Abnormalities of sphingolipid metabolism play an important role in diabetes. We compared sphingolipid levels in plasma and in isolated lipoproteins between healthy control subjects and two groups of patients, one with chronic kidney disease without diabetes (ND-CKD), and the other with type 2 diabetes and macroalbuminuria (D-MA). Ceramides, sphingomyelins, and sphingoid bases and their phosphates in LDL were higher in ND-CKD and in D-MA patients compared to controls. However, ceramides and sphingoid bases in HDL2 and HDL3 were lower in ND-CKD and in D-MA patients than in controls. Sphingomyelins in HDL2 and HDL3 were lower in D-MA patients than in controls but were normal in ND-CKD patients. Compared to controls, lactosylceramides in LDL and VLDL were higher in ND-CKD patients but not in D-MA patients. However, lactosylceramides in HDL2 and HDL3 were lower in both ND-CKD and D-MA patients than in controls. Plasma hexosylceramides in ND-CKD patients were increased and sphingoid bases decreased in both ND-CKD and D-MA patients. However, hexosylceramides in LDL, HDL2, and HDL3 were higher in ND-CKD patients than in controls. In D-MA patients, only C16:0 hexosylceramide in LDL was higher than in controls. The data suggest that sphingolipid measurement in lipoproteins, rather than in whole plasma, is crucial to decipher the role of sphingolipids in kidney disease.

Understanding the whole body (systemic) and cellular metabolism of lipoproteins, including that of the modified lipoproteins that occur in diabetes mellitus, has potential to improve the quantitative and qualitative changes in lipoproteins that contribute to the macrovascular and microvascular complications of type 1 and type 2 diabetes [1, 2] and facilitate development of therapeutics that can improve clinical outcomes. An excellent example of how understanding lipoprotein metabolism has improved clinical outcomes is that an understanding of the LDL receptor, intracellular cholesterol metabolism, and the central role of HMG-CoA reductase led to the development of HMG-CoA reductase inhibitors (statins), which substantially reduce cardiovascular events in both diabetic and nondiabetic people [3–5].

BACKGROUND:We have previously shown that very long ceramides/lactosylceramides predicted the development of macroalbuminuria (MA) in type 1 diabetes and expanded our studies into type 2 diabetes. OBJECTIVE:This study proposes comparing the levels of plasma sphingolipids and their distribution in circulating lipoproteins (VLDL/IDL, LDL, HDL2 and HDL3) between a healthy control group and two groups of subjects with type 2 diabetes, one with and other without MA. METHODS:Plasma and lipoprotein sphingolipids/glycosphingolipids were measured using HPLC-MS/MS in 114 subjects (40 controls; 74 type 2 diabetes, 40 without MA; and 34 with MA) and the levels were compared between controls and the two groups of diabetes. Group effect sizes were calculated using Cohen's d. RESULTS:Sphingomyelin species carried by LDL are significantly higher in diabetic patients with MA than in those with normal albumin excretion rate (AER). Compared to controls, significant decreases in the levels of sphingolipids carried by HDL in patients with diabetes with normal AER or MA were observed for all sphingolipid classes except for hexosylceramide, which was normal in diabetic patients without MA. Although lower than in controls, the levels of lactosylceramides carried by HDL2/HDL3 were significantly higher in diabetes with MA. CONCLUSIONS:Considering the critical role sphingolipids play in major cell biological responses and cell signaling pathways, the consequences for disease development of changes in the distribution of sphingolipids/glycosphingolipids carried by lipoproteins could be considerable. Our work is just a first step to address a considerable gap in our present knowledge in this important field.

