Association between plasma endocannabinoids and appetite in hemodialysis patients: A pilot study

Uremia-associated anorexia may be related to altered levels of long chain n-6 and n-3 polyunsaturated fatty acid (PUFA) derived circulating endocannabinoids (EC) and EC-like compounds that are known to mediate appetite. Our study's hypothesis was that such molecules are associated with appetite in patients with end-stage renal disease. A cross-sectional observational study was performed in 20 chronic hemodialysis patients (9 females, 11 males) and 10 healthy female controls in whom appetite was assessed using the Simplified Nutritional Appetite Questionnaire (SNAQ) and blood drawn in the fasting (and when applicable) pre-dialysis state. Blood levels of PUFA and EC were also measured. Higher blood levels of the long chain n-6 fatty acid 20:4n6 (arachidonic acid) and lower levels of the long chain n-3 fatty acid 20:5n3 (eicosapentaenoic acid) were observed in female hemodialysis patients compared to controls. No differences were observed between male and female patients. In female study participants strong correlations between specific EC-like compounds and total SNAQ scores were noted, including with the n-6 PUFA derived linoleoyl ethanolamide (L-EA; ρ=-0.60, P<.01) and the n-3 PUFA derived docosahexaenoyl ethanolamide (DH-EA; ρ=0.63, P<.01). The L-EA:DH-EA ratio was most strongly associated with the SNAQ score (ρ=-0.74, P≤.001), and its questions associated with appetite (ρ=-0.69, P≤.01) and satiety (ρ=-0.81, P≤.001). These findings support a link between circulating EC and appetite in hemodialysis patients.