Association between inflammatory markers and frailty in institutionalized older men

To determine whether higher serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and high sensitivity C-reactive protein (CRP) were associated with frailty in the older institutionalized men.

The study enrolled 386 residents from a veterans care home in northern Taiwan in 2007. All participants were men. Residents younger than 65 years or with acute illness were excluded.

Frailty status was determined based on the frailty phenotype (indicators include weight loss, exhaustion, and low grip strength, slow walking speed). Participants with 3 or more of the indicators were defined as frail, with 1 or 2 as intermediate frail, with no as non-frail. Serum IL-6, TNF-α, and hsCRP levels were measured using enzyme-linked immunosorbent assay and modeled as tertile for severely skewed distributions.

The mean age of the participants was 81.5±4.9 years. The percentages of frail were 33.2%, intermediate frail 59.1% and nonfrail 7.8%. Higher IL-6 level was positively associated with the frail status. Adjusting for age, body mass index, smoking status, and comorbid conditions, serum IL-6 showed significant trend across frailty categories (P=0.03 [95% CI 1.40-5.24]). No significant associations of TNF-α, and CRP level with frailty were observed. An IL-6 level of 1.79pg/mL had the optimal predictive value for frailty, with an area under the receiver operating characteristic (ROC) curve of 0.66 (P=0.01 [95% CI 0.53-0.78]).

Higher serum levels of IL-6 were associated with frailty status in the older institutionalized men with multiple comorbidities.