Association of Urinary Iodine Status With All-Cause and Cause-Specific Mortality Among US Adults

Abstract Objectives To examine the association of urinary iodine concentration with all-cause and cause-specific mortality in a nationally representative sample of US middle-aged and older adults. Methods This study included 5,762 participants aged between 45–79 years from a nationally representative study, the National Health and Nutrition Examination Survey 2001–2014. Urinary iodine concentrations, an established biomarker of body iodine status, were determined by inductively coupled plasma mass spectrometry. All-cause mortality, cardiovascular disease mortality and cancer mortality were ascertained by linkage to death records through December 31, 2015. Results During 41,625 person-years of follow-up, 533 deaths occurred including 90 deaths from cardiovascular disease and 167 death from cancer. After adjustment for age, gender, race/ethnicity, socioeconomic status, dietary and lifestyle factors, BMI, and urinary creatinine levels, compared with participants with urinary iodine concentration of 100–199.9 ng/mL, the hazard ratio of mortality among participants with urinary iodine concentration of 0–49.9 ng/ml was 0.92 (95% CI, 0.58–1.46) for all-cause mortality, 3.30 (95% CI, 1.35–8.06) for cardiovascular mortality, and 0.73 (95% CI, 0.27–2.00) for cancer mortality. Conclusions Low level of urinary iodine was significantly associated with increased risk of cardiovascular death in US adults. Funding Sources N/A