Objective: To assess the effectiveness of a village doctor-led mobile health intervention on cardiovascular risk reduction among residents in rural China. Design: Cluster randomised controlled trial. Setting: 127 villages from five provinces and autonomous regions in China. Participants: 4533 participants from 127 villages: 2297 (64 villages) were randomly assigned to the intervention group and 2236 (63 villages) to the control group. Participants were aged ≥35 years, had no established atherosclerotic cardiovascular disease (ASCVD) but a predicted 10 year risk of ≥10%, had contracted a family doctor service with the local village doctor, and owned a smart phone. Interventions: In addition to usual clinical care and basic public health services provided for the control group, the intervention led by village doctors included five components: assessing risk factors to identify individualised intervention targets, setting gradual goals based on doctor-participant communication, providing targeted short videos on health education, conducting health monitoring with periodic feedback, and providing motivation to reduce risk based on gamification. Main outcome measure: Mean change in predicted 10 year risk of ASCVD from baseline to 12 months. Results: Enrolment took place between March 2023 and May 2023. During the 12 month follow-up (completion rate 99.4%), the 10 year risk of ASCVD decreased from 18.0% to 11.7% in the intervention group and from 17.8% to 13.6% in the control group (absolute difference −1.88% (95% confidence interval (CI) −2.57% to −1.19%; P<0.001). Compared with the control group, the intervention group showed larger reductions in lifetime ASCVD risk (−15.9% v −11.0%; difference −4.59%; Plt;0.001), systolic blood pressure (−23.2 mm Hg v −15.2 mm Hg; difference −7.64 mm Hg; Plt;0.001), diastolic blood pressure (−10.9 mm Hg v −6.9 mm Hg; difference: −3.59 mm Hg; Plt;0.001), fasting blood glucose (−0.9 mmol/L v −0.5 mmol/L; difference −0.30 mmol/L; P=0.008), proportion of daily smokers (−3.1% v −0.6%; odds ratio 0.60, 95% CI 0.43 to 0.84; P=0.003), and insufficient physical activity (−3.0% v 1.3%; odds ratio 0.63, 0.42 to 0.95; P=0.03). No significant differences were observed for change in non-high density lipoprotein cholesterol or proportion of participants with obesity. Conclusions: The village doctor-led mobile health intervention was effective at reducing cardiovascular risk and improving control of behavioural and metabolic risk factors. This feasible approach could be scaled up in rural China and other under-resourced settings to improve health management based on the local primary healthcare system. Trial registration: ClinicalTrials.gov NCT05645640 .

Although studies have reported the modification effect of air pollutants on heat-related health risk, little is known on the modification effect among various particulate matter with different particle size on mortality. We aimed to investigate whether the associations of hot temperatures with daily mortality were modified by different air pollutant levels in Shandong Province, China. Daily data of air pollutants, meteorological factors, and mortality of 1,822 subdistricts in Shandong province from 2013 to 2018 were collected. We used a time-stratified case-crossover model with an interaction term between the cross-basis term for ambient temperature and the linear function of particulate matter ≤1 µm (PM₁), PM_2.5, nitrogen dioxide (NO₂), and ozone to obtain heat-mortality associations during the hot season. Results showed that the cumulative odds ratio of extreme heat on mortality over 0 to 10 days was 3.66 (95% CI: 3.10–4.31). The mortality risk during hot seasons was stronger at high air pollutant levels. The modification effect of particulate matters on heat-related mortality decreased by its aerodynamic diameter. Females and older adults over 75 years were more vulnerable to the modification effect of air pollutants, and significant differences were detected in the association between temperatures and mortality stratified by PM₁ and PM_2.5. Higher heat-related mortality risks were observed at high NO₂ levels, especially for cardiorespiratory disease. The findings suggest that more consideration should be given to the combined effect of very fine particles and NO₂ with ambient heat when developing healthcare strategies, and women and older adults should be given priority in health-related settings.

Compared to common salt, low-sodium salt can reduce blood pressure to varying degrees. However, the exact dosage relationship remains unclear. We aimed to investigate the dose–response relationships between low-sodium salt intake and systolic blood pressure (SBP) and diastolic blood pressure (DBP), as well as the risk of hypertension, and to determine the optimal range for low-sodium salt intake. We investigated the basic characteristics and dietary profile of 350 individuals who consumed low-sodium salt. The samples were divided into three groups according to the 33.3rd and 66.6th percentiles of low-sodium salt intake in condiments (Q1: <4.72 g/d, Q2: ≥4.72 g/d, and <6.88 g/d, and Q3: ≥6.88 g/d). The restricted cubic spline results indicated that low-sodium salt intake decreased linearly with SBP and DBP, while low-sodium intake demonstrated a non-linear, L-shaped relationship with the risk of hypertension, with a safe range of 5.81 g to 7.66 g. The multiple linear regression analysis revealed that compared with group Q1, the DBP in group Q2 decreased by 2.843 mmHg (95%CI: −5.552, −0.133), and the SBP in group Q3 decreased by 4.997 mmHg (95%CI: −9.136, −0.858). Exploratory subgroup analyses indicated that low-sodium salt intake had a significant impact on reducing SBP in males, DBP in females, SBP in rural populations, and DBP in urban populations. The intake of low-sodium salt adheres to the principle of moderation, with 5.81–7.66 g potentially serving as a pivotal threshold.

This study assessed the reliability of equations for estimating 24-hour urinary sodium excretion using first-time morning urine samples. In this study, a t