The Cross-Sectional and Longitudinal Associations of Chromium with Dyslipidemia: A Prospective Cohort Study of Urban Adults in China

Chromium exposure can induce altered lipoprotein metabolism in animals, but the health effects of chromium on dyslipidemia in humans have not been fully evaluated. In this study, we aimed to investigate the cross-sectional and longitudinal effects of urinary chromium on lipid levels and dyslipidemia risk among urban adults from two cities in China. A total of 3762 urban adults from the Wuhan-Zhuhai cohort were included in the initial investigation, and followed up three years later. Urinary chromium concentration was measured at baseline and repeated at follow-up. Associations of urinary chromium concentration with lipid levels and risk of dyslipidemia were analyzed by generalized linear and binary logistic regression models, respectively. We found significant relationships between increased urinary chromium concentration and both reduced triglyceride (TG) level and elevated high-density lipoprotein cholesterol (HDL-C) level at baseline and follow-up. In the cross-sectional analysis, each 1-unit increase in log-transformed urinary chromium was associated with a 0.25 mmol/L decrease in TG and a 0.05 mmol/L increase in HDL-C (P < 0.05); also, downward trends for odds ratios of hyperTG (TG level ≥ 1.7 mmol/L) and hypoHDL-C (HDL-C level < 1.0 mmol/L) were significantly associated with increasing quartiles of urinary chromium (P trend < 0.05). In the longitudinal analysis, each 1-unit increase in log-transformed urinary chromium concentration was associated with a 3% and 6% decrease in the risk of developing hyperTG and hypoHDL-C, respectively (P > 0.05). Our study indicated that significant dose-response relationships between urinary chromium concentration and lipid levels were observed at baseline and at follow-up.