[Osteoporosis in chronic liver disease: a mathematical method to screen high-risk patients based on clinical findings]

ABSTRACT

Patients with chronic liver disease [CLD] have an increased prevalence of osteoporosis but it is unclear which patients are at high risk for developing bone disease. The goal of this study was to evaluate the bone mineral density [BMD] among Iranian CLD patients and to compare it with healthy controls. We have also established a mathematical method, which can be used to determine high-risk patients based on clinical findings. A total of 65 patients [36 male, 29 female mean age 51.1years] with chronic liver disease were recruited over a 1-year period. BMD measurements were done using dual energy X-ray absorptiometry in the lumbar spine [LS] and femoral neck [FN]. Osteoporosis and osteopenia were defined by WHO criteria and BMD of patients was compared with the BMD of 65 age and sex matched normal individuals as controls. Finally we constructed a mathematical function to identify CLD patients who are at high risk for decreased BMD. The overall prevalences of osteopenia and osteoporosis in both sites were 47/7% and 23/1% respectively. BMDs at LS and FN were significantly lower in CLD patients than BMD in controls [p<0.005 and p<0.05, respectively]. BMD at LS and FN among women and BMD at LS among men was significantly lower in patients compared to controls [p<0.005 for all]. Increasing age was inversely correlated to BMD of females at LS and BMD of males at FN when the effect of BMI was controlled [r=-0.43 and rs=-0.5, respectively]. BMI was also correlated to BMD of females at LS and FN and BMD of males at FN when the effect of age was controlled [r=0.37, r=0.44 and rs=0.4, respectively]. At FN, BMD in Women with autoimmune, idiopathic and cholestatic liver disease was lower than BMD in viral hepatitis. Osteoporosis was more frequent in women with ascites and decreased [p<0.05]. Longer duration of CLD was correlated with lower BMD in women [p<0.05]. Women with Child C liver disease had higher abnormal BMD frequency compared to Child A [p<0.05] in men, no statistically significant correlation was found. Two functions were built based on sex, age, BMI and presence or absence of ascites, which could predict the abnormal BMD with sensitivity and positive predictive values of 85% and 87% respectively, which is significantly better than purely by guessing[p<0.05]. Osteoporosis is fairly common in CLD. We could screen high-risk patients by clinical indices as sex, age, BMI and presence of ascites so diagnostic and preventive measures could be instituted earlier in the course of the disease