Ultrasonic Value is Not Useful to Detect Bone Changes Following a Biliopancreatic Diversion

Abstract

To study the evolution of the bone mass by ultrasonic transmission after biliopancreatic diversion. Forty eight morbid obese patients were prospectively studied during 36 months following the Larrad biliopancreatic diversion. The bone metabolism was studied by PTHi and the urinary pirydinolines. The bone mass by echography and bone densitometry, which correlate to the levels of PTHi and pyridinolines. After 3 years the bone mass decreased from 50.15 +/- 7.31 kg/m(2), preoperatively, to 34.03 +/- 4.53 kg/m2 (p < 0.001). There was an increase of the PTHi value (from 71.4 +/- 79.6 to 91.65 +/- 43.06 pg/ml) (p = 0.01), and the urinary pirydinolines (from 7.93 +/- 4.06 an 11.4 +/- 10.12 nM/mM) (p < 0.05). The ultrasonic transmission speed increased (from 1,990.93 +/- 62.38 to 2,035.25 +/- 53.98 m/s). However, the bone mineral content (BMC) did not show changes (from 3,016.5 +/- 562.8 to 2,909.6 +/- 304.2 g), as well as the Bone Mineral Density (BMD) (of 1,174.2 +/- 98.8 g/cm2). Neither correlation was found between the BMD (r = 0.212; p = 0.6), the BMC (r =-0.125; p = 0.768), and the T-score (r = 0.592, p = 0.093). The study of the bone mass through ultrasonic transmission speed revealed low sensitivity during the assessment of the morbid obese patients. A percentage of cases of osteopenia were observed despite the fact that they are not reflected in the bone content or in the bone mass. Ultrasonic evaluation of bone mass has no value in the morbidly obese, by the clear negative correlation between ultrasound velocity and thickness of soft tissue.

Bone Metabolism After Bariatric Surgery

“…Several longitudinal studies have reported that bone markers remain elevated, (16,19,36,44,50,100,101) and bone loss may continue into the second and third years after surgery. (18,19,25,45,48,50) Cross-sectional studies also suggest that bone markers are higher than expected even 3 years after bariatric surgery.…”

Association between obesity and risk of fracture, bone mineral density and bone quality in adults: A systematic review and meta-analysis

“…Radius volumetric BMD (vBMD) by pQCT and HR-pQCT . The two studies that reported radius vBMD by pQCT in premenopausal women revealed no difference between those with or without obesity ( S5 Fig ) [ 122 , 123 ].…”

“…Tibia vBMD by pQCT and HR-pQCT . Two studies reported tibia vBMD measured by pQCT, which included 331 premenopausal women [ 122 , 123 ]. Similar to the radius vBMD findings by pQCT, obesity was not associated with any difference in tibia vBMD ( S5 Fig ) [ 122 , 123 ].…”

“…Radius cortical thickness by pQCT and HR-pQCT . Radius cortical thickness by pQCT was reported in two studies [ 122 , 123 ], which included 163 premenopausal women. Those studies did not reveal any association between radius cortical thickness and obesity ( S6 Fig ).…”

“…Tibia cortical thickness by pQCT and HR-pQCT . Three studies reported tibia cortical thickness by pQCT [ 95 , 122 , 123 ] in premenopausal women and found no difference between premenopausal women with and without obesity ( S6 Fig ).…”