A clinical trial of cognitive and biological effects of citrus phytochemicals in subjective cognitive decline: baseline sociodemographic, clinical, and cognitive characteristics

Abstract

AbstractBackgroundWe designed a clinical trial to evaluate cognitive and biological effects of a 36‐week treatment with citrus peel extract in older adults with subjective cognitive decline (SCD) (ClinicalTrials.gov identifier: NCT04744922). Here we present baseline sociodemographic, clinical, and cognitive characteristics of the enrolled subjects.MethodEighty subjects were enrolled between April 2021 and August 2022, and randomly assigned to receive either active treatment (400 mg citrus peel extract standardized in content of auraptene ‐ 0.1 mg ‐ and naringenin – 3 mg) or placebo in a 1:1 ratio for 36 weeks. Data about nutritional state and comorbidity, current therapy, health‐related behaviours, cognitive performance on verbal and non‐verbal memory, attention, executive and visuospatial functions were collected. Differences between groups (termed group A and B to avoid unblinding – the treatment allocation is unknown to the investigators) were compared using independent t‐test or Fisher’s exact test.ResultThe enrolled subjects have a mean age of 69.2±4.3 years, a high level of education (mean 13.7±3.5 years) and a higher prevalence of females (75%), with no significant differences between groups A and B. Nutritional state and comorbidity were similar (Body Mass Index: 25.1±4.8 vs 24.0±3.9, p = .27 and Cumulative Illness Rating Scale: 1.46±0.22 vs 1.51±0.24, p = .38, groups A and B, respectively). The most frequent concurrent therapies included cardiovascular system and alimentary tract and metabolism drugs, with no significant differences between A and B (55% vs 63%, p = .32; 61% vs 66%, p = .41, respectively). Health‐related behaviours were also similar between A and B (Mediterranean Diet Adherence Screener: 9.0±1.9 vs 8.8±1.8; Smoking: 13% vs 8%; Alcohol consumption: wine 81% vs 83%, coffee consumption 93% vs 88%, all p = >.30). Cognitive scores were all within the normal range and similar between groups, except for the Wisconsin Card Sorting test total score, where group A performed marginally better than group B (27.9±21.6 vs 40.7±32.2, p = .049).ConclusionThe trial is expected to complete the longitudinal assessment in April 2023. The results of this trial will enable to evaluate the efficacy of citrus phytochemicals in SCD, informing the design of future nutritional interventions in people at risk of decline cognitive.