Perceived social position, active engagement with life, and depressive symptoms among older adults.

RATIONALE: Despite the existing literature on the relationship between perceived social position (PSP) and depressive symptoms, there remain gaps in our understanding, particularly regarding the potential for asymmetric effects of increases and decreases in PSP and the underlying mechanisms involved. OBJECTIVE: This study aims to examine whether increases and decreases in PSP are differentially associated with depressive symptoms and to explore the potential mediating role of active engagement with life in these associations. METHODS: This study utilized data from the Korean Longitudinal Study of Aging (KLoSA), collected between 2008 and 2018, involving a sample of 3506 individuals aged 65 or older. Asymmetric fixed effects (FE) models were employed, which enable the estimation of differential effects for increases and decreases in PSP, while accounting for unobserved individual-level heterogeneity. To assess the mediating role of active engagement in life, Sobel mediation tests were conducted. RESULTS: The asymmetric FE estimates revealed a stronger association between decreases in PSP and increases in depressive symptoms compared to the association between increases in PSP and decreases in depressive symptoms. The Sobel mediation tests indicated that formal social activities had the most substantial mediating effect, explaining 14% and 9% of the total effect mediated for increased and decreased PSP and depressive symptoms, respectively. Leisure/hobby activities explained 10% and 4% of the total effect mediated for increased and decreased PSP and depressive symptoms, respectively. CONCLUSION: This study provides evidence that increases and decreases in PSP have differential effects on depressive symptoms among older adults in Korea. Policy interventions aimed at improving the psychological well-being of older adults should prioritize efforts to both enhance PSP and minimize declines, as the latter can have a stronger negative impact on depressive symptoms. Active engagement in life may serve as a potential pathway for achieving the desired effects.

The use of assistive devices and social engagement among older adults: heterogeneity by type of social engagement and gender.

Little is known about the relationship between the use of assistive devices for functional loss and social engagement. This study investigated whether wearing assistive devices (dentures and hearing aids) is associated with social engagement among older adults in South Korea. Potential heterogeneity by type of social engagement (informal social contact versus formal social activity) and gender was also examined. This study analyzed data from 3725 individuals aged 65 or older collected over the course of 6 waves of the Korean Longitudinal Study of Ageing (KLoSA) from 2008 to 2018 (2150 women and 1575 men). Individual fixed effects models were used to account for unobserved individual-level heterogeneity that could confound the relationship between wearing assistive devices and social engagement. The fixed effects estimates showed that wearing assistive devices is associated with a decrease in formal social activity (b = - 0.034 for dentures and b = - 0.077 for hearing aids), but not informal social contact. Gender-stratified fixed effects revealed that the association between wearing assistive devices and social engagement is statistically significant only for men. In men, wearing assistive devices is associated with a decrease in formal social activity (b = - 0.049 for denture and b = - 0.095 hearing aids). The findings of this study suggest that wearing assistive devices may reduce the formal social activity of older adults, particularly men. Policymakers should consider developing interventions to help older adults overcome the stigma associated with assistive devices, which can hinder their social integration.

A longitudinal study of immigrant mothers' destination-language proficiency and their children's psychological well-being: Evidence and mechanisms from a study in South Korea.

RATIONALE: Despite the well-established link between an immigrant's destination-language proficiency and psychological well-being, little is known about the relationship between an immigrant's destination-language proficiency and well-being of their children. OBJECTIVE: This study investigated whether and how immigrant mothers' Korean proficiency is associated with life satisfaction and depressive symptoms among their children in South Korea. A comprehensive set of potential underlying mechanisms was also examined. METHODS: Using four waves of data from the Multicultural Adolescents Panel Study (MAPS), this study estimated fixed effects regression models to reduce the possibility of bias due to individual-level heterogeneity. To test for mediation formally, Sobel mediation tests were conducted. RESULTS: Fixed effects estimates suggested that immigrant mothers' Korean proficiency is positively associated with their children's psychological well-being. Specifically, a one-standard-deviation increase in Korean proficiency was associated with an increase in life satisfaction by 13% of a standard deviation and a decrease in depressive symptoms by 9% of a standard deviation. Mediation tests revealed that this association is explained by a combination of social-psychological factors. Friend support was the most salient mediator, followed by lower acculturation stress, positive perceptions of local community, and teacher support. CONCLUSIONS: The findings of this study suggest that efforts to improve immigrant mothers' destination-language proficiency would also benefit their children's psychological well-being. Furthermore, promoting children's relationships with peers at school may mitigate the negative psychological consequences of immigrant mothers' limited language proficiency.

