The relationship between occupational physical activity and dyslipidaemia in farmers with varying working modes in southwest China: the China multi-ethnic cohort study

BACKGROUND: Farmers are the integral members of rural communities. In the present study, we determined the association between occupational physical activity (OPA) of farmers and dyslipidaemia. METHODS: We included 7649 farmers from The China Multi-Ethnic Cohort (CMEC) Study. The working modes of all farmers were divided into four types according to their self-reported seasonal changes in farming work and/or other job changes (1: no change; 2: changing job; 3: seasonal changes; and 4: seasonal and job changes). OPA was self-reported, and the OPA levels in the four groups were classified as Q1, Q2–Q3, and Q4 by quantile. Dyslipidaemia was defined as the presence of abnormalities in lipid indicators. Binary logistic regression was used to estimate the association between OPA and dyslipidaemia. RESULTS: Compared with those in the no change group, the participants in other three groups were younger with lower level of education, annual income, and leisure-time physical activity (LTPA). Active OPA could reduce the risk of dyslipidaemia in the no change [men: odds ratios (OR) = 0.21, 95% confidence intervals (CI): 0.07–0.64; women: OR = 0.43, 95% CI: 0.20–0.93] and seasonal change (men: OR = 0.46, 95% CI: 0.27–0.77; women: OR = 0.59, 95% CI: 0.41–0.86) groups. However, in the seasonal and job change group (men: OR = 3.23, 95% CI: 1.06–9.80; women: OR = 3.24, 95% CI: 1.42–7.41), active OPA increased the risk of dyslipidaemia. CONCLUSIONS: Different OPA levels might lead to differences in association with blood lipid levels. Thus, OPA guidelines must be developed for farmers, especially for those who experience seasonal changes in farming work and job changes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-13266-x.