Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Insulin Resistance and Its Association with Phospholipid Profile, Carotid Intimal- Medial Thickness and Carotid Plaque Area in Women with Systemic Lupus Erythematosus.

Aghdassi1,  Ellie, Ma2,  David WL., Eder3,  Lihi, Balitsky4,  Amaris K., Morrison5,  Stacey, Frattasi5,  Michael, Su5,  Jiandong

University Health Network, Toronto, ON
University of Guelph, Guelph, ON
Toronto Western Hospital, University of Toronto, Toronto, ON
The University of Toronto, Toronto, ON
The Toronto Western Hospital, Toronto, ON
The Arthritis Program, Toronto Western Hospital and Division of Rheumatology, Toronto Western Hospital and University of Toronto, Toronto, ON
Toronto Western Hospital, Toronto, ON

Background/Purpose:

Insulin resistance (IR) is associated with the metabolic syndrome and has been linked to inflammation and an increased risk for cardiovascular disease (CVD). The ratio of Phosphatidylcholine (PC) to Phosphatidyl-ethanolamine (PE) and the composition of PC and PE are important determinants of the cell membrane integrity and PC/ PE ratio may be a novel inflammatory marker. The purpose of this study was to estimate the prevalence of insulin resistance (IR) in women with Systemic Lupus Erythematosus (SLE) and to determine whether there are associations between IR and: PC/PE ratio, carotid intimal-medial thickness (cIMT) and carotid plaque area (cPA).

Methods:

Consecutive SLE women, meeting the ACR criteria for classification of SLE were enrolled into this study. Data on demographic variables, cardiovascular risk profile, SLE disease activity index-2000 (SLEDAI-2K) and SLICC (Systemic Lupus International Collaboration Clinic)-damage index (SDI) were collected. Blood was collected after 12-hr fast and analyzed for glucose and insulin. Insulin resistance was calculated using the homeostatic model assessment formula (HOMA: {glucose (mmol/l) × insulin (mU/l}/22.5). HOMA >3 was considered IR. Phospholipid profile was determined in red blood cells (RBC) using thin layer and gas chromatography. cIMT and cPA were determined using B-mode ultrasonography only in a subset of patients (n=36). cIMT, cPA, SDI, SLEDAI-2K, demographic variables and CVD risk profiles were compared between patients with and without IR using student's t-test. Pearson correlation was used to determine associations.

Results:

Among 78 subjects, 53 (67%) had IR (HOMA>3). Compared to those with HOMA<3, subjects with IR had higher: BMI [24.3 (6.5) vs. 27.2 (7.3) kg/m2, p=0.09], systolic blood pressure [113.7 (8.5) vs. 123.0 (19.8) mmHg, p=0.02], waist circumference [76.2 (11.6) vs. 86.2 (15.0) cm, p=0.003], cPA [0.06 ( 0.06) vs. 0.19 (0.25) cm2 p= 0.02] and were older [40.7 (13.9) vs. 50.6 (12.3) year, p=0.004]. PC to PE ratio was significantly lower in those with IR compared to those without IR [1.37 (0.21) vs. 1.27 (0.17), p=0.024). SLEDAI, SDI and cIMT were similar between the two groups. However, there was a significant negative correlation between RBC PC content and: cIMT (r=- 0.35, p=0.03) and cPA (r=-0.32, p=0.46).

Conclusion:

IR is prevalent in SLE patients and is accompanied by alterations in RBC phospholipid profile. Alteration in RBC phospholipids profile was associated with a higher cIMT and cPA. The data suggest that IR and alterations in phospholipids profile play a role in the pathophysiology of atherosclerosis in patients with SLE and warrants further investigations.

To cite this abstract, please use the following information:
Aghdassi, Ellie, Ma, David WL., Eder, Lihi, Balitsky, Amaris K., Morrison, Stacey, Frattasi, Michael, et al; Insulin Resistance and Its Association with Phospholipid Profile, Carotid Intimal- Medial Thickness and Carotid Plaque Area in Women with Systemic Lupus Erythematosus. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :2275
DOI:

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