Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease.
OBJECTIVE
To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG.


METHODS
Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity.


RESULTS
Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT.


CONCLUSIONS
Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG.
Tai
E Shyong
ES
Department of Endocrinology, Singapore General Hospital, Singapore. eshyong@pacific.net.sg
Goh
Su Yen
SY
Lee
Jeannette J M
JJ
Wong
Moh-Sim
MS
Heng
Derrick
D
Hughes
Kenneth
K
Chew
Suok Kai
SK
Cutter
Jeffery
J
Chew
William
W
Gu
Ken
K
Chia
Kee Seng
KS
Tan
Chee Eng
CE
D001786:Blood Glucose / Q000032:analysis*; D003430:Cross-Sectional Studies; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013997:Time Factors
D001786:Blood Glucose