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I m p a i red Skin Microvascular Function in C h i l d ren, Adolescents, and Young Adults With Type 1 Diabetes O R I G I N A L A R T I C L EO B J E C T I V E -Vascular disease in type 1 diabetes is a complex and multifactorial pro c e s s , which probably begins in childhood in association with the onset of diabetes. To determine the possible factors involved, we measured microvascular responses to endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitro p russide) vasodilators in 56 patients with type 1 diabetes (aged 9-22 years) and 22 control subjects.RESEARCH DESIGN AND METHODS -Skin perfusion was measured at the dorsum of the foot using laser Doppler flowmetry during low-current iontophoresis of acetylcholine and sodium nitro p russide. Maximum vasodilator function was measured during local 44°C skin heating. R E S U LT S -Vascular responses were significantly reduced in patients with type 1 diabetes c o m p a red with responses in control subjects: acetylcholine (P 0.01, analysis of variance [ A N O VA]), sodium nitro p russide (P 0.01, ANOVA), and local heating (P 0.02. MannWhitney U test). Endothelium-dependent responses were related to duration of diabetes (r = 0.38, P 0.01) and to glycemic control (r = 0.37, P 0.01). Significant correlations were found in the patient group between responses to acetylcholine and sodium nitro p russide (r = 0.28, P 0.05) but not to heating, suggesting that a common factor (e.g., nitric oxide activity) may be responsible for the abnormal vascular responses to these chemicals.C O N C L U S I O N S -Early changes in microvascular function are present in young patients with type 1 diabetes, long before the initial clinical presentation. These abnormalities may be related to complex interactions between structural abnormalities and functional changes in the endothelium, smooth muscle, and nitric oxide activity. Diabetes P a t h o p h y s i o l o g y / C o m p l i c a t i o n s 216DIABETES CARE, VOLUME 23, NUMBER 2, FEBRUARY 2000Vascular impairment in young type 1 diabetic patients young adult categories were classified as adolescents. Accord i n g l y, in the gro u p with type 1 diabetes, there were 13 prep u b e rtal children, 19 adolescents, and 24 young adults.Glycemic control was assessed by measuring HbA 1 c using ion-liquid chro m a t o gr a p h y. Five of the young adults with diabetes and none of the control gro u p w e re current smokers. None of the patients had any clinical evidence of diabetic re t i n o p a t h y, and all but one had urinary albumin excretion values within the normal re f e rence range.Endothelium-dependent and -independent microvascular responses Studies were conducted in a temperaturec o n t rolled room (25-26°C) in the morn i n g , 2 h after a light breakfast. Patients took their usual morning insulin. Subjects were lying in the supine position with their feet at h e a rt level. After a 25-min equilibration, skin perfusion (termed skin ery t h rocyte flux [SkEF]) was measured continuously at the dorsum of the right foot...

BackgroundE-cigarette (EC) use is increasing exponentially worldwide. The early cardiovascular effects of switching from tobacco cigarettes (TC) to EC in chronic smokers is unknown. Meta-analysis of flow-mediated dilation (FMD) studies indicate 13% lower pooled, adjusted relative risks of cardiovascular events with every 1% improvement in FMD.ObjectivesThis study sought to determine the early vascular impact of switching from TC to EC in chronic smokers.MethodsThe authors conducted a prospective, randomized control trial with a parallel nonrandomized preference cohort and blinded endpoint of smokers ≥18 years of age who had smoked ≥15 cigarettes/day for ≥2 years and were free from established cardiovascular disease. Participants were randomized to EC with nicotine or EC without nicotine for 1 month. Those unwilling to quit continued with TC in a parallel preference arm. A propensity score analysis was done to adjust for differences between the randomized and preference arms. Vascular function was assessed by FMD and pulse wave velocity. Compliance with EC was measured by carbon monoxide levels.ResultsWithin 1 month of switching from TC to EC, there was a significant improvement in endothelial function (linear trend β = 0.73%; 95% confidence interval [CI]: 0.41 to 1.05; p < 0.0001; TC vs. EC combined: 1.49%; 95% CI: 0.93 to 2.04; p < 0.0001) and vascular stiffness (−0.529 m/s; 95% CI: −0.946 to −0.112; p = 0.014). Females benefited from switching more than males did in every between-group comparison. Those who complied best with EC switch demonstrated the largest improvement. There was no difference in vascular effects between EC with and without nicotine within the study timeframe.ConclusionsTC smokers, particularly females, demonstrate significant improvement in vascular health within 1 month of switching from TC to EC. Switching from TC to EC may be considered a harms reduction measure. (Vascular Effects of Regular Cigarettes Versus Electronic Cigarette Use [VESUVIUS]; NCT02878421; ISRCTN59133298)