[What will be the proper criteria for impaired fasting glucose for Korean men? Based on medical screening data from a general hospital].
OBJECTIVE
Recently, the American Diabetes Association (ADA) redefined the criteria of prediabetes, which has lowered the diagnostic level of fasting plasma glucose (FPG) from 110 to 125 mg/dl, down to levels between 100 to 125mg/dl. The purpose of this study was to determine the predictive cutoff level of FPG as a risk for the development of diabetes mellitus in Korean men.


METHODS
A retrospective cohort study was conducted on 11,423 (64.5%) out of 17,696 males < or =30 years of age, and who met the FPG of < or = 125 mg/dl and hemoglobin A1c of < or = 6.4% criteria, without a history of diabetes, and who were enrolled at the screening center of a certain university hospital between January and December 1999. The subjects were followed from January 1999 to December 2002 (mean follow-up duration; 2.3(+/-0.7) years). They were classified as normal (FPG <100mg/dl), high glucose (FPG > or =100 mg/dl and < 110 mg/dl) and impaired fasting glucose (FPG 2110 mg/dl and < 125 mg/dl) on the basis of their fasting plasma glucose level measured in 1999. We compared the incidence of diabetes between the 3 groups by performing Cox proportional hazards model and used receiver operating characteristic analyses of the FPG level, in order to estimate the optimal cut-off values as predictors of incident diabetes.


RESULTS
At the baseline, most of the study subjects were in age in their 30s to 40s (mean age, 41.8(+/-7.1) year). The incidence of diabetes mellitus in this study was 1.19 per 1,000 person-years (95% CI=0.68-1.79), which was much lower than the results of a community-based study that was 5.01 per 1,000 person-years. The relative risks of incident diabetes in the high glucose and impaired fasting glucose groups, compared with the normal glucose group, were 10.3 (95% CI=2.58-41.2) and 95.2 (95% CI= 29.3-309.1), respectively. After adjustment for age, body mass index, and log triglyceride, a FPG greater than 100 mg/dl remained significant predictors of incident diabetes. Using the receiver operating characteristic (ROC) curve, the optimal cutoff level of FPG as a predictor of incident diabetes was 97.5 mg/dl, with a sensitivity and a specificity of 81.0% and 86.0%, respectively.


CONCLUSIONS
These results suggest that lowering the criteria of impaired fasting glucose is needed in Korean male adults. Future studies on community-based populations, including women, will be required to determine the optimal cutoff level of FPG as a predictor of incident diabetes.
Ryu
Seungho
S
Department of Occupational Medicine, Kangbuk Samsung Hospital & Sungkyunkwan University.
Chang
Yoo-Soo
YS
Kim
Dong-Il
DI
Suh
Byung-Seong
BS
Kim
Woon Sool
WS
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D015331:Cohort Studies; D005215:Fasting; D006769:Hospitals, General; D006801:Humans; D007723:Korea; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood / Q000175:diagnosis*; D012189:Retrospective Studies
D001786:Blood Glucose