Background 
The quality and quantity of individuals' social relationships has been linked not only to mental health but also to both morbidity and mortality.
Objectives 
This meta-analytic review was conducted to determine the extent to which social relationships influence risk for mortality, which aspects of social relationships are most highly predictive, and which factors may moderate the risk.
Data Extraction 
Data were extracted on several participant characteristics, including cause of mortality, initial health status, and pre-existing health conditions, as well as on study characteristics, including length of follow-up and type of assessment of social relationships.
Results 
Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95% CI 1.42 to 1.59), indicating a 50% increased likelihood of survival for participants with stronger social relationships. This finding remained consistent across age, sex, initial health status, cause of death, and follow-up period. Significant differences were found across the type of social measurement evaluated (p<0.001); the association was strongest for complex measures of social integration (OR = 1.91; 95% CI 1.63 to 2.23) and lowest for binary indicators of residential status (living alone versus with others) (OR = 1.19; 95% CI 0.99 to 1.44).
Conclusions 
The influence of social relationships on risk for mortality is comparable with well-established risk factors for mortality.

Please see later in the article for the Editors' Summary

/pdf/social-relationships-and-mortality-risk-a-meta-analytic-2ghmxi4ksm.pdf

Social Relationships and Mortality Risk: A Meta-analytic Review

The recent availability of longitudinal data on the possible association of different lifestyles with dementia and Alzheimer's disease (AD) allow some preliminary conclusions on this topic. This review systematically analyses the published longitudinal studies exploring the effect of social network, physical leisure, and non-physical activity on cognition and dementia and then summarises the current evidence taking into account the limitations of the studies and the biological plausibility. For all three lifestyle components (social, mental, and physical), a beneficial effect on cognition and a protective effect against dementia are suggested. The three components seem to have common pathways, rather than specific mechanisms, which might converge within three major aetiological hypotheses for dementia and AD: the cognitive reserve hypothesis, the vascular hypothesis, and the stress hypothesis. Taking into account the accumulated evidence and the biological plausibility of these hypotheses, we conclude that an active and socially integrated lifestyle in late life protects against dementia and AD. Further research is necessary to better define the mechanisms of these associations and better delineate preventive and therapeutic strategies.

https://www.thelancet.com/pdfs/journals/laneur/PIIS1474442204007677.pdf

An active and socially integrated lifestyle in late life might protect against dementia.

Insomnia, or inability to sleep, is the most commonly reported sleep problem in the industrialized world. Estimates suggest that between 40 and 70 million Americans are affected by either intermittent or chronic sleep problems, representing approximately 20 percent of the population. The Sleep in America Poll, conducted by the National Sleep Foundation, revealed that almost 50 percent of people surveyed had complaints of frequent insomnia, but only 6 percent were formally diagnosed. Moreover, approximately, 30 to 35 percent of respondents complained of nightly insomnia. The most prevalent symptoms of insomnia, experienced at least a few nights a week by people with insomnia, include waking up feeling unrefreshed (34 percent) and being awake often during the night (32 percent). The symptoms of difficulty falling asleep and waking up too early are less common, but still experienced at least a few nights a week by about one-fourth of adults with insomnia (23 to 24 percent).

Manifestations and management of chronic insomnia in adults.

This meta-analysis integrates results of 87 studies on the associations of perceived social support, network size, and marital status with cancer survival. In controlled studies, having high levels of perceived social support, larger social network, and being married were associated with decreases in relative risk for mortality of 25%, 20%, and 12%, respectively. Moderator analyses revealed that never married patients had higher mortality rates than widowed and divorced/separated patients. Associations of social network with mortality were stronger in younger patients, and associations of marital status with mortality were stronger in studies with shorter time intervals, and in early-stage cancer. Relationships varied by cancer site, with stronger associations of social support observed in studies of patients with leukemia and lymphomas and stronger associations of network size observed in studies of breast cancer. Further randomized intervention studies are needed to test causal hypotheses about the role of social support and social network for cancer mortality.

Associations of social networks with cancer mortality: a meta-analysis.

