Dietary flavonoid intake and frailty in middle-aged and older U.S. adults with prediabetes or diabetes: A population-based study

The relationship between flavonoids and frailty in individuals with prediabetes or diabetes remains unclear. This study aimed to investigate the relationship between dietary flavonoid intake and frailty risk in U.S. adults with prediabetes or diabetes. This study used data from the 2007-2008, 2009-2010, and 2017-2018 cycles of the National Health and Nutrition Examination Survey. Dietary flavonoid intake was assessed via 24-hour dietary recalls, and frailty was evaluated using a 53-item frailty index. Multivariate-adjusted logistic regression models were employed to assess the association between dietary flavonoid intake and frailty risk. Restricted cubic spline models were used to evaluate the potential non-linear relationships. The study enrolled a total of 2558 adults (aged ≥ 40 years) with diabetes or pre-diabetes. Participants in the highest tertile of total flavonoid intake exhibited a 32% (odds ratio [OR] = 0.68, 95% confidence interval [CI]: 0.48-0.96) lower risk of frailty compared to those in the lowest tertile. Among flavonoid subclasses, anthocyanidins and flavones were also significantly associated with lower frailty risk, with ORs and 95% CIs of 0.64 (0.48-0.85) and 0.70 (0.52-0.94) for the highest tertile compared with the lowest tertile, respectively. Restricted cubic spline analysis revealed an L-shaped relationship between total flavonoid intake and risk of frailty in patients with prediabetes or diabetes (Pnonlinearity < .001). In contrast, anthocyanidins (Pnonlinearity = .167) and flavones (Pnonlinearity = .092) demonstrated linear dose-response relationships with frailty risk in this population. Higher dietary flavonoid intake, particularly anthocyanidins and flavones, was significantly associated with lower frailty risk in adults with prediabetes or diabetes.