Homocysteine, nutritional status and insulin in renal transplant recipients.

Background: Hyperhomocysteinemia is an independent risk factor for the development of cardiovascular conditions in chronic stable renal-transplant recipients (RTR). Major determinants of plasma total homocysteine (tHcy) in RTR are renal function and folate levels. The data dealing with the possible regulation of the tHcy metabolism by insulin and nutritional status is conflicting in non-transplant populations.

Methods: We examined the relationship between tHcy, insulin and nutritional status in 103 chronic, stable RTR. Demographic, clinical, and biochemical parameters were assessed for each patient.

Results: Mean tHcy was 19.7+/-9.2 micro mol/l (range 8.6-53). The tHcy was strongly related to creatinine clearance (r=0.55, P<0.0001). Fasting tHcy levels were negatively related to folate concentrations (r=-0.32, P=0.01). There was a positive relationship between tHcy and LDL-cholesterol (r=0.34, P=0.03) and a significant negative correlation between tHcy and insulin (r=-0.38, P=0.01). Fasting tHcy concentrations were significantly higher in the lower quartile of insulin concentration than in the upper quartile (27.7+/-12.7 vs 15.9+/-9.5, P=0.01). In multivariate analysis, tHcy was associated with serum creatinine (P=0.001), insulin (P=0.02) and folate concentration (P=0.03). Patients with the highest IGF-1 concentration had lower tHcy than patients with the lowest IGF-1 concentration (16.8+/-5.7 vs 23.3+/-11 micro mol/l, P=0.01).

Conclusions: We observed an inverse relationship between insulin and tHcy in chronic, stable RTR.