Objective and subjective rapid frailty screening tools in people with HIV.

OBJECTIVES: As people with HIV (PWH) age, the prevalence of frailty increases. Rapid screening tests to identify frailty within HIV outpatient settings are required to identify at-risk individuals. We undertook a service evaluation to assess three short frailty assessments in PWH. METHODS: We assessed two objective [gait speed (GS), timed-up-and-go test (TUGT)] and one subjective [the self-reported health questionnaire (SRH)] frailty screening tools in PWH aged > 40 years attending a single HIV outpatient department. Factors associated with positive frailty screening tests (defined as GS < 0.8 m/s, TUGT ≥ 10 s and SRH score < 6) were assessed using logistic regression models. ETHICAL CONSIDERATIONS: This was a service evaluation and was approved as a service evaluation by the Imperial College Healthcare NHS trust HIV clinical research committee (February 2020). All participants were given verbal information and were able to terminate the screening tests at any time. RESULTS: Of 84 PWH approached, 80 individuals completed all screening tests (median age = 56 years, range: 40-80) with a positive frailty screening prevalence in 19%, 33% and 20% for GS, TUGT and SRH, respectively. All tests were considered acceptable to participants. Factors statistically significantly associated with frailty included age (GS and TUGT), detectable HIV RNA (TUGT), number of comorbidities (GS and TUGT), presence of polypharmacy (GS and TUGT) and total number of concomitant medication (GS and SRH). CONCLUSIONS: Rates of positive screening tests for frailty are dependent on screening tool used, with all three tools being acceptable to participants. Objective measures of frailty screening (GS and TUGT) are more closely associated with clinical parameters than is a subjective measure of frailty screening (SRH).

The in vitro manipulation of carbohydrate metabolism: a new strategy for deciphering the cellular defence mechanisms against nitric oxide attack.

This study was aimed at examining the effects of manipulating the carbohydrate source of the culture medium on the cellular sensitivity of epithelial cells to an oxidative attack. Our rationale was that substituting galactose for glucose in culture media would remove the protection afforded by glucose utilization in two major metabolic pathways, i.e. anaerobic glycolysis and/or the pentose phosphate pathway (PPP), which builds up cellular reducing power. Indeed, we show that the polarized human colonic epithelial cell line HT29-Cl.16E was sensitive to the deleterious effects of the NO donor PAPANONOate [3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine] only in galactose-containing medium. In such medium NO attack led to cytotoxic and apoptotic cell death, associated with formation of derivatives of NO auto-oxidation (collectively termed NOx) and peroxynitrite, leading to intracellular GSH depletion and nitrotyrosine formation. The addition of 2-deoxyglucose, a non-glycolytic substrate, to galactose-fed cells protected HT29-Cl. 16E cells from NO attack and maintained control GSH levels through its metabolic utilization in the PPP, as shown by (14)CO(2) production from 2-deoxy[1-(14)C]glucose. Therefore, increasing the availability of reducing equivalents without interfering with energy metabolism is able to prevent NO-induced cell injury. Finally, this background provides the conceptual framework for establishing nutritional manipulation of cellular metabolic pathways that could provide new means for (i) deciphering the mechanisms of cell injury by reactive nitrogen species and reactive oxygen species at the whole-cell level and (ii) establishing the hierarchy of intracellular defence mechanisms against these attacks.