Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study.
In this study, we characterized longitudinal changes of volumetric bone mineral density and cortical and trabecular microstructure at the distal radius using HR-pQCT in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. Cortical thinning and increased cortical porosity are the major features of longitudinal microstructural deterioration in SLE patients.


BACKGROUND
The study aims to characterize longitudinal changes of volumetric bone mineral density (vBMD) and bone microstructure at distal radius in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids.


METHODS
This 2-year case-control study consisted of 166 premenopausal subjects (75 SLE patients and 91 controls) and 79 postmenopausal subjects (44 SLE patients and 35 controls). We obtained areal BMD (aBMD) by dual-energy X-ray absorptiometry at multiple skeletal sites and indices of vBMD and microstructure at distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline, 12 and 24 months.


RESULTS
In either premenopausal or postmenopausal subjects, changes in aBMD did not differ between patients and controls except that decrease in aBMD at total hip at 24 months in premenopausal patients was significantly higher. In premenopausal subjects, decrease in cortical area (-0.51 vs. -0.06 %, p = 0.039) and thickness (-0.63 vs. 0.02 %, p = 0.031) and increase in cortical porosity (21.7 vs. 7.16 %, p = 0.030) over study period were significantly larger in patients after adjustment of age and body mass index. Decreased in trabecular vBMD was significantly less (-0.63 vs. -2.32 %, p = 0.001) with trabecular microstructure better maintained in patients. In postmenopausal subjects, decrease in cortical vBMD (-2.66 vs. -1.56 %, p = 0.039) and increase in cortical porosity (41.6 vs. 16.3 %, p = 0.021) were significantly higher in patients, and there was no group-wise difference in change of trabecular microstructure.


CONCLUSIONS
Longitudinal microstructural deterioration in SLE is characterized by cortical thinning and increased cortical porosity. Cortical bone is an important source of bone loss in SLE patients on glucocorticoids.
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.|Bone Quality and Health Center, Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
T Y
TY
Zhu
Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
J F
JF
Griffith
Bone Quality and Health Center, Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
L
L
Qin
Bone Quality and Health Center, Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
V W Y
VW
Hung
Bone Quality and Health Center, Department of Orthopedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
T-N
TN
Fong
The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
S-K
SK
Au
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
X-L
XL
Tang
Department of Medicine and Geriatrics, Tai Po Hospital, Tai Po, Hong Kong SAR, China.
E W
EW
Kun
The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
A W
AW
Kwok
The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
P-C
PC
Leung
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
E K
EK
Li
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China. lstam@cuhk.edu.hk.|Department of Medicine & Therapeutics, The Prince of Wales Hospital, 9/F Clinical Sciences Building, 30-32 Ngan Shing Street, Shatin, N.T, Hong Kong SAR, China. lstam@cuhk.edu.hk.
L-S
LS
Tam
D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D008875:Middle Aged; D010024:Osteoporosis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D015663:Osteoporosis, Postmenopausal / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D016062:Porosity; D017697:Premenopause / Q000502:physiology; D011884:Radius / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods
D005938:Glucocorticoids
Bone microstructure; Glucocorticoids; HR-pQCT; Osteoporosis; Systemic lupus erythematosus