The cross-talk between arterial stiffness and microvascular complications in diabetes mellitus: a systematic review of the literature

Arterial stiffness (AS) is a well-established index of macrovascular damage and predicts cardiovascular complications in many diseases including diabetes mellitus (DM). DM is strongly linked with microcirculatory changes, including retinopathy, microalbuminuria and neuropathy. We aimed to review in a systematic manner the possible correlation between AS and microvascular impairment in patients with DM, type 1 or 2. We performed a systematic literature search in PubMed, Scopus and Embase database. We included studies evaluating the correlation of AS and impaired microcirculation in adult patients with type 1 or 2 DM. AS could be evaluated with pulse wave velocity, carotid-ankle vascular index, ambulatory arterial stiffness index and augmentation index. Impaired microcirculation was defined by the presence of one or more of the following: retinopathy, albuminuria, neuropathy, dermal capillary alterations. We eventually included 51 studies in our systematic review. Data were extracted by two investigators and were critically appraised with ROBINS-I tool of Cochrane Library for non-randomized trials. The majority of studies have demonstrated positive correlation between AS and microvascular impairment, usually in a dose-response association. However, most studies have focused on the association of AS with retinopathy, whereas the association with dermal microvascular alterations remains scarcely investigated. Disease duration was underlined by most authors as an independent predictor of increased AS. These findings suggest that AS should be sought upon detection of microvascular complications in patients with T1DM or T2DM; vice versa, patients with T1DM or T2DM with increased levels of AS should be screened for microvascular alterations.