The interaction between obesity and visceral hypersensitivity.

Obesity has been a worldwide problem associated with numerous chronic diseases such as cardiovascular disease, type 2 diabetes, and metabolic disorders. It may also play a role in visceral hypersensitivity, contributing to irritable bowel syndrome. (i) Adipose tissue secretes various inflammatory mediators, causing intestinal hyperpermeability and nerve endings activation. (ii) Obesity and gastrointestinal microbiota could affect each other, and microbial metabolites can increase sensitivity of the colon. (iii) Vitamin D deficiency contributes to both fat accumulation and disruption of the intestinal mucosal barrier. (iv) Brain-gut axis may be another bridge from obesity to visceral hypersensitivity.

Chronic Illness and Social Network Bridging in Later Life.

Chronic disease has profound impacts on the structural features of individuals' interpersonal connections such as bridging - ties to people who are otherwise poorly connected to each other. Prior research has documented competing arguments regarding the benefits of network bridging, but less is known about how chronic illness influences bridging and its underlying mechanisms. Using data on 1,555 older adults from the National Social Life, Health, and Aging Project (NSHAP), I find that older adults diagnosed with chronic illness tend to have lower bridging potential in their networks, particularly between kin and non-kin members. They also report more frequent interactions with close ties but fewer neighbors, friends, and colleagues in their networks, which mediates the association between chronic illness and social network bridging. These findings illuminate both direct and indirect pathways through which chronic illness affects network bridging and highlight the context-specific implications for social networks in later life.

Tied Infections: How Social Connectedness to Other COVID-19 Patients Influences Illness Severity.

Expanding on recent research on the transmission of COVID-19 via social networks, this article argues that exposure to familial and other close contacts who already have the disease may increase the severity of one's subsequent illness. We hypothesize that having family members or close contacts who were diagnosed with COVID-19 before one's own diagnosis exacerbates illness severity due to several potential mechanisms including changes in available social support access, increased stress and strain, and increased viral load due to the nature of one's exposure to the novel coronavirus. We analyze administrative data of all 417 patients who were diagnosed with COVID-19 in the Chinese city of Shenzhen between January 8 and February 25, 2020. Our analyses show that, when patients had family members or close ties diagnosed with COVID-19, they experienced more severe illness. We also find that patients with infected family members or close contacts did not have significantly extended total illness duration, due to their reduced time to diagnosis. The implications of both findings are discussed.

A bridge too far? Social network structure as a determinant of depression in later life.

Existing research has documented various determinants of mental health related to individuals' social connections, but less is known about the role of the structural features of interpersonal networks. This is especially true in the case of bridging, which refers to ties to people who are otherwise disconnected from each other. By intersecting theories of social networks and gerontology, this study employs within- and between-person analysis with data from the National Social Life, Health, and Aging Project (NSHAP) to examine the association between social network bridging and depression in later life. The study finds that bridging, particularly between kin and non-kin members in the network, is associated with increased depressive symptoms in later life. This association is contingent on social support and strain respondents experienced, and it exhibits variations within individuals over time, especially among older adults in the youngest age cohort (57-64 years old included in NSHAP in 2005). In closing, the paper discusses the extent to which heterogeneous network structures may be one mechanism that shapes mental health trajectories in the context of later life-course experiences.

The Social Connectedness of Older Adults during the COVID-19 Pandemic: Evidence by Survey Mode and Respondent Dementia.

OBJECTIVES: The COVID-19 pandemic has affected many aspects of social life, especially among older adults who may face cognitive impairments. Concerning this combination of circumstances, the study evaluates the degree to which data collection on social connectedness among older adults might be affected by the social complexities of the COVID-19 pandemic. METHOD: We use data from the National Social Life, Health and Aging Project (NSHAP), a nationally representative study of community-dwelling older adults in the U.S., which conducted a special multi-mode COVID study between September 2020 and January 2021, in part to examine social impacts of the COVID-19 pandemic and to assess how alternative survey modes performed during the pandemic. Our final sample includes 2,251 older adults, ages 55 and older. RESULTS: Older adults' social connectedness was adversely affected by the pandemic. People reported a tendency to move toward electronic communication and away from in-person contact. Concomitantly, there is some evidence of survey mode effects that are related to electronic communication. Those who elected to participate on the phone, or the internet disproportionately reported using those means of communication with their social network members. Notably, this pattern was stronger among those who did not suffer from dementia, suggesting cognition effects on survey completion. DISCUSSION: Researchers should remain cognizant of how data on social connections were collected during the COVID-19 pandemic. These findings may indicate the role dementia plays in preventing people from adapting to new social networking realities with alternative means of communication during the pandemic.

"I Love You to Death": Social Networks and the Widowhood Effect on Mortality.

Research on "the widowhood effect" shows that mortality rates are greater among people who have recently lost a spouse. There are several medical and psychological explanations for this (e.g., "broken heart syndrome") and sociological explanations that focus on spouses' shared social-environmental exposures. We expand on sociological perspectives by arguing that couples' social connections to others play a role in this phenomenon. Using panel data on 1,169 older adults from the National Social Life, Health, and Aging Project, we find that mortality is associated with how well embedded one's spouse is in one's own social network. The widowhood effect is greater among those whose spouses were not well connected to one's other network members. We speculate that the loss of a less highly embedded spouse signals the loss of unique, valuable, nonredundant social resources from one's network. We discuss theoretical interpretations, alternative explanations, limitations, and directions for future research.