Title:
Dynamic Cerebral Autoregulation Assessed by Breath-holding Test in Type 2 Diabetes Mellitus Patients

Authors:
Myint Thein Naing, Tun Tun Naing, Nyan Sint Htun, Ohnmar Saw Nwe Nwe Win & Marlar Than, Myanmar

Abstract:

Background: Type 2 diabetes mellitus (T2DM) is known to affect blood vessels throughout the body, including the brain. Changes in cerebral blood flow regulation may occur early, even before obvious neurological complications develop. Dynamic cerebral autoregulation is an important mechanism that helps maintain stable cerebral perfusion under physiological stress.

Objective: This study aimed to assess dynamic cerebral autoregulation in patients with T2DM using transcranial Doppler (TCD) and the breath-holding test (BHT), and to examine its relationship with diabetic microvascular complications.

Methods: A cross-sectional analytical study was carried out among 154 patients with T2DM attending No. (2) Military Hospital, Yangon. Mean flow velocities (MFV) of the middle cerebral arteries were measured at rest and during breath-holding using TCD. The breath-holding index (BHI) was calculated as an indicator of cerebrovascular reactivity. Clinical and laboratory data, including the presence of microvascular complications, were recorded. Statistical analyses were performed to compare groups and identify factors associated with impaired autoregulation.

Results: More than half of the patients (60.4%) had at least one microvascular complication. Those with complications had lower baseline MFV and a smaller increase in flow velocity during breath-holding. BHI values decreased as the number of complications increased. Lower BHI was also associated with older age, poorer glycemic control, and higher serum creatinine levels. Further analysis showed that HbA1c and serum creatinine were significant predictors of impaired autoregulation

Discussion: The findings indicate that cerebral autoregulation is reduced in patients with T2DM, particularly in those with microvascular complications. This impairment appears to worsen with increasing disease burden and may be present even before complications become clinically evident.

Conclusion: The breath-holding test, combined with TCD, offers a simple and practical way to assess cerebrovascular function and may be useful for early detection and risk assessment in routine clinical practice.

DOI: http://dx.doi.org/10.51505/ijmshr.2026.10209