Osteoporosis Common Among Postmenopausal Lupus Nephritis Patients, Study Shows

"We identified advanced age, lower body weight, and the lack of bisphosphonate treatment as key risk factors for osteoporosis in this patient population," the researchers wrote in BMC Nephrology.

Systemic lupus erythematosus (SLE) causes multisystemic damage, and lupus nephritis (LN) is a severe manifestation with significant health risks. Female SLE patients are at increased risk of reduced bone mineral density, osteoporosis, and fractures. The prevalence of osteoporosis in LN patients varies globally, with factors like glucocorticoid use and early menopause contributing to bone loss.

Against the above background, Yi Yang, Department of Nephrology, Tongji Hospital affiliated with Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, and colleagues examined the prevalence of osteoporosis and identified risk factors contributing to the condition in both premenopausal and postmenopausal LN patients, highlighting the lack of data specific to the Chinese population. It aims to fill this gap by providing insights into the unique risk factors in this demographic.

For this purpose, the researchers conducted a cross-sectional study involving patients with renal biopsy-proven lupus nephritis. These patients underwent bone mineral density (BMD) measurements using dual X-ray absorptiometry at the lumbar spine, total hip, and femoral neck. The study took place at Tongji Hospital from May 2011 to June 2018.

The key findings of the study were as follows:

• 130 patients, including two males and 128 females, were evaluated, with a mean age of 46.2 ± 12.9 years.
• Among female patients, 52.3% (n = 67) were postmenopausal.
• BMD measurements revealed that 40.0% of patients had osteoporosis in at least one site.
• Spearman rank correlation showed that age at menopause, weight, height, and body mass index were positively correlated with BMD. In contrast, age, age at diagnosis of lupus nephritis, and menopause duration were negatively correlated with BMD at the lumbar spine, total hip, and/or femoral neck.
• Multivariable linear regression analysis showed that body mass index was positively associated with BMD. In contrast, disease duration and menopause duration were negatively associated with BMD in both all patients and postmenopausal patients.
• Postmenopausal patients had a consistently higher prevalence of osteoporosis across all measured sites.
• Risk factors such as older age, lower weight, and the absence of bisphosphonate therapy were independently associated with an increased risk of osteoporosis in LN patients.

"Our findings suggest that patients with LN are at a considerable risk of developing osteoporosis, especially in the lumbar spine and among postmenopausal individuals. Identified risk factors for osteoporosis include older age, lower body weight, and the absence of bisphosphonate treatment," the researchers concluded.

Reference:

Hong, Y., Yang, Y. & Yao, Y. Prevalence and risk factors of osteoporosis in lupus nephritis patients in China: a cross-sectional study. BMC Nephrol 25, 428 (2024). https://doi.org/10.1186/s12882-024-03882-7