Among individuals with a fasting plasma glucose of less than 100 mg/dL as children, increasing levels were associated with greater risks of prediabetes (P<0.001) and Type 2 diabetes (P=0.03) in adulthood, according to Gerald Berenson, MD, of Tulane University Health Sciences Center in New Orleans, and colleagues.
There appeared to be a threshold -- 85 mg/dL -- above which the risk of adult problems began to increase, the researchers reported.
"It is not surprising that a higher fasting glucose level in childhood predicts prediabetes and diabetes in adulthood," Matthew Gillman, MD, of Harvard, wrote in an accompanying editorial.
More surprising, he said, was the existence of the apparent threshold, although "the authors are appropriately circumspect about recommending lowering glucose cutoff points to diagnose children at risk of developing prediabetes or diabetes."
"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," he wrote. "After all, the right interventions for individuals with prediabetes are still obscure, so identifying more of them may be more trouble than it's worth."
Previous studies have suggested that higher plasma glucose levels, even if still in the normal range, might be a predictor of diabetes.
Berenson's group wanted to see whether elevated fasting plasma glucose in childhood would predict prediabetes or Type 2 diabetes in adulthood. To find out, they turned to the Bogalusa Heart Study, which began tracking children from that Louisiana town in 1978. All had a fasting plasma glucose lower than 100 mg/dL.
The current analysis included those same individuals assessed as adults after a mean follow-up of 21 years -- 1,723 were normoglycemic (99 mg/dL or lower), 79 were prediabetic (100 to 125 mg/dL), and 47 had Type 2 diabetes.
Using a childhood fasting plasma glucose of 86 mg/dL or higher as a predictor for prediabetes yielded a 76.9% sensitivity and 85.2% specificity. For diabetes, sensitivity was 75% and specificity was 76%.
In a multivariate analysis controlling for anthropometric, hemodynamic, and metabolic variables from childhood to adulthood, as well as baseline fasting plasma glucose level, those individuals who had a childhood level 86 mg/dL or higher had increased risks of both prediabetes (OR 3.40, 95% CI 1.87 to 6.18) and Type 2 diabetes (OR 2.06, 95% CI 1.01 to 4.23) as adults.
The authors acknowledged some limitations of the study, including the lack of data on postchallenge glucose, in vivo insulin action and secretion, and glycosylated hemoglobin in childhood.
Gillman, the editorialist, also noted that the findings' generalizability to children today is unclear because obesity was much less prevalent when the adults in this study were children.
Explain to interested patients that this study suggests that children with fasting plasma glucose levels above 85 mg/dL might have an increased risk of prediabetes and Type 2 diabetes in adulthood.
Nguyen Q, et al "Fasting plasma glucose levels within the normoglycemic range in childhood as a predictor of prediabetes and Type 2 diabetes in adulthood: the Bogalusa Heart Study" Arch Pediatr Adolesc Med 2010; 164: 124-28.
Additional source: Gillman M "Predicting prediabetes and diabetes: Can we do it? Is it worth it?" Arch Pediatr Adolesc Med 2010; 164: 198-99.