Sugar consumption and cardiometabolic risk. With a focus on the urinary sucrose and fructose biomarkers.

Introduction: In contrast to the intake of sugar-sweetened beverages (SSBs), the evidence linking added sugar intake to the risk of cardiometabolic disease (primarily referring to cardiovascular disease and type 2 diabetes (T2D)) is contradictory.
Aim: The aim of this thesis is to elucidate the role of added sugar intake in the risk for cardiometabolic diseases. To obtain further understanding of such a potential association, the aims include exploring differences between the intake of added sugar and different added sugar sources, studying an objective biomarker of sugar intake and investigating various pathways through which added sugar intake could possibly affect cardiometabolic risk.
Method: In the Malmö Diet and Cancer study and the Malmö Offspring Study, both cross-sectional and prospective associations of intake of added sugar and sugar-rich foods and beverages were investigated along with various cardiometabolic risk markers, cardiometabolic incidence outcomes, the gut microbiota composition and the plasma proteome. Furthermore, the urinary sucrose and fructose biomarkers were investigated from overnight urine samples in the Malmö Offspring Study and from 24-h urine samples in individuals with prediabetes in the PREVIEW study.
Results: U-shaped associations between added sugar intake and all-cause and cardiovascular mortality, T2D incidence and C-reactive protein have been observed, whereas SSB intake was associated with increased all-cause mortality, a higher Firmicutes:Bacteroidetes ratio and a lower abundance of the genus Lachnobacterium in the gut, as well as a T2D-related plasma proteomic profile. Furthermore, the urinary sucrose and fructose biomarkers in overnight urine samples was found to be a useful complement to self-reported sugar intake, but the 24-h urinary sucrose and fructose biomarkers did not perform optimally in a population with prediabetes.
Conclusion: The intake of SSBs was consistently associated with higher cardiometabolic risk via various measures, whereas the total intake of added sugars showed a U-shaped association with cardiometabolic risk. Future evaluation of these associations can be aided by the use of the urinary sucrose and fructose biomarkers, except in already metabolically impaired individuals, in whom this biomarker may not provide an accurate enough measure of sugar intake.