To determine the effects of Yishenjiangzhuo granules ( YJG ) on bone metabolism and to explore the changes in levels of bone Gla protein ( BGP ) , tartrate-resistant acid phosphatase ( TRAP ) , as well as their relationships with levels of B cells , regulatory T cells ( Treg ) and interleukin ( IL ) -17 in patients with stage 3-4 chronic kidney disease ( CKD ) before and after treatment .