Сomparative Evaluation of Bone Mineral Density Based upon the Results of Ultrasound Osteodensitometry, X-ray Osteodensitometry, and Dual-Energy X-ray Absorptiometry Tests in Premenopausal Women with Systemic Lupus Erythematosus

摘要

Introduction. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the chronic inflammation and multisystemic damages, accompanied by lesions in osteoarticular system, including secondary osteoporosis (OP) ­ an important risk factor for low­energy fractures. The most common noninvasive osteoporosis tests currently in use in Ukraine include ultrasound densitometry and X­ray densitometry (dual­energy X­ray absorptiometry (DXA) and hand bone X­ray densitometry). The objective is to compare diagnostic values of bone mineral density tests that employ ultrasound densitometry, X­ray osteodensitometry, and dual­energy X­ray absorptiometry in premenopausal women with SLE.Materials and methods. The study randomly included 51 women aged between 21 and 53 (mean age at the time of the study – 38.21 ± 1.66) which were diagnosed with SLE according to the criteria of the American College of Rheumatology (1982, 1997); all women at the time of the study were premenopausal. 100.0 % of the patients received methylprednisolone at a dose of 4.0 to 24.0 mg/day (average dose – 11.12 ± 0.81 mg/day) and calcium supplements at a dose of 1000.0 mg/day in combination with vitamin D at a daily dose of 400.0 IU. The average duration of treatment with glucocorticoids and calcium supplements corresponded to the average disease duration. Bone mineral density was assessed through calcaneus ultrasound bone densitometry performed with SONOST-2000 device (OsteoSys Co., Ltd, Seoul, Korea), hand bone X­ray densitometry performed with “ARM­Osteoloh” application, and dual­energy X­ray absorptiometry of lumbar spine and proximal femur performed with dual­energy X­ray absorptiometer (Stratos, France).Statistical analysis of the obtained results was carried out in MS Excel and IBM SPSS Statistics applications.Results and their discussion. The results of ultrasound densitometry among 51 patients with SLE were as follows: 13 (25.49 %) women were diagnosed with osteoporosis (average T­score ­(­2.77) ± 0.08); 26 (50.98 %) women were diagnosed with osteopenia (average T­score ­ (­1.81) ± 0.08), 6 of them (11.76 %) ­ with the first degree of osteopenia (average T­score ­ (­1.25) ± 0.04), 9 of them (17.65 %) ­ with the second degree of osteopenia (average T­score ­ (­1.74) ± 0.06), 11 of them (21.57 %) ­ with third degree of osteopenia (average T­score ­ (­2.17) ± 0.02); 12 (23.53 %) women had normal BMD (average T­score ­ (­0.7) ± 0.07).The results of hand bone X­ray densitometry among all patients with SLE showed changes in bone mineral density. 20 (39.22 %) women were diagnosed with osteoporosis (average T­score ­ (­3.03) ± 0.08); 23 (45.09 %) women ­ with osteopenia (average T­score ­ (­2.01) ± 0.08), 4 of them (7.84 %) ­ with the first degree of osteopenia (average T­score ­ (­1.2) ± 0.11), 19 of them (37.25 %) ­ with the third degree of osteopenia (average T­score ­ (­2.18) ± 0.03); 8 women (15.69 %) had normal BMD (average T­score ­ (­0.38) ± 0.01).The results of lumbar spine bone density test employing dual­energy X­ray absorptiometry (DXA) were as follows: 16 (31.37 %) patients with SLE were diagnosed with osteoporosis (average T­score ­ (­3.14) ± 0.13); 21 (41.18 %) patients were diagnosed with osteopenia (average T­score ­ (­1.56) ± 0.13), 10 of them (19.61 %) ­ with the first degree of osteopenia (average T­score ­ (­1.14) ± 0.03), 7 of them (13.73 %) ­ with the second degree of osteopenia (average T­score ­ (­1.70) ± 0.07), 4 of them (7.84 %) ­ with the third degree of osteopenia (average T­score ­ (­2.35) ± 0.03); 14 patients (27.45 %) had normal levels of BMD (average T­score ­ (­0.36) ± 0.15).The results of proximal femur bone density test employing DXA were as follows: only 12 (23.53 %) patients with SLE were diagnosed with osteopenia (average T­score ­ (­1.28) ± 0.08), 5 of them (9.80 %) ­ with the first degree of osteopenia (average T­score ­ (­1.03) ± 0.03), 3 of them (5.86 %) ­ with the second degree of osteopenia (average T­score ­ (­1.65) ± 0.04), 4 of them (7.84 %) ­ with the third degree of osteopenia (average T­score ­ (­2.05) ± 0.03); 39 patients (76.47 %) had normal levels of BMD (average T­score ­ (0.2) ± 0.14).The findings demonstrate direct correlation between T­score results obtained by ultrasound heel bone densitometry and T­score results obtained by lumbar spine DXA (r = 0.72, p < 0.001) as well as T­score results obtained proximal femur DXA (r = 0.38, p < 0.05). The findings also indicate direct relationship between the results of BMD tests employing hand bone X­ray densitometry and lumbar spine DXA (r = 0.56, p < 0.001) as well as proximal femur DXA (r = 0.37, p < 0.05). There is also direct correlation between the results of the BMD tests obtained by ultrasound heel bone densitometry and X­ray hand bone densitometry (r = 0.7, p < 0.001).Both ultrasound heel bone densitometry and X­ray hand bone densitometry identified 89.0 % of patients who had lowered BMD levels according to the results of lumbar spine DXA and 100.0 % of patients who had lowered BMD levels according to the results of proximal femur DXA (sensitivity – 0.89 and 0.1 respectively). Ultrasound densitometry demonstrated higher specificity compared to X­ray osteodensitometry: it identified 57.0 % of the patients who had normal BMD levels according to the results of lumbar spine DXA and 31.0 % of the patients who had normal BMD levels according to the results of proximal femur DXA (specificity ­ 0,57 and 0,31 respectively).X­ray osteodensitometry identified 29.0 % of the patients who had normal BMD levels according to the results of lumbar spine DXA and 21.0 % of the patients who had normal BMD levels according to the results of proximal femur DXA (specificity ­ 0,29 and 0,21, respectively).Conclusions. The study demonstrated that both ultrasound heel bone densitometry and X­ray hand bone densitometry are highly sensitive compared to dual­energy X­ray absorptiometry and acceptable methods for diagnosis of osteoporosis in patients with SLE.