Abstract: OBJECTIVE: To verify the Traditional Chinese Medicine(TCM) theory that kidney-Qi deficiency(KQD)is considered to be the main cause of aging using cross-sectional study.METHODS: Demographic and lifestyle characteristics of 90 healthy participants were collected with a self-administered questionnaire. KQD syndrome was diagnosed according to Deng's diagnosis standard. Creatinine-adjusted urinary 8-hydroxy-2'-deoxyguanosine(8-OH-dG) and 8-isomeric-prostaglandin2α(8-iso-PGF2α), salivary advanced oxidation protein products(AOPPs), malondialdehyde(MDA) and dehydroepiandrosterone-sulfate(DHEA-S) were selected as aging markers and measured using enzyme-linked immunosorbent assay.RESULTS: No significant differences were observed in participant characteristics between the KQD group and non-KQD(NKQD) group(P > 0.05). Levels of 8-OH-dG, 8-iso-PGF2α, AOPPs, and MDA increased with age, except for a slight decrease in8-OH-dG in the older group. The increase in8-iso-PGF2α was significant(P < 0.05). DHEA-S significantly decreased with increasing age(P < 0.01).8-OH-dG levels were higher in the KQD group compared with the NKQD group. Levels of urinary8-iso-PGF2α, salivary AOPPs, and MDA in the KQD group were lower than in the NKQD group. Salivary DHEA-S was higher in the KQD group compared with the NKQD group. However, differences between KQD group and NKQD group were not significant.CONCLUSION: The current results suggested that KQD syndrome, as diagnosed by Deng's standard,does not underlie the aging phenotype.

Key words: Aging, Kidney-Qi deficiency, Advanced oxidation protein products, Malondialdehyde, Dehydroepiandrosterone sulfate, Cross-sectional studies