Serum folate concentrations and all-cause, cardiovascular disease and cancer mortality: A cohort study based on 1999-2010 National Health and Nutrition Examination Survey (NHANES).
BACKGROUND
The relationships between serum folate levels and all-cause, cardiovascular disease (CVD), and cancer mortality are controversial.


METHODS
Utilizing 1999-2010 National Health and Nutrition Examination Survey (NHANES) and linked mortality data, we performed a cohort study with 28,845 participants and used Cox proportional hazards models and restricted cubic spline plots to elucidate the dose-response relationships between serum folate status and all-cause, CVD and cancer mortality.


RESULTS
During an average follow-up for 6.2years, 2821, 545 and 628 deaths were attributed to all-causes, CVD and cancer, respectively. Lower folate levels were associated with increased mortality, with hazards ratios of 1.30 (95% confidence interval [CI]: 1.16-1.47) for all-cause mortality, 1.33 (95% CI: 1.01-1.76) for CVD mortality, and 1.47 (95% CI: 1.16-1.87) for cancer mortality (first quartiles versus second quartiles). A reversed J-shaped pattern was apparently observed in males and younger participants when analyzing all-cause mortality and in younger participants when it comes to CVD and cancer mortality.


CONCLUSIONS
Lower folate levels, but not restricted to folate deficiency, are linked with higher rates of all-cause, CVD and cancer mortality. Adverse effects of excess folate as well as age and gender differences on mortality need further investigation.
Centre for Chronic Disease, School of Medicine, The University of Queensland, Herston, Australia. Electronic address: yang.peng@uq.net.au.
Yang
Y
Peng
Centre for Chronic Disease, School of Medicine, The University of Queensland, Herston, Australia.
Bin
B
Dong
Centre for Chronic Disease, School of Medicine, The University of Queensland, Herston, Australia.
Zhiqiang
Z
Wang
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D009749:Nutrition Surveys / Q000639:trends*; D011446:Prospective Studies
D015415:Biomarkers; D005492:Folic Acid
Folate; Mortality; NHANES