Omega-3s may counter sudden cardiac death in dialysis patients

Heart attack: omega-3s protect against heart attacks in dialysis patients

Sudden cardiac death, the leading cause of death in renal dialysis patients, can be prevented by Omega 3s. High levels of the polyunsaturated fatty acids in which fish oil is rich are in fact associated with a strong reduction in the risk of unexpected death from cardiac causes.

This was discovered by researchers at the Indiana School of Medicine, in collaboration with researchers at Massachusetts General Hospital (USA). The study was published in the journal Kidney International.

Action of Omega-3s in hemodialysis patients 

Hemodialysis is a method used to treat kidney failure, during which a patient's blood is extracted, filtered through a semi-permeable membrane, and then reintroduced into the vein. Patients undergoing this treatment are particularly vulnerable to sudden cardiac death, with an annual incidence of 6-7%, especially in the first few months of therapy, for reasons not yet well understood. Although no other studies have been published on the relationship between the blood concentration of Omega-3 and the risk of sudden cardiac death in dialysis patients, these fatty acids have been shown in clinical and experimental models to have a protective effect against ventricular arrhythmias. Other studies show that Omega-3 consumption by dialysis patients in America is very low on average.

Omega-3 concentration is associated with the risk of sudden cardiac death 

During the case-control study, led by Alon Friedmann, professor of medicine, data were collected from patients who had started dialysis, at one of the 1,000 centers involved in the project, between June 2004 and July 2005. Omega-3 levels in the 100 patients who died during the first year of dialysis and in the 300 survivors were then compared. The results showed that in subjects who died of sudden cardiac death, concentrations of saturated and monounsaturated fatty acids were high, while those of Omega-3 polyunsaturated fatty acids, such as DHA (docosahexaenoic acid), were significantly lower than in survivors. Among other things, the data collected showed that serum phospholipid-bound Omega-3 levels were inversely associated with sudden cardiac death events, during the first year of dialysis and during the first few months, the period when the risk is greatest. Specifically, the researchers estimated that patients with higher levels of Omega-3, were as much as 80 percent less likely to die, compared to those with the lowest levels.

Omega-3 in hemodialysis, effects to be further investigated

These results represent the first step in identifying a possible treatment against cardiac death in dialysis patients. Among other things, this study could have important implications for the type of diet that dialysis patients should follow, Omega-3s being present in large amounts in certain types of foods such as fish oil.

 Source: Allon N. Friedman, Zhangsheng Yu, Rebeka Tabbey, Cheryl Denski, Hector Tamez, Julia Wenger, Ravi Thadhani, Yong Li, and Bruce Watkins "Inverse relationship between long chain n-3 fatty acids and risk of sudden cardiac death in patients starting hemodialysis." Kidney Int. 2013 June ; 83(6): 1130-1135. doi:10.1038/ki.2013.4.