Metabolomic Profiles of Plasma Retinol-Associated Dyslipidemia in Men and Women.

Background and Aims: Studies of both animals and humans show that a high intake of vitamin A is associated with a lower risk of dyslipidemia. However, an association of plasma retinol levels with dyslipidemia is unclear. Therefore, the aim of this study is to investigate an association between plasma retinol and dyslipidemia and to identify related metabolites and pathways in the general population. Methods: We included 250 participants aged 20-80 years from the Wellness Living Laboratory (WELL) China cohort. Associations between plasma retinol levels and dyslipidemia were analyzed using adjusted logistic models. Related metabolites were identified using ANCOVA, adjusted for the false discovery rate (FDR) and used for pathway analyses. Because there are sex differences in plasma retinol levels, all analyses were conducted separately by sex. Results: Plasma retinol was significantly higher in men than in women. A positive association between plasma retinol and dyslipidemia was found in both sexes. In men, the 2nd and 3rd tertiles showed significantly higher proportions of dyslipidemia than the 1st tertile (1st tertile vs. 2nd tertile: p = 0.026; 1st tertile vs. 3rd tertile: p = 0.003). In women, the 3rd tertile showed a significantly higher proportion of dyslipidemia than the 1st and 2nd tertile (3rd tertile vs. 1st tertile: p = 0.002, 3rd tertile vs. 2nd tertile: p = 0.002). Overall, 75 and 30 metabolites were significantly associated with retinol levels in men and women, respectively. According to these metabolites, lipid metabolic pathways, including glycerophospholipid, arachidonic acid, linoleic acid, alpha-linolenic acid, and glycosylphosphatidylinositol (GPI), as well as steroid hormone biosynthesis pathways were found to overlap across the sexes. These pathways showed that elevated retinol levels might be associated with hormone metabolism and inflammation status. Conclusions: We found a positive association between plasma retinol levels and dyslipidemia. Related metabolomic profiles and interrupted pathways showed that such an increase might be associated with steroid hormone synthesis and inflammation. In addition, large, population-based longitudinal studies and intervention studies are needed to confirm the role of retinol in lipid metabolism and the prevention of cardiovascular disease (CVD).

Characterization of dietary patterns and assessment of their relationships with metabolomic profiles: A community-based study.

BACKGROUND & AIMS: Determining dietary patterns in China is challenging due to lack of external validation and objective measurements. We aimed to characterize dietary patterns in a community-based population and to validate these patterns using external validation cohort and metabolomic profiles. DESIGN: We studied 5145 participants, aged 18-80 years, from two districts of Hangzhou, China. We used one district as the discovery cohort (N = 2521) and the other as the external validation cohort (N = 2624). We identified dietary patterns using a k-means clustering. Associations between dietary patterns and metabolic conditions were analyzed using adjusted logistic models. We assessed relationships between metabolomic profile and dietary patterns in 214 participants with metabolomics data. RESULTS: We identified three dietary patterns: the traditional (rice-based), the mixed (rich in dairy products, eggs, nuts, etc.), and the high-alcohol diets. Relative to the traditional diet, the mixed (ORadj = 1.7, CI 1.3-2.4) and the high-alcohol diets (ORadj = 1.9, CI 1.3-2.7) were associated with type 2 diabetes and hypertension, respectively. Similar results were confirmed in the external validation cohort. In addition, we also identified 18 and 22 metabolites that could distinguish the mixed (error rate = 12%; AUC = 96%) and traditional diets (error rate = 19%; AUC = 88%) from the high-alcohol diet. CONCLUSIONS: Despite the complexity of Chinese diet, identifying dietary patterns helps distinguish groups of individuals with high risk of metabolic diseases, which can also be validated by external population and metabolomic profiles.

Multiplicity and complexity of food environment in China: full-scale field census of food outlets in a typical district.

OBJECTIVES: Community food environment is closely associated with residents' health status, and it has received substantial research attention in recent years. However, such studies are sparse in China. This study aims to reveal the characteristics of food environment in China. SUBJECTS: A ground-truthing field census of food outlets was conducted in Xi Hu district, Hangzhou. A novel categorizing system was developed to better characterize food outlets in the study area. Geocoding and food environment analysis were performed by Arc-GIS software. RESULTS: A total of 9274 food outlets were identified, of these, 6161 (66.43%) were food service places and 3113 (33.57%) were food stores. Fast-food restaurants (2692) and convenience stores (1764) were the two most numerous outlet types. The density of food outlets was 29.72/km2 and 113.97/10,000 people. Availability of BMI-unhealthy food outlets was four times greater than that of BMI-healthy ones. Further, 41.86% of total food outlets provided food-delivery services; among them, fast-food restaurants were the highest (65.53%) providers. In the urban area, the average density of food outlets was 104/km2. While, it was only 29/km2 in the rural area. CONCLUSIONS: Availability of food outlets was excellent in our study area, though it showed regional imbalance. Food environment tends to be obesogenic and high prevalence of food delivery service might increase this trend. Thus, policy makers should guarantee the smooth development of catering industry in China, so as to ensure a balanced nutrition environment.