The interplay between micro RNAs and genetic liability to Alzheimer's Disease on memory trajectories in the general population

Deficits in cognitive function and memory are common early symptoms of neurodegenerative disorders, such as Alzheimer's Disease (AD). Several studies have discussed micro RNAs (miRNAs) as potential epigenetic early detection biomarkers. In a longitudinal general population sample (n = 548) from the Study of Health in Pomerania, we analyzed the associations between 167 baseline miRNA levels and changes in verbal memory scores with a mean follow-up time of 7.4 years. We additionally assessed the impact of an individual's genetic liability for AD on verbal memory scores in n = 2,334 subjects and a possible interactions between epigenetic and genetic markers. Results revealed two miRNAs associated with changes in immediate verbal memory over time. In interaction analyses between miRNAs and a polygenic risk score for AD, five miRNAs showed a significant interaction effect on changes in verbal memory. All of these miRNAs have previously been identified in the context of AD, neurodegeneration or cognition. Our study provides candidate miRNAs for a decline in verbal memory as an early symptom of neurodegeneration and AD. Further experimental studies are needed to verify the diagnostic value of these miRNA markers in the prodromal stage of AD.

Is social participation associated with good self-rated health among visually impaired older adults?: the JAGES cross-sectional study

Background

While it has been recognized that visual impairment is associated with poor self-rated health (SRH), in addition to various negative health outcomes of visual impairment, the number of older adults with visual impairment is increasing due to population aging. As increasing evidence has been found for the effectiveness of social participation on good SRH, we examined whether there was an association between social participation and SRH and investigated whether the effect differed by visual status.

Methods

Questionnaire data on self-reported visual status, social participation, socioeconomic status, and SRH were obtained in 2016. A total of 24,313 community-dwelling individuals aged 65 and over participated. We examined the association of social participation and SRH status among older adults with visual impairment. Stratified analysis and analysis with an interaction term between social participation and visual status were also conducted. Social participation was assessed by the number of participating groups (no participation, one, two, and three or more).

Results

Overall visual impairment prevalence was 9.3% (95% CI: 8.9–9.7). Among those with and without visual impairment, prevalence of poor SRH was 38.4 and 13.1%, respectively. However, the association between social participation with SRH was similar, especially for those who participated in one or two groups. For people with (PR = 0.54) and without visual impairment (PR = 0.50), those who participated in two groups showed lower prevalence ratios for poor SRH compared to people without social participation.

Conclusion

Social participation showed a beneficial association with SRH among older adults with visual impairment. Future interventions could focus on the potentially positive role of social participation on SRH among older adults with visual impairment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02554-7.

Increased chronic kidney disease development and progression in diabetic patients after appendectomy: a population-based cohort study

Background

The vermiform appendix serves as a "safe house" for maintaining normal gut bacteria and appendectomy may impair the intestinal microbiota. Appendectomy is expected to profoundly alter the immune system and modulate the pathogenic inflammatory immune responses of the gut. Recent studies have shown that a dysbiotic gut increases the risk of cardiovascular disease and chronic kidney disease (CKD). Therefore, we hypothesized that appendectomy would increase the risk of CKD.

Methods

This nationwide, population-based, propensity-score-matched cohort study included 10,383 patients who underwent appendectomy and 41,532 propensity-score-matched controls. Data were collected by the National Health Insurance Research Database of Taiwan from 2000 to 2013. We examined the associations between appendectomy and CKD and end-stage renal disease (ESRD). The major outcome was a new diagnosis of CKD based on an outpatient diagnosis made at least three times or hospital discharge diagnosis made once during the follow-up period. ESRD was defined as undergoing dialysis therapy for at least 90 days, as in previous studies.

Results

The incidence rates of CKD and ESRD were higher in the appendectomy group than in the control cohort (CKD: 6.52 vs. 5.93 per 1,000 person-years, respectively; ESRD: 0.49 vs. 0.31 per 1,000 person-years, respectively). Appendectomy patients also had a higher risk of developing CKD (adjusted hazard ratio [aHR] 1.13; 95% CI [1.01-1.26]; P = 0.037) and ESRD (aHR 1.59; 95% CI [1.06-2.37]; P = 0.024) than control group patients. Subgroup analysis showed that appendectomy patients with concomitant diabetes mellitus (aHR 2.08; P = 0.004) were at higher risk of incident ESRD than those without diabetes mellitus. The interaction effects of appendectomy and diabetes mellitus were significant for ESRD risk (P = 0.022); no interaction effect was found for CKD risk (P = 0.555).

Conclusions

Appendectomy increases the risk of developing CKD and ESRD, especially in diabetic patients. Physicians should pay close attention to renal function prognosis in appendectomy patients.