The Effect of Frailty on Independent Living After Surgery: A Population-Based Retrospective Cohort Study.

BACKGROUND: Most people value quality of life over mere duration. At least 50% of people are extremely averse to ever living in a nursing home (NH). OBJECTIVES: Assess whether pre-operative frailty is associated with new, post-operative NH placement. DESIGN, SETTING: Retrospective, population-based cohort study in the Canadian province of Manitoba, 2000-2017. PARTICIPANTS: 7408 persons ≥65 years undergoing any of 16 specific, elective, noncardiac surgeries of varying Operative Surgical Stress (OSS). MEASUREMENTS: The primary outcome was new admission to a NH, or being placed on a waiting list for a NH, within 180 days of index hospital admission, among index hospital survivors. Frailty was assessed from administrative data by the Preoperative Frailty Index (pFI), which ranges 0-1. Other outcomes were 30-day and 90-180 day mortality, and post-hospital medical resource use to 180 days. Analyses used multivariable regression models, adjusted for age, sex, OSS, year of surgery, anesthetic technique, and socioeconomic status. P-values were adjusted for the six outcomes. RESULTS: Subjects had mean age (±SD) of 74±7 yrs; 61% were male. pFI ranged 0-0.68, with a mean±SD of 0.21±0.09. All six outcomes were significantly associated with greater frailty. Each additional 0.1 unit increase in pFI was associated with a hazard ratio for new NH admission or wait-listing of 3.01 (p<0.0006). CONCLUSIONS: While our study agrees with prior work indicating that greater frailty is associated with higher probability of post-operative discharge to a NH, it overcomes a number of limitations of all prior work. Strong arguments follow that prospective surgical candidates be evaluated for their degree of frailty, and that their informed consent include discussion of the possibility of survival with loss of independence.

Thyroxine regulation of monolysocardiolipin acyltransferase activity in rat heart.

Treatment of rats with thyroxine has been shown to elevate the biosynthesis and content of cardiolipin in the heart [Cao, Cheng, Angel and Hatch (1995) Biochim. Biophys. Acta 1256, 241-244]. Treatment with thyroxine resulted in a 1.8-fold increase (P<0.025) in [1-(14)C]linoleate and a 1.7-fold increase (P<0.025) in [1-(14)C]oleate incorporated into cardiolipin in perfused hearts, compared with controls. The mechanism for the elevation in incorporation of unsaturated fatty acids into cardiolipin was a 1. 6-fold (P<0.025) increase in mitochondrial monolysocardiolipin acyltransferase activity. The results demonstrate that the acylation of cardiac monolysocardiolipin is regulated by thyroid hormone. Thus an elevation in cardiolipin biosynthesis is accompanied by an elevation in monolysocardiolipin acyltransferase activity to maintain the appropriate molecular species composition of cardiolipin in the cardiac mitochondrial membrane. We postulate that monolysocardiolipin acyltransferase might be a rate-limiting enzyme for the molecular remodelling of cardiolipin in the heart.