Apolipoprotein M (apoM), primarily carried by HDL, has been associated with several conditions, including cardiovascular disease and diabetic nephropathy. This study proposes to examine whether plasma apoM levels are associated with the development of diabetic kidney disease, assessed as progression to macroalbuminuria (MA) and chronic kidney disease (CKD). Plasma apoM was measured using an enzyme immunoassay in 386 subjects from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) cohort at DCCT entry and closeout and the concentrations used to determine the association with risk of progression to kidney dysfunction from the time of measurement through 18 years of EDIC follow-up. apoM levels, at DCCT baseline, were higher in patients who developed CKD than in those who retained normal renal function. At DCCT closeout, participants who progressed to MA, CKD, or both MA and CKD also had significantly higher apoM levels than those who remained normal, and increased levels of apoM were associated with increased risk of progression to both MA (risk ratio [RR] 1.30 [95% CI 1.01, 1.66]) and CKD (RR 1.69 [95% CI 1.18, 2.44]). Our results strongly suggest that alterations in apoM and therefore in the composition and function of HDL in type 1 diabetes are present early in the disease process and are associated with the development of nephropathy.

Sphingolipids are a heterogeneous class of lipids and essential components of the plasma membrane and plasma lipoproteins. Studies have shown that plasma deoxysphingolipid (DSL), a newly identified sphingolipid class, is increased in diabetic patients and associated with diabetic neuropathy. However, it remains unknown if there is a causal relationship between plasma DSL increase and diabetic neuropathy. Since matrix metalloproteinases (MMPs) play an important role in diabetic neuropathy by degrading extracellular matrix in the peripheral nervous system, we investigated the effect of DSLs on the expression of MMPs and tissue inhibitor of metalloproteinase (TIMPs), and cytotoxicity in human Schwann cells. We quantified protein secretion, gene expression, and collagenase activity, and performed cytotoxicity assays. Results showed that DSLs upregulated MMP-1, downregulated TIMP-1, and induced cytotoxicity in Schwann cells. Furthermore, we quantified DSLs in VLDL, LDL, HDL2, and HDL3 isolated from type 2 diabetes mellitus (T2DM) patients with or without neuropathy. Interestingly, lipidomic analysis showed that only HDL2 isolated from T2DM patients with neuropathy contains significantly higher level of DSLs than that isolated from T2DM patients without neuropathy. Additionally, results showed that HDL2 isolated from T2DM patients with neuropathy was more potent than that isolated from T2DM patients without neuropathy in upregulating MMP-1, downregulating TIMP-1, and stimulating collagenase activity in Schwann cell. Taken together, this study demonstrated for the first time a potential causal relationship between DSLs and diabetic neuropathy and that DSL-containing HDL2 from T2DM patients with neuropathy was more potent than that from T2DM patients without neuropathy in stimulating collagenase activity.

Sphingolipids are bioactive lipids associated with cellular membranes and plasma lipoproteins, and their synthesis and degradation are tightly regulated. We have previously determined that low plasma concentrations of certain ceramide species predict the development of nephropathy in diabetes patients with normal albumin excretion rates at baseline. Herein, we tested the hypothesis that altering the sphingolipid content of circulating lipoproteins can alter the metabolic and signaling pathways in podocytes, whose dysfunction leads to an impairment of glomerular filtration. Cultured human podocytes were treated with lipoproteins from healthy subjects enriched in vitro with C16 ceramide, or D-erythro 2-hydroxy C16 ceramide, a ceramide naturally found in skin. The RNA-Seq data demonstrated differential expression of genes regulating sphingolipid metabolism, sphingolipid signaling, and mTOR signaling pathways. A multiplex analysis of mTOR signaling pathway intermediates showed that the majority (eight) of the pathway phosphorylated proteins measured (eleven) were significantly downregulated in response to C16 ceramide-enriched HDL2 compared to HDL2 alone and hydroxy ceramide-enriched HDL2. In contrast, C16 ceramide-enriched HDL3 upregulated the phosphorylation of four intermediates in the mTOR pathway. These findings highlight a possible role for lipoprotein-associated sphingolipids in regulating metabolic and signaling pathways in podocytes and could lead to novel therapeutic targets in glomerular kidney diseases.

