Cardiovascular disease (CVD) is one of the major chronic diseases that cause death and disability, and is an important public health problem in China. At present, there are few studies on the effect of ethnic minority speciality diets on CVD.

To analyse the current situation of CVD prevalence among ethnic minorities in Guizhou Province, and to explore the relationship between ethnic speciality diets and the risk of CVD.

The data were obtained from the epidemiological survey database of the＂Cohort Study of Natural Populations Living in Ethnic Minority Aggregation Areas in the Southwest Region＂from July 2018 to August 2019. Multi-stage stratified sampling was adopted. A baseline survey was conducted on 18 790 Dong, Miao and Bouyei residents aged 30 to 79 in Qiandongnan Miao and Dong Autonomous Prefecture and Qiannan Bouyei Miao Autonomous Prefecture of Guizhou Province. A total of 17 085 people were included in the analysis. According to whether the survey subjects suffered from CVD, they were divided into two groups: CVD group (530 participants) and non-CVD group (16 555 participants). Face-to-face interviews were conducted by professional investigators using a special electronic questionnaire developed by the project team, which included surveys on basic information, living habits, disease history, and diet. As known from the study of ethnic minority dietary culture, the respondents were asked to recall the frequency (times/month) of eating 11 food items in the past 1 year: pickled vegetables, glutinous rice and its products, pickled fish/meat, preserved/smoked meat, white sour soup, red sour soup, cow/sheep deflated, purple-blooded meat, heartleaf houttuynia herb, fern, and oil tea. Unconditional Logistic regression model and restricted cubic spline were used to analyze the relationship between ethnic diet and CVD.

The total prevalence of CVD among ethnic minorities in Guizhou province was 3.20% (530/17 085), and the prevalence of CVD among each ethnic group was 3.14% (207/6 599) for the Dong, 3.13% (158/5 043) for the Miao, and 3.03% (165/5 443) for the Bouyei. The prevalence of CVD among males (3.68%) was higher than that among females (2.80%). Multivariate Logistic regression analysis showed that glutinous rice and its products were protective factors for CVD in the general population 1 to 3 times/month (OR=0.720, 95%CI=0.553-0.937, P=0.015). In the Dong population, fern≤1 time/month (OR=2.172, 95%CI=1.162-4.059, P=0.015) was a risk factor for CVD. In the Miao population, glutinous rice and its products <1 time/month (OR=0.563, 95%CI=0.340-0.933, P=0.026) and oil tea >1 time/month (OR=0.442, 95%CI=0.202-0.967, P=0.041) were protective factors for CVD. In the Bouyei population, cow/sheep deflated≤1 time/month (OR=1.935, 95%CI=1.046-3.579, P=0.035) was a risk factor for CVD. Subgroup analyses showed that in the male population, glutinous rice and its products 1-3 times/month (OR=0.639, 95%CI=0.427-0.957, P=0.030) reduced the risk of CVD. In people <60 years old, glutinous rice and its products 1-3 times/month (OR=0.656, 95%CI=0.443-0.971, P=0.035) and heartleaf houttuynia herb <1 time/month (OR=0.642, 95%CI=0.418-0.986, P=0.043) reduced the risk of CVD, while fern >1 time/month (OR=1.655, 95%CI=1.011-2.709, P=0.045) increased the risk of CVD. In the population with normal body mass, glutinous rice and its products <1 time/month (OR=0.584, 95%CI=0.393-0.868, P=0.008) and 1-3 times/month (OR=0.666, 95%CI=0.452-0.981, P=0.039) could reduce the risk of CVD; in the overweight population, purple-blooded meat ≤1 time/month (OR=0.658, 95%CI=0.453-0.955, P=0.027) could reduce the risk of CVD; in obese population, red sour soup 1-3 times/month (OR=0.592, 95%CI=0.360-0.973, P=0.039) could reduce the risk of CVD. In non-smokers, glutinous rice and its products <1 time/month (OR=0.716, 95%CI=0.532-0.965, P=0.028) and 1-3 times/month (OR=0.711, 95%CI=0.530-0.955, P=0.023) reduced the risk of CVD, and in those who had quit smoking, fern >1 time/month (OR=7.507, 95%CI=1.324-42.556, P=0.023) increased the risk of CVD, while oil tea >1 time/month (OR=0.319, 95%CI=0.103-0.990, P=0.048) decreased the risk of CVD; among people who had quit smoking, glutinous rice and its products were consumed 1-3 times/month (OR=0.710, 95%CI=0.531-0.948, P=0.020) and red sour soup 1-3 times/month (OR=0.775, 95%CI=0.613-0.980, P=0.033) could reduce the risk of CVD, while preserved/smoked meat 1-3 times/month (OR=1.400, 95%CI=1.040-1.884, P= 0.027) could increase the risk of CVD. Glutinous rice and its products, pickled fish/meat and purple-blooded meat were all associated with the risk of developing CVD in a non-linear quantitative manner (P<0.05, P_nonlinear<0.05) .

The prevalence of CVD in ethnic minority populations in Guizhou Province is low. The consumption frequency of glutinous rice and its products, oil tea, heartleaf houttuynia her, purple-blooded meat, red sour soup, fern, fern, cow/sheep deflated, and preserved/smoked meat may affect the prevalence risk of CVD. Knowledge of the intake frequency of ethnic minority speciality diets should be publicized, and dietary interventions should be made to prevent and control CVD in ethnic minority populations in Guizhou Province.