URINARY-EXCRETION OF APO(A) FRAGMENTS IN NIDDM PATIENTS

Lp(a), one of the most atherogenic lipoproteins, is believed to contri bute significantly to vascular diseases in non-insulin-dependent diabe tic (NIDDM) patients. Contradictive data have been published on these patients concerning plasma concentrations of Lp(a) and their relation to renal function. Since apo(a) fragments appear in urine, we measured urinary apo(a) in 134 NIDDM patients and 100 matched controls and rel ated urinary apo(a) concentrations to plasma Lp(a) levels and kidney f unction. Plasma Lp(a) values were found to be significantly higher in NIDDM patients. NIDDM patients also secreted significantly more apo(a) into their urine as compared to control subjects. There was no correl ation between creatinine clearance or albumin excretion and urinary ap o(a) concentrations. Patients with macroalbuminuria exhibited a twofol d higher apparent fractional excretion of apo(a) in comparison to pati ents with normal renal function. Urinary apo(a) values in both patient s and control subjects were highly correlated to plasma Lp(a), yet no correlation was found with HbA(1c) or serum lipoproteins. It is conclu ded that urinary apo(a) excretion is correlated to plasma Lp(a) levels but not to creatinine clearance in patients suffering from NIDDM.