Longitudinal association of dietary spermidine with hepatic function indexes and cardiometabolic traits in older adults with metabolic syndrome.

PURPOSE: Spermidine administration ameliorates hepatic steatosis and cardiometabolic dysfunction in animal models. However, evidence in humans remains limited. We aimed to explore the 1-year longitudinal associations between changes in dietary spermidine intake and changes in hepatic function indexes and cardiometabolic traits in overweight and obese older adults with metabolic syndrome.
METHODS: We used baseline and 1-year follow-up data from 2664 participants from the PREDIMED-Plus trial. Dietary spermidine intake was estimated using a semi-quantitative food frequency questionnaire. Time series clustering identified temporal patterns of 1-year change in spermidine intake. Linear mixed-effects models assessed the associations between spermidine intake clusters and changes in hepatic and cardiometabolic markers.
RESULTS: Three distinct spermidine intake patterns were identified across baseline, six months and 1 year follow-up. Cluster 3, characterized by the highest baseline and increased 1-year spermidine intake, was associated with mean reductions in fatty liver index (- 8.97 [- 9.96 to - 7.97], p-int < 0.001), hepatic steatosis index (- 1.88 [- 2.13 to - 1.63], p-int < 0.001), alanine aminotransferase (- 2.93 [- 3.83 to - 2.02] U/L, p-int < 0.05), aspartate aminotransferase (- 1.11 [- 1.76 to - 0.45] U/L, p-int < 0.05) and glycated hemoglobin levels (- 0.14 [- 0.18 to - 0.10]%, p-int < 0.01). Cluster 3 also showed, mean decreases in body mass index (- 1.26 [- 1.37 to - 1.15]), waist (- 3.72 [- 4.11 to - 3.32] cm) and hip circumference (- 2.33 [- 2.67 to - 1.99] cm) (all p-int < 0.001).
CONCLUSION: A 1-year increase in dietary spermidine intake was associated with improvements in hepatic function indexes and cardiometabolic traits in overweight and obese older adults with metabolic syndrome.