Objectives: To evaluate the relationship between oxidative stress and frailty in elderly people.

Design: Cross-sectional study.

Setting: Community and hospital-based outpatient clinic.

Participants: Ninety participants aged 65 and older.

Measurements: Frailty status was determined according to the presence of weak handgrip strength, weight loss, slow walking speed, exhaustion, and low activity level and was classified as frail (> or =3 criteria), prefrail (1 or 2 criteria), or robust (0 criteria). An oxidative stress marker (serum 8-hydroxy-2'-deoxyguanosine, 8-OHdG), metabolic markers (body mass index, waist-hip ratio, serum lipids, glucose, and albumin), an inflammatory marker (serum high-sensitivity C-reactive protein, hs-CRP), demographic information, and comorbidities (diabetes mellitus, hypertension, congestive heart failure, osteoarthritis, overweight or obesity, impaired fasting plasma glucose, renal insufficiency, and depression) were assessed.

Results: Of the 90 participants, 21 (23.3%) were frail, 56 (62.2%) were prefrail, and 13 (14.4%) were robust. Frail subjects had higher median (range) serum 8-OHdG (2.5 ng/mL (1.5-6.2 ng/mL) vs 2.3 ng/mL (0.5-8.1 ng/mL) and 1.0 ng/mL (0.5-5.3 ng/mL)) and serum hs-CRP (2.5 mg/L (0.3-32.1 mg/L) vs 1.8 mg/L (0.3-50.5 mg/L) and 1.7 mg/L (0.3-4.0 mg/L)) levels, lower mean+/-standard deviation serum albumin levels (4.1+/-0.4 g/dL vs 4.4+/-0.4 g/dL and 4.6+/-0.2 g/dL) and higher mean waist-hip ratios (0.96+/-0.11 vs 0.91+/-0.07 and 0.89+/-0.05)) than prefrail and robust subjects, respectively (P<.05 for all). In multivariable regression analysis, high serum 8-OHdG level was still significantly associated with frailty after adjusting for age, smoking status, comorbidities, waist-hip ratio, serum albumin level, and hs-CRP level.

Conclusion: High oxidative stress, characterized by high serum 8-OHdG level, was independently associated with frailty in the selected sample of elderly Chinese.