Statin therapy reduces cardiovascular risk in type 2 diabetes (T2DM), partly by improving dyslipidemia, and partly through ‘pleiotropic’ effects. Sphingolipids, including ceramides, are amphiphilic components of lipoprotein surface monolayers. Sphingolipids regulate lipoprotein surface fluidity, and include key signaling molecules: ceramides are specifically associated with apoptosis and risk for premature coronary heart disease. Effects of statins on the sphingolipid content of lipoproteins are poorly defined. Using liquid chromatography/electrospray ionization-tandem mass spectrometry, we determined fasting plasma concentrations of individual ceramides (Cer), sphingomyelins (SM), and glycosphingolipids (hexosyl- and lactosyl-Cer) in plasma from 19 men and 21 women with T2DM, before and after treatment with rosuvastatin (10 mg/day, 6 weeks). Exclusion criteria were use of ‘statins’ in the preceding 6 months, and any current use of lipid-modifying agents. Using existing lipoprotein compositional data, we calculated effects of rosuvastatin therapy on non-HDL sphingolipid content. Results: Rosuvastatin reduced total cholesterol (C) (by 33%), triglycerides (20%), LDL-C (49%), and non-HDL particle number (34%); HDL-C was unaffected. It decreased total SM (15%), Cer (29%), and hexosyl- (30%) and lactosyl- (34%) Cer, independent of gender. Assuming HDL composition was unaffected, rosuvastatin reduced non-HDL SM by 42% and Cer by 61%: these reductions remained significant after correction for non-HDL-C and/or non-HDL lipoprotein surface area. Conclusions: In T2DM, rosuvastatin lowers not only the number of non-HDL particles, but also the sphingolipid, and especially the Cer, content of each particle. This effect is independent of gender, potentially anti-atherogenic, and may represent a new pleiotropic effect of statins. Further studies are needed to confirm these findings in isolated lipoprotein classes, and to determine mechanism(s). Disclosure C.B. Kelly: None. S.M. Hammad: None. R.L. Klein: None. M.F. Lopes-Virella: None. A. Gosmanova: None. M.J. Leyva: None. C.E. Aston: None. T. Lyons: None.

Background: To determine if serum pigment epithelium-derived factor (PEDF) levels predict cardiovascular events, renal dysfunction and mortality in the Veterans Affairs Diabetes Study (VADT). Methods: PEDF was evaluated in relation to subsequent cardiovascular outcomes, mortality, and renal dysfunction (defined as urinary albumin creatinine ratio (ACR) >= 300 mg/g), or chronic kidney disease (CKD) stages 3 (eGFR<60 ml/min) or 4 (eGFR<60 and <30 ml/min respectively). PEDF was measured by ELISA on sera from 881 participants collected a median (range) of 1.7 (0-5.0) years post-baseline, and later, from 832 participants 4.0 (1.5-6.9) years post-baseline. Results: In 743 participants, PEDF was measured at both time-points. PEDF increased over time from (mean +/- SD) 10.5 +/- 4.03 to 11.0 +/- 4.86 ng/ml (paired t-test p = 0.0092). Lower eGFR (p < 0.01), higher serum creatinine (p < 0.01) and urinary ACR (p < 0.01) were associated with increasing PEDF. Multivariate event time models included either one or two follow-up windows (i.e., between first and second PEDF measures; and, when available, from second PEDF measure until study-end). PEDF tertiles were not associated with cardiovascular events, but were significantly associated with all-cause mortality [HR = 2.00 (1.03, 3.89) comparing first to third tertile] in models adjusted for age, minority status, VADT treatment arm and prior cardiovascular event status. Higher PEDF levels also associated with development of kidney dysfunction with adjusted HRs (95% CI comparing third to first PEDF tertiles: 2.74 (1.71, 439) for stage 3 CKD; and 3.84 (95% CI: 1.17, 12.5) for stage 4 CKD. Conclusions: Over 2-years, higher serum PEDF levels predicted advanced nephropathy in patients with type 2 diabetes. (C) 2019 Published by Elsevier Inc.

