Allostatic load measures in older adults with subjective cognitive decline and mild cognitive impairment: A cross-sectional analysis from the Brazilian Memory and Aging Study.

INTRODUCTION: An increasing body of research suggests that stress and allostatic load are related to cognitive dysfunction and neurodegeneration. OBJECTIVES: to determine the relationship between allostatic load (AL) and cognitive status in older adults classified with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). METHODOLOGY: Using the Brazilian Memory and Aging Study (BRAMS) database, we analyzed data from 57 older adults with SCD and MCI. Blood neuroendocrine (cortisol, DHEA-s), inflammatory (C-reactive protein, fibrinogen), metabolic (HbA1c, HDL-cholesterol, total cholesterol, creatinine), and cardiovascular (blood pressure, waist/hip ratio) were transformed into an AL index. RESULTS: Despite a significant difference in the univariate analysis between waist/hip ratio (0.94 in the MCI group vs. 0, 88 in the SCD group, p = 0.03), total cholesterol levels (194 vs. 160, p = 0.02), and AL index (36.9 % in the MCI group vs. 27.2 % in the SCD group, p = 0.04), AL was not associated with SCD or MCI in the multivariate analysis. CONCLUSION: Our data suggest that different profiles of AL in MCI compared to individuals with SCD could be due to cofounding factors. These findings need to be confirmed in longitudinal studies investigating profiles of AL changes at preclinical and prodromal stages of Alzheimer's disease.

Driving pressure, as opposed to tidal volume based on predicted body weight, is associated with mortality: results from a prospective cohort of COVID-19 acute respiratory distress syndrome patients.

OBJECTIVE: To evaluate the association between driving pressure and tidal volume based on predicted body weight and mortality in a cohort of patients with acute respiratory distress syndrome caused by COVID-19. METHODS: This was a prospective, observational study that included patients with acute respiratory distress syndrome due to COVID-19 admitted to two intensive care units. We performed multivariable analyses to determine whether driving pressure and tidal volume/kg predicted body weight on the first day of mechanical ventilation, as independent variables, are associated with hospital mortality. RESULTS: We included 231 patients. The mean age was 64 (53 - 74) years, and the mean Simplified Acute and Physiology Score 3 score was 45 (39 - 54). The hospital mortality rate was 51.9%. Driving pressure was independently associated with hospital mortality (odds ratio 1.21, 95%CI 1.04 - 1.41 for each cm H2O increase in driving pressure, p = 0.01). Based on a double stratification analysis, we found that for the same level of tidal volume/kg predicted body weight, the risk of hospital death increased with increasing driving pressure. However, changes in tidal volume/kg predicted body weight were not associated with mortality when they did not lead to an increase in driving pressure. CONCLUSION: In patients with acute respiratory distress syndrome caused by COVID-19, exposure to higher driving pressure, as opposed to higher tidal volume/kg predicted body weight, is associated with greater mortality. These results suggest that driving pressure might be a primary target for lung-protective mechanical ventilation in these patients.

Driving pressure, as opposed to tidal volume based on predicted body weight, is associated with mortality: results from a prospective cohort of COVID-19 acute respiratory distress syndrome patients / Driving pressure, em oposição ao volume corrente ajustado para o peso corporal predito, associa-se com a mortalidade: resultados de uma coorte prospectiva de pacientes com síndrome do desconforto respiratório agudo por COVID-19

ABSTRACT Objective: To evaluate the association between driving pressure and tidal volume based on predicted body weight and mortality in a cohort of patients with acute respiratory distress syndrome caused by COVID-19. Methods: This was a prospective, observational study that included patients with acute respiratory distress syndrome due to COVID-19 admitted to two intensive care units. We performed multivariable analyses to determine whether driving pressure and tidal volume/kg predicted body weight on the first day of mechanical ventilation, as independent variables, are associated with hospital mortality. Results: We included 231 patients. The mean age was 64 (53 - 74) years, and the mean Simplified Acute and Physiology Score 3 score was 45 (39 - 54). The hospital mortality rate was 51.9%. Driving pressure was independently associated with hospital mortality (odds ratio 1.21, 95%CI 1.04 - 1.41 for each cm H2O increase in driving pressure, p = 0.01). Based on a double stratification analysis, we found that for the same level of tidal volume/kg predicted body weight, the risk of hospital death increased with increasing driving pressure. However, changes in tidal volume/kg predicted body weight were not associated with mortality when they did not lead to an increase in driving pressure. Conclusion: In patients with acute respiratory distress syndrome caused by COVID-19, exposure to higher driving pressure, as opposed to higher tidal volume/kg predicted body weight, is associated with greater mortality. These results suggest that driving pressure might be a primary target for lung-protective mechanical ventilation in these patients.

RESUMO Objetivo: Avaliar a associação entre driving pressure e volume corrente ajustado pelo peso predito com a mortalidade em uma coorte de pacientes com síndrome do desconforto respiratório agudo por COVID-19. Métodos: Estudo prospectivo e observacional que incluiu pacientes com síndrome do desconforto respiratório agudo por COVID-19 admitidos em duas unidades de terapia intensiva. Foi realizada análise multivariada para determinar se a driving pressure e o volume corrente/kg de peso predito, aferidos no primeiro dia de ventilação mecânica, associavam-se de forma independente com a mortalidade hospitalar. Resultados: Foram incluídos 231 pacientes. A mediana de idade foi de 64 (53 - 74) anos, e a mediana do Simplified Acute and Physiology Score 3 foi de 45 (39 - 54). A mortalidade hospitalar foi de 51,9%. A driving pressure se associou de forma independente com a mortalidade hospitalar (razão de chance de 1,21; IC95% de 1,04 - 1,41 para cada cm H2O de aumento da driving pressure, p = 0,01). Com base na análise de dupla estratificação, encontrou-se que, para o mesmo nível de volume corrente/kg de peso predito, o risco de mortalidade hospitalar aumentava com o incremento da driving pressure. No entanto, mudanças no volume corrente/kg de peso predito não se associaram com a mortalidade quando não resultavam em aumento da driving pressure. Conclusão: Em pacientes com síndrome do desconforto respiratório agudo por COVID-19, exposição a maior driving pressure, ao contrário da exposição a maior volume corrente/kg de peso predito, associou-se com maior mortalidade hospitalar. Os resultados sugerem que a driving pressure poderia ser o alvo primário para a condução da ventilação mecânica protetora nesses pacientes.