[Reference Intervals of Standard Test Items in Ningen Dock Examination].

OBJECTIVE

Reference intervals (RIs) were derived from records of 1,499,288 individuals who underwent ningen dock examination in 188 institutes which belong to Japan Society of Ningen Dock in 2012.

METHODS

Targets were 27 basic laboratory tests, including the body mass index (BMI) and systolic and diastolic blood pressures (SBP, DBP). Individuals fulfilling strict criteria were chosen: SBP < 130, DBP < 85 mmHg, BMI < 25 Kg/m2, non-smoking, ethanol consumption < 20 g/day, under no medication, with no remarkable current/past illness. The latent abnormal values exclusion (LAVE) method was applied to ensure normal results. RLs were derived using a parametric method with modified Box-Cox power transformation.

RESULTS

Among all attendees, 23% fulfilled the criteria. Application of the LAVE method further reduced the dataset by 40-50%. RIs without distinction of the sex and age were SBP, DBP, TP, TB, MCV, WBC, and Plt. Sex-specific RIs were BMI, CRE, UA, TG, HDL-C, ALT, GGT, Glu, RBC, Hb, and Ht. Age-specific RIs in either sex were Alb, AST, HbA1c, TC, LDL-C, FW-LDL-C, nonHDL-C, and ALP. An age-specific RI without distinction of the sex was eGFR. Comparison of derived RIs with clinical decision limits (CDLs) revealed that the upper limits of RIs differed from CDLs according to the sex and age.

CONCLUSION

Implementation of sex- and age-related RIs derived from individuals with fully normal ningen dock results will enable the appropriate interpretation of test results in health screening, and promote the effective application of CDLs for therapeutic intervention, taking into account the sex, age, and other health attributes.