Advanced glycation end products (AGEs) may be involved in the pathogenesis
of complications of chronic renal failure. Pentosidine, a carbohydrate-deri
ved AGE? is considerably elevated in uraemic patients. This compound per se
has no biological activities but is highly correlated to the levels of pre
cursors of carbonyl compounds, and for this reason is considered a reliable
surrogate marker for AGEs. The modification of proteins in uraemia is not
limited to AGEs, since advanced lipoxidation end products are also demonstr
able in plasma proteins in uraemia. The accumulation of these compounds doe
s not seem to be dependent only on the decline of renal function. Carbonyl
precursors of AGEs and advanced lipoxidation end products are markedly elev
ated in uraemic patients. On this basis, the 'carbonyl stress' theory has b
een formulated. This theory holds that increased oxidation of carbohydrates
and lipids and/or inadequate detoxification of carbonyl compounds may cont
ribute to long-term complications of end-stage renal disease such as dialys
is amyloidosis and cardiovascular diseases. Preliminary cross-sectional stu
dies in haemodialysis patients seem to indicate that the AGEs and carbonyl
stress may be involved in the pathogenesis of alterations in left ventricul
ar geometry and function in these patients.