Renal disease as a determinant of increased lipoprotein(a) concentrations in diabetic patients

OBJECTIVE - This study examined the hypothesis that kidney function is an independent determinant of lipoprotein(a) [Lp(a)] concentrations in people with diabetes. RESEARCH DESIGN AND METHODS - Lp(a) concentrations were measured in plasma samples from 273 type 2 and 223 type 1 diabetic patients recruited from a diabetes clinic. Kidney function was categorized as normal or pathological according to plasma creatinine levels and creatinine clearance rates. RESULTS - Macroalbuminuria was uniformly associated with significantly raised plasma concentrations of Lp(a) regardless of the marker used to identify kidney dysfunction. In contrast, in patients with microalbuminuria, significantly raised plasma Lp(a) levels were observed only when creatinine clearance rates or plasma creatinine levels indicated pathological kidney function. These conclusions were independent of diabetes type. CONCLUSIONS - In microalbuminuria and apparently in normoalbuminuria, altered kidney function determined by creatinine clearance rates or creatinine levels appears to be a major determinant of raised Lp(a) levels in both type 1 and type 2 diabetic patients. In contrast, Lp(a) concentrations were uniformly raised in patients with macroalbuminuria.