in diet, Dr. Cappa said.
In his study, 24 of the 215 children had IGT, none had impaired fasting glucose, and one had type 2 diabetes mellitus. Their mean age was 12 years (range 5–18 years).
In a multivariate analysis that controlled for gender, family history of obesity and type 2 diabetes, and pubertal stage, age was the only parameter significantly related to glucose tolerance status, Dr. Cappa and his colleagues reported. The incidence of IGT was found to increase during midpuberty (Tanner stages 3 and 4), at around age 13.5 years.
Metabolic syndrome had an overall prevalence of 22% and was present in 20% of girls and 24% of boys, even though the average weight of the girls was higher, he said. Metabolic syndrome was defined by three or more of the following criteria: BMI greater than two standard deviations; triglycerides greater than the 95th percentile; an HDL cholesterol level less than the 5th percentile; systolic or diastolic blood pressure greater than the 95th percentile; and impaired glucose tolerance.
The findings compare favorably to an American study, in which the prevalence of metabolic syndrome was 39% in moderately obese participants and reached 50% in severely obese participants among 439 obese, 31 overweight, and 20 nonobese American children and adolescents (N. Engl. J. Med. 2004;350:2362–74).
Because patients with metabolic syndrome have an increased risk of cardiovascular disease prior to the development of IGT or diabetes, early identification and intervention is essential for these children, Dr. Cappa said.