An acylcarnitine profile related to total dietary fibre intake, and its association with 24-hr blood pressure: The African-PREDICT study.

Background and aims: A fibre rich diet is linked to a healthier cardiometabolic profile and may promote fatty acid oxidation to lower acylcarnitine accumulation. This study aimed to determine whether total dietary fibre intake was related to cardiometabolic risk markers as well as acylcarnitine levels in apparently healthy adults, which concurrently may be related to blood pressure (BP).

Methods and results: This study included 983 adults from the African-PREDICT study (aged 24 ± 3 years). Total fibre intake was determined using 24-hr dietary recalls, and 24-hr ambulatory BP was measured. Acylcarnitines were analysed in spot urine samples using liquid chromatography-tandem mass spectrometry-based metabolomics. Lower dietary fibre intake was related to a higher waist circumference (WC) and body mass index (BMI) as well as higher total cholesterol, low-density lipoprotein-cholesterol (LDL-C), triglycerides, Apo-lipoprotein-B, C-reactive protein (CRP), free carnitine, and short-chain acylcarnitine (C2-, C4- and C5-carnitine) levels (all p trend <0.05). Concurrently, all traditional cardiometabolic risk markers (WC, BMI, total cholesterol, LDL-C, triglycerides, Apo-B, and CRP) correlated positively with 24-hr BP. In multiple regression analyses, 24-hr SBP was associated with WC (β = 0.44; p < 0.001) and total energy intake (β = 0.096; p = 0.002), while 24-hr DBP was associated with WC (β = 0.283; p < 0.001), triglyceride levels (β = 0.085 p = 0.008), dietary fibre intake (β = -0.120; p < 0.001) and total energy intake (β = 0.128; p < 0.001). There was no relationship between acylcarnitine levels and 24-hr BP.

Conclusion: We demonstrate that participants consuming a higher fibre diet had a more favourable metabolic profile than those consuming a low fibre diet, which was ultimately associated with lower BP.