To study the dynamic cerebral autoregulation in patients with type 2 diabetes mellitus.

The neurological disorders are still challenging in both morbidity and mortality as a rising trend of cerebrovascular diseases in a recent decade. These challenges are enhanced with the increasing in the prevalence of type 2 diabetes mellitus (T2DM). T2DM contributes to the endothelial dysfunction, which primes to impairing cerebral blood flow (CBF) and its capability of autoregulation. The CBF itself is the highly sensitive to the arterial concentration of carbon dioxide.

A hospital based cross-sectional analytical study was conducted among 154 T2DM patients in No (2) Military Hospital, Yangon, Myanmar. Their flow velocities of middle cerebral arteries were assessed bilaterally using transcranial Doppler sonography as a baseline and during a 90-second hyperventilation test. The mean flow velocity (MFV) and cerebral vasomotor reactivity (VMR) were evaluated as markers for microvascular complications.

MFV (cm/sec) response at baseline (44.37±37.19 versus 52.61±5.06; P<0.001) as well as during the 90-second hyperventilation test (35.27±2.22 versus 37.05±3.53; P=0.001) were found to be statistically significant between two groups of T2DM patients with and without microvascular complications. The VMR decreased in the increment in number of microvascular complications (P<0.001). Age, duration of diabetes and triglycerides were noted as predictors of impaired dynamic cerebral autoregulation (P=0.028, P=0.013, P=0.001).

This study provided the important information about impaired cerebral autoregulation which was found in T2DM patients with microvascular complications as well as in those without microvascular complications. The bedside non-invasive transcranial Doppler sonography examination with the use of respiratory manoeuvre was useful and valuable in assessing dynamic cerebral autoregulation and should be performed as a routine investigation among T2DM patients for early detection of cerebrovascular consequences.