Breastfeeding has no protective effects on the development of coronary artery lesions in Kawasaki disease: a retrospective cohort study

BACKGROUND: Kawasaki disease (KD) is a self-limiting vasculitis with an unknown etiology. It has been reported that breastfeeding has a potential protective effect on KD development. However, whether breastfeeding has an effect on the development of coronary artery lesions (CALs) remains unclear. METHODS: We retrospectively reviewed the medical records of patients with the main diagnosis of KD hospitalized in our hospital from May 2017 to November 2018. Standardized telephone interviews were carried out to obtain feeding practices before KD was onset. RESULTS: Two hundred and ninety-three (51.6%) were exclusively breastfed, 223 (39.3%) were partially breastfed and 52 (9.2%) were formula fed. There were no significant differences in the characteristics regarding age, gender, incomplete KD, intravenous immunoglobulin (IVIG) resistance, and the laboratory variables among the three groups. With formula feeding as a reference, patients exclusively breastfed and partially breastfed seemed to have a higher incidence of CALs, even after adjusting confounders, but were not statistically significant. After grouping patients who were older than six months into formula feeding, partial breastfeeding for < 2 months, partial breastfeeding for ≥ 2 and < 4 months, partial breastfeeding for ≥ 4 and < 6 months and exclusively breastfeeding based on the length of breastfeeding, the results remained the same (P > 0.05). CONCLUSIONS: Breastfeeding has no protective effect on the development of CALs in KD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-022-03422-y.