Highly elevated serum phyto-oestrogen concentrations in patients with diabetic nephropathy.
OBJECTIVE
Phyto-oestrogens, naturally occurring phenolic, hormone-like compounds, have raised considerable interest due to their anticarcinogenic, antiatherogenic and antioxidative potential. Oxidative stress may be one of the key factors in the development of vascular complications in patients with type 1 diabetes. Here, we tested the hypothesis that high concentrations of phyto-oestrogens in serum may be associated with lower occurrence of vascular complications in these patients.


METHODS
A total of 400 patients, recruited consecutively from the participant register of the nationwide FinnDiane study of type 1 diabetes and divided into four parallel groups according to the severity of their renal disease with 100 patients to each group: (i) normoalbuminuric patients, (ii) microalbuminuric patients, (iii) macroalbuminuric patients, and (iv) patients with end-stage renal disease (ESRD).


METHODS
Phyto-oestrogen concentrations in serum (enterolactone, daidzein, genistein and equol) and urine (enterolactone), assessed by time-resolved fluoroimmunoassay.


RESULTS
Highly elevated serum concentrations of phyto-oestrogens were measured amongst patients with diabetic nephropathy, and low concentrations amongst patients without diabetic complications. The pattern was similar for all phyto-oestrogens measured, although the increase in mean serum concentrations along with the increasing severity of renal disease was steepest for enterolactone, ranging from 13 nmol L(-1) amongst women and 18 nmol L(-1) amongst men in normoalbuminuric patients to 181 and 206 nmol L(-1) in women and men, respectively, in patients with ESRD (P < 0.001 for both genders between the groups). A strong correlation between serum enterolactone and creatinine concentration was found (r = 0.60, P < 0.001).


CONCLUSIONS
The serum concentration of phyto-oestrogens and the severity of diabetic renal disease showed a close positive association, suggesting that phyto-oestrogens are unable to provide any major protective effect, through antioxidative or other mechanisms, on the development of diabetic renal and cardiovascular complications.
von Hertzen
L
L
Folkhälsan Genetic Institute, Folkhälsan Research Centre, Biomedicum Helsinki, Helsinki University, Helsinki-00014, Finland.
Forsblom
C
C
Stumpf
K
K
Pettersson-Fernholm
K
K
Adlercreutz
H
H
Groop
P-H
PH
D000328:Adult; D003404:Creatinine / Q000097:blood / Q000652:urine; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000652:urine; D003928:Diabetic Nephropathies / Q000097:blood* / Q000652:urine; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000097:blood* / Q000652:urine; D007676:Kidney Failure, Chronic / Q000097:blood / Q000652:urine; D008297:Male; D008875:Middle Aged; D048789:Phytoestrogens; D028321:Plant Preparations / Q000097:blood* / Q000652:urine
D007529:Isoflavones; D048789:Phytoestrogens; D028321:Plant Preparations; D003404:Creatinine