Childhood fasting plasma glucose predicted diabetes later in life

Issue: March 2010

Elevated fasting plasma glucose rates during childhood — even those inside the normoglycemic range — appeared to be a significant predictor of type 2 diabetes in adulthood, according to new study results.

Researchers gathered data from the cross-sectional, long-term Bogalusa Heart Study, which followed participants from childhood to young adulthood (ages 4 to 18 years) for an average 21 years; 1,723 participants were classified as having normoglycemia, 79 prediabetes and 47 diabetes.

The likelihood of developing prediabetes (P<.001) or diabetes (P=.03) in young adulthood was elevated twofold for participants with fasting plasma glucose levels of 86 mg/dL to 99 mg/dL during childhood.

Moreover, this association was “independent of other traditional cardiometabolic risk factors,” according to the researchers.

For the prediction value of the 86 mg/dL threshold, the area under the receiver operating curve analysis yielded a C value of 0.855 for prediabetes and 0.789 for diabetes models. Sensitivity models were 76.9% for prediabetes and 75% for diabetes; specificity models were 85.2% for prediabetes and 76% for diabetes.

Results of a multivariate analysis that factored anthropometric, hemodynamic and metabolic variables indicate that participants with elevated fasting plasma glucose levels during childhood were 3.4 times more likely to develop prediabetes (P<.001) and 2.06 times more likely to develop diabetes (P=.05) in adulthood compared with children without elevated levels.

These results are not surprising, Matthew W. Gillman, MD, of Harvard Medical School and Harvard Pilgrim Health Care Institute, wrote in an accompanying editorial.

“The prevalence of prediabetes was 6% to 7% among adults whose childhood glucose exceed 86 mg/dL, but only around 2% for lower childhood glucose levels. For frank diabetes, no clear threshold was apparent,” he wrote.

Gillman said, “Even if there is a threshold over which children are at substantially higher risk of later prediabetes, it is unclear exactly how high the risk should be to make changing guidelines a good thing. After all, the right interventions for individuals with prediabetes are still obscure, so identifying more of them may be more trouble that it’s worth.”

However, he noted that obesity was less common when the Bolagusa Heart Study started in 1978. Further, no child had the current recommended cutoff point of fasting plasma glucose less than100 mg/dL.

“From this cohort, therefore, it is impossible to know the magnitude of increased risk among children with today’s definition of impaired fasting glucose level compared with children who have lower glucose levels,” Gillman wrote. – by Matthew Brannon

Gillman MW. Arch Pediatr Adolesc Med. 2010;164:198-199.

Nguyen QM. Arch Pediatr Adolesc Med. 2010;164:124-128.

Nguyen et al report from a large, prospective cohort that fasting glucose values above 86 mg/dL in childhood convincingly predict increased risk for developing prediabetes or diabetes in adulthood. Data from this important study will help identify youth at greater risk of developing glucose abnormalities in adulthood. However, further research is needed on whether interventions aimed at such youth are effective at preventing later glucose abnormalities. In addition, fasting glucose has inherent limitations due to fasting requirements, thus recent American Diabetes Association criteria for diabetes have changed to being based on HbA1c. Therefore, additional data are also now required regarding how childhood HbA1c predicts later development of prediabetes or diabetes, especially in contemporary youth, who are more obese than the Bogalusa cohort.

- Kristen Nadeau, MD
Assistant professor of pediatrics, University of Colorado Health Sciences Center