Native American children with severe obesity are two to five times more likely to develop diabetes before age 20 years and twice as likely to develop the disease before age 45 years vs. those with the least-severe form of obesity, according to findings reported in Pediatric Diabetes.
Stephanie K. Tanamas, PhD, of the diabetes, epidemiology and clinical research section of the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, and colleagues analyzed data from Native American children and adolescents without diabetes at baseline, stratified into two age cohorts: children aged 5 to younger than 10 years (n = 2,728; mean baseline age, 8 years) and adolescents aged 10 to younger than 18 years (n = 4,317; mean baseline age, 14 years; 1,805 participants were included in both cohorts). As part of a longitudinal study of diabetes prevalence among Native American children in the southwestern United States that began in 1965, the children were examined every 2 years until 2007. Researchers followed participants until development of diabetes or their last exam at age 20 years, and similar analyses were performed for the onset of diabetes before age 45 years. Obesity was defined as age-adjusted BMI in at least the 95th percentile; the severity of obesity was quantified as the percentage of the 95th percentile.
Within the two age cohorts, 18% of the younger cohort had obesity and 12% had severe obesity; 21% of the older cohort had obesity and 17% had severe obesity.
Researchers found that prevalence of impaired glucose tolerance was greater at higher BMI percentiles. In the younger cohort, 0.9% of children without obesity and 2.9% of those with BMI at 100% to 120% of the 95th percentile had IGT, whereas 8.6% of children with BMI at 140% of the 95th percentile had IGT. Among the adolescent cohort, 2.9% of those without obesity and 9.8% of those with BMI at 100% to 120% of the 95th percentile had IGT, whereas 13.3% of children with BMI at 160% of the 95th percentile had IGT.
During a median follow-up of 10.8 years, 98 children in the younger cohort developed diabetes, for a rate of 3.8 per 1,000 person-years. During a median follow-up of 5.5 years, 111 children and adolescents in the older cohort developed diabetes, for an incident rate of 4.9 per 1,000 person-years. Median follow-up time was 13.7 and 12.1 years, respectively, for the onset of diabetes before age 45 years in the younger and older cohorts, and researchers observed 543 and 1,014 incident cases of diabetes, respectively.
Across age cohorts and sexes, both diabetes incidence rates and cumulative incidence of diabetes increased with increasing BMI percentile categories, according to researchers. Compared with participants without obesity in the 65th to 85th percentile, the RR for developing youth-onset diabetes among children who with BMI at 100% to 120% of the 95th BMI percentile was 5.7 for boys (95% CI, 1.9-17.2) and 2.3 for girls (95% CI, 0.9-5.8) in the younger cohort, and 3.3 for boys (95% CI, 0.9-12.1) and 7.4 for girls (95% CI, 2.2-24.5) in the older cohort.
Researchers found that the risk for youth-onset diabetes in children and adolescents with BMI at 140% of the 95th percentile was twice as high when compared with children with BMI at 100% to 120% of the 95th percentile: RRs in the younger cohort were 2.3 for boys (95% CI, 1-5.1) and 5.1 for girls (95% CI, 2-12.5), whereas RRs in the older cohort were 3.1 for boys (95% CI, 1.2-7.8) and 2.4 for girls (95%CI, 1.2-4.8)
The researchers also noted that parental diabetes and exposure to maternal diabetes in utero are “profound risk factors” for obesity and type 2 diabetes in children. The 10-year cumulative incidence of diabetes was zero in Native American children with no parental diabetes vs. 8.2% to 16% among peers with two parents with diabetes, depending on the age group, according to researchers.
“This study suggests that severe obesity in youth is driving the epidemic of youth-onset diabetes and this will undoubtedly lead to development of late-stage complications of diabetes in midlife as well as premature mortality,” the researchers wrote. “Children and adolescents who are severely obese rarely transition to a lower weight category, therefore isolating the effect of childhood obesity, independent of BMI trajectory, was not feasible in this cohort. Nevertheless, early identification of those with severe obesity and prompt institution of effective interventions or therapeutic measures may help mitigate future health risks.” – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.