Session Information
Date: Thursday, May 18, 2017
Session Type: Abstract Submissions
Session Time: 5:30PM-7:00PM
Background/Purpose: Endothelial pulse amplitude testing (Endo-PAT) measures changes in vascular tone by post-occlusive hyperemic response. A reduced hyperemic response suggests endothelial dysfunction and serves as a surrogate marker for subclinical atherosclerosis. Children with juvenile dermatomyositis (JDM) may be at increased risk of premature atherosclerosis due to risk factors including dyslipidemia, insulin resistance, obesity, systemic inflammation, high corticosteroid burden, sedentary activity and underlying vasculopathy. The aim of this study was to determine the prevalence of endothelial dysfunction and atherogenic risk factors in JDM patients compared to healthy controls.
Methods: Twenty patients with JDM and 20 age-, gender-, race-, and BMI- matched healthy controls were recruited. Atherosclerotic risk factor assessments included anthropometrics, family history, smoking history, lipid panel, lipoprotein A, apolipoprotein A1 and B, homocysteine, hsCRP, HOMA-IR, and hemoglobin A1C. JDM assessments included muscle enzymes, vWF antigen, Childhood Myositis Assessment Scale (CMAS), Disease Activity Score (DAS) for JDM, and Myositis Damage Index (MDI). The Endo-PAT reactive hyperemia index (RHI) was calculated, dichotomized using the adult cutoff of <1.67 and log-transformed to meet statistical assumptions.
Results: A summary of clinical and laboratory data are shown in Table 1. JDM patients had a median disease duration of 44 months [IQR: 27,75] with minimal evidence of active disease and damage (median CMAS=52, range 47-52; median DAS=0, range 0-5; median MDI (extent) =0, range 0-3). Among the JDM patients, 7 were currently on prednisone (35%), 13 on hydroxychloroquine (65%), 15 on methotrexate (75%) and 9 on IVIG (45%).
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Table 1: Clinical and laboratory data in JDM patients and healthy controls (n=40)a
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Total (n=40) |
Healthy controls (n=20) |
JDM patients (n=20) |
p-value |
|
Age (years) |
12.4 ± 4.1 |
12.7 ± 3.9 |
12.1 ± 4.4 |
0.651 |
|
Female gender |
28 (70%) |
14 (70%) |
14 (70%) |
>0.999 |
|
Race White, non-Hispanic African American, non-Hispanic Hispanic |
14 (35%) 8 (20%) 18 (45%) |
5 (25%) 4 (20%) 11 (55%) |
9 (45%) 4 (20%) 7 (35%) |
0.392 |
|
BMI |
20.9 ± 5 |
20.9 ± 4.9 |
21 ± 5.1 |
0.950 |
|
BMI category Healthy Overweight/Obese |
24 (60%) 16 (40%) |
12 (60%) 8 (40%) |
12 (60%) 8 (40%) |
>0.999 |
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Positive cardiac family history |
23 (58%) |
12 (60%) |
11 (58%) |
0.894 |
|
Systolic blood pressure (mmHg) |
109.8 ± 10.8 |
106.9 ± 10.5 |
112.8 ± 10.5 |
0.081 |
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Diastolic blood pressure (mmHg) |
66 ± 7 |
63.7 ± 6.9 |
68.4 ± 6.6 |
0.035 |
|
Total cholesterol (mg/dL) |
159.1 ± 32.9 |
163.1 ± 29.1 |
154.8 ± 36.7 |
0.441 |
|
LDL (mg/dL) |
87.6 ± 25.5 |
92.8 ± 23.5 |
82.3 ± 27.0 |
0.203 |
|
HOMA-IRb |
2.1 [1.4, 3.1] |
2 [1.7, 2.8] |
2.1[1.2, 3.3] |
0.922 |
|
Hemoglobin A1c |
5.5 ± 0.3 |
5.6 ± 0.3 |
5.4 ± 0.3 |
0.084 |
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Lipoprotein A (nnmol/L)c |
46 [14,87] |
66 [24,91] |
16.5 [10, 70] |
0.055 |
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Apolipoprotein B/A1 ratio |
0.5 ± 0.1 |
0.53 ± 0.1 |
0.46 ± 0.1 |
0.082 |
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hsCRP (mg/L) |
0.2 [0.1, 0.7] |
0.3 [0.2, 0.8] |
0.2 [0.1, 0.4] |
0.178 |
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RHI |
1.57 [1.2,1.9] |
1.43 [1.2, 1.7] |
1.72 [1.3, 2.4] |
0.148 |
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Abnormal RHI < 1.67 |
25 (63%) |
15 (75%) |
10 (50%) |
0.103 |
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Log RHI |
0.45 ± 0.33 |
0.36 ± 0.24 |
0.54 ± 0.39 |
0.089 |
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a Continuous variables expressed as mean ± standard deviation or median [IQR]. Categorical variables expressed as frequency (percentages). b Homeostatic Model Assessment for Insulin Resistance (HOMA-IR): HOMA-IR = fasting insulin x fasting glucose / 22.5 (43). c Only evaluated in 31 participants (17 healthy controls and 14 JDM patients) |
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Although healthy controls show a higher proportion of endothelial dysfunction compared to JDM patients (75% versus 50%) and lower mean log RHI (0.36 ± 0.24 versus 0.54 ± 0.39 respectively), these results were not statistically significant. Healthy controls had relatively higher lipoprotein A levels (p=0.055). In a model adjusting for lipoprotein A, JDM status became a significant predictor for increased log RHI (p=0.006).
Conclusion: This is the first study to evaluate for the prevalence of premature atherosclerosis in a pediatric population with JDM. In this study, patients with JDM did not appear to be at higher risk for endothelial dysfunction compared to healthy controls. Lipoprotein A, a traditional atherogenic risk factor, may be an important confounder in these results.
To cite this abstract in AMA style:
Wahezi D, Liebling E, Parekh J, Dionizovik-Dimanovski M, Choi J, Gao Q. Assessment of Endothelial Dysfunction and Atherogenic Risk Factors in Children with Juvenile Dermatomyositis [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 4). https://acrabstracts.org/abstract/assessment-of-endothelial-dysfunction-and-atherogenic-risk-factors-in-children-with-juvenile-dermatomyositis/. Accessed .ACR Meeting Abstracts - https://acrabstracts.org/abstract/assessment-of-endothelial-dysfunction-and-atherogenic-risk-factors-in-children-with-juvenile-dermatomyositis/