Does online hemodiafiltration lead to reduction in trace elements and vitamins?

Area of Science:

• Nephrology
• Clinical Nutrition
• Biochemistry

Background:

• Hemodiafiltration (HDF) is a dialysis modality that enhances convective clearance.
• Concerns exist regarding potential increased micronutrient losses with HDF due to convective transport.
• Understanding the impact of HDF on essential micronutrients is crucial for patient management.

Purpose of the Study:

• To prospectively evaluate the effect of switching to HDF on vitamin B12, zinc, and selenium levels.
• To compare micronutrient levels in patients undergoing HDF versus those on high-flux hemodialysis (HD).

Main Methods:

• A prospective audit involving 34 patients switching from HD to HDF (T/Th/Sa schedule).
• A control group of 44 patients remained on high-flux HD (M/W/F schedule).
• Micronutrient levels (vitamin B12, folate, zinc, selenium) were monitored over 12 months, alongside dialysis adequacy and nutritional markers.

Main Results:

• No significant differences in vitamin B12 or folate levels were observed between HDF and HD groups over 12 months.
• Serum zinc and selenium levels remained stable after switching to HDF, despite pre-existing subnormal levels in approximately 50% of patients.
• Dialysis adequacy, weight, hemoglobin, and serum albumin showed no significant changes in either group.

Conclusions:

• Hemodiafiltration does not appear to cause a reduction in vitamin B12, folate, zinc, or selenium levels.
• The study highlights a prevalent issue of low zinc and selenium in the studied dialysis population.
• Further investigation into the causes and management of zinc and selenium deficiency in dialysis patients is warranted.