408-P: Associations between Apolipoprotein B (apoB): Apolipoprotein A1 (apoA1) Ratio and Metabolic and Kidney Disease in Youth with Type 1 Diabetes

ApoA1 is a major protein component of high-density lipoprotein (HDL) and apoB the main protein component of low-density lipoprotein (LDL). The ratio between apoB and apoA1 (ApoB:ApoA1) is often used to measure cardiovascular disease (CVD) risk in adults, yet little is known about its relationship with insulin resistance, central adiposity and early kidney disease, important CVD risk factors, in youth with T1D. In a study of 50 youth with type 1 diabetes, glomerular filtration rate (GFR) and renal plasma flow (RPF) were assessed using iohexol and p-aminohippurate clearance, and urine albumin-to-creatinine ratio (UACR) was also measured. Central adiposity was assessed using DXA and insulin sensitivity was estimated (eIS). Intraglomerular pressure was estimated using the Gomez equations. The study participants were 16±3.0 years old, 50% were female, and their average HbA1c was 8.7±1.3%. They had an average T1D duration of 5.7±2.6 years, with UACR levels of 6[5-14] mg/g and GFR of 189±40 ml/min. Concentrations of apoA1 and apoB were quantified by targeted nuclear magnetic resonance spectroscopy. ApoA1 (185±35 vs. 150±36 mg/dl, p=0.001) and apoB (108±29 vs. 90±27 mg/dl, p=0.03) were higher in girls vs. boys, but the apoB:apoA1 ratio was similar between the sexes (p=0.59). ApoB correlated with PGLO (r: 0.42, p=0.01), log UACR (r: 0.33, p=0.02), and trunk mass (r: 0.34, p=0.02), whereas ApoB:ApoA1 correlated with GFR (r: 0.44, p=0.002), PGLO (r: 0.48, p=0.01), log UACR (r: 0.38, p=0.008), trunk mass (r: 0.45, p=0.001), BMI (r: 0.40, p=0.004) and inversely with eIS (-0.44, p=0.001). The ratio of apoB to apoA1 associated with markers of metabolic and kidney disease in youth with T1D. Further research is needed to fully understand the mechanisms behind these associations and to identify potential strategies for preventing or mitigating cardiovascular disease in young persons with T1D.