After genetic tests confirmed the presence of the mutation, the researchers collected birth dates and, for those deceased, death dates for the dwarves and their 128 unaffected siblings among 34 families.
They compared these life spans with each other, as well as with the death rate in the general local population.
The researchers found that those deficient in HGH lived just as long as their unaffected siblings.
Compared to the general population, those deficient in HGH had a slightly shorter lifespan, based solely on higher death rates in five females under age 20.
When this subgroup was excluded from the analysis, average lifespan among the dwarves and the general population was identical.
While the researchers are not sure why this subgroup had a shorter lifespan, but speculate that lower growth hormone levels may affect the immune system's ability to fight off sometimes deadly infections.
Of the five, four were known to have died from diarrhoeal disease, Salvatori explains.
However, why this factor affected only females is unknown.
Salvatori said that the findings suggest that levels of HGH don't affect lifespan positively or negatively.
The study has been published in the latest issue of the Journal of Clinical Endocrinology and Metabolism.
Source-ANI