Decreased free fatty acid levels associated with adverse clinical outcomes in coronary artery disease patients with type 2 diabetes: findings from the PRACTICE study

AIMS: Increased free fatty acid (FFA) levels are known to be strongly associated with mortality in coronary artery disease (CAD) patients and the development of type 2 diabetes (T2DM). However, few studies have been large enough to accurately examine the relationship between FFA levels and mortality in CAD patients with T2DM. METHODS AND RESULTS: From December 2016 to October 2021, 10 395 CAD patients enrolled in PRACTICE, a prospective cohort study in China, were divided into four groups according to baseline FFA concentration. We investigated mortality, including all-cause mortality (ACM) and cardiac mortality (CM), as the primary endpoint. The secondary endpoints were major adverse cardiovascular and cerebrovascular events (MACCEs) and major adverse cardiovascular events (MACEs). The median follow-up time was 24 months. In the total cohort, there were 222 ACMs, 164 CMs, 718 MACEs, and 803 MACCEs recorded. After controlling for baseline variables, the association between FFA levels and the risk of mortality presented a non-linear U-shaped curve, with the lowest risk at 310 µmol/L. We also identified a non-linear U-shaped relationship for ischaemic events (MACE or MACCE) with the lowest risk at 500 µmol/L. Subgroup analysis showed that a U-shaped relationship between FFA and mortality or ischaemic events was observed only in individuals with T2DM but not in non-diabetic CAD patients. CONCLUSIONS: A non-linear U-shaped association was identified between baseline FFA levels and mortality or ischaemic events in CAD patients with T2DM.