Aredisease duration anddegree offunctional impairment determinants ofboneloss inrheumatoid arthritis

SUMMARY Onehundred andfivepatients withrheumatoid arthritis treated witha variety of antirheumatic drugs, excepting glucocorticoids, were stratified according tothedegree of functional impairment (functional classes ItoIV)andduration ofthedisease (0-3 years;4-8 years;and>8 years). Thevariables investigated were distal forearm bonemineral content (BMC),biochemical markers ofboneformation: serum alkaline phosphatase andserum bone gamma-carboxyglutamic acidcontaining protein (BGP)andbiochemical markersofbone resorption: fasting urinary calcium andfasting urinary hydroxyproline. Significant relationships were foundbetween BMC andfunctional impairment andduration ofthedisease. Indices of boneformation andboneresorption rosewithincreasing functional impairment, particularly those ofboneresorption. Itisconcluded thatdisability induces osteopenia inrheumatoid arthritis byincreasing theboneturnoverwitha more markedincreased inresorption thaninthe formation processes.Theeffect ofthedisease duration ismerely thatofadding more yearsof functional impairment.