Carotid atherosclerosis severity in relation to glycemic status: a cross-sectional population study.

OBJECTIVE: Intima-media thickness (IMT) is increased in subjects with prediabetes or newly diagnosed diabetes. However, no previous studies have evaluated the relationship between the severity of carotid atherosclerosis, assessed by the presence of carotid plaques or stenosis, and the glycemic status, assessed either by fasting glucose, an oral glucose tolerance test (OGTT) or A1C levels.
METHODS: Cross-sectional analysis of 1475 subjects (mean age 62 years, 44% males), randomly selected from the population. A fasting blood sample was obtained to determine glucose, lipids, and A1C levels. An OGTT was performed in non-diabetic subjects. Carotid atherosclerosis was evaluated by echo-doppler.
RESULTS: A 10.5% of the population had a previous diagnosis of diabetes. Of the 1320 non-diabetic participants, 349 (26.4%) had normal fasting glucose, normal glucose tolerance and A1C < 5.7%, and were considered controls. Prediabetes was diagnosed in 850 subjects (64.4%), and diabetes was newly diagnosed in 121 (9.2%). The prevalence of patients with carotid plaques was 34.2% in controls, 45.1% in prediabetics, 64.2% in newly diagnosed diabetics, and 72.9% in established diabetic patients. These numbers were 0.3%, 1.1%, 5.0% and 7.7% for carotid stenosis, respectively. In multivariate analysis, glycemic status remained significantly associated with the prevalence of carotid plaques after adjusting for age, sex, statin treatment, and cardiovascular risk factors.
CONCLUSIONS: Glycemic status is associated with all grades of carotid atherosclerosis, from early signs, as demonstrated by the IMT, to intermediate degrees, as demonstrated by the presence of carotid plaques, to advance atherosclerosis, as established by the presence of carotid stenosis.