Exposure to microplastics via hemodialysis: differences between women and men

Abstract Background Hemodialysis (HD) may contribute to microplastics (MPs) burden in dialysis patients. The aim of the study was to estimate any differences in exposure to MPs between cases (on dialysis patients) and controls (not on dialysis patients), investigating any sex differences. Methods We organized a case-control study. Both cases and controls were recruited at the Policlinic “G. Rodolico-San Marco” Hospital Nephrology Unit. Preparation and determination of MPs smaller than 10 µm in blood samples were carried out using a patented method (Italian Patent n. 102018000003337-07 March 2018, European Patent n.3788344 20 July 2022) and SEM-EDX electron microscopy analysis, respectively. Results A convenience sample was recruited including 15 dialysis (60.0% women) and 10 not on dialysis patients (60.0% women) with a median (IQR) age of 77.0 (59.0-83.0) in dialysis patients and 65.5 (49.3-79.0) in those not on dialysis. No significant differences were found between cases and controls on the consumption of bottled water (100% vs 80%, p = 0.07), bagged foods (93.3% vs 70%, p = 0.12) unlike the use of drugs (100% vs 70%, p = 0.02). Women in general declared a greater use of drugs than men (F 93.3%, M 80.0%, p = 0.32). Dialysis patients had higher MPs levels than non-dialysis patients [9132(4896-15847) vs 3554(1661-7340), p-value=0.06]. In particular, female dialysis patients had values comparable to males [9132 (4665-17205) p/d vs men: 10438 (3672-16699) p/d] while non-dialysis female patients had higher levels than males [3274 (1681- 7814) p/g vs 1661 (1661-3354) p/g]. No difference was detected about the diameter of the MPs (IQR) [dialysis patients 4.28 (3.72-4.66) µm vs non-dialysis patients [4.67 (4.15-5.08) µm]. Conclusions Future studies must focus on studying the relationship between exposure to MPs and their levels in dialysis patients as well as investigating the differences between men and women and the possible consequences of dialysis as a further source of exposure. Key messages • On dialysis patients, both men and women, had higher MPs exposition compared to not on dialyzed ones. • Not on dialysis women had higher MPs levels than not on dialysis men.