Factors associated with lipoprotein(a) in chronic kidney disease.
BACKGROUND
It is unclear whether lipoprotein(a) (Lp[a]) levels in patients with chronic kidney disease (CKD) are elevated as a result of reduced glomerular filtration rate (GFR) or other factors associated with CKD. The goal of this study is to describe the association of Lp(a) level with GFR in the context of apoprotein(a) (apo[a]) isoform size, race, and other kidney disease-related factors, such as proteinuria, serum albumin level, C-reactive protein (CRP) level, and serum lipid levels.


METHODS
Lp(a) and apo(a) isoforms were measured in serum samples obtained at baseline from 804 participants in the Modification of Diet in Renal Disease study (GFR range, 13 to 55 mL/min/1.73 m2). The cross-sectional association between Lp(a) level and GFR, apo(a) isoform size, race, and other variables was analyzed in univariate and multivariate linear regression.


RESULTS
Median Lp(a) level was greater in blacks than whites (97.5 versus 28.1 nmol/L; P < 0.001). Those with a low-molecular-weight apo(a) isoform size had greater Lp(a) levels than those with a high-molecular-weight apo(a) isoform size (57.5 versus 21.3 nmol/L; P < 0.001). Lp(a) level was not associated with GFR. Low-molecular-weight apo(a), black race, and greater levels of proteinuria, CRP, and triglycerides were independently associated with greater Lp(a) levels.


CONCLUSIONS
In this population with CKD stages 3 to 4, GFR was not associated with Lp(a) level, whereas other factors related to CKD, such as proteinuria, CRP level, and triglyceride level, as well as genetic factors such as apo(a) isoform size and race, were associated with Lp(a) level.
Uhlig
Katrin
K
Department of Medicine, Division of Nephrology, Tufts-New England Medical Center, Boston, MA 02111, USA. kuhlig@tufts-nemc.org
Wang
Shin-Ru
SR
Beck
Gerald J
GJ
Kusek
John W
JW
Marcovina
Santica M
SM
Greene
Tom
T
Levey
Andrew S
AS
Sarnak
Mark J
MJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D044383:Black People; D002097:C-Reactive Protein / Q000378:metabolism; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D005615:Freezing; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007674:Kidney Diseases / Q000097:blood* / Q000208:ethnology / Q000503:physiopathology / Q000652:urine; D008055:Lipids / Q000097:blood; D017270:Lipoprotein(a) / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020033:Protein Isoforms / Q000097:blood / Q000737:chemistry; D011507:Proteinuria; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D012709:Serum Albumin; D014280:Triglycerides / Q000097:blood; D044465:White People
D008055:Lipids; D017270:Lipoprotein(a); D020033:Protein Isoforms; D012709:Serum Albumin; D014280:Triglycerides; D002097:C-Reactive Protein