Detailed analyses of periarticular osteoporosis in rheumatoid arthritis

Periarticular osteopenia is the earliest radiographic sign of rheumatoid ar thritis (RA). Recent studies using dual-energy X-ray absorptiometry (DXA) h ave indicated that the loss of periarticular BMD can be quantified by whole -hand bone mineral density (BMD) measurements. The aim of this study was to analyze periarticular BMD in more detail by DXA and quantitative ultrasoun d (QUS). In a cross-sectional study 23 women aged 30-76 years with early RA , mean disease duration 26 +/- 19 months, and 18 men aged 42-69 years, mean disease duration 24 +/- 25 months, were examined. All patients received an tirheumatic therapy. The reference population consisted of 103 age-matched controls (68 females, 35 males) and young healthy controls. BMD measurement s were performed using a DXA Expert XL densitometer (Lunar). BMD of the who le-hand and two subregions was determined: two subchondral regions of inter est (S.CH.) were set within the trabecular bone, distal to the proximal int erphalangeal joints of digits II and III excluding the dense subchondral bo ne of the metacarpophalangeal (MCP) joint and two metacarpal regions of int erest (MCP) were set including the entire MCP joint of these fingers. QUS m easurements at the proximal phalanges of digits II-V were performed using a DBM Sonic (Igea); amplitude-dependent speed of sound (Ad-SoS) was determin ed. In comparison with whole-hand BMD measurements, bone loss was pronounce d in patients with a disease duration of 18-72 months at the subchondral re gions of interest in both genders compared with age-matched controls (women : mean BMD loss S.CH. -23%, p<0.001, whole-hand -16%, p<0.001; men: mean BM D loss S.CH. -19%, p<0.05, whole-hand -12%, p<0.05). The bone changes were also shown by QUS (women: Ad-SOS values of 1950 +/- 90 m/s in RA vs 2137 +/ - 35 m/s in young healthy controls (p<0.005); men AD-SOS 1956 +/- 87 mis in RA vs 2146 +/- 41 m/s in young healthy controls (p<0.05)). These results s how that BMD and Ad-SOS values are significantly lowered in patients with e arly RA and indicate that periarticular osteoporosis in early RA might poss ibly be better detected using detailed hand scan analyses.