Characteristics Of Bone Metabolism And Osteoporosis In Patients With Systemic Lupus Erythematosus

Objective Osteoporosis(OP)secondary to systemic lupus erythematosus(SLE)is insidious and dangerous,but not appreciated by clinicians.In this study,we retrospectively analyzed the characteristics of bone metabolic index expression and correlation with disease activity in patients with primary SLE.By analyzing the earliest time and characteristics of OP during the disease progression in SLE patients,the clinical characteristics of secondary OP in SLE patients can be clarified,providing reference data for earlier identification and intervention of OP in clinical work.MethodClincal study 1:51 premenopausal patients with newly diagnosed SLE from July 2015 to February 2022 were included,and 36 healthy controls of the same sex and age during the same period.Inclusion criteria: 1)All SLE patients met the 1997 or 2019 American College of Rheumatology SLE Diagnosis and Treatment Standards.2)All SLE patients were premenopausal women or men aged less than 50 years.3)All patients were newly diagnosed at enrollment and had not taken any medications such as glucocorticoids or immunosuppressive drugs.The general conditions(name,sex,age,weight/height index,SLEDAI score),routine blood test,biochemical test and immune indices of SLE patients at initial diagnosis were collected.General information(age,sex,weight/height index)was collected for the healthy control group.Bone metabolism indices(OC、PINP、β-CTX 、25-OH-Vit D3)and the level of bone metabolism indices in SLE patients with stable condition after treatment.The levels of bone metabolic indexes were collected in the SLE group at the time of disease stabilization after treatment.The differences of bone metabolism indices between the two groups and before and after treatment in the SLE group were compared by t-test using SPSS 22.0 statistical software.The correlation between disease activity and bone metabolism in SLE patients was evaluated by Pearson correlation analysis.Clinical Study 2:From April 2003 to July 2021,84 patients with SLE treated in the Department of Rheumatology and Immunology of the First Hospital of Jinan University were included.Inclusion criteria for SLE patients: 1)All SLE patients met the 1997 or 2019 American College of Rheumatology SLE diagnosis and treatment standards;2)Patients who could provide complete clinical data at initial diagnosis.General information(name,age,sex,height,weight,weight/height index,etc.)was collected for each study subject.The results of bone mineral density examination of SLE patients were collected and the values of bone mineral density of lumbar spine,femoral and both hip joints were recorded,and the time of occurrence of bones changes,disease duration and hormone accumulation were recorded.The time of the earliest appearance of OP in the disease progression of SLE patients and the bone density characteristics of OP were calculated using SPSS 22.0 statistical software and analyzed by t-test.Result1.51 patients in the SLE group had significantly lower serum OC(9.66±6.96 vs 14.49±4.26),25-OH-Vit D3(12.76±7.05 vs 21.28±7.07)than healthy controls(P < 0.01);serum β-CTX(0.62±0.65 vs 0.41±0.18)was significantly higher than healthy controls(P < 0.05).2.Serum OC was negatively correlated with SLEDAI score(r=-0.314)and positively correlated with Hb(r=0.461);serum 25-OH-Vit D3 was positively correlated with complement C3(r=0.482)and Hb(r=0.461)(P < 0.05).18 patients in the SLE group had stable disease after treatment,serum 25-OH-Vit D3 levels increased(13.00±7.31 vs 17.46±4.72)(P < 0.05).3.84 patients were included in study 2,of whom 36.9% had changes in bone mass(osteopenia +osteoporosis).Among them,14.3% were premenopausal osteoporosis.Postmenopausal bone loss accounted for 13.1% and postmenopausal osteoporosis accounted for 8.3%.The time to OP in SLE was(5.39 ± 4.07)years,with 57.9% of SLE patients experiencing OP within 5 years of diagnosis.4.83.3% of SLE patients with premenopausal osteoporosis were diagnosed with lupus nephritis,the initial diagnosis of SLEDAI was(17.83 ± 5.29)points,osteoporosis occurred(4.83 ± 3.55)years after diagnosis,and the daily glucocorticoid was(15.35 ± 10.29)mg.5.BMD of lumbar spine(0.859 ± 0.146 vs 1.072 ± 0.084),left femoral neck(0.690 ± 0.058 vs0.849 ± 0.055),right femoral neck(0.678 ± 0.069 vs 0.846 ± 0.060)and right hip joint(0.712 ±0.082 vs 0.881±0.064)were significantly lower in SLE patients with premenopausal osteoporosis than those of SLE patients without osteoporosis(P < 0.05).6.No significant differences were seen in lumbar spine,bilateral femoral neck,and bilateral hip bone density in postmenopausal SLE patients with combined OP compared with premenopausal SLE patients with combined OP(P > 0.05).Conclusion1.SLE patients showd bone metabolic changes at the beginning of the disease,which manifested as an uncoupled bone reconstruction with reduced bone formation and increased bone resorption,and the bone metabolism indexes were correlated with disease activity.2.25-OH-Vit D3 deficiency was obvious in SLE patients with disease activity.After treatment,25-OH-Vit D3 deficiency could be significantly improved,suggesting that 25-OH-Vit D3 can be used as an indicator of disease activity in SLE patients.3.Osteoporosis is more likely to occur in patients with lupus nephritis with moderate to high disease activity at the time of initial diagnosis,and may occur within 5 years of diagnosis.4.Osteoporosis may occur in the lumbar spine and hip joint of premenopausal SLE patients,with more pronounced bone loss in the lumbar spine.