Background/Purpose: Our center previously reported increased carotid intima media thickness, and lower high-density lipoprotein (HDL) levels in young or middle-age adults with a history of JDM, who were not taking medication for JDM symptoms compared to normal controls.  Whether even younger adults with JDM have evidence of subclinical cardiovascular disease (CVD) is not known.

Objective: To determine whether an inception cohort of young adults with JDM have lower brachial artery reactivity (BAR) or HDL antioxidant function compared to normal controls.

Methods: After obtaining informed consent, we enrolled an inception cohort of 20 white adults, 14 F, mean age at study 21.8± 4.2 years, and mean age at JDM onset 7.6 ± 3.7 years, mean duration of untreated disease (DUD) at diagnosis 5.4 ± 4.8 months, and mean total duration of disease 14.2 ±3.9 years. JDM adults had a mean Total disease activity score (DAS) 1.9 ± 2.5, but were not taking medications for JDM symptoms.  They were matched by age, race, sex and BMI with 20 healthy volunteers (mean age 23.8 ± 4.2 years).  Both groups were tested for: BAR, nailfold capillary end row loop number (ERL), height and weight.  To determine the antioxidant function of HDL, we measured change in fluorescence intensity caused by oxidation of dichlorfluorescein-diacetate by oxidized low density lipoprotein ±HDL. Fluorescence in the absence of HDL was normalized to 1.0.  Values greater than 1.0 after the addition of HDL indicated pro-inflammatory HDL (mean HDL function in healthy controls ranges from 0.44 to 0.66).

BAR reflects endothelial function. Normal endothelial cells release nitric oxide in response to sheer stress, causing vasodilation. For BAR measurement individuals presented fasting, and lay supine in a temperature-controlled room for 10 minutes before imaging.  Brachial artery diameter was measured with an 8L5 linear array transducer, 1 cm distal to the antecubital fossa. To create sheer stress, a BP cuff was inflated 50 mm Hg above the baseline BP for 4.5 min. Brachial artery diameter was then re-measured 60 seconds after cuff deflation.  BAR was defined as [(post-deflation – baseline diameter)/baseline diameter] x100%.

Results: The ERL numbers were significantly different in the JDM group, 6.35 ± 1.29 vs the controls, 7.4±0.58, p=0.003. The TNF-α -308A allele was increased in the JDM group 40% vs 15% in controls (p=0.15 ).  Of note, the group with JDM were shorter in stature than their controls, for both JDM women, 159.7 ±8.8 cm vs 165.6 ±5.4 cm, p=0.048, and for JDM men, 172.7±3.6cm compared to controls, 181.5 ±4.6cm, p=0.0046.  BAR in adults with JDM was 3.35±3.06%, and 5.22±3.07%- in normal controls (p=0.068). After adjusting for height and sex, BAR in adults with JDM was significantly decreased by 2.78 unit when compared with controls (p=0.018). There was no significant association of BAR values with the following:  ERL, DUD, or DAS.  The oxidized lipids did not differ between the JDM and controls.

Conclusion: The decrease in height in JDM may be a consequence of previous corticosteroid administration. The data show a marginal association of BAR in JDM, p=0.068 and a significant association with decreased BAR, p=0.018 after adjustment for height. Larger studies in young adults with JDM are needed to validate our finding.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-pilot-study-of-young-adults-with-juvenile-dermatomyositis-with-decreased-nailfold-capillary-end-row-loops-brachial-artery-reactivity-and-oxidized-lipids/