Dietary intake, fatty acid in adipose tissue and cardio-metabolic health: cross-sectional study from the TwinsUK cohort

Background Subcutaneous adipose tissue, the largest fat depot buffering fatty acids, correlates with cardio-metabolic diseases. Diet plays a major role in fatty acid metabolism and correlates with cardio-metabolic diseases. Studies have revealed clear links between plasma fatty acids with diet and cardio-metabolic diseases, but limited research focuses on fatty acids in subcutaneous adipose tissue. Methods In TwinsUK, 18 subcutaneous adipose tissue fatty acid proportions were measured ( N = 569) alongside dietary intake and clinical phenotypes. We investigated the association of adipose fatty acid levels and: (1) proxies of circadian factors; (2) eight dietary patterns; (3) cardio-metabolic risk phenotypes; and (4) the mediation effects of adipose fatty acids on the associations between diet and cardio-metabolic diseases. Results (1) Proxies of circadian factors: We observed no association between adipose fatty acids and fasting hours or time of visit. (2) Dietary pattern: We identified associations between eight dietary patterns and adipose fatty acids, where the Healthy Diet Indicator showed the most associations. Most dietary scores positively correlated with polyunsaturated fatty acid (Beta = 0.10 [95% CI: 0.005, 0.19] − 0.23 [0.14, 0.32], P FDR < 0.05), but Dietary Approaches to Stop Hypertension negatively correlated with two polyunsaturated fatty acids, arachidonic acid (Beta = −0.09 [−0.17,−0.006], P FDR = 0.04) and adrenic acid (Beta = −0.09 [−0.18, −0.004], P FDR = 0.04). Follow-up analysis showed that the intake of fat-rich food and fat-related nutrients were highly associated with fatty acid proportions. (3) Cardio-metabolic risk phenotypes including adiposity, lipids, glycemic and cardiovascular factors were associated with adipose fatty acids, where saturated and unsaturated fatty acids showed opposite directions. (4) Mediation effect: Adipose tissue proportion of arachidonic acid putatively mediated 24.7% of the total effect of Dietary Approaches to Stop Hypertension on visceral to gluteofemoral fat ratio. Conclusion Adipose tissue fatty acid proportions represent dietary intakes and are associated with cardio-metabolic phenotypes. We provide a resource summarising the association between dietary measurements (dietary scores, nutrients and foods) and adipose tissue fatty acid proportions.