A Spatial Ecological Study on Serum Selenium and Keshan Disease in Heilongjiang Province, China

Background: There are no reports on the spatial ecology of serum selenium and Keshan disease in Heilongjiang Province in China.

Objective: This study aimed to conduct a spatial assessment of Keshan disease elimination at the level of the etiological molecular marker.

Methods: An ecological study design was used. The levels of serum selenium of the 571 residents aged between 17 and 35 years and living in rural areas, townships, and cities in 63 Keshan disease endemic counties and 46 non-endemic counties in Heilongjiang Province were measured using atomic fluorescence spectrometry. A spatial analysis of serum selenium levels was conducted.

Results: The median serum selenium level of the 571 participants was 1.00 μmol/L, and that of participants living in Keshan disease endemic areas was 0.97 μmol/L, which was significantly lower compared to the level of those living in non-endemic areas (1.01 μmol/L, P = 0.0037). Serum selenium levels of the participants living in rural areas, townships, and cities were significantly different (P < 0.001) at 0.95 μmol/L, 1.00 μmol/L, and 1.04 μmol/L, respectively. Spatial regression analysis showed that the distribution of serum selenium levels was positively correlated with the per capita gross domestic product.

Conclusion: The analysis of the spatial distribution of serum selenium levels provided precise visual evidence that selenium deficiency may still be present among residents of Keshan disease endemic counties of Tangyuan, Mulan, Lingdong, Suiling, and Dongshan. Selenium levels should therefore be included in the national surveillance of Keshan disease.