Effects of co-existing autoimmune diseases on serum lipids and lipoprotein subclasses profile in paediatric patients with type 1 diabetes mellitus

Dragana Bojanin, Tatjana Milenkovic, Jelena Vekic, Rade Vukovic, Aleksandra Zeljkovic, Jelena Janac, Jasmina Ivanisevic, Sladjana Todorovic, Ilijana Mazibrada, Vesna Spasojevic-Kalimanovska

Paediatric patients with type 1 diabetes mellitus (T1DM) frequently develop other autoimmune disorders; most commonly autoimmune thyroiditis (ATD) and celiac disease (CD). In this study we evaluated whether co-existing autoimmune diseases had significant impact on lipid and lipoprotein subclasses, as known cardiovascular risk factors in T1DM. Study included 201 subjects with T1DM (14.1 ± 2.9 years) and 141 age- and gender-matched controls. ATD was presented in 30 and CD in 15 T1DM patients. Serum lipid parameters were determined by routine laboratory methods and plasma low-density (LDL) and high-density lipoprotein (HDL) subclasses by gradient-gel electrophoresis method. Both groups of T1DM patients with concomitant autoimmune disease had significantly lower HDL-C levels (P < 0.05) than the patients with T1DM only, but comparable to control group (P = 0.436). T1DM patients had significantly higher (P < 0.001) proportion of small HDL subclasses than controls. Mean value of atherosclerosis index in patients with T1DM + CD was the highest (1.75 ± 0.86) and it was significantly higher than the index in patients with T1DM only (1.33 ± 0.51; P < 0.05). LDL size did not differ between the groups of T1DM patients and control group (P = 0.619). The size of HDL particles was significantly reduced (P < 0.05) in the groups with associated autoimmune diseases. The patients with co-existing autoimmune diseases had higher risk of low HDL-C level (OR: 2.96; P < 0.05). The results have shown significant impact of co-existing autoimmune diseases on lipid profile in patients with T1DM. The most prominent changes were found in HDL lipoprotein characteristics in T1DM + CD group.