High-sensitivity cardiac troponin I and frailty: associations with the frailty index and Fried phenotype in older women

Despite the nexus between cardiovascular health and frailty, the relevance of high-sensitivity cardiac troponin I (hs-cTnI), a biomarker of myocardial injury, to frailty is poorly understood. We examined whether hs-cTnI concentrations were associated with frailty in a well-characterized cohort of older women. A total of 1151 community-dwelling women from the Perth Longitudinal Study of Aging Women (mean age ± SD = 75.2 ± 2.7 years) were included. Frailty was operationalized using a validated frailty index (FI) of cumulative deficits and a modified Fried phenotype. Plasma hs-cTnI were categorized into quartiles. Cross-sectional associations between hs-cTnI quartiles and frailty were assessed using multivariable-adjusted logistic regression models. A total of 235 (20.4%) women were classified as frail using the FI, while 74 (6.4%) were considered frail by Fried's phenotype. In a multivariable-adjusted model, compared to women in the lowest hs-cTnI quartile (Q1), those in Q3 and Q4 had 1.38 (95% CI, 1.00-1.90) and 1.79 (1.20-2.67) greater odds for frailty when classified by the FI. When classified according to Fried's phenotype, women in Q2, Q3, and Q4 had 2.25 (1.10-4.09), 2.64 (1.19-5.21), and 2.44 (1.10-5.33) greater odds for frailty, compared to Q1. Associations remained largely unchanged when further adjusted for daily protein intake or systemic inflammation (lipocalin-2) and restricted to those with subclinical hs-cTnI levels (<15.6ng/L). Higher hs-cTnI levels are associated with greater odds for frailty, classified using an FI or Fried's phenotype, among older women. hs-cTnI may have applications beyond its typical use in cardiology, offering insight into the implications of underlying cardiovascular dysfunction relating to frailty.