Affiliations: Department of Internal Medicine, University-Hospital of Pisa, Pisa, Italy
Note: [] Corresponding author: Dr. Marco Rossi, Department of Internal Medicine, University of Pisa, Via Roma 67, 56100 Pisa, Italy. Tel.: +39 050 993207; Fax: +39 050 553414; E-mail: [email protected]
Abstract: It has been recently hypothesized that peripheral microvascular dysfunction may contribute to atherosclerotic damage (AD) in diabetic patients. In order to test this hypothesis, we assessed forearm skin post-occlusive reactive hyperaemia (skin-PORH), an index of peripheral microvascular function, using laser-Doppler flowmetry, in 40 type 1 diabetes patients (T1D-pts), aged 49 ± 11 years, with no known cardiovascular complications, and in 50 age and sex-matched healthy control subjects (CS). T1D-pts also underwent carotid arteries ultrasound scanning (Ca-US) and ankle-brachial index (ABI) measurement. An arbitrary index of AD (AD-index), ranging from “0” (normal ABI, normal Ca-US) to “3” (abnormal ABI, one or more plaques at the Ca-US), was determined in T1D-pts. Linear and multiple regression analyses were performed to identify independent predictors of AD in T1D-pts. T1D-pts had a lower skin-PORH compared with CS (p = 0.015). In T1D-pts AD-index resulted to be negatively related with skin-PORH (R = 0.44; p < 0.005) or deep-breathing test (DBT) (R = 0.53; p < 0.0005), and positively related with systolic arterial pressure (R = 0.31; p < 0.05), microalbuminuria (R = 0.46; p < 0.005), patients' age (R = 0.51; p < 0.001) and diabetes duration (R = 0.39; p < 0.05). At the multiple regression analysis skin-PORH (R = 0.36; p < 0.005), patients' age R = 0.24; p < 0.05) and DBT (R = 0.4 – p < 0.005) resulted to be independent predictors of AD-index in T1D-pts. These preliminary findings support the hypothesis that peripheral microvascular dysfunction may contribute to AD in T1D-pts.
Keywords: Microvascular dysfunction, type 1 diabetes, atherosclerosis, skin post-occlusive reactive hyperaemia, laser-Doppler flowmetry, carotid intima-media thickness, ankle-brachial index
