HOUSTON – Oral relaxin therapy resulted in significantly improved cognitive and functional recovery in poststroke patients participating in a randomized controlled trial.
"We speculate that in the near future, relaxin hormone could represent a new therapeutic and preventative tool to afford reduction of both incidence and disability of vascular ischemic diseases, not only of the brain but also of other organs and apparatuses," Dr. Paolo Milia declared in presenting the study findings at the annual meeting of the Endocrine Society.
The trial involved 36 poststroke patients admitted to a rehabilitation unit, where they were randomized to rehabilitation therapy plus 40 mg/day of oral porcine relaxin or to rehab alone. Investigators administered validated tests of cognitive function, global impairment, and daily activity at admission and again on days 20 and 40.
Cognitive function as assessed using the Trail Making Test was significantly better in the relaxin group on day 20, when their mean score was 3.5, compared with 2.0 in controls. The difference in cognitive outcome broadened by day 40, when the average score in the relaxin group was 4.0, compared with 2.0 in controls on rehabilitation therapy only, reported Dr. Milia of the Prosperius Institute in Umbertide, Italy.
Daily activity as measured using the Functional Independence Measure improved in the relaxin group from a baseline score of 53 to 78 at day 20 and 96 on day 40. In the control group, the average score was 59 at baseline, 69 at day 20, and 75 at day 40, indicating significantly greater functional recovery in the relaxin group at the 40-day mark.
Global function as assessed using the Modified Rankin Scale was higher in the relaxin group than in controls on days 20 and 40, with the difference between groups significant at both times.
The hormone treatment was safe as well as efficacious. No side effects occurred, he said.
Relaxin, discovered in 1926, belongs to the same peptide hormone superfamily as the insulin-like peptides. Relaxin’s known function revolves around pregnancy; however, the hormone also promotes angiogenesis, inhibits collagen synthesis, enhances nitric oxide synthesis, and boosts production of matrix metalloproteinases, a spectrum of effects leaving the door open to possible broader functions not well characterized as yet. In animal models, relaxin protects against ischemic injury to the myocardium and brain (J. Chem. Neuroanat. 2011;42:262-75), Dr. Milia noted.
The porcine relaxin utilized in this study, known as Vitalaxin Plus, is marketed by Sky BioHealth. The investigators reported having no financial disclosures.