Polyamines, cardiorespiratory fitness, body composition, and mitochondrial function in older patients with coronary...

Higher dietary spermidine intake has been associated with lower cardiovascular mortality. Spermidine and spermine support cellular homeostasis and mitochondrial function across species, but their relevance to physical and mitochondrial function in humans remains unclear. We examined associations of dietary spermidine and circulating and skeletal muscle spermidine and spermine with physical performance, body composition, and mitochondrial respiratory capacity in older patients with coronary artery disease.

We included 187 patients with coronary artery disease [median age 72 (68-76) years; 80% men; 95% with prior coronary revascularization]. The primary outcomes were peak oxygen uptake and appendicular lean mass. Each doubling of dietary spermidine intake was associated with higher peak oxygen uptake (β 2.6 mL·kg^-1·min^-1, 95% CI 0.9-4.4; P = 0.003). This association remained after adjustment for age, sex, and physical activity. Dietary spermidine intake was also associated with higher appendicular lean mass, but this association was attenuated after adjustment. Among secondary outcomes, higher spermidine intake was associated with higher appendicular lean mass/body mass index and lower body fat percentage. In a subgroup, higher spermidine intake was associated with greater mitochondrial respiration. In exploratory analyses, a higher skeletal muscle spermine-to-spermidine ratio showed similar associations (all P ≤ 0.035).

These observational findings warrant randomized trials to determine whether dietary spermidine interventions may influence physical and mitochondrial function in older patients with coronary artery disease.