Association between blood manganese levels and stroke in US adults: a national cross‑sectional study

Methods

The association between blood manganese levels and stroke was explored using univariate analysis, multifactorial logistic regression equations, and smoothed-fit curves. After identifying a non-linear relationship, the inflection point was calculated using a recursive algorithm. Further stratified analyses were conducted to explore differences between groups.

Results: After adjusting for all covariates, the association between blood manganese levels and stroke was not statistically significant (OR = 0.99, 95 % CI: 0.96-1.02). However, the linear trend results indicated that there may be a non-linear correlation between the two. Smoothed fitted curves confirmed this non-linear relationship and an inflection point (7.25 μg/L) was discovered. Blood manganese levels were negatively correlated with stroke before the inflection point (OR = 0.87, 95 % CI: 0.77-0.98).

And there was no statistical significance between the two after the inflection point. This non-linear association persisted in men, and women, age ≥60 years, BMI ≥30, and BMI <30.Conclusions: A nonlinear association was discovered between blood manganese levels and stroke risk.