Lipoprotein (a), apolipoprotein (a) phenotypes, and thyroid autoimmunity in uremic patients

Patients with end-stage renal disease (ESRD) on hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD), as well as undialyzed patients with chronic renal failure (CRF) exhibit raised serum lipoprotein [Lp(a)] Levels. It is also known that uremia is often associated with thyroid function disturbances. There is conflicting evidence about the association of thyroid autoimmunity and elevated Lp(a) levers in euthyroid males and postmenopausal females. Hence, it would be intriguing to demonstrate a pathophysiologic interrelation between thyroid autoimmunity and Lp(a) concentrations in patients with renal function impairment. We undertook the present study to examine the correlation of thyroid autoimmunity with Lp(a) levels and the corresponding apolipoprotein [Apo(a)] phenotypes in patients with ESRD on dialysis and in undialyzed patients with mild/moderate CRF. 80 patients undergoing maintenance HD, 22 patients undergoing CAPD, 56 undialyzed CRF patients (serum creatinine 1.8-8 mg/dL) and 115 normal subjects were studied. All patient groups had increased serum Lp(a) concentrations compared to controls. Thyroid autoantibodies were present in a considerable proportion of uremic patients (23.75% HD, 40.9% CAPD, and 19.65% CRF patients). Patients with high molecular weight (HMW) Apo(a) isoforms had significant elevations in Lp(a) levels compared to controls, whereas these differences were minor with regard to low molecular weight (LMW) isoforms. There was no evidence of significant differences in serum Lp(a) concentrations between subjects with or without thyroid autoimmunity in all groups studied regardless of the stage of renal failure or the dialysis modality.