Excessive iodine intake linked to low LDL-C in adults

An increase in iodine concentration is associated with low total cholesterol and low-density lipoprotein cholesterol (LDL-C), reveals a China study.

In this study, the authors selected three counties from Dezhou city and Liaocheng city in the Shandong province of China as survey locations. They picked out three to five villages from each county and categorized these by the iodine concentration detected in the groundwater: low (<10 µg/L), medium (10–150 µg/L), high (150–300 µg/L), and excessive (>300 µg/L) groups.

Each participant completed a self-reported questionnaire to provide demographic characteristics. A trained staff then recorded body height, weight, and blood pressure. Finally, blood lipids were measured.

The final analysis included 2,156 participants. The excessive group had significantly higher serum triglyceride than the other three groups (p<0.05). Total cholesterol and LDL-C exhibited downward trends with increases in water iodine concentrations.

The crude correlation coefficient was statistically significant between water iodine concentration and serum triglyceride, total cholesterol, or LDL-C (p<0.05). Water iodine concentration was also significantly associated with total cholesterol and LDL-C after adjustment for covariates.

Of note, high iodine concentration was a significant protective factor for total cholesterol and LDL-C in adults, while elevated body mass index and advancing age were risk factors.

“In areas with excessive iodine, iodine intake should be considered in studies examining the factors that influence blood lipids,” the authors said.