To date we have published four papers using data from the Stanford WELL for Life Study, provided to us by all participants. Two papers were submitted this month and many more will be submitted over the next few months. Click on the links below to read about our findings!

Associations Between Body Fat, Muscle Mass, and Nonalcoholic Fatty Liver Disease: A Population-Based Study

Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of liver disease worldwide and has emerged as a significant public health concern in China. A better understanding of the etiology of NAFLD can inform effective management strategies for this disease. We examined factors associated with NAFLD in two districts of Hangzhou, China, focusing on the relationship of regional body fat distribution, muscle mass, and NAFLD. Multivariate logistic regressions were performed to assess independent associations between NAFLD and metabolic risk factors and dual x-ray absorptiometry (DX A)-derived measures (e.g., android fat ratio [AFR] and skeletal muscle index [SMI]). According to our analysis, android fat ration (AFR), insulin resistance, high alanine aminotransferase levels, smoking, and male sex were positively associated with NAFLD risk, while skeletal muscle index (SMI) was inversely associated with NAFLD risk.

Julianna C. Hsing, M. Nguyen, B. Yang, Y. Min, S. Han, E. Pung, S. J. Winter, X. Zhao, D. Gan, A. W. Hsing, S. Zhu. C. J. Wang. “Associations Between Body Fat, Muscle Mass, and Nonalcoholic Fatty Liver Disease: A Population-Based Study,” Hepatology Communications 0, no. 0, accessed July 12, 2019, https://doi.org/10.1002/hep4.1392.

Sex-specific Association Between Gut Microbiome and Fat Distribution

The gut microbiome has been linked to host obesity; however, sex-specific associations between microbiome and fat distribution are not well understood. Here we show sex-specific microbiome signatures contributing to obesity despite both sexes having similar gut micro-biome characteristics, including overall abundance and diversity. Our comparisons of the taxa associated with the android fat ratio in men and women found that there is no widespread species-level overlap. We did observe overlap between the sexes at the genus and family levels in the gut microbiome, such as Holdemanella and Gemmiger; however, they had opposite correlations with fat distribution in men and women. Our findings support a role for fat distribution in sex-specific relationships with the composition of the microbiome. Our results suggest that studies of the gut microbiome and abdominal obesity-related disease outcomes should account for sex-specific differences.

Min, Yan, Xiaoguang Ma, Kris Sankaran, Yuan Ru, Lijin Chen, Mike Baiocchi, and Shankuan Zhu. "Sex-specific Association between Gut Microbiome and Fat Distribution." Nature Communications10, no. 1 (June 03, 2019). doi:10.1038/s41467-019-10440-5.

Understanding Where We Are Well: Neighborhood-Level Social and Environmental Correlates of WEll-Being in the Stanford Well for Life Study

Individual well-being is a complex concept that varies among and between individuals and is impacted by individual, interpersonal, community, organizational, policy and environmental factors. This research explored associations between select environmental characteristics measured at the ZIPcode level and individual well-being. Twelve identical or analogous neighborhood (ZIP-code level) indicators were selected to test against the SWLS measure and data were collected from secondary sources to describe socio-economic, demographic, and physical environment, and healthcare. Linear mixed models were fit to assess relationships between each neighborhood measure and each of the ten domains of well-being, as well as the overall SWLS well-being measure, and were adjusted for spatial autocorrelation and individual-level covariates. Our observational insights suggest that neighborhood factors are associated with individuals’ overall self-rated well-being, though variation exists among its constituent domains.

Chrisinger BW, Gustafson JA, King AC, Winter SJ. Understanding Where We Are Well: Neighborhood-Level Social and Environmental Correlates of Well-Being in the Stanford Well for life Study. Int J Environ Res Public Health. 2019 May 20;16(10).pii: E1786. doi: 10.3390/ijerph16101786. PubMed PMID: 31137589; PubMed Central PMCID: PMC6571676

Dry eye and sleep quality: a large community-based study in Hangzhou

Dry eye and sleep dysfunction draw global  public health concerns with their high prevalence and extensive adverse effects. Our study discovered a strong association between these two conditions. This is the firstpopulation-based study to evaluate the association of dry eye and sleep quality using previously validated tools, the Ocular Surface Disease Index (OSDI) and the Chinese version of the Pittsburg Sleep Quality index (CPS!I), respectively. Results indicated a strong positive association between poor sleep quality and higher severity for dry eye. It is plausible to suggest that improvement of sleep quality would alleviate the syndromes of dry eye, and vice versa. Our large comunity-based study showed a strong association between poor sleep quality and an increased severity of dry eye, suggesting that preventing either one of the discomforts might alleviate the other. 

Zhu S, Yao K. Dry eye and sleep quality: a large community-based study in Hangzhou. Sleep. 2019 Jul 15. pii: zsz160. doi: 10.1093/sleep/zsz160. [Epub ahead of pring] PubMed PMID: 31310315.

A qualitative exploration of well-being: What is well-being? How do we know? Why do we care? 

Well-being is a concept that has been broadly explored, but using different definitions and conceptual frameworks depending on the academic discipline or the research question being addressed. This study attempets to break free of disciplinary lenses by using a grounded narrative inquiry approach to explore the construct of well-being from the point of view of the people experiencing it. Semi-structured interviews were conducted with 102 adults in the San Francisco Bay Area and, through rigorous inductive coding, ten domains or well-being were identified: social connectedness, lifestyle and daily pratices, experience of emotions, stress and resilience, physical health, purpose and meaning in life, sense of self, financial security and satisfaction, exploration and creativity, and spirituality and religiousity. Well-being emerged as a multi-component construct that includes a wide variety of experiences, perceptions, feelings and behaviors. The same level of well-being was constructed from very different domains by different people. This lived experience of well-being expressed by the voices of the diverse people in the study may offer guidance in terms of strategies to enhance the effectiveness of disease risk reduction and improve medical care outcomes, as well as support the flourishing of well-being.