The risk for preeclampsia (PE) is increased 4-fold in women with type 1 diabetes (T1D), in whom we previously demonstrated that elevated cholesterol-rich lipoproteins confer risk at the 1st trimester. Sphingolipids, including ceramides (Cer) and glycosphingolipids (hexosyl- (HexCer) and lactosyl-ceramides (LacCer)), are lipoprotein constituents that regulate cell signaling. We propose that these bio-active lipids could be modulators of PE risk. In a prospective T1D pregnancy cohort (studied at 12, 22, 32 weeks’ gestation), we used liquid chromatography/electrospray ionization-tandem mass spectrometry to determine plasma levels of 12 species of Cer, HexCer, and LacCer in 23 women with T1DM who did vs. 24 who did not develop PE, and in 19 normotensive nondiabetic pregnant women. All were free of microalbuminuria and hypertension at enrolment; all visits preceded clinical PE onset. Results: Plasma levels of C22-Cer (1st and 3rd study visits); C26:1-Cer (1st and 2nd visits); C26-Cer (1st visit); C18-Cer and C18:1-Cer (2nd visit) were significantly higher in women with T1DM who did vs. did not develop PE. C22-Cer and C26-Cer were significantly lower in T1DM vs. non-T1DM (1st visit). There were no overall PE- or diabetes-related differences in any HexCer- or LacCer species. Longitudinally, most Cer and HexCer species increased throughout pregnancy in all groups (except C14- and C18-Cer; and C14 and C26-HexCer). C16-LacCer increased, while C22:1-, C26-, and C26:1-LacCer decreased as pregnancy advanced, independent of PE status. Independent of LDL-C, total Cer increased throughout pregnancy in all groups. Conclusions: Maternal Cer species may serve as early biomarkers for PE in women with T1DM. T1DM was associated with lower levels of two Cer species. Like cholesterol-rich lipoproteins, Cer, HexCer and some LacCer species increase as pregnancy advances in all groups, but other LacCer species decrease: the significance of these findings requires further study. Disclosure C.B. Kelly: None. S.M. Hammad: None. R.L. Klein: None. M.F. Lopes-Virella: None. M.J. Leyva: None. J. Yu: None. A.J. Jenkins: Advisory Panel; Self; Abbott, Australian Diabetes Society, Medtronic. Research Support; Self; Abbott, GlySens Incorporated, Medtronic, Mylan. Speaker's Bureau; Self; Eli Lilly and Company, Novo Nordisk Inc. A.J. Nankervis: None. K.F. Hanssen: None. S.K. Garg: Advisory Panel; Self; Eli Lilly and Company, Roche Pharma, Sanofi-Aventis, Zealand Pharma A/S. Research Support; Self; Eli Lilly and Company, WebMD. J.A. Scardo: None. C.E. Aston: None. T. Lyons: None. Funding JDRF; Novo Nordisk; National Institutes of Health

