Poor vitamin C status is associated with increased carotid intima-media thickness, decreased microvascular function, and delayed myocardial repolarization in young patients with type 1 diabetes.
Am J Clin Nutr
; 90(2): 447-52, 2009 Aug.
Article
in En
| MEDLINE
| ID: mdl-19553299
ABSTRACT
BACKGROUND:
Vascular endothelial dysfunction, accelerated thickening of arterial intima, and changes in ventricular repolarization contribute to increased cardiovascular morbidity in type 1 diabetes (T1D). Although vitamin C has important antioxidant functions and increased oxidative stress is a central mechanism of cardiovascular dysfunction in T1D, the relation between vitamin C and the cardiovascular system in young diabetic patients has not been investigated.OBJECTIVE:
In a cohort of young patients with T1D, we investigated the relation of plasma concentrations of vitamin C with indexes of vascular function and structure and duration of the QT interval corrected for heart rate (QT(c)).DESIGN:
Carotid artery intima-media thickness, cutaneous microvascular function, and duration of the QT(c) interval were measured in 59 patients (mean age 17 y; range 10-22 y) with T1D (diabetes duration 3-20 y). Plasma vitamin C was analyzed by HPLC with coulometric detection.RESULTS:
Carotid artery intima-media thickness and duration of the QT(c) interval were higher in patients in the lowest tertile of vitamin C than in those in the highest tertile (P < 0.05 for both). The cutaneous microvascular response to acetylcholine was lower (P = 0.003) in the lowest tertile group than in the highest tertile group, but the response to sodium nitroprusside was not significantly different between these 2 groups. All differences remained significant after adjustment for age, sex, diabetes duration, body mass index, and glycated hemoglobin.CONCLUSIONS:
In this relatively small-scale cross-sectional study of young patients with T1D, lower plasma concentrations of vitamin C seem to be associated with adverse changes in the microcirculation, peripheral arteries, and ventricular repolarization. Large-scale prospective studies are needed to confirm these results and to clarify the underlying mechanisms.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ascorbic Acid
/
Endothelium, Vascular
/
Carotid Arteries
/
Diabetes Mellitus, Type 1
/
Heart Rate
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Adult
/
Child
/
Female
/
Humans
/
Male
Language:
En
Journal:
Am J Clin Nutr
Year:
2009
Document type:
Article
Affiliation country:
Sweden