Frailty Is a Risk Factor for Falls in the Older Adults: A Systematic Review and Meta-Analysis

OBJECTIVES

There is little evidence in the literature about the relationship between frailty and falls in older adults. Our objective was to explore the relationship between frailty and falls, and to analyze the effect factors (e.g., gender, different frailty assessment tools, areas, level of national economic development, and year of publication) of the association between frailty and falls among older adults.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

Cohort studies that evaluated the association between frailty and falls in the older adults were included. We excluded any literature outside of cohort studies.

METHODS

We did a systematic literature search of English databases PubMed, Scopus, Web of Science, EBSCOhost, and SciElO, as well as the Chinese databases CNKI, WANFANG, and VIP from 2001 until October 2022. The eligible studies were evaluated for potential bias using the Newcastle-Ottawa Scale (NOS). Study selection, data extraction and assessment of study quality were each conducted by two investigators. In Stata/MP 17.0 software, we calculated pooled estimates of the prevalence of falls by using a random-effects model, Subgroup analysis was conducted based on gender, different frailty assessment tools, areas, level of economic development, and year of publication. The results are presented using a forest plot.

RESULTS

Twenty-nine studies were included in this meta-analysis and a total of 1,093,270 participants aged 65 years and above were enrolled. Among the older adults, frailty was significantly associated with a higher risk for falls, compared with those without frailty (combined RR-relative risk = 1.48, 95% CI-confidence interval: 1.27-1.73, I2=98.9%). In addition, the results of subgroup analysis indicated that men had a higher risk for falls than women among the older adults with frailty (RR 1.94, 95% CI: 1.18-3.2 versus RR 1.44, 95% CI: 1.24-1.67). Subgroup analysis by different frailty assessment tools revealed an increased risk of falls in older adults with frailty when assessed using the Frailty Phenotype (combined RR 1.32, 95%CI: 1.17-1.48), FRAIL score (combined RR 1.82, 95%CI: 1.36-2.43), and Study of Osteoporotic Fractures index (combined RR 1.54, 95%CI: 1.10-2.16). Furthermore, subgroup analysis by areas and level of national economic development found the highest fall risk in Oceania (combined RR 2.35, 95%CI: 2.28-2.43) and the lowest in Europe (combined RR 1.20, 95%CI: 1.05-1.38). Developed countries exhibited a lower fall risk compared to developing countries (combined RR 1.44, 95%CI: 1.21-1.71). Analysis by year of publication showed the highest fall risk between 2013-2019 (combined RR 1.79, 95%CI: 1.45-2.20) and the lowest between 2001-2013 (combined RR 1.21, 95%CI: 1.13-1.29).

CONCLUSION

Frailty represents a significant risk factor for falls in older adults, with the degree of risk varying according to the different frailty assessment tools employed, and notably highest when using the FRAIL scale. Additionally, factors such as gender, areas, level of national economic development, and healthcare managers' understanding of frailty may all impact the correlation between frailty and falls. Thus, it's imperative to select suitable frailty diagnostic tools tailored to the specific characteristics of the population in question. This, in turn, facilitates the accurate identification of frailty in older adults and informs the development of appropriate preventive and therapeutic strategies to mitigate fall risk.

Exogenous citric acid enhances drought tolerance in tobacco (Nicotiana tabacum)

Organic acids play a pivotal role in improving plant response to long-term drought stress. External application of organic acids has been reported to improve drought resistance in several species. However, whether organic acids have similar effects in tobacco remains unknown. A screening study of the protective function of organic acids in tobacco and understanding the underlying molecular mechanism would be useful in developing a strategy for drought tolerance. Several physiological and molecular adaptations to drought including abscisic acid, stomatal closure, reactive oxygen species homeostasis, amino acid accumulation, and drought-responsive gene expression were observed by exogenous citric acid in tobacco plants. Exogenous application of 50 mm citric acid to tobacco plants resulted in higher chlorophyll content, net photosynthesis, relative water content, abscisic acid content and lower stomatal conductance, transpiration and water loss under drought conditions. Moreover, reactive oxygen species homeostasis was better maintained through increasing activity of antioxidant enzymes and decreasing hydrogen peroxide content after citric acid pretreatment under drought. Amino acids involved in the TCA cycle accumulated after external application of citric acid under drought stress. Furthermore, several drought stress-responsive genes also dramatically changed after application of citric acid. These data support the idea that external application of citric acid enhances drought resistance by affecting physiological and molecular regulation in tobacco. This study provides clear insights into mechanistic details of regulation of amino acid and stress-responsive gene expression by citric acid in tobacco in response to drought, which is promising for minimizing growth inhibition in agricultural fields.