PHILADELPHIA – The diabetes drug rosiglitazone appears to preserve cognitive function in patients with mild cognitive impairment and Alzheimer's disease, G. Stennis Watson, Ph.D., reported at the Ninth International Conference on Alzheimer's Disease and Related Disorders.
The finding, from a small randomized clinical trial funded by GlaxoSmithKline, suggests that “there may be a therapeutic window … a novel approach to treating cognitive dysfunction,” study coauthor Dr. Suzanne Craft said at a press briefing.
Twenty subjects with either mild cognitive impairment or Alzheimer's disease were randomized to receive 4 mg/day of rosiglitazone for 24 weeks, while another 10 subjects with similar degrees of cognitive impairment were randomized to receive placebo. Tests of cognition were performed at 2, 4, and 6 months, said Dr. Watson of the University of Washington, Seattle.
On the eight-word delayed recall part of the Buschke Selective Reminding Test, subjects who received rosiglitazone remembered significantly more words than did the placebo subjects at 4 months (5.7 vs. 5.4) and 6 months (5.4 vs. 4.9), after adjustment for baseline performance. Similarly, the rosiglitazone group made fewer errors on the Stroop Color-Word Interference test, which measures selective attention. At 6 months, the rosiglitazone subjects made an average of 1.9 errors, compared with the expected 3.2 in the placebo group.
The effects are likely due to the drug's insulin-sensitizing and anti-inflammatory properties, and perhaps also to the amyloid-processing modulation action of rosiglitazone and other agents of the same class, Dr. Watson said at the conference, presented by the Alzheimer's Association.
A larger trial aimed at replicating these findings is underway in Europe, he noted.