Homeownership and Psychological Resources Among Older Adults: Do Gender and Mortgage Status Moderate Homeownership Effects?

Objectives: This study examined whether homeownership is associated with life satisfaction and depressive symptoms among older adults aged 65 or over and whether these associations differ by gender. This study further distinguished mortgagors from owner-occupiers. Methods: Using six waves of the Korean Longitudinal Study of Ageing (N = 3540), we used generalized estimating equations as well as random- and fixed-effects regression analyses. Results: Gender-stratified fixed-effects models showed that the associations between homeownership and psychological resources are largely driven by men. Owner-occupiers are more satisfied with life and report fewer depressive symptoms than renters. By contrast, although mortgagors are more satisfied with life than renters, they have depressive symptoms similar to those of renters. These patterns are more pronounced among men than women. Discussion: Our findings lend support to policies that promote affordable homeownership as a way to reduce social inequalities in psychological well-being and health, especially among older men.

Asn-Linked Glycosylation Contributes to Surface Expression and Voltage-Dependent Gating of Cav1.2 Ca²âº Channel.

The Cav1.2 Ca2+ channel is essential for cardiac and smooth muscle contractility and many physiological functions. We mutated single, double, and quadruple sites of the four potential Asn (N)-glycosylation sites in the rabbit Cav1.2 into Gln (Q) to explore the effects of Nglycosylation. When a single mutant (N124Q, N299Q, N1359Q, or N1410Q) or Cav1.2/WT was expressed in Xenopus oocytes, the biophysical properties of single mutants were not significantly different from Cav1.2/WT. In comparison, the double mutant N124,299Q showed a positive shift in voltage-dependent gating. Furthermore, the quadruple mutant (QM; N124,299,1359,1410Q) showed a positive shift in voltage-dependent gating as well as a reduction of current. We tagged EGFP to the QM, double mutants, and Cav1.2/WT to chase the mechanisms underlying the reduced currents of QM. The surface fluorescence intensity of QM was weaker than that of Cav1.2/WT, suggesting that the reduced current of QM arises from its lower surface expression than Cav1.2/WT. Tunicamycin treatment of oocytes expressing Cav1.2/WT mimicked the effects of the quadruple mutations. These findings suggest that Nglycosylation contributes to the surface expression and voltage-dependent gating of Cav1.2.

Asp residues of the Glu-Glu-Asp-Asp pore filter contribute to ion permeation and selectivity of the Ca(v)3.2 T-type channel.

Voltage-activated Ca2+ channels are membrane protein machinery performing selective permeation of external calcium ions. The main Ca2+ selective filters of all high-voltage-activated Ca2+ channel isoforms are commonly composed of four Glu residues (EEEE), while those of low-voltage-activated T-type Ca2+ channel isoforms are made up of two Glu and two Asp residues (EEDD). We here investigate how the Asp residues at the pore loops of domains III and IV affect biophysical properties of the Ca(v)3.2 channel. Electrophysiological characterization of the pore mutant channels in which the pore Asp residue(s) were replaced with Glu, showed that both Asp residues critically control the biophysical properties of Ca(v)3.2, including relative permeability between Ba2+ and Ca2+, anomalous mole fraction effect (AMFE), voltage dependency of channel activation, Cd2+ blocking sensitivity, and pH effects, in distinctive ways.