Researchers Identify Environmental Risk Factors for IgAN and MN

Certain genetically predicted environmental factors increase the risk of IgA nephropathy (IgAN) and membranous nephropathy (MN), according to study findings published in Renal Failure.

Researchers in China used data from a large-scale genome-wide association study to examine the relationships between 68 environmental exposures and IgAN and MN. Then, they divided the risk factors into five categories: socioeconomic factors, air pollution, behavioral factors, metabolic factors, and physical measurements.

To determine possible connections between the environmental factors and MN and IgAN, the researchers used weighted median, Mendelian randomization (MR)-Egger, and inverse variance weighted methods.

They identified 20 causal associations that were considered significant. Results showed that the risk of IgAN was associated with the frequency of alcohol consumption, insomnia, triglycerides, transferrin saturation, percentage of body fat, BMI, waist circumference, and BP. Specifically, MR analysis showed that people with higher triglyceride levels and higher transferrin saturation were at an increased risk of IgAN.

Furthermore, the study revealed a connection between the risk of IgAN and both systolic and diastolic BP. “Managing blood pressure serves as a crucial preventive measure against IgAN,” the researchers said.

A reduced risk of IgAN was associated with educational attainment (EA), average household income, gluten-free diet, cheese intake, fresh fruit intake, cognitive performance, and intelligence. Moreover, EA and moderate to vigorous physical activity have been shown to lower the risk of MN. However, risk factors, such as beef intake, waist-to-hip ratio, and exposure to nitrogen oxides, increased the risk of MN.

Upon further investigation, the researchers also observed that insomnia, BMI, and waist circumference partially mediated the causal link between EA and IgAN (12.5%, 11%, and 9.9%, respectively).

“This research provides a potential foundation for the establishment of precise etiological and risk assessment evidence for IgAN and MN,” the researchers said. In understanding these risk factors, the investigators hope for improved disease assessment and prevention strategies.

Source: Li C, et al. Ren Fail. 2025;47(1):2486620. doi:10.1080/0886022X.2025.2486620