Tomographic-biomechanical analysis of bones and muscles in forearms and legs of chronic cirrhotics.

SEBASTIAN EDUARDO FERRETTI; RICARDO FRANCISCO CAPOZZA; GUSTAVO ROBERTO COINTRY; SARA FELDMAN; HUGO TANNO; JOSÉ LUIS FERRETTI

Colonia (Alemania)

Workshop; VI INTERNATIONAL WORKSHOP FOR MUSCULOSKELETAL & NEURONAL INTERACTIONS.; 2008

International Society of Musculoskeletal & Neuronal Interactions (ISMNI),

TOMOGRAPHIC-BIOMECHANICAL ANALYSIS OF BONES AND MUSCLES IN FOREARMS AND LEGS OF CHRONIC CIRRHOTICS. Ferretti SE, Capozza R, Cointry G, Feldman S, Tanno HE, Ferretti JL. Center of P-Ca Metabolism Studies (CEMFoC) and Service of Gastroenterology & Hepatology, Univ Hospital, Faculty of Medicine, Natl Univ of Rosario, Argentina.     This is the first pQCT study of bone and muscle structural and mechanical properties and interactions in chronic cirrhotics. Previous studies employing DEXA described only decreases in BMC and areal BMD in specific regions, with no specific biomechanical correlates, in about 30-40% of the patients, proportional to the severity of the disease.         In order to describe the musculoskeletal status following biomechanical criteria, pQCT indicators of bone mass (cortical and trabecular CSA, BMC, vBMD), cortical tissue mineralization (cortical vBMD corrected from the PVE as per Rittweger et al [JMNI 4:436,2004], Rho-vCtD), design (cross-sectional area moments of inertia, CSMI´s) and strength (Stress-Strain Index, SSI) and muscle strength (muscle CSA) were determined in radii (4% and 66% sites) and tibiae (4%, 14%, 38% & 66% sites) of 40 chronic cirrhotics (17 men) of alcoholic, viral, cryptogenetic, autoimmune or cholestatic etiology, aged 18-69 yr. Two hundred and sixty healthy controls (60 men) of comparable age were studied as a normal reference. Z-scores of these data, and of the individual points in correlation graphs between bone and muscle indicators which were analyzed as needed, were calculated for every patient as per the normal references and correlated with the Child-Pugh Score (CPS, capturing bilirrubinemia, albuminemia, prothrombin time, ascitis and encephalopathy) and other laboratory indicators.     The cirrhotic condition reduced trabecular mass and muscle CSA. Diaphyseal cortical CSA, Rho-vCtD, CSMI´s and SSI were unaffected. However, the proportion between cortical bone (tibia + fibula) and muscle CSA´s (calf) at the 66% site of the leg was reduced.     After excluding alcohol abusers from the analysis, trabecular bone loss correlated with CPS, especially with its component, albuminemia, and with the degree of cholestasis (as assessed by plasma alkaline phosphatase and bilirrubin). Muscle loss correlated with CPS but not with the degree of cholestasis. Alcohol abusers showed always these alterations, regardless of CPS and degree of cholestasis. Serum Ca did not correlate with any other indicator.     Results show that chronic cirrhosis 1. reduced trabecular mass (and obviously the compressive strength of the trabecular network) in correlation with the severity of the disease and cholestasis; 2. reduced also correlatively muscle mass (unrelated to the degree of cholestasis), and 3. tended to reduce the impact of muscle-bone interactions in terms of bone mass (not material quality, design, or strength) in the studied sample. Alcohol abuse seemed to impair all those properties as an independent factor.