Preeclampsia (PE) occurs four times more frequently in pregnant women with type 1 diabetes (T1D) than in nondiabetic women. We hypothesized that elevated plasma advanced glycoxidation products (AGEs) predict PE in T1D women. In a prospective T1D pregnancy cohort (study visits at 12, 22, 32 weeks' gestation), we used liquid chromatography/mass spectrometry, with internal stable heavy isotope substituted standards, to determine plasma levels of nine AGE and oxidation products (carboxymethyl-lysine [CML], carboxyethyl-lysine [CEL], methylglyoxal-hydroimidazolone [MGHI], 3-deoxyglucosone hydroimidazolones [3DGH], methionine sulfoxide [MetSO], glyoxal hydroimidazolone [GHI], 3-nitrotyrosine [3NT], dityrosine [DT], 2-aminoadipic acid [2AAA]) in 23 women with T1DM who developed PE vs. 24 who did not, and in 19 nondiabetic normotensive pregnant women. These products have been associated with CVD and renal failure in non-pregnant cohorts. All women were free of microalbuminuria and hypertension at enrolment, and all visits preceded clinical PE onset. GFR was estimated (Chronic Kidney Disease Epidemiology Collaboration equation). Results: Plasma CML, CEL, MGHI, 3DGH, MetSO, GHI, and 2AAA did not differ between the three groups at any study visit, and thus did not predict preeclampsia in T1D. In T1D women who later developed PE, eGFR was inversely associated at V3 with CML (p=0.008), CEL (p=0.03), MGH1 (p=0.03), 3DGH (p=0.03), GHI (p<0.001), and 2AAA (p<0.05); and at V2 with CEL (p=0.04), MGHI (p=0.02), and GHI (p=0.02). No such associations were observed in normotensive T1D or in nondiabetic pregnant women. Plasma levels of 3NT and DT were undetectable in all participants. Conclusions: Plasma AGEs did not predict PE in well-controlled, previously healthy T1D women, and levels did not differ from healthy nondiabetic controls. Uniquely, in T1D women who developed PE, plasma AGEs were associated with renal function, consistent with the notion that subclinical alterations in renal function precede PE. Disclosure H. Karanchi: None. C.B. Kelly: None. S.M. Hammad: None. R.L. Klein: None. M.F. Lopes-Virella: None. M.J. Leyva: None. J. Yu: None. A.J. Jenkins: Advisory Panel; Self; Abbott, Australian Diabetes Society, Medtronic. Research Support; Self; Abbott, GlySens Incorporated, Medtronic, Mylan. Speaker’s Bureau; Self; Eli Lilly and Company, Novo Nordisk Inc. A.J. Nankervis: None. K.F. Hanssen: None. C.E. Aston: None. S. Howell: Employee; Self; PreventAGE Health Care, LLC. P.J. Beisswenger: Other Relationship; Self; PreventAGE Health Care, LLC. T. Lyons: None.

Preeclampsia (PE), a major cause of maternal and fetal morbidity and mortality worldwide, has significantly higher incidence in women with type 1 diabetes mellitus (T1DM) than in nondiabetic populations (∼20% vs. 5%, respectively). Sphingolipids are key signaling molecules, and have many roles in the structure and regulation of cellular functions. Sphingomyelin (SM) is the most abundant sphingolipid in plasma lipoproteins. There is evidence that altered SM metabolism may contribute to cardiovascular and renal complications in diabetes. We aimed to determine whether plasma concentrations of 12 SM species were associated with PE in T1DM in a prospective study of pregnancy of 23 T1DM women who developed PE and 24 T1DM who remained normotensive. Additionally, 19 normotensive nondiabetic pregnant women were included for reference. All subjects were free of microalbuminuria and hypertension at enrolment, and all visits (12, 22, 32 weeks’ gestation) preceded clinical PE onset. Results: There were no cross-sectional differences in total SM, or in any individual SM species, between diabetic women with and without PE, or between normotensive women with and without diabetes at any stage of gestation. With advancing gestation in all groups, C18-SM, C18:1-SM, C20-SM, C20:1-SM, C22-SM, C22:1-SM, C24-SM, and C24:1-SM increased (all p<0.001). LDL- and VLDL-cholesterol also increased, while HDL-cholesterol did not change. In contrast, C14-SM, C16-SM, C26-SM and C26:1-SM decreased (all p<0.001). There were no correlations between any SM species and conventional lipid profiles. Conclusions: With advancing gestation, plasma concentrations of most SM species increased, as did LDL and VLDL; however, two long-chain and two very long-chain SM species decreased. Although there were no differences in SM according to diabetes or PE status at any time point, further studies should address the significance of differential changes of SM species during pregnancy. Disclosure C.B. Kelly: None. S.M. Hammad: None. R.L. Klein: None. M.F. Lopes-Virella: None. M.J. Leyva: None. J. Yu: None. A.J. Jenkins: Advisory Panel; Self; Abbott, Australian Diabetes Society, Medtronic. Research Support; Self; Abbott, GlySens Incorporated, Medtronic, Mylan. Speaker's Bureau; Self; Eli Lilly and Company, Novo Nordisk Inc. A.J. Nankervis: None. K.F. Hanssen: None. S.K. Garg: Advisory Panel; Self; Eli Lilly and Company, Roche Pharma, Sanofi-Aventis, Zealand Pharma A/S. Research Support; Self; Eli Lilly and Company, WebMD. J.A. Scardo: None. C.E. Aston: None. T. Lyons: None. Funding JDRF; Novo Nordisk; National Institutes of Health

