The validity of the "Kihon Check-list" as an index of frailty and its biomarkers and inflammatory markers in elderly people

Abstract

AIM: The present study was designed to assess the validity of the "Kihon ("basic") Check-list (KCL)" as a frailty index, and to investigate its biomarkers in an elderly population. METHODS: We enrolled 420 elderly persons aged 65 years and over in comprehensive geriatric assessments in 2007 and 2008. We examined the temporal relationship between the Fried frailty criteria (external criteria) and KCL items 1-20 to evaluate concurrent validity. In 2008, 665 elderly people aged 65 years and over who participated in the comprehensive geriatric assessment in 2008 were assessed based on their frailty and non-frailty using the KCL. We compared biomarkers, including TNF-α, IL-6, CRP and β(2)-microglobulin (β(2)-MG) between frail and non-frail groups. RESULTS: The KCL items 1-20 showed good concurrent validity against the Fried criteria in terms of frailty. When using a cut-off point of 5/6, the KCL items 1-20 showed a sensitivity of 60.0% and a specificity of 86.4% for the Fried frailty criteria. Overall, 34 males (12.3%) and 74 females (19.0%) were defined as frail. Among varying biomarkers, IL-6 (odds ratio [OR] of highest tertile vs. lowest tertile, 2.05; 95% confidence interval [CI]: 1.15-3.64), grip strength (OR: 0.19; 95% CI: 0.07-0.46) and walking speed (OR: 0.23; 95% CI: 0.12-0.45) were significantly associated with risks of frailty. The highest tertile of IL-6 and β(2)-MG combined highly increased the risk of frailty (OR: 5.61; 95% CI: 2.34-13.11) compared with those in the lowest tertile of the 2 markers combined. CONCLUSIONS: The KCL items 1-20 can be used as a frailty index for Japanese elderly population. IL-6 and β(2)-MG are potential candidates for biomarkers of frailty.