The significance of serum homocysteine levels in diabetic patients on haemodialysis

Background. Atherosclerotic diseases are the major cause of mortality and morbidity in patients on haemodialysis (HD). Furthermore, the prognosis of diabetic patients on HD is especially poor due to atherosclerotic complications. Because homocysteine (Hcy), a sulfur-containing amino acid, is emerging as an important risk factor for atherosclerosis in patients with endstage renal disease, we examined the significance of serum Hcy levels in diabetic patients on HD. Methods. We measured total serum Hcy levels (tHcy) in 31 patients with diabetes mellitus on HD (DM group) and 37 non-diabetic patients on HD (N group), adjusting for age and HD duration. Linear regression analysis was used to assess the correlation of multiple variables to tHcy. Results. The proportion of atherosclerotic disease in the DM group was significantly higher than in the N group. However, serum tHcy, serum creatinine and per cent creatinine generation rate in the DM group were significantly lower than in the N group. In the DM group, serum tHcy was positively correlated with creatinine, albumin and per cent creatinine generation rate, respectively. This was not the case in the N group. Conclusions. The demethylation pathway in methionine metabolism in the liver, which is linked directly to the creatinine generation system, may be disturbed in diabetic patients on HD. This may be the reason why serum tHcy and creatinine in diabetic patients on HD are lower than in non-diabetic patients on HD. Therefore, it is necessary to consider the possibility of an altered relation between serum tHcy and vessel disease when evaluating the atherogenic risk in diabetic patients on HD.