ObjectiveTo systematically review the relationship between frailty and risk of orthostatic hypotension.MethodsPubMed, EMbase, Web of Science, CNKI, CBM, VIP and WanFang Data databases were electronically searched to collect studies on the association between frailty and orthostatic hypotension from inception to July 7th, 2020. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Meta-analysis was then performed by RevMan 5.3 software.ResultsFive cross-sectional studies involving 8 671 patients were included. The results of meta-analysis showed that prefrailty (OR=1.04, 95%CI 0.99 to 1.09, P=0.11) and frailty (OR=1.02, 95%CI=0.92 to 1.13, P=0.70) were not associated with orthostatic hypotension. The results of subgroup analysis showed that differences of sample size (<500 or ≥500), using different frailty assessment tools (Fried scale, clinical frailty scale, and frailty index), different regions (Europe, Asia, and America) and different sources of studied subjects (hospitals and communities), the risk of orthostatic hypotension were not increased with frailty.ConclusionsCurrent evidence shows that frailty does not increase the risk of orthostatic hypotension. Due to limited quality and quantity of included studies, the above conclusions are needed to be validated by more high-quality studies.
ObjectiveTo systematically review the dose-response relationship between body mass index (BMI) and all-cause mortality in the elderly with frailty.MethodsPubMed, EMbase, Web of Science, CNKI, VIP, WanFang Data, and CBM databases were electronically searched to collect cohort studies on the association of BMI and mortality in frail adults from inception to November 2019. Two reviewers independently screened literature, extracted data and assessed risk bias of included studies; Stata 15.0 software was then used to analyze the dose-response analysis of BMI and mortality by restricted cubic spline function and generalized least squares method.ResultsA total of 4 cohort studies involving 12 861 frail adults were included. Meta-analysis results showed that compared with normal BMI, the frail elderly who were overweight (HR=0.80, 95%CI 0.74 to 0.88, P<0.001) and obese (HR=0.89, 95%CI 0.79 to 1.00, P=0.047) had lower all-cause mortality. The results of dose-response meta-analysis showed that there was a non-linear relationship between BMI and all-cause mortality in the elderly with frailty (P value for nonlinearity was 0.035), for which the elderly with frailty had a BMI nadir of 27.5-31.9 kg/m2. For linear trends, and when BMI was less than 27.5 kg/m2, the risk of all-cause death was reduced by 4% for every 1 kg/m2 increase in BMI (RR=0.96, 95%CI 0.90 to 1.03, P=0.320), when BMI was greater than 27.5 kg/m2, the risk of all-cause death increased by 4% for every 1 kg/m2 increase in BMI (RR=1.04, 95%CI 1.03 to 1.05, P<0.001).ConclusionsThere is a paradox of obesity and a significant nonlinear relationship between BMI and all-cause mortality in the frailty elderly, with the lowest all-cause mortality in the frailty elderly at BMI 27.5-31.9 kg/m2. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusions.