Issue 127 Item 4 A New Two-Step Screening Protocol for Type 2 Diabetes

OGTT was not required to identify the large majority of diabetic patients in this two-step screening procedure.” A two-step screening protocol for type 2 diabetes, which incorporates both universal screening and screening tests targeted to high-risk subjects, has been well received by the general population in the Netherlands, researchers report in the October issue of Diabetes Care.

Early diagnosis of type 2 diabetes has not been conclusively proven to be important, Dr. Annemieke M. W. Spijkerman and colleagues maintain. Noting that screening benefits only a small number of the people involved, they argue that the initial screening test should be noninvasive.

Accordingly, the research team, which is based at VU University Medical Center in Amsterdam, mailed the Symptom Risk Questionnaire (SRQ) to 11,679 residents of three Dutch municipalities. Altogether, 9169 individuals returned the SRQ or a form explaining why they did not feel a need to participate, for a total response rate of 78%.

The 3301 respondents with an SRQ score >6 were invited to undergo fasting blood glucose measurement, and 2885 accepted. Of these, 570 had glucose levels between 5.5 and 8.5 mmol/L and were offered a 75-g oral glucose tolerance test (OGTT). Of the 473 people who underwent the test, 217 were diagnosed with type 2 diabetes.

The diagnosed patients had relatively low hemoglobin A1c (HbA1c) levels, a mean of 6.7%, according to the report. About 70% had hypertension, about one third had high triglyceride and/or low HDL cholesterol levels, and 73% had a high cholesterol level. "One could argue that our screening procedure identified diabetic patients who might benefit most from early treatment of dyslipidemia and hypertension," the researchers remark.

They note that 36 patients had fasting glucose levels >8.5 mmol/L and were diagnosed on the basis of a second fasting glucose test, instead of the OGTT. These patients "were relatively young, had high HbA1c levels, and frequently reported thirst and a family history of diabetes on the SRQ," the team explains. "We expect that these patients would…have come to rapid clinical recognition without the screening."

The only diabetics who would not have been identified if the OGTT had been omitted were 29 individuals who were diagnosed on the basis of a 2-hour plasma glucose level of at least 11.1 mmol/L. "These results seem to imply," the researchers conclude, "that the OGTT added relatively few cases and may not be required to identify the large majority of diabetic patients in this two-step screening procedure."

Diabetes Care 2002;25:1784-1789.