Fasting Glucose Levels In Normal Range Independent Risk Factor For Diabetes

The risk of diabetes may increase with higher levels of fasting plasma glucose within the normal range.

Researchers from the Center for Health Research at Kaiser Permanente Northwest assessed 46,578 patients with fasting plasma glucose levels <100 mg/dL. Patients did not previously have diabetes or impaired fasting glucose, according to the study.

Patients were divided into one of four groups based on their fasting plasma glucose levels: <85 mg/dL, 85 to 89 mg/dL, 90 to 94 mg/dL or 95 to 99 mg/dL. The researchers followed the patients until they developed diabetes, died, left the health center or until April 30, 2007.

During a mean follow-up of 81 months, patients had developed diabetes at a rate of <1% per year, according to the study.
After controlling for other risk factors, the risk for diabetes increased by 6% with every milligram per deciliter of fasting plasma glucose (HR=1.06; P<.0001). Patients with fasting plasma glucose levels of 95 to 99 mg/dL were 2.33 times more likely to develop diabetes, compared with those patients who had levels <85 mg/dL (HR=2.33; P<.0001).

Progression toward diabetes was 49% more likely among patients in the 90 to 94 mg/dL group (HR=1.49; P<.0001).
“Fasting plasma glucose levels seem to impart diabetes risk that begins well below the currently accepted normal level,” the researchers wrote.

Am J Med. 2008;121:519-524.