Diagnostic tests for early prediabetes screening using blood glucose usually suffer from poor sensitivity as these individuals often exhibit slight increase or even normoglycemic blood levels. Conversely, they manifest markedly elevated insulin to compensate for initial insulin resistance. This renders insulin a more sensitive biomarker for prediabetes detection. To date, there is no official guideline for a normal fasting insulin range demarcating healthy individuals from those with prediabetes.
We performed a meta-analysis to establish healthy fasting insulin reference ranges for different Asian ethnicities (Chinese, Malays, South Asians, Koreans and Japanese).
The mean (and 95% reference range) for lean Asians with BMI <25 kg/m2 is 6.12 µU/mL (1.53-24.53 µU/mL). When stratified by ethnicity, the values for Chinese, Malay, South Asians, Japanese and Korean are 6.21 µU/mL (1.55-24.95 µU/mL), 5.95 µU/mL (1.75-20.16 µU/mL), 8.27 µU/mL (1.45-47.19 µU/mL), 5.17 µU/mL (2.10-12.72 µU/mL) and 4.77 µU/mL (0.88-25.82 µU/mL) respectively. Mean and 95% reference range for Asians with BMI ≥ 25 kg/m2 were higher versus lean Asians at 11.23 µU/mL (3.06-41.15 µU/mL).
The fasting insulin ranges reported can serve as references for establishing official healthy fasting insulin ranges customized to specific ethnicities for assessing early insulin resistance for prediabetes diagnosis.
K. Hor Cheng: None. J.C.Y. Chan: None.
