Association between frailty and incident risk of disability in community-dwelling elder people: evidence from a meta-analysis.

OBJECTIVE: Frailty is considered to be one of the risk factors of disability. However, the results of original reported studies are not consistent with respect to the frailty and incidence of disability, and previously published meta-analyses have also shown inconsistent results. This meta-analysis was conducted to investigate the relationship between the different stages of frailty and the incidence of disability by examining updated overall trends in community-dwelling elders. STUDY DESIGN: Cohort studies in English or Chinese based on associations between frailty and incident disability risks that were published from 2000 until the current date were researched using PubMed, Embase, Web of Science, and CENTRAL databases. METHODS: The Q test and I2 statistic were used to examine between-study heterogeneity. Random-effect models were adopted to synthesize the results based on the study heterogeneity. Subgroup analyses were also conducted to explore the possible sources of between-study heterogeneity based on the characteristics of participants. RESULTS: Eighteen cohort studies with 88,906 participants were included in our meta-analyses. Compared with the non-frailty category, the combined relative risks (RRs) (95% confidence interval [CI]) of the disability were 1.66 (1.49-1.85) and 2.53 (2.01-3.14) for the category of prefrailty and frailty, respectively. Results suggested that the incident risk of disability at follow-up times <5 (RR = 3.19, 95% CI = 2.25-4.53) was significantly higher than for follow-up times ≥5 in the frailty category (RR = 2.00, 95% CI = 1.55-2.56). The risk in a sample size of ≥1000 (RR = 2.78, 95% CI = 2.04-3.14) was significantly higher than that when the sample size was <1000 (RR = 1.91, 95% CI = 1.53-2.37) in the frailty group. Compared with a value adjusted for comorbidity, the unadjusted comorbidity was significantly higher in the prefrailty category (1.90 vs. 1.52). Compared with a value adjusted for education, the unadjusted education was significantly higher in the prefrailty category (1.81 vs. 1.46). No publication bias was observed. CONCLUSION: The overall meta-analysis confirms that frailty has significantly increased the incident risk of disability. Frail, elderly people are at the highest risk of future disability and may be adequate candidates for taking part in prevention and intervention programs.

Expression of SRG3, a chromatin-remodelling factor, in the mouse oocyte and early preimplantation embryos.

SRG3 (Smarcc1) is a core subunit of the SWI/SNF complex. In the absence of SRG3, embryonic development ceases during peri-implantation stages, indicating that SRG3, as well as the chromatin-remodelling process, plays an essential role in early mouse development. To gain a better understanding of chromatin remodelling during the early stages of development, we examined SRG3 expression during oogenesis and preimplantation stages using immunofluorescence and western blot assays. SRG3 was detected in nuclei of oocytes during growth and maturation. Following fertilization, SRG3 was detected in pronuclei shortly after their formation. Nuclear concentrations of SRG3 increased in a time-dependent fashion and were found to be greater in the male pronucleus than in the female pronucleus. The increase in nuclear SRG3 was partially inhibited by a protein synthesis inhibitor, but not by a transcriptional inhibitor. Expression of SRG3 is accompanied by expression of Brg1 and Ini1, two other core subunits of the SWI/SNF complex. The expression of these three remodelling factors parallels that of SP1 and TBP, both spatially and temporally, in the mouse embryo, suggesting a role for remodelling factors in chromatin structure and function during early development.