Genetic and epigenetic Muller's ratchet as a mechanism of frailty and morbidity during aging: a demographic genetic model

Association of a mixture of phthalates and phenols with frailty among middle-aged and older adults: A population-based cross-sectional study

BACKGROUND

Frailty is a complex geriatric syndrome caused by degenerative changes in the body or various chronic diseases. The use of personal care and consumer products is associated with a wide range of health outcomes, but its relationship with frailty remains unknown. Therefore, our primary aim was to explore the potential links between exposure to phenols and phthalates, either separately or in combination, and frailty.

METHODS

The exposure levels of phthalates and phenols were evaluated through the measurement of metabolites in urine samples. Frailty state was assessed by a 36-item frailty index with values ≥ 0.25 indicating frailty. Weighted logistic regression was used to explore the relationship between individual chemical exposure and frailty. In addition, multi-pollutant strategies (WQS, Qgcomp, BKMR) were used to examine the joint effect of chemical mixture on frailty. A series of subgroup analyses and sensitivity analyses were conducted as well.

RESULTS

In the multivariate logistic regression model, each unit increase in natural log-transformed BPA (OR: 1.21; 95%CI: 1.04, 1.40), MBP (OR: 1.25; 95%CI: 1.07, 1.46), MBzP (OR: 1.18; 95%CI: 1.03, 1.36), and MiBP (OR: 1.19; 95%CI: 1.03, 1.37) were significantly associated with higher odds of frailty. The results of the WQS and Qgcomp indicated that increasing quartiles of chemical mixture was associated with odds of frailty with ORs of 1.29 (95%CI: 1.01, 1.66) and 1.37 (95%CI: 1.06, 1.76). The weight of MBzP is dominant in both the WQS index and the positive weight of Qgcomp. In the BKMR model, the cumulative effect of chemical mixture was positively correlated with the prevalence of frailty.

CONCLUSIONS

In summary, higher levels of BPA, MBP, MBzP, and MiBP are significantly associated with higher odds of frailty. Our study provides preliminary evidence that phenol and phthalate biomarker mixture is positively associated with frailty, with MBzP contributing most to the positive association.

Effects of preoperative frailty on outcomes following surgery among patients with digestive system tumors: A systematic review and meta-analysis

BACKGROUND

Frailty is common in patients who undergo digestive system tumor surgery. This review aimed to explore the effects of preoperative frailty on multiple outcomes following surgery among patients with digestive system tumors.

METHODS

PubMed (Medline), Embase, Web of Science, and other databases were searched from the inception of each database to April 2021. Meta-analysis or qualitative synthesis was performed to examine the relationship between preoperative frailty and adverse postoperative outcomes.

RESULTS

A total of 29 studies encompassing 122,548 patients were included. Through meta-analysis, frailty was associated with an increased risk of total complications (risk ratio [RR] 1.44; 95 % confidence interval [CI] 1.39 to 1.50), major complications (RR 1.72; 95 % CI 1.51 to 1.95), 30-d mortality (RR 2.40; 95 % CI 2.14 to 2.70), and 5-year mortality (RR 1.74; 95 % CI 1.35 to 2.24). Through qualitative synthesis, compared with non-frail patients, two studies found that frail patients had a worse quality of life, and three studies reported that frail patients experienced greater rates of non-home discharge. However, two studies demonstrated inconsistent conclusions regarding the relationship between frailty and functional status.

CONCLUSIONS

Preoperative frailty was an important risk factor for multiple adverse postoperative outcomes of patients with digestive system tumors, including objective clinical outcomes and patient-centered outcomes. Future studies focusing on the effects of frailty on patient-centered outcomes such as quality of life and functional status are needed.

Cell-to-cell variation in gene expression and the aging process

There is tremendous variation in biological traits, and much of it is not accounted for by variation in DNA sequence, including human diseases and lifespan. Emerging evidence points to differences in the execution of the genetic program as a key source of variation, be it stochastic variation or programmed variation. Here we discuss variation in gene expression as an intrinsic property and how it could contribute to variation in traits, including the rate of aging. The review is divided into sections describing the historical context and evidence to date for nongenetic variation, the different approaches that may be used to detect nongenetic variation, and recent findings showing that the amount of variation in gene expression can be both genetically programmed and epigenetically controlled. Finally, we present evidence that changes in cell-to-cell variation in gene expression emerge as part of the aging process and may be linked to disease vulnerability as a function of age. These emerging concepts are likely to be important across the spectrum of biomedical research and may well underpin what we understand as biological aging.