Background To assess the associations of body mass index (BMI) with all-cause and cause-specific mortalities among rural Chinese.
Methods A prospective study of 28 895 individuals was conducted from 2006 to 2014 in rural Deqing, China. Height and weight were measured. The association of BMI with mortality was assessed by using Cox proportional hazards model and restricted cubic spline regression.
Results There were a total of 2062 deaths during an average follow-up of 7 years. As compared with those with BMI of 22.0–24.9 kg/m2, an increased risk of all-cause mortality was found for both underweight men (BMI <18.5 kg/m2) (adjusted HR (aHR): 1.45, 95% CI: 1.18 to 1.79) and low normal weight men (BMI of 18.5–21.9 kg/m2) (aHR: 1.20, 95% CI: 1.03 to 1.38). A J-shaped association was observed between BMI and all-cause mortality in men. Underweight also had an increased risk of cardiovascular disease and cancer mortalities in men. The association of underweight with all-cause mortality was more pronounced in ever smokers and older men (60+ years). The results remained after excluding participants who were followed up less than 1 year.
Conclusion The present study suggests that underweight is an important predictor of mortality, especially for elderly men in the rural community of China.
- cohort studies
Data availability statement
Data are available upon reasonable request. The data are not in a repository and are available from the corresponding author (firstname.lastname@example.org) upon reasonable request.
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YC and NW contributed equally.
Contributors YunC and NW contributed to the study conduct, statistical analysis, results interpretation and draft, and revision of the manuscript. XD, XW, JZ and Q-WJ contributed to the study concept and design, results interpretation and revision of the manuscript. YueC and CF provided overall guidance and contributed to the study concept and design, results interpretation and substantial revisions for the manuscript. All authors approved the final version for publication. CF and YueC are the guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Funding This work was supported by the National Nature Science Foundation of China (81473038); Shanghai Leading Academic Discipline Project of Public Health (15GWZK0801) and Shanghai 3-Year Public Health Action Plan (GWTD2015S04).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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