Mean HbA1c over 18 years predicts carotid intima media thickness in women with type 1 diabetes.
OBJECTIVE
Intima media thickness (IMT) of the common carotid artery (CCA) is a validated surrogate marker of early atherosclerosis. The aim of our study was to assess the association between IMT in CCA and long-term mean HbA1c in type 1 diabetes. We also elucidated the association between carotid IMT and preclinical coronary atherosclerosis.


METHODS
In 39 individuals with type 1 diabetes, HbA1c was measured prospectively over 18 years. The IMT examinations were performed with high-resolution ultrasound. The association between carotid IMT and preclinical coronary atherosclerosis (assessed by intravascular ultrasound [IVUS]) was tested in 29 of the patients.


RESULTS
Mean HbA1c over 18 years was 8.2% (range: 6.6-11.3%). Mean age at follow-up after 18 years was 43 years and mean duration of diabetes was 30 years. IMT was significantly higher in diabetic patients than in an age- and sex-matched reference population. The IMT values were at the same level as for controls who were 20 years older. In women, HbA1c was significantly associated with mean average CCA IMT (r2=0.77, p<0.0001 when adjusted for age), whereas there was no significant association for men. Among women, a significant association was also found between carotid IMT and the percentage of coronary vessel area stenosis (r=0.65, p=0.03).


CONCLUSIONS
The present findings suggest an important role of long-term hyperglycaemia in the development of atherosclerosis, especially in women with type 1 diabetes. Type 1 diabetes patients have earlier development of, and more advanced, atherosclerosis compared with an age- and sex-matched reference population. In women, carotid IMT reflects preclinical coronary atherosclerosis.
Larsen
J R
JR
Diabetes Research Centre, Aker and Ulleval University Hospitals, Oslo, Norway. jakob.larsen@medisin.uio.no
Brekke
M
M
Bergengen
L
L
Sandvik
L
L
Arnesen
H
H
Hanssen
K F
KF
Dahl-Jorgensen
K
K
D000328:Adult; D000367:Age Factors; D001161:Arteriosclerosis / Q000209:etiology; D016893:Carotid Stenosis / Q000209:etiology / Q000473:pathology*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D006943:Hyperglycemia / Q000150:complications; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012307:Risk Factors; D012737:Sex Factors; D017540:Tunica Media / Q000473:pathology*; D014652:Vascular Diseases / Q000209:etiology / Q000473:pathology
D006442:Glycated Hemoglobin