The role of loneliness in the development of depressive symptoms among partnered dementia caregivers: Evidence from the English Longitudinal Study of Aging.

BACKGROUND: Depressive symptoms are highly prevalent among partnered dementia caregivers, but the mechanisms are unclear. This study examined the mediating role of loneliness in the association between dementia and other types of care on subsequent depressive symptoms. METHODS: Prospective data from partnered caregivers were drawn from the English Longitudinal Study of Aging. The sample consisted of 4,672 partnered adults aged 50-70 living in England and Wales, followed up between 2006-2007 and 2014-2015. Caregiving was assessed across waves 3 (2006-2007), 4 (2008-2009), and 5 (2010-2011), loneliness at wave 6 (2012-2013), and subsequent depressive symptoms at wave 7 (2014-15). Multivariable logistic regression models were used to assess the association between caregiving for dementia and depressive symptoms compared to caregiving for other illnesses (e.g., diabetes, coronary heart disease (CHD), cancer, and stroke). Binary mediation analysis was used to estimate the indirect effects of caregiving on depressive symptoms via loneliness. RESULTS: Care for a partner with dementia was associated with higher odds of depressive symptoms at follow-up compared to those not caring for a partner at all (odds ratio [OR] = 2.6, 95% confidence intervals [CI]: 1.4, 5.1). This association was partially mediated by loneliness (34%). Care for a partner with other conditions was also associated with higher odds of depressive symptoms compared to non-caregiving partners (OR = 1.7, 95% CI: 1.2, 2.5), but there was no evidence of an indirect pathway via loneliness. CONCLUSION: Loneliness represents an important contributor to the relationship between dementia caregiving and subsequent depressive symptoms; therefore, interventions to reduce loneliness among partnered dementia caregivers should be considered.

Optimism moderates psychophysiological responses to stress in older people with Type 2 diabetes.

Optimism is thought to be beneficial for health, and these effects may be mediated through modifications in psychophysiological stress reactivity. Type 2 diabetes (T2D) is associated with reduced cardiovascular responses to stress and heightened cortisol over the day. This study assessed the relationships between optimism, stress responsivity, and daily cortisol output in people with T2D. A total of 140 participants with T2D were exposed to laboratory stress. Heart rate (HR), systolic (SBP), diastolic blood pressure (DBP), and cortisol were measured throughout the session. Cortisol output over the day was also assessed. Optimism and self-reported health were measured using the revised Life Orientation Test and the Short Form Health Survey. Optimism was associated with heightened SBP and DBP stress reactivity (ps < .047) and lower daily cortisol output (p = .04). Optimism was not related to HR, cortisol stress responses, or the cortisol awakening response (ps > .180). Low optimism was related to poorer self-reported physical and mental health (ps < .01). Optimism could have a protective role in modulating stress-related autonomic and neuroendocrine dysregulation in people with T2D.

Experimental Escherichia coli epididymitis in rabbits.

We describe an experimental model of bacterial epididymitis in New Zealand white rabbits. Inoculation of 10(7) colony-forming units of Escherichia coli in a retrograde fashion into the vas deferens reliably produced clinical, bacteriologic, and pathologic epididymitis. Inflammation was maximum at two weeks and subsided by one month without treatment. E. coli could be reisolated from the epididymides for up to two weeks post inoculation. We detected loss of spermatogenesis in both the ipsilateral and contralateral testes and the appearance of antisperm antibodies subsequent to the infection in some animals. There were 2 cases (11%) of histologic bilateral epididymitis after unilateral inoculation; one of these had bilateral clinical epididymitis with E. coli recovered from both epididymides at two weeks.