Effects of orthostatic hypotension on cognition in type 2 diabetes mellitus.

Objective: To evaluate the effect of a decrease in blood pressure (BP) fulfilling the diagnostic criteria for orthostatic hypotension (OH) on performance in each domain of cognitive function in patients with type 2 diabetes mellitus using a cross-sectional and within-group design.

Methods: Subjects were individuals without dementia and with type 2 diabetes mellitus, including 107 individuals without OH and 94 with OH (DMOH); 95 control participants were also included. BP was assessed in both the supine and standing positions. A detailed neuropsychological assessment was made in each posture for all subjects.

Results: There were statistically significant differences between the patients without OH and the DMOH group with regard to some cognitive measures while supine. Standing posture exacerbated and broadened cognitive deficits in the DMOH group for all measures in the different domains of cognition including executive functioning, memory, visuospatial skills, information processing speed, and attention. When group-specific supine scores were used as baseline anchors, both the patients without OH and the DMOH group showed cognitive changes when transitioning from a supine to a standing, upright position, with the DMOH group exhibiting a wider range of neuropsychological deficits in memory, visuospatial skills, executive function, and sustained attention, as well as significant changes in information processing speed.

Interpretation: These data demonstrate that type 2 diabetes mellitus patients with OH had transient, posture-mediated cognitive deficits in excess of those found in diabetes mellitus without OH. Understanding the effects of OH on cognition due to autonomic failure is important, particularly as clinical assessments and neuroimaging collect data only in the seated or supine positions. ANN NEUROL 2019;86:754-761.