To determine the functional age of an individual, a quantitative system for the assessment of aging status was developed in the present study. A total of 1579 subjects were selected randomly from patients undergoing physical examination. The index of organic mild impairment (IOMI) and IOMI corrected for age (COMI) were calculated. By receiver operating characteristic (ROC) curve analysis of the IOMIs of younger and elderly subjects, a cutoff value for COMI of 30% was obtained. About 95% of <30-year-old subjects were healthy. These data suggest that organs and systems reflect the aging status of an individual and may be a useful tool for evaluating health status.

The aim of the study was to establish a two-dimensional system based on organic and functional biological age (BA) using a biomarker of organic and functional impairment with aging for precisely assessing roles of natural aging and other risk factors in chronic disease. Material and methods: The index of organic mild impairment, which is similar to the frailty index, was determined with imaging parameters as organic BA. The functional BA was calculated with the following formula: Functional BA = [systolic-diastolic BP (mm Hg)] × waist circumference 2 (m) × height 0.5 (m)/weight (kg). A total of 1047 subjects undergoing routine health examination were randomly selected to establish a system with organic BA on the X-axis, functional BA on the Y-axis; organic and functional BAs from chronological age with 60 years as a center point of the coordinate system. A total of 85 patients with type 2 diabetes controls were recruited to verify the system. Results: Organic and functional BA contributed to chronological age almost equally. Both organic and functional BA increased with chronological age in the two-dimensional system for a random population. There were significant difference for distribution between diabetes and control groups in two-dimensional system (p < 0.05). That both more in quadrant II and lesser in quadrant IV for diabetes were suggested that diabetes was more sensitive to other risk factors than aging. Conclusions: Combination of the two BAs could precisely recognized aging and other risk factors according to locations of the disease in each quadrant and quantitatively assessed status of nature aging and disease-related aging in a individual.