Evaluating mental function in patients with type 2 diabetes who have low blood pressure when standing up

This study evaluated the effects of low blood pressure when standing up (orthostatic hypotension; OH) on cognitive (mental) function in patients with type 2 diabetes (T2D). This study concluded that patients with T2D who had OH showed poorer cognitive function compared to patients who did not have OH.

Orthostatic hypotension (OH) is a condition where blood pressure drops when a person stands up from either laying or sitting down. As a person moves to stand up, they may feel lightheaded, drowsy, or have blurry vision. OH is a key risk factor for cognitive decline; previous studies have shown that OH was associated with a 15% increased risk of dementia.

T2D has also been associated with cognitive decline and a higher risk of dementia. About 28 – 30.5% of elderly patients with diabetes also have OH. Whether OH also affects cognitive function in patients with T2D is unclear.

This study had a total of 299 patients. 97 patients had T2D and OH, and 107 patients had T2D without OH. 95 participants who did not have T2D were included as a control group. All patients had their blood pressure (BP) measured while standing and while laying down. Systolic BP (blood pressure when the heart beats) and diastolic BP (blood pressure in between heartbeats) were measured. Patients also received multiple mental performance (cognition) tests.

There were no significant differences in blood pressure or heart rate among all three groups when laying down. When standing up, patients with T2D and OH had a significantly higher drop in systolic BP compared to patients who did not have OH (33.7 mmHg vs. 5.9 mmHg). Diastolic BP also dropped by 14.1 mmHg in patients with OH compared to a 4.7 mmHg increase in patients without OH.

While laying down, patients with T2D and OH had recalled significantly fewer words in a memory test compared to the control group (4.5 words vs. 7.5 words). These patients also produced the fewest number of words per minute on a verbal fluency test compared to the control group (19.5 words vs. 26.2 words). Scores on an attention test were also significantly lower (5.3 points vs. 6.1 points).

While standing, patients with T2D and OH had recalled significantly fewer words in a memory test compared to the control group (14.4 words vs. 22.6 words). These patients also produced the fewest number of words per minute on a verbal fluency test compared to the control group (14.8 words vs. 25.3 words). Scores on an attention test were also significantly lower (4.1 points vs. 6.0 points).

This study concluded that among patients with T2D, those who had OH showed poorer cognitive function compared to patients who did not have OH. The authors suggest that neuropsychological exams should be given to patients with T2D in a variety of postures.

This study had fewer patients with T2D and OH compared to patients with T2D only. The patient groups were also not randomly divided. More studies are needed to confirm these results.