Association between visual impairment and sleep duration: analysis of the 2009 National Health Interview Survey (NHIS)

BACKGROUND: Visual impairment (VI) is associated with increased mortality and health factors such as depression and cardiovascular disease. Epidemiologic studies consistently show associations between sleep duration with adverse health outcomes, but these have not systematically considered the influence of VI. The aim of this study was to ascertain the independent association between VI and sleep duration using the National Health Interview Survey (NHIS) data. We also examined whether race/ethnicity influenced these associations independently of sociodemographic and medical characteristics. METHODS: Our analysis was based on the 2009 NHIS, providing valid sleep and vision data for 29,815 participants. The NHIS is a cross-sectional household interview survey utilizing a multistage area probability design. Trained personnel from the US census bureau gathered data during face-to-face interview and obtained socio-demographic, self-reported habitual sleep duration and physician-diagnosed chronic conditions. RESULTS: The mean age of the sample was 48 years and 56% were female. Short sleep and long sleep durations were reported by 49% and 23% of the participants, respectively. Visual impairment was observed in 10%. Multivariate-adjusted logistic regression models showed significant associations between VI and short sleep (OR = 1.6, 95% CI = 1.5-1.9 and long sleep durations (OR = 1.6, 95% CI = 1.3-1.9). These associations persisted in multivariate models stratified by race-ethnic groups. CONCLUSION: Visual impairment was associated with both short and long sleep durations. Analysis of epidemiologic sleep data should consider visual impairment as an important factor likely to influence the amount of sleep experienced habitually

A comparative examination of healthcare use related to hearing impairment in europe

Introduction: The economic burden of hearing impairment is an area of increased interest. In this paper we examine the relationship between hearing impairment and service use in 14 European countries. Methods: Based on the Survey of Health Ageing and Retirement in Europe (SHARE) undertaken in 2013, Poisson regression models are used to analyse the relationship between the number of visits/number of nights in hospital, and hearing impairment controlling for a number of covariates. Results: We find that hearing impairment is generally associated with increased use of primary and secondary healthcare services when other aspects of health have been controlled. Comparative analysis revealed that where access to hearing assistive technology was greatest the additional use of services was least. Conclusions: The comparative analysis suggests that variations exist across countries in respect of the additional healthcare use occasioned by hearing impairment. They may also provide valuable insights into how the burden of illness might be reduced

Asymmetric conformational changes in a GPCR dimer controlled by G-proteins

G-protein-coupled receptors (GPCRs) are key players in cell communication. Although long considered as monomeric, it now appears that these heptahelical proteins can form homo- or heterodimers. Here, we analyzed the conformational changes in each subunit of a receptor dimer resulting from agonist binding to either one or both subunits by measuring the fluorescent properties of a leukotriene B(4) receptor dimer with a single 5-hydroxytryptophan-labeled protomer. We show that a receptor dimer with only a single agonist-occupied subunit can trigger G-protein activation. We also show that the two subunits of the receptor dimer in the G-protein-coupled state differ in their conformation, even when both are liganded by the agonist. No such asymmetric conformational changes are observed in the absence of G-protein, indicating that the interaction of the G-protein with the receptor dimer brings specific constraints that prevent a symmetric functioning of this dimer. These data open new options for the differential signaling properties of GPCR dimers