Objectives: 

Frailty is a geriatric term used as a marker of vulnerability, identifying individuals with a diminished capacity to respond to external stressors. Those who are frail are at increased risk of death, institutionalization and worsening disability. With the phenotype better defined, attention has shifted to pathophysiology, trying to identify some possible biomarkers. In this study we aimed to find some possible biomarkers of frailty related to oxidative damage (malondialdehyde or MDA and protein carbonilation) and cognitive impairment (brain derived neurotrophic factor or BDNF), and its possible relationship with the patient´s age or gender.

Materials: 

In 150 patients (aged 65- 95 years), classified as frail (50), prefrail (50) and non- frail (50) according to Fried's criteria, we measured plasma MDA levels by high performance liquid chromatographic techniques (HPLC), protein carbonilation levels by western blot with the "OxyBlot TM Protein Oxidation Detection kit", and BDNF levels with the "BDNF Sandwich ELISA kit"

Results: 

A significant increase in MDA and protein carbonilation levels was shown in frail patients when compared to non- frail. Regarding to BDNF levels, they were lower in frail patients when compared to non frail. In all three parameters, there was no relation with age or gender.

Conclusions: 

Circulating oxidative damage and cognitive impairment biomarkers, such as MDA, protein carbonilation and BDNF are related to frailty, and not to age or gender. These parameters could be considered as biomarkers that can predict frailty.

This work was supported by grants SAF2010-19498, ISCIII2006-RED13-027, PROMETEO2010/074, 35NEURO GentxGent and EU Funded COSTB35 and CM1001. This study has been co-financed by FEDER funds from the European Union.