The Effects of Social Activities and Living Arrangements on Cognitive Functions in Middle-aged and Elderly Adults: A Panel Study Using the 2006-2018 Korean Longitudinal Study of Aging

OBJECTIVES

Previous studies have shown that participation in social activities (SA) can prevent cognitive decline (CD) and that living arrangements (LA) can affect cognitive function. This study aimed to evaluate the effects of SA and LA on CD, as well as their interactions, using longitudinal data.

METHODS

Data were used from the 2006-2018 Korean Longitudinal Study for Aging, which followed 10 254 adults older than 45 years over a 12-year period. CD was defined as a ≥4-point score decrease in the Mini-Mental Status Exam over 2 years. We developed an extended Cox proportional hazards model for time-dependent covariates to estimate the hazard ratio (HR) of CD in 4 groups: (1) socially active and living with others, (2) socially active and living alone, (3) socially inactive and living with others (SILO), and (4) socially inactive and living alone (SILA). The model was stratified by gender and adjusted for important confounders.

RESULTS

The HR of CD was significantly higher in the SILO group in men (HR,1.36; 95% confidence interval [CI], 1.08 to 1.78) and in the SILA group in women (HR, 1.72; 95% CI, 1.08 to 2.75). However, the interaction term for gender was not significant.

CONCLUSIONS

Among socially inactive elderly adults, the HR of CD was elevated in men who lived with others and in women who lived alone, although the interaction term for gender was not significant. Socially inactive men who live with others and socially inactive women who live alone are particularly encouraged to participate in SA to prevent CD.

Ru-catalyzed cyclocarbonylation of alpha- and beta-allenic sulfonamides: synthesis of gamma- and delta-unsaturated lactams

[reaction: see text]. The Ru-catalyzed cyclocarbonylation of alpha- or beta-allenic sulfonamides in the presence of Ru(3)(CO)(12) (1 mol %) and Et(3)N (1.5 equiv) under CO atmosphere (20 atm) in dioxane at 100 degrees C for 9 h gave heterocyclic gamma- and delta-unsaturated lactams in good yields.

Ribosomal DNA intergenic spacer of the swimming crab, Charybdis japonica

We have determined the full sequence of the ribosomal DNA intergenic spacer (IGS) of the swimming crab, Charybdis japonica, by long PCR for the first time in crustacean decapods. The IGS is 5376 bp long and contains two nonrepetitive regions separated by one long repetitive region, which is composed mainly of four subrepeats (subrepeats I, II, III, and IV). Subrepeat I contains nine copies of a 60-bp repeat unit, in which two similar repeat types (60 bp-a and 60 bp-b) occur alternatively. Subrepeat II consists of nine successive repeat units with a consensus sequence length of 142 bp. Subrepeat III consists of seven copies of another 60-bp repeat unit (60 bp-c) whose sequence is complementary to that of subrepeat I. Immediately downstream of subrepeat III is subrepeat IV, consisting of three copies of a 391-bp repeat unit. Based on comparative analysis among the subrepeats and repeat units, a possible evolutionary process responsible for the formation of the repetitive region is inferred, which involves the duplication of a 60-bp subrepeat unit (60 bp-c) as a prototype.