Determinants of plasma homocyst(e)ine in patients with nephrotic syndrome

Hyperhomocyst(e)inemia is an independent risk factor for atherothrombosis i n several clinical settings in which renal function is impaired, but its pr evalence in the nephrotic syndrome has not been investigated in detail, eve n though this syndrome provides an excellent model in which to study a poss ible link between albuminuria, proteinuria, and hyperhomocyst(e)inemia. We obtained plasma and urine from 27 patients with biopsy-confirmed membranous glomerulonephritis presenting nephrotic syndrome and 27 matched controls a nd determined the concentrations of homocyst(e)ine and proteins considered putative markers of glomerular and tubular function. Hyperhomocyst(e)inemia , defined as the mean +SD of the plasma homocyst(e)ine concentration of the controls [plasma homocyst(e)ine concentration >10.8 mu mol/l] was present in 26% of the patients with nephrotic syndrome but in only 7.4% of the cont rols. Furthermore, the degree of hyperhomocyst(e)inemia was more severe in the nephrotic patients than in the controls, The existence of renal failure , tubular damage, and, interestingly, relatively well conserved glomerular function barrier were the main predictors of increased levels of plasma hom ocyst(e)ine. In conclusion, hyper homocyst(e)inemia is a frequent cardiovas cular risk factor present in patients with nephrotic syndrome and renal fai lure, but it is not directly associated with proteinuria.