Bone mineral density and bone metabolism are not related to leptin in hemodialyzed and peritoneally dialyzed uremic patients.
BACKGROUND
In chronic renal failure leptin levels are elevated and BMD decreased, however, so far data about correlations between leptin and BMD in dialyzed patients are scarce. It has been suggested that leptin is a predictor of BMD in postmenopausal women. We examined the relationships between leptinemia, BMD and bone metabolism in HD and CAPD patients. We also assessed whether leptin is significant and independent predictor of BMD in dialyzed patients.


METHODS
BMD was measured using dual energy X-ray absorptiometry (DEXA) at lumbar spine and femoral neck in 25 HD and 23 CAPD patients. Markers of bone turnover and leptin were studied using commercially available kits.


RESULTS
In femoral neck BMD was significantly higher in CAPD patients, without significant differences in BMD in lumbar spine. There was a negative correlation between BMD at the femoral neck and time on hemodialysis (r= -0.45, p < 0.05). In CAPD patients BMD at the lumbar spine correlated negatively with vitamin D3 (r= -0.54, p < 0.05), osteocalcin (r= 0.54, p < 0 .05), and positively with BMI (r= 0.63, p < 0.01). BMD at the femoral neck correlated positively with BMI (r= 0.59, p < 0.01), and negatively with osteocalcin (r= -0.63, p < 0.05) and time on CAPD (r= -0.52, p < 0.05). Leptin correlate only with cholesterol (r= 0.25, p < 0.05), TSH (r= 0.35, p < 0.01), ss(2) microglobulin (r= 0.32, p < 0.001) and BMD at the femoral neck (r= -0.23, p < 0.05)in all dialyzed (HD and CAPD) patients.


CONCLUSIONS
BMD depends on time of renal replacement therapy. Biochemical markers of bone metabolism poorly correlate with BMD and leptin in dialyzed patients. Leptin is not a predictor of BMD in dialyzed patients.
Department of Nephrology and Transplantology, Medical University, Białystok, Poland. jolmal@poczta.onet.pl
Jolanta
J
Małyszko
Jacek S
JS
Małyszko
Zofia
Z
Bondyra
Sławomir
S
Wołczyński
Urszula
U
Łebkowska
Michał
M
Myśliwiec
D000328:Adult; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D002762:Cholecalciferol / Q000097:blood; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010531:Peritoneal Dialysis, Continuous Ambulatory; D006435:Renal Dialysis; D014511:Uremia / Q000097:blood / Q000378:metabolism* / Q000628:therapy*
D015415:Biomarkers; D020738:Leptin; D015675:Osteocalcin; D002762:Cholecalciferol