APOB, APOC3, and APOE and apolipoprotein-defined lipoprotein subclasses (ADLSs; based on qualitative apolipoprotein complement) have been associated with dyslipidemia and CVD. Our main objective was to define associations of serum apolipoproteins and ADLSs with “any CVD” and “major atherosclerotic cardiovascular events” (MACEs) in a prospective study of T1D. Serum apolipoproteins and ADLSs (14 biomarkers in total) were measured in sera (obtained between 1997 and 2000) from a subset (n = 465) of the Epidemiology of Diabetes Interventions and Complications cohort. Prospective associations of “any CVD” (myocardial infarction, stroke, confirmed angina, silent myocardial infarction, revascularization, or congestive heart failure) and MACEs (fatal or nonfatal myocardial infarction or stroke), over 5,943 and 6,180 patient-years follow-up, respectively, were investigated using Cox proportional hazards models that were unadjusted and adjusted for risk factors. During 15 years of follow-up, 50 “any CVD” events and 24 MACEs occurred. Nominally significant positive univariate associations with “any CVD” were APOB, APOC3 and its subfractions [heparin precipitate, heparin-soluble (HS)], and ADLS-defined Lp-B. In adjusted analyses, APOC3-HS remained nominally significant. Nominally significant positive univariate associations with MACEs were APOC3 and its subfractions and Lp-B:C; those with total APOC3 and APOC3-HS persisted in adjusted analyses. However, these associations did not reach significance after adjusting for multiple testing. There were no significant associations of APOA1, APOA2, APOE, or other ADLSs with either “any CVD” or MACEs. These hypothesis-generating data suggest that total serum APOC3 and APOC3 in HDL are potentially important predictive biomarkers for any CVD and MACEs in adults with T1D.

BACKGROUND: Glycosphingolipids are important components of cell membranes, modulators of cell-cell interactions and cell recognition, and have recently emerged as bioactive molecules and important players in nearly all cell biological processes. We previously have shown that decreased plasma levels of long and very long species of ceramides were able to predict the development of macroalbuminuria (MA) in type 1 diabetes. OBJECTIVE: This study proposed to examine whether plasma glycosphingolipids could predict development of diabetic nephropathy, assessed as MA or chronic kidney disease (CKD). METHODS: Measurement of plasma hexosylceramides (H) and lactosylceramides (L) were conducted in the Lipidomics Core Facility of our Institution in a subcohort of 432 patients from the DCCT/Epidemiology of Diabetes Interventions and Complications cohort in plasma collected at entry into the study. Inverse probability weighted Cox proportional hazards regression models were used to assess the effect of glycosphingolipids levels on the risk of developing MA (albumin excretion rate >= 300 mg/24 hours) or CKD (glomerular filtration rate <60 mL/min) over a period of 21 to 28 years. RESULTS: Decreases of several long and very long chain lactosylceramides were significantly associated with increased risk of progression to MA but not CKD. Among the hexosylceramides, the only significant association observed was between one of its minor species C18:1-H and CKD. CONCLUSION: Our findings showed that decreased levels of long and very long lactosylceramides were able to predict the development of MA in type I diabetes. This finding is similar to previous findings showing that low levels of long and very long ceramides were also able to predict development of MA in the same cohort. Further studies are needed to determine the changes in sphingolipid metabolism leading to the development of complications. (C) 2019 Published by Elsevier Inc. on behalf of National Lipid Association.

