Generating a reference interval for fasting serum insulin in healthy nondiabetic adult Chinese men.
Level 4 - case-series / case-control
Cross-sectional reference interval study
What was done
Data from 1,434 healthy, nondiabetic adult men aged 20–69 years from the Fangchenggang Area Male Health and Examination Survey in China were analyzed. Fasting serum insulin was measured via electrochemiluminescence immunoassays, and nonparametric statistical methods were used to calculate the population reference interval.
What was found
The reference interval for fasting serum insulin was 1.57–16.32 μU/mL, with a median of 5.79 μU/mL. Fasting serum insulin correlated significantly with blood glucose and diastolic blood pressure (p < 0.001). Significant differences in insulin concentration were observed according to age and body mass index (BMI; p < 0.001), with higher concentrations found in younger men and in those with higher BMI. Smoking, alcohol consumption, and physical activity were not significantly associated.
Why it matters
This study provides an updated population-specific fasting insulin reference interval for Chinese men, which was lower than previously suggested values, aiding clinical and research assessment of metabolic disorders.
Limits
The study included only men from a single geographic region, limiting generalizability to women and other populations. Being cross-sectional, it does not assess longitudinal metabolic outcomes. The abstract does not specify the exact percentile cutoffs used or control for assay variability across different laboratory platforms.
Cited by
- supports Standard clinical laboratory reference ranges commonly report fasting insulin levels up to 16 or 18 as normal.