Growth hormone dysfunction is common after ischaemic stroke and may be related to delayed recovery in areas such as cognitive function, muscle and bone strength, neurologists in NSW have shown.
In a preliminary human study that may open up the way to using human Growth Hormone (hGH) treatment to aid stroke recovery, researchers at the John Hunter Hospital in Newcastle showed that almost 70% of patients with severe ischaemic stroke had a poor pituitary response shortly after their stroke.
In a study involving 13 patients with severe ischaemic stroke they found that nine (69%) had a poor response when challenged with arginine and human Growth Hormone Releasing Hormone (GHRH) within a week of stroke. Of these patients, seven patients (54%) met the clinical criteria for hGH deficiency and two had a borderline response.
Most other measures of pituitary function such as TSH and cortisol were within normal ranges.
The study authors, led by Dr Thomas Lillicrap of the John Hunter’s Department of Neurology, said the findings of low GH levels suggested they may play a role in stroke recovery.
They noted that hypopituitarism had been noted relatively frequently in other acute brain conditions such as traumatic brain injury. Low hGH could be associated with impaired attention and memory, reduced energy, cognitive dysfunction and decreased muscle and bone strength and mass.
Since all of these are common in stroke survivors, the findings of low hGH levels opened up the possibility
“Animal studies have indicated that GH treatment after stroke accelerates physical recovery and leads to better learning and memory,” they wrote in Frontiers in Neurology.
“Importantly, GH supplementation has also been shown to reduce neuronal loss in animals, which is attributed to either neuroprotection or stimulation of neurogenesis,” they added.
In addition, human trials of hGH had also shown improvements in cognitive function in people with deficiency, the authors said.
“GH receptors are expressed in many regions of the brain, but importantly those expressed in the hippocampus may help explain the cognitive enhancement of GH therapy and may represent a viable intervention in the future,” they wrote.
Further studies in stroke survivors are needed to see if growth hormone deficiency is related to poor recovery.