Cut-off values of fasting and post-load plasma glucose and HbA1c for predicting Type 2 diabetes in community-dwelling Japanese subjects: the Hisayama Study

Diabet Med. 2012 Jan;29(1):99-106. doi: 10.1111/j.1464-5491.2011.03378.x.

Abstract

Aims: We examined the optimal cut-off values of fasting plasma glucose, 2-h post-load glucose and HbA(1c) for predicting Type 2 diabetes in community-dwelling Japanese subjects.

Methods: A total of 1982 subjects without diabetes aged 40-79 years who underwent a 75-g oral glucose tolerance test were followed prospectively for 14 years by annual health examination.

Results: During the follow-up, 295 subjects developed Type 2 diabetes. Compared with the first decile, the crude hazard ratio for incident Type 2 diabetes was significantly higher in the fifth fasting plasma glucose decile [5.4-5.4 mmol/l (97-98 mg/dl)] or higher, in the seventh 2-h post-load glucose decile [6.9-7.2 mmol/l (124-131 mg/dl)] or higher, and in the fifth HbA(1c) decile [34-36 mmol/mol (5.3-5.4%)] or higher. These associations remained substantially unchanged even after adjustment for confounding factors. The receiver operating characteristic curve analysis showed that the optimal cut-off values for predicting Type 2 diabetes were 5.6 mmol/l (101 mg/dl) for fasting plasma glucose, 6.9 mmol/l (124 mg/dl) for 2-h post-load glucose and 37 mmol/mol (5.5%) for HbA(1c). In a stratified analysis, the cut-off values were approximately 5.6 mmol/l (101 mg/dl) for fasting plasma glucose and 37 mmol/mol (5.5%) for HbA(1c), and these values were unchanged over BMI quartile levels, whereas the 2-h post-load glucose cut-off values declined with decreasing BMI levels.

Conclusions: Our findings suggest that the cut-off value for predicting Type 2 diabetes in the Japanese population is 5.6 mmol/l (101 mg/dl) for fasting plasma glucose and 37 mmol/mol (5.5%) for HbA(1c), while the 2-h post-load glucose cut-off value is lower than the diagnostic criterion for impaired glucose tolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Asians* / statistics & numerical data
  • Blood Glucose / metabolism*
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Fasting / blood
  • Female
  • Follow-Up Studies
  • Glucose Tolerance Test
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Incidence
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • ROC Curve
  • Residence Characteristics
  • Risk Factors
  • Sensitivity and Specificity

Substances

  • Blood Glucose
  • Glycated Hemoglobin A