To evaluate the quality of available evidence on the effects of environmental noise exposure on sleep a systematic review was conducted. The databases PSYCINFO, PubMed, Science Direct, Scopus, Web of Science and the TNO Repository were searched for non-laboratory studies on the effects of environmental noise on sleep with measured or predicted noise levels and published in or after the year 2000. The quality of the evidence was assessed using GRADE criteria. Seventy four studies predominately conducted between 2000 and 2015 were included in the review. A meta-analysis of surveys linking road, rail, and aircraft noise exposure to self-reports of sleep disturbance was conducted. The odds ratio for the percent highly sleep disturbed for a 10 dB increase in Lnight was significant for aircraft (1.94; 95% CI 1.61–2.3), road (2.13; 95% CI 1.82–2.48), and rail (3.06; 95% CI 2.38–3.93) noise when the question referred to noise, but non-significant for aircraft (1.17; 95% CI 0.54–2.53), road (1.09; 95% CI 0.94–1.27), and rail (1.27; 95% CI 0.89–1.81) noise when the question did not refer to noise. A pooled analysis of polysomnographic studies on the acute effects of transportation noise on sleep was also conducted and the unadjusted odds ratio for the probability of awakening for a 10 dBA increase in the indoor Lmax was significant for aircraft (1.35; 95% CI 1.22–1.50), road (1.36; 95% CI 1.19–1.55), and rail (1.35; 95% CI 1.21–1.52) noise. Due to a limited number of studies and the use of different outcome measures, a narrative review only was conducted for motility, cardiac and blood pressure outcomes, and for children’s sleep. The effect of wind turbine and hospital noise on sleep was also assessed. Based on the available evidence, transportation noise affects objectively measured sleep physiology and subjectively assessed sleep disturbance in adults. For other outcome measures and noise sources the examined evidence was conflicting or only emerging. According to GRADE criteria, the quality of the evidence was moderate for cortical awakenings and self-reported sleep disturbance (for questions that referred to noise) induced by traffic noise, low for motility measures of traffic noise induced sleep disturbance, and very low for all other noise sources and investigated sleep outcomes.

WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Effects on Sleep.

Background No prospective studies have examined the association between social networks and all-cause and cause-specific mortality among middle-aged Japanese. The study of varied populations may contribute to clarifying the robustness of the observed effects of social networks and extend their generalizability. Methods To clarify the association between social networks and mortality among middle-aged and elderly Japanese, a community-based prospective study, the Komo-Ise Study, was conducted in two areas of Gunma Prefecture, Japan. A total of 11 565 subjects aged 40-69 years at baseline in 1993 completed a self-administered questionnaire. During the 7-year follow-up period, 335 men and 155 women died and the relative risk (RR) of each social network item was estimated by the Cox proportional hazard model. Results Single women had significantly increased risks of all-cause (multivariate RR = 2.2), and all circulatory system disease (age-area adjusted RR = 2.6) mortality. Men who did not participate in hobbies, club activities, or community groups had significantly higher multivariate RR for all-cause (RR = 1.5), all circulatory system disease (RR = 1.6) and non-cancer and non-circulatory system disease (RR = 2.3) mortality. Urban women who rarely or never met close relatives had significantly elevated risks of all-cause (RR = 2.4), all cancer (RR = 2.6), and non-cancer and non-circulatory system disease (RR = 2.7) mortality after adjustment for established risk factors. Conclusions This study provides evidence that social networks are an important predictor of mortality risk for middle-aged and elderly Japanese men and women. Lack of participation, for men, and being single and lack of meeting close relatives, for women, were independent risk factors for mortality.

/pdf/social-networks-and-mortality-based-on-the-komo-ise-cohort-57a9y9xcjd.pdf

Social networks and mortality based on the Komo-Ise cohort study in Japan

Population study on the prevalence of insomnia and insomnia-related factors among Japanese women.

Rural-urban differences in sociodemographic, social network and lifestyle factors related to mortality of middle-aged Japanese men from the Komo-Ise cohort study.

Lifestyle and sociodemographic risk factors for death among middle-aged and elderly residents in japan from a five-year follow-up cohort study.

The prevalence rate of insomnia among 424 married women and its associated factors were surveyed Insomnia is defined as having one of the following symptoms one or more times per week: difficulty inducing sleep (Fl), difficulty maintaining sleep (F2), early morning awakening (F3), light sleep (F4), or worry about poor sleep quality (F5) Poor sleep as a whole in the past one month (F6) was also inquired about Percentages of Fl, F2, F3 and F5 among the subjects in their sixties were 213%, 133%, 67% and 107%, respectively, relatively higher than those of subjects in their thirties or forties There was a significant difference in the percentage of F6 among four age categories (p < 005), and the percentage of F6 was highest (233%) in those in their thirties Depressive state correlated with six insomnia items, Fl to F6 (rs=-0195, -0161, -0117,-0221, -0176, 0284, respectively) Perceived health status correlated with Fl (-0237), F4 (-0213), F5 (-0259), and F6 (0373) Present medical condition correlated with Fl (-0195), F3 (-0146), and F5 (-0220) The prevalence rates of insomnia for subjects in their thirties, forties, fifties and sixties were 167%, 177%, 257%, and 240%, respectively Increases in the percentages of difficulty in inducting and maintaining sleep, early morning awakening and worry about poor sleep quality in the subjects in their sixties, and sleep dissatisfaction of those in their thirties were recognized

Sasazawa Yosiaki

Papers

Social networks and mortality based on the Komo-Ise cohort study in Japan

Population study on the prevalence of insomnia and insomnia-related factors among Japanese women.

Rural-urban differences in sociodemographic, social network and lifestyle factors related to mortality of middle-aged Japanese men from the Komo-Ise cohort study.

Lifestyle and sociodemographic risk factors for death among middle-aged and elderly residents in japan from a five-year follow-up cohort study.

Prevalence of insomnia and its relationship to the health habits or status of women living along a city road part 1. epidemiologie study.