Background: Serum uric acid (UA) is associated with the pathogenesis of diabetes complications, including cardiovascular disease (CVD) and kidney injury. Current epidemiological evidence is limited regarding the association between UA and the development of CVD in type 1 diabetes mellitus (T1DM). Objective: To examine associations of serum UA with CVD and major atherosclerotic cardiovascular events (MACE) in T1DM. Methods: UA was measured in sera (1997-2000) from a subset of participants (n=973; males=540, females=433) in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. Subsequent CVD events were adjudicated by a review committee masked to DCCT assignment and HbA1c levels, and defined as the time to the first of any of the following: non-fatal myocardial infarction (MI) or stroke, CVD death, silent MI on annual ECG, angina confirmed by ischemic changes with exercise tolerance testing, congestive heart failure, or revascularization; MACE were defined as a composite of CVD death, nonfatal MI, or stroke. Cox proportional hazards models were used to evaluate prospectively the effect of UA as a fixed covariate on CVD and MACE, separately by gender, and adjusted for age and HbA1c. Results: Over 15 years follow-up, there were 201 adjudicated CVD events among 110 participants (HR=1.10 per 1 mg/dl change in UA, 95% CI 0.93-1.30); 61 males experienced 96 events (HR=1.15, 95% CI 0.90-1.46) and 49 females, 105 events (HR=1.17, 95% CI 0.88-1.56). There were 62 adjudicated MACE among 53 participants (HR=1.18, 95% CI 0.93-1.49); 29 males experienced 31 events (HR=1.10, 95% CI 0.77-1.58) and 24 females, 31 events (HR=1.47, 95% CI 1.01-2.14). No significant associations between quartiles of UA and either CVD or MACE were observed in either sex. Conclusions: Our results show UA may not serve as a predictive biomarker for CVD events in T1DM adults. Sex-specific associations with MACE deserve further investigation. Disclosure A. Basu: None. B. Braffett: None. A. Jenkins: Research Support; Self; Medtronic, Mylan, Sanofi-Aventis. I. Bebu: None. R.L. Klein: None. M.F. Lopes-Virella: None. S. Dagogo-Jack: None. T.J. Orchard: None. A. Wallia: Research Support; Self; UnitedHealth Group. Consultant; Self; Glytec Systems, Lexicon Pharmaceuticals, Inc.. Research Support; Self; Eli Lilly and Company. J. Lachin: Board Member; Self; AbbVie Inc., Celgene Corporation. W. Garvey: Advisory Panel; Self; Novo Nordisk Inc., Merck & Co., Inc.. Research Support; Self; Sanofi, Pfizer Inc., Novo Nordisk Inc., AstraZeneca, Merck & Co., Inc., Elcelyx Therapeutics, Inc., Lexicon Pharmaceuticals, Inc., Eisai Inc.. T. Lyons: None.

