Changes of Serum Lipoprotein (a) Concentrations According to the Severity of Diabetic Nephropathy

Eun, Yeon Ki; Ryu, Mee Sook; Hong, Sung Pyo; Lee, Tae Won; Ihm, Chun Gyoo; Kim, Myung Jae

Abstract

BACKGROUND: Lipoprotein(a)[Lp(a)] is a subspecies of low-density lipoprotein and has been shown to be associated with pathogenesis of thrombosis-related disease. It is already known that patients with diabetic nephropathy are usually complicated by vascular complications such as coronary artery diseases and cerebrovascular accidents. According to the recent data, Lp(a) level tends to be increased as the proteinuria is increased and renal function are decreased. We evaluated the Lp(a) level to know whether its level is correlated to the severity of diabetic nephropathy.
METHODS
We investigated Lp(a) levels in eighty-one patients with Type 2 (non-insulin-dependent) diabetic patients. They were divided into four groups according to the level of urinary albumin excretion and serum creatinine level: Group 1 (n=30): normal renal function + urine microalbumin or=1.5mg/dL. Blood samples were obtained during the morning in the fasting state and separated serum from the it and reserved at -70degrees C. Lp(a) concentration was checked by one-step sandwich ELISA test. All grouped data were expressed as mean+/-SD. ANOVA and unpaired t-test was used to assess the statistical difference between any two means.
RESULTS
Lp(a) levels were 30.2+/-4.6mg/dL in Group 1, 42.7+/-8.2mg/dL in group 2, 73.4+/-19.7mg/dL in group 3, and 80.7+/-14.8mg/dL in group 4. The level of Lp(a) in group4, group 3, and group 2 was significantly higher than that of group 1 respectively (P=0.009, 0.001, 0.038). However, no significant correlation was observed between the level of Lp(a) and that of total cholesterol, triglyceride and total lipid in all groups.
CONCLUSIONS
these results indicate that Lp(a) concentrations are increased in the patients with diabetic nephropathy with microalbuminuria or overt proteinuria. So, the presence of albuminuria may be the important determinant for the elevated Lp(a) level in diabetic nephropathy.