Endothelial dysfunction is present only in the microvasculature and microcirculation of early diffuse systemic sclerosis patients.
OBJECTIVE
To evaluate endothelial function and vascular stiffness in large, medium, small and microcirculatory blood vessels in very early diffuse systemic sclerosis (SSc).


METHODS
We studied consecutive early diffuse SSc patients, defined as <2 years from first SSc symptom who did not have a prior cardiovascular event. Age, gender and race-matched controls were recruited. All underwent assessment of aortic pulse wave velocity (PWV), carotid intima-media thickness (IMT) brachial flow-mediated dilation (FMD), digital peripheral artery tonometer (EndoPAT) assessment and laser speckle contrast imaging (LSCI).


RESULTS
Fifteen early diffuse SSc and controls were evaluated. The average age was 49 years, 63% were female and 93% were Caucasian. There were no differences in body mass index, hypertension, diabetes or hyperlipidaemia between controls and SSc patients. Mean SSc disease duration was 1.3 years. In the large central vessels, there was no difference in aortic PWV (p=0.71) or carotid IMT (p=0.92) between SSc patients and controls. Similarly, there was no difference in endothelial dysfunction with brachial artery FMD after ischaemia (p=0.55) and nitroglycerin administration (p=0.74). There were significantly lower values for digital EndoPAT measures (p=0.0001) in SSc patients. LSCI revealed a distinct pattern of microcirculatory abnormalities in response to ischaemia in SSc patients compared to controls. Imaging demonstrated a blunted microcirculatory hyperaemia of the hand with greater subsequent response to nitroglycerin.


CONCLUSIONS
These findings suggest that the earliest endothelial changes occur in smaller arterioles and microvascular beds, but not in medium or macrovascular beds, in early diffuse SSc.
Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. rtd4@pitt.edu.
R T
RT
Domsic
C
C
Dezfulian
Al
A
Shoushtari
D
D
Ivanco
E
E
Kenny
C K
CK
Kwoh
T A
TA
Medsger
H C
HC
Champion
D000328:Adult; D001011:Aorta / Q000503:physiopathology*; D001916:Brachial Artery / Q000503:physiopathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D059168:Carotid Intima-Media Thickness; D015331:Cohort Studies; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005385:Fingers / Q000098:blood supply; D006801:Humans; D008297:Male; D008365:Manometry; D008833:Microcirculation / Q000502:physiology; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D063177:Pulse Wave Analysis; D045743:Scleroderma, Diffuse / Q000150:complications / Q000503:physiopathology*; D014652:Vascular Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D059289:Vascular Stiffness; D014664:Vasodilation / Q000502:physiology*