Objective: To investigate the potential association between 23 urinary metals and mean platelet volume (MPV) among a community population in Wuhan.
Methods: A total of 3 053 community residents who lived in the sampling buildings for more than 5 years, aged from 18 to 80 years, were recruited using a stratified, cluster sampling approach in Wuhan city, China. Blood and urine samples were obtained from participants in the morning under fasting conditions. Urinary metals, including aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, rubidium, strontium, molybdenum, cadmium, tin, antimony, barium, tungsten, thallium, lead and uranium, were measured by inductively coupled plasma mass spectrometry. The MPV contents were determined using a fully automated clinical chemistry analyzer. Participants with missing data on covariates or cardiovascular disease were excluded. According to the reference intorvals of MPV for Chinese adults, the participants were classified into normal (7.0-11.0 fl) and high MPV (>11.0 fl) subgroups. Data from 2 203 participants were used to evaluate the associations between urinary metals and MPV levels using generalized linear regression models, and the risk of abnormal elevation of MPV using multivariable logistic regression models. The false discovery rate (FDR)-corrected P-value from 23 hypothesis tests was used to adjust for multiple testing.
Results: After adjusting for potential confounders, urinary concentrations of arsenic (P50=2.431 μg/mmol creatinine) and molybdenum (P50=4.035 μg/mmol creatinine) were significantly associated with increased MPV levels and the risk of abnormal elevation of MPV. In contrast, urinary aluminum (P50=2.706 μg/mmol creatinine) and thallium (P50=0.046 μg/mmol creatinine) were associated with decreased MPV levels, but also the risk of abnormal elevation of MPV. The regression coefficients and 95% CIs were 0.119 (0.043-0.196) for arsenic (FDR-adjusted P=0.018), 0.119 (0.042-0.195) for molybdenum (FDR-adjusted P=0.018), -0.115 (-0.195--0.034) for aluminum (FDR-adjusted P=0.029), and -0.307 (-0.386- -0.228) for thallium (FDR-adjusted P<0.001), respectively. When comparing the extreme quartiles for arsenic, molybdenum, aluminum and thallium, adjusted OR and the 95%CIs were 1.830 (1.382-2.423), 1.496 (1.125-1.989), 0.566 (0.412-0.779) and 0.302 (0.219-0.416), respectively, and FDR-adjusted P-values were <0.001,<0.014,<0.008 and<0.001, respectively. Moreover, significant associations were found between an increased risk of abnormal MPV elevation with urinary iron (P50=6.716 μg/mmol creatinine) , antimony (P50=0.014 μg/mmol creatinine) and uranium (P50=0.003 μg/mmol creatinine) , and a decreased risk with urinary tungsten (P50=0.010 μg/mmol creatinine) and lead (P50=0.265 μg/mmol creatinine) . When comparing the extreme quartiles for iron, antimony and uranium, the respective adjusted OR (95%CI) were 1.866 (1.395-2.496), 1.507 (1.111-2.043) and 1.452 (1.063-1.984), and the respective FDR-adjusted P-values were <0.001,<0.022 and<0.012. The respective adjusted OR (95%CI) were 0.551 (0.417-0.726) and 0.534 (0.394-0.725), and the respective FDR-adjusted P-values were<0.001 and<0.001, when comparing the extreme quartiles for tungsten and lead. Based on multi-metal models, urinary chromium (P50=0.120 μg/mmol creatinine) and selenium (P50=0.646 μg/mmol creatinine) were associated with increased risk of abnormal MPV, while urinary nickel (P50=0.193 μg/mmol creatinine) was associated with decreased risk of abnormal MPV. When comparing the extreme quartiles for chromium, selenium and nickel, adjusted OR (95% CI) were 1.578 (1.054-2.363), 1.718 (1.159-2.549) and 0.535 (0.373-0.767), respectively, and the FDR-adjusted P-values were 0.017, 0.028 and 0.002, respectively.
Conclusion: In the general population of Wuhan city, exposure to aluminum, chromium, iron, nickel, arsenic, selenium, molybdenum, antimony, tungsten, thallium, lead and uranium were all associated with abnormal MPV elevation.