Blood Fatty Acid Status and Clinical Outcomes in Dialysis Patients: A Systematic Review

Abstract

Blood fatty acids (FAs) are derived from endogenous and dietary routes. Metabolic abnormalities from kidney dysfunction, as well as cross-cultural dietary habits, may alter the FA profile of dialysis patients (DP), leading to detrimental clinical outcomes. Therefore, we aimed to (i) summarize FA status of DP from different countries, (ii) compare blood FA composition between healthy controls and DP, and (iii) evaluate FA profile and clinical endpoints in DP. Fifty-three articles from 1980 onwards, reporting FA profile in hemodialysis and peritoneal DP, were identified from PubMed, Embase, and the Cochrane library. Studies on pediatric, predialysis chronic kidney disease, acute kidney injury, and transplant patients were excluded. Moderate to high levels of n-3 polyunsaturated fatty acids (PUFA) were reported in Japan, Korea, Denmark, and Sweden. Compared to healthy adults, DP had lower proportions of n-3 and n-6 PUFA, but higher proportion of monounsaturated fatty acids. Two studies reported inverse associations between n-3 PUFAs and risks of sudden cardiac death, while one reported eicosapentaenoic acid + docosahexaenoic acid)/arachidonic acid ratio was inversely associated with cardiovascular events. The relationship between all-cause mortality and blood FA composition in DP remained inconclusive. The current evidence highlights a critical role for essential FA in nutritional management of DP.

Effects of hemodialysis on blood fatty acids

“…A low omega‐3 index independently increases cardiovascular disease risk and mortality, perhaps also in CKD (Kim et al, (); Kleber et al, ; Kleber et al, ; Thuppal et al, ; Schacky, ). Consistent with a number of previous studies (for review see Khor et al ()), we detected decreased RBC EPA (C20:5 n‐3) levels in our CKD patients, compared to the control subjects. These changes were paralleled by decreased RBC C18:3 n‐6 and C20:3 n‐6 levels and decreased plasma levels of C18:2 n‐6, C20:3 n‐6, C20:4 n‐6, C20:5 n‐3, and C22:5 n‐6, which is similar to previous findings (Dasgupta, Kenny, & Ahmad, ; Dessi et al, ; Friedman, Moe, Perkins, Li, & Watkins, ; Friedman et al, ; Gomez Dumm, Giammona, Touceda, & Raimondi, ; Pazda, Stepnowski, Sledzinski, Chmielewski, & Mika, ; Peuchant et al, ; Sertoglu et al, ; Sikorska‐Wisniewska et al, ; Yerlikaya, Mehmetoglu, Kurban, & Tonbul, ), for review see Khor et al ()).…”

“…Consistent with a number of previous studies (for review see Khor et al ()), we detected decreased RBC EPA (C20:5 n‐3) levels in our CKD patients, compared to the control subjects. These changes were paralleled by decreased RBC C18:3 n‐6 and C20:3 n‐6 levels and decreased plasma levels of C18:2 n‐6, C20:3 n‐6, C20:4 n‐6, C20:5 n‐3, and C22:5 n‐6, which is similar to previous findings (Dasgupta, Kenny, & Ahmad, ; Dessi et al, ; Friedman, Moe, Perkins, Li, & Watkins, ; Friedman et al, ; Gomez Dumm, Giammona, Touceda, & Raimondi, ; Pazda, Stepnowski, Sledzinski, Chmielewski, & Mika, ; Peuchant et al, ; Sertoglu et al, ; Sikorska‐Wisniewska et al, ; Yerlikaya, Mehmetoglu, Kurban, & Tonbul, ), for review see Khor et al ()). However, the omega‐3 quotient did not vary between CKD patients and control subjects, which contrasts to numerous studies detecting a low omega‐3 index in CKD patients (for review see Khor et al ()).…”

“…Two more recent large‐scale trials showed that dietary EPA (C20:5 n‐3) (4 g daily) is effective for prevention of major coronary events in hypercholesterolemic patients (Yokoyama et al, ) and reduces cardiovascular events in patients with established CVD, including in those with diabetes mellitus and other risk factors (Bhatt et al, ). Current evidence suggests that circulating n‐3 PUFA is also associated with lower risk of cardiovascular events and mortality in ESRD patients undergoing regular hemodialysis treatment (Chowdhury et al, ; Khor et al, ).…”

“…A low omega‐3 index (the percentage of EPA + DHA in red‐blood‐cell lipids) independently increases cardiovascular disease risk and mortality (Kim, Lee, & An, ; Kleber, Delgado, Lorkowski, & Marz, ; Kleber, Delgado, Lorkowski, Marz, & Schacky, ; Schacky, ; Thuppal et al, ). RBC fatty acid status is similarly important in patients with CKD and ESRD (Khor et al, ; Kim et al, ). However, the impact of fatty acid measurements in the blood or RBC membranes for the prediction of CVD and mortality has not been previously elucidated.…”

Plasma fatty acids and kidney function decline in post-myocardial infarction patients of the Alpha Omega Cohort

“…Altered fatty acid (FA) profiles in blood have been observed in patients with CKD [11,12] and cardiometabolic disease [13]. In prospective population-based studies, plasma FAs in various lipid compartments, including cholesteryl esters (CE), were associated with cardiometabolic endpoints [14,15].…”