Fish oil for prevention of sudden death in hemodialysis patients?

Effects of Marine n-3 Polyunsaturated Fatty Acids on Heart Rate Variability and Heart Rate in Patients on Chronic Dialysis: A Randomized Controlled Trial

Marine n-3 polyunsaturated fatty acids (PUFA) may improve autonomic dysfunction, as indicated by an increase in heart rate variability (HRV) and reduce the risk of sudden cardiac death. Hence, the aim of this study was to investigate the effects of marine n-3 PUFA on 24-h HRV in patients on chronic dialysis, who have a high risk of sudden cardiac death. Between June 2014 and March 2016, 112 patients on chronic dialysis from Denmark were allocated to a daily supplement of 2 g marine n-3 PUFA or control for three months in a randomized, double-blinded, controlled trial. A 48-h Holter monitoring was performed and mean 24-h HRV indices for the two days were available in 85 patients. The mean age was 62.3 years (SD: 14.3) and median dialysis vintage was 1.7 years (IQR: 0.5, 6.4). Within-group and between-group changes in outcome were evaluated by a paired and two sample t-test, respectively. Marine n-3 PUFA did not change the primary endpoint SDNN (SD of all RR-intervals) reflecting overall HRV, but other HRV indices increased and the mean RR-interval increased significantly, corresponding to a decrease in heart rate by 2.5 beats per minute (p = 0.04). In conclusion, marine n-3 PUFA did not change SDNN, but the mean heart rate was significantly reduced and changes in other HRV-indices were also observed, indicating an increase in vagal modulation that might be protective against malignant ventricular arrhythmias.

Eicosapentaenoic Acid and Prevalence of Cardiovascular Disease in Hemodialysis Patients

Eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio showed inverse associations with cardiovascular disease (CVD) in general population. However, this has not been examined enough in dialysis patients. We cross-sectionally investigated the relationship between EPA/AA ratio and prevalence of CVD in 321 chronic hemodialysis patients (64 ± 11 years old; 110 women; dialysis vintage 10 ± 8 years) in an urban area of Tokyo. CVD was defined as a composite of ischemic heart disease, ischemic stroke and hemorrhagic stroke. The frequency of dietary fish intake was also examined. Logistic regression was used to quantify the association of EPA/AA ratio with CVD. EPA/AA ratio was 0.31 ± 0.19 and 154 patients (48%) consumed fish once or less weekly. One hundred and thirty patients (41%) had CVD, including 65 with ischemic heart disease, 70 with ischemic stroke, and 20 with hemorrhagic stroke. Age (odds ratio [OR], 1.04; P = 0.01), hypertension (OR, 2.25; P = 0.002), and dialysis vintage (OR, 1.04; P = 0.02) were associated with CVD; however, EPA/AA was not after adjustment for other risk factors. A similar relationship was observed between fish intake and CVD prevalence. We did not find any significant association between EPA/AA ratio and prevalence of CVD, although traditional risk factors such as age, hypertension and dialysis vintage were associated with CVD. These results might have been influenced by the fact that only a small proportion of our patients showed a high EPA/AA ratio.

Mitochondria: a new therapeutic target in chronic kidney disease

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.