May 2009: Volume 35, Number 5
New Study Shows Growing Burden of Diabetes
Recently published data from the 2005–2006 National Health and Nutrition Examination Survey (NHANES) indicates that >40% of the adult population now has diabetes or pre-diabetes (Diabetes Care 2009;32:287–294). Conducted by NIH and CDC, the study was the first since the 1988-1994 NHANES to use both fasting blood glucose (FBG) and oral glucose tolerance (OGTT) tests to measure prevalance. The new analysis revealed that 12.9% of individuals age 20 or older had diabetes, with 7.7% being previously diagnosed, and 5.1% not diagnosed before, as determined by either FBG or OGTT. Another 29.5% had either impaired fasting glucose (IFG) or impaired glucose tolerance (IGT).
Use of the two tests enabled researchers to assess differences in the populations defined by IFG and IGT. The test results corresponded most closely in identifying survey participants who either had diabetes or normal blood glucose levels. Both tests identified >90% of subjects in those categories. They differed in defining previously undiagnosed diabetics, the crude prevalence of which was nearly double when determined by OGTT versus IFG (4.9% versus 2.5%, respectively). Other descrepancies appeared in participants defined as having IFG; only 31.3% also were determined to have IGT, while 60.2% were normal based on OGTT. In contrast, only 8.9% of participants defined as having normal blood glucose levels by IFG were determined to have IGT based on OGTT.
The study also underscored the disproportionate burden of diabetes in minority populations. Compared with non-Hispanic whites age 20 or older, the prevalence of diabetes was about 70% higher in non-Hispanic blacks and 80% higher in Mexican Americans. “The sheer magnitude of prevalance found in 2005–2006 portends all the consequences of diabetes including its myriad complications and costs to both individuals and society,” the authors conclude.