By Stephen Beech via SWNS
People with an ultra-rare condition that stunts growth are less likely to suffer a heart attack or stroke, suggests new research.
The few hundred patients worldwide with growth hormone receptor deficiency (GHRD) – also known as Laron syndrome – also appear to at lower risk of cardiovascular disease, say scientists.
They believe that drugs that cause similar effects could reduce the risk of a heart attack or stroke – and could even extend how long people live.
GHRD, which is characterized by the body’s impaired ability to use its own growth hormone and results in stunted growth, has been linked in mice to a record 40 percent longevity extension and lower risks for various age-related diseases.
But, until now, the risk of cardiovascular disease in people with GHRD has remained unclear.
Professor Valter Longo, of the USC Leonard Davis School of Gerontology, and endocrinologist Dr Jaime Guevara-Aguirre, of the Universidad San Francisco de Quito, Ecuador, have been working together on GHRD for nearly 20 years.
They have previously examined the health and aging of people with the gene mutation that causes GHRD.
The rare mutation – found in just 400 to 500 people worldwide – was identified in a group of Ecuadorians whose ancestors had fled Spain during the Inquisition more than 300 years ago.
Longo explained that the mutation leaves them with ineffective growth hormone receptors and results in a type of dwarfism.
The team’s previous research has indicated that while GHRD reduces growth, it also appears to reduce the risk of several age-related diseases.
Although Ecuadorians with GHRD have a higher rate of obesity, they have a very low risk of cancer and Type 2 diabetes.
They also appear to have healthier brains and better performance on tests of cognition and memory, according to the research team.
For the new study, the researchers examined cardiovascular function, damage, and risk factors in GHRD subjects and their relatives.
The team conducted two phases of measurements in Los Angeles and Ecuador, involving a total of 51 people, with 24 diagnosed with GHRD and 27 relatives who didn’t have it serving as controls.
Their findings, published in the journal Med, showed the patients with GHRD had lower blood sugar, insulin resistance, and blood pressure compared to the control group.
They also had smaller heart dimensions and similar pulse wave velocity – a measure of stiffness in the arteries – but had lower carotid artery thickness compared to the control group.
Despite elevated low-density lipoprotein (LDL) – or “bad cholesterol” levels – GHRD subjects (seven percent) showed a trend for lower carotid artery atherosclerotic plaques compared to controls (36 percent).
Study senior author Longo said: “These findings suggest that individuals with GHRD have normal or improved levels of cardiovascular disease risk factors compared to their relatives.”
He added: “Although the population tested is small, together with studies in mice and other organisms this human data provide valuable insights into the health effects of growth hormone receptor deficiency and suggest that drugs or dietary interventions that cause similar effects could reduce disease incidence and possibly extend longevity.”
