Adherence to the Healthy Nordic Food Index is associated with reduced plasma levels of inflammatory markers in patients with heterozygous familial hypercholesterolemia

Abstract

Background and aims

Familial hypercholesterolemia (FH) is an inherited disease associated with hypercholesterolemia, and dietary treatment is part of the treatment. We aimed to assess the dietary pattern in relation to the Healthy Nordic Food Index (HNFI) in adults with and without heterozygous FH (HeFH), and to examine the associations between dietary quality and biomarkers related to cardiovascular disease in adults with HeFH.

Methods

We included 205 adults (≥18 years) with HeFH who received follow-up at the Lipid Clinic in Oslo and compared them to controls (n = 228). Dietary intake was assessed using a food frequency questionnaire and dietary quality was assessed using the HNFI. Blood samples were analysed for levels of blood lipids, plasma fatty acids (FAs), and markers of inflammation and platelet activation.

Results

The HeFH patients (median 60 years; 50.2 % female; 25.9 % in secondary prevention) had lower intake of total and saturated fat compared to controls (32.6 energy percent (E%) vs. 34.9 E%, and 9.6 E% vs 12.0 E%, respectively; p < 0.001 for both). In the HeFH patients, increasing dietary quality was associated with increased plasma levels of the n-3 polyunsaturated FAs (PUFAs) eicosapentaenoic acid and docosahexaenoic acid, and the n-6 PUFA linoleic acid, and lower plasma levels of the inflammatory cytokines Tumor Necrosis Factor and interleukin-6, and of the platelet-derived inflammatory cytokines Platelet Factor 4 and Neutrophil-Activating Peptide-2.

Conclusion

Norwegian patients with HeFH followed up at a Lipid Clinic eat healthier than controls. Adherence to a healthy dietary pattern is associated with higher plasma levels of n-3 and n-6 PUFA, and lower levels of inflammatory markers, including platelet markers. This may suggest that adherence to an overall healthy dietary pattern might be beneficial for HeFH patients independent of the cholesterol-lowering effect of the diet.