Leonid Ivanovyc Stadnyk (Ukrainian: Леонід Іванович Стадник) (born 1971 in Zhytomyr Oblast, Ukrainian SSR, Soviet Union) is the world's tallest living man according to Guinness World Records 2008. He is a certified veterinarian and veterinary surgeon and lives with his mother in the village of Podolyantsi, Ukraine. Leonid Stadnyk's excessive growth began after brain surgery when he was 14 years old. He developed a pituitary gland tumor which caused the gland to secrete large amounts of growth hormone, resulting in what doctors describe as acromegalic gigantism. On August 8, 2007, Guinness book's spokeswoman Amarilis Espinoza stated that in the 2008 edition of the record book, Mr Stadnyk at 2.57m, replaces Bao Xishun, a native of Inner Mongolia in China who stands 2.36 m. In the past, Stadnyk refused to be measured and consequently denied the GWR recognition. In 2007, the Guinness World Records was permitted to take height measurements, thereby officially recognizing Stadnyk as the world's tallest man.