Polyphenols are widely abundant dietary constituents in plants that are associated with health-promoting effects. This review summarizes factors influencing the bioavailability of polyphenols, specifically flavanols, flavonols, flavanones, flavones, and hydroxycinnamic (phenolic) acids. Most factors tested so far indicate that bioaccessibility, defined as the amount of compound reaching the enterocyte in a form suitable for absorption, is the most important factor determining the absorption in the gut. Factors leading to an improved absorption of flavonols, notably quercetin and its metabolites, are primarily the nature of the attached sugar, and secondly, the solubility as modified by ethanol, fat, and emulsifiers. The absorption of flavanols, notably green tea catechins, is affected by epimerization reactions occurring during processing, the presence of lipid and carbohydrate, and is improved by the presence of piperine and tartaric acid. Flavanones, such as hesperidin, are strongly affected by the type of attached sugar. Phenolic acids are affected by the attached sugar, which can covalently link these compounds to the cereal bran matrix. In the few examples tested, absorption of polyphenols is dependent on release from the food matrix. There are only a few examples reported, but where information is available, the absorption increases with dose but is sometimes linear and sometimes saturated. The lack of systematic information on the effects of other components on the bioavailability of polyphenols needs to be addressed, and more human studies should be conducted in this field to establish general principles affecting absorption in vivo. Information derived from such experiments could be useful for the optimal design of future bioefficacy studies.
Aims
Weight management seems to be beneficial for obese atrial fibrillation (AF) patients; however, randomized data are sparse. Thus, this study aimed to investigate the influence of weight reduction on AF ablation outcomes.
Methods and results
SORT-AF is an investigator-sponsored, prospective, randomized, multicentre, and clinical trial. Patients with symptomatic AF (paroxysmal or persistent) and body mass index (BMI) 30–40 kg/m2 underwent AF ablation and were randomized to either weight-reduction (group 1) or usual care (group 2), after sleep–apnoea–screening and loop recorder (ILR) implantation. The primary endpoint was defined as AF burden between 3 and 12 months after AF ablation. Overall, 133 patients (60 ± 10 years, 57% persistent AF) were randomized to group 1 (n = 67) and group 2 (n = 66), respectively. Complications after AF-ablation were rare (one stroke and no tamponade). The intervention led to a significant reduction of BMI (34.9 ± 2.6–33.4 ± 3.6) in group 1 compared to a stable BMI in group 2 (P < 0.001). Atrial fibrillation burden after ablation decreased significantly (P < 0.001), with no significant difference regarding the primary endpoint between the groups (P = 0.815, odds ratio: 1.143, confidence interval: 0.369–3.613). Further analyses showed a significant correlation between BMI and AF recurrence for patients with persistent AF compared with paroxysmal AF patients (P = 0.032).
Conclusion
The SORT-AF study shows that AF ablation is safe and successful in obese patients using continuous monitoring via ILR. Although the primary endpoint of AF burden after ablation did not differ between the two groups, the effects of weight loss and improvement of exercise activity were beneficial for obese patients with persistent AF demonstrating the relevance of life-style management as an important adjunct to AF ablation in this setting.
Trial registration number
NCT02064114.
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