Background: Apolipoproteins Apo-B, Apo-C-III, and Apo-E are atherogenic and are associated with diabetic dyslipidemia and cardiovascular disease (CVD). Apolipoprotein-defined lipoprotein subclasses (ADLS) also show associations with CVD, but prospective associations of these detailed metrics with CVD in people with type 1 diabetes (T1DM) have not been explored. Objective: Prospective associations of serum apolipoproteins and ADLS with CVD and major atherosclerotic cardiovascular events (MACE: composite of CVD death, nonfatal myocardial infraction or nonfatal stroke) in T1DM. Methods: Serum apolipoproteins and ADLS (14 biomarkers in total) measured in sera (1997-2000) in a subset (n=465) of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications cohort. Prospective associations of CVD and MACE over 5942 and 6180 patient-years follow-up, respectively, were investigated using Cox proportional hazards models unadjusted and adjusted for risk factors. Results: During 15 years follow-up, 50 CVD and 24 MACE events occurred. Significant positive univariate associations for CVD were: Lp-B, Apo-B, Apo-C-III (total, heparin precipitate (HP), i.e., Apo-C-III in VLDL, and heparin soluble (HS), i.e., Apo-C-III in HDL) and Lp-B:C; for MACE: Apo-C-III sub fractions (total, Apo-C-III-HP, and Apo-C-III-HS). Adjusting for sex, age, HbA1c, systolic blood pressure, pulse rate, LDL-cholesterol, and triglycerides: for CVD, Apo-C-III-HS remained significant (HR (95% CI): 1.18 (1.03, 1.35); P=0.01). For MACE, total Apo-C-III and Apo-C-III-HS persisted when adjusted for age, HbA1c and LDL [1.11 (1.01, 1.22); P=0.02, and 1.22 (1.02, 1.45); P=0.02, respectively], but not for age, HbA1c and (log) triglycerides. No significant associations of other ADLS, Apo-A-I, A-II and Apo-E with CVD/MACE were observed. Conclusions: Total serum Apo-C-III and Apo-C-III in HDL and Apo-B-containing lipoproteins may serve as predictive biomarkers for CVD events in T1DM adults. Disclosure A. Basu: None. I. Bebu: None. A. Jenkins: Research Support; Self; Medtronic, Mylan, Sanofi-Aventis. J. Stoner: None. Y. Zhang: None. R.L. Klein: None. M.F. Lopes-Virella: None. W. Garvey: Advisory Panel; Self; Novo Nordisk Inc., Merck & Co., Inc.. Research Support; Self; Sanofi, Pfizer Inc., Novo Nordisk Inc., AstraZeneca, Merck & Co., Inc., Elcelyx Therapeutics, Inc., Lexicon Pharmaceuticals, Inc., Eisai Inc. M. Budoff: Speaker's Bureau; Self; Janssen Pharmaceuticals, Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Amarin Corporation. T. Lyons: None.

Circulating apolipoprotein-defined lipoprotein subclasses (ADLS) and apolipoproteins predict vascular events in the general and type 2 diabetes populations, but data in T1D are limited. We examined associations of ADLS, serum apolipoproteins, and conventional lipids with carotid intima-media thickness (IMT) measured contemporaneously and 6 years later in 417 T1D participants [men: n = 269, age 42 ± 6 y (mean ± SD); women: n = 148, age 39 ± 8 y] in the Epidemiology of Diabetes Interventions and Complications study, the follow-up of the Diabetes Control and Complications Trial (DCCT). Date were analyzed by multiple linear regression stratified by sex, and adjusted for time-averaged hemoglobin A1C, diabetes duration, hypertension, BMI, albuminuria, DCCT randomization, smoking, statin treatment, and ultrasound devices. In cross-sectional analyses, lipoprotein B (Lp-B), Lp-B:C, Lp-B:E+Lp-B:C:E, Apo-A-II, Apo-B, Apo-C-III-HP (heparin precipitate; i.e., Apo-C-III in Apo-B-containing lipoproteins), and Apo-E were positively associated with common and/or internal carotid IMT in men, but only Apo-C-III (total) was (positively) associated with internal carotid IMT in women. In prospective analyses, Lp-B, Apo-B, and Apo-C-III-HP were positively associated with common and/or internal carotid IMT in men, while Lp-A1:AII and Apo-A1 were inversely associated with internal carotid IMT in women. The only significant prospective association between conventional lipids and IMT was between triacylglycerols and internal carotid IMT in men. ADLS and apolipoprotein concentrations may provide sex-specific biomarkers and suggest mechanisms for IMT in people with T1D.