Occupational Disparities in the Association between Self-Reported Salt-Eating Habit and Hypertension in Older Adults in Xiamen, China

Blood pressure responses to sodium intake are heterogeneous among populations. Few studies have assessed occupational disparities in the association between sodium intake and hypertension in older people. We used cross-sectional data from 14,292 participants aged 60 years or older in Xiamen, China, in 2013. Self-reported salt-eating habit was examined with three levels: low, medium, and high. The main lifetime occupation was classified into indoor laborer and outdoor laborer. Multivariable logistic regression was used to examine associations of hypertension with self-reported salt-eating habit, main lifetime occupation, and their interactions by adjusting for some covariates, with further stratification by sex. Overall, 13,738 participants had complete data, of whom 30.22% had hypertension. The prevalence of hypertension was 31.57%, 28.63%, and 31.97% in participants who reported to have low, medium, and high salt-eating habit, respectively. Outdoor laborers presented significantly lower prevalence of hypertension than indoor laborers (26.04% vs. 34.26%, p < 0.001). Indoor laborers with high salt-eating habit had the greatest odds of hypertension (OR = 1.32, 95% CI [1.09-1.59]). An increased trend of odds in eating habit as salt-heavier was presented in indoor laborers (p-trend = 0.048), especially for women (p-trend = 0.001). No clear trend presented in men. Conclusively, sex-specific occupational disparities exist in the association between self-reported salt-eating habit and hypertension in older individuals. Overlooking the potential moderating role of sex and occupation might affect the relationship between sodium intake and hypertension.