Social isolation and subsequent health and well-being in older adults: A longitudinal outcome-wide analysis.

BACKGROUND: Social isolation has become a serious public health issue. However, most previous studies examine the relationship between social isolation and a single outcome. We aimed to conduct holistic assessments to understand the multidimensional impacts of social isolation on health and well-being. METHODS: We used the three-wave data (2013, 2016, and 2019) obtained from the Japan Gerontological Evaluation Study. Our exposure, obtained from the 2016 survey, was the Social Isolation Index (SII) comprising five components: no partner, poor interaction with children, poor interaction with relatives, poor interaction with friends, and no social participation). We assessed 36 health and well-being outcomes across six dimensions obtained from the 2019 survey: physical/cognitive health, health behaviours, mental health, subjective well-being, social isolation, and cognitive social capital. Pre-exposure characteristics and prior outcome levels in 2013 were adjusted. We included 47,318 respondents for 4 outcomes (death, dementia, and functional disability) and 34,187 respondents for 32 other outcomes. The Bonferroni correction was used to correct for multiple tests. RESULTS: The total SII scores were associated with a wide range of health and well-being outcomes across the six dimensions. Specifically, we found a robust association between an SII score of four or greater with mortality (Odds ratio: 1.89; 95% CI: 1.46-2.43). Among the five components of the SII, poor interaction with friends and no social participation showed robust associations with a wide range of health and well-being. We also found some robust evidence regarding effect modification by gender and age in the associations between the components of the SII and health and well-being. CONCLUSIONS: Social isolation, specifically social interaction with friends and social participation, may affect a wide range of health and well-being among older adults.

Effects of N-acetyl glucosamine and chondroitin sulfate supplementation on knee pain and self-reported knee function in middle-aged and older Japanese adults: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: There was no evidence of satisfying the standard to decide the efficacies of glucosamine and chondroitin in middle-aged and older Japanese adults with knee pain and/or stiffness. AIM: To investigate the effects of 24 week oral N-acetyl glucosamine and chondroitin sulfate supplementation on knee pain, self-reported knee function, physical activity, and physical performance. METHODS: We randomly assigned 11 men and 39 women (aged 52-87 years) to receive 100 mg of N-acetyl glucosamine and 180 mg of chondroitin sulfate daily (Glu/Cho group) or a placebo (control, C group) for 24 weeks. The primary outcomes were a 100 mm visual analog pain scale (VAS) and the Japanese Knee Osteoarthritis Measure (JKOM) score. The secondary outcomes were physical activity and physical performance. RESULTS: We observed a significant group × time interaction on the JKOM score. According to the post hoc test, it significantly decreased (i.e., improved knee function) from the 4- to 12-week follow-up in the Glu/Cho group and the Glu/Cho group score was significantly lower than the C group at the 12-week follow-up. We found a significant interaction on household physical activity. There was no significant interaction on VAS or physical performance tests. DISCUSSION: The results of the present study were consistent with previous studies mainly conducted in European and American countries. CONCLUSION: These results suggest that consumption of N-acetyl glucosamine and chondroitin sulfate for 12 weeks or longer has a positive effect on self-reported knee function and household physical activity in middle-aged and older Japanese adults with knee pain and/or stiffness.