Page 174 - Ebook-Book JCMS 2025

The Effect of Bisphosphonates on Kidney Function in
Osteoporotic Geriatric Patients with Impaired Renal Function
Akarawin Tweekittikul, Unchana Sura-amonrattana*, Varalak Srinonprasert
Division of Geriatric Medicine, Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital
*Corresponding Author E-mail: praewun@gmail.com
Background: Methods: Results : Conclusions: Abstract
Bisphosphonates are the mainstay treatment for osteoporosis, with initiation guided by
creatinine clearance (CrCl) from the Cockcroft-Gault equation. However, many clinicians
use estimated glomerular filtration rate (eGFR) from the CKD-EPI equation, primarily for
chronic kidney disease (CKD) staging. This study compared renal function assessments
from these equations and evaluated changes over 12 months.
A retrospective cohort study was conducted to compare the renal outcomes in osteoporotic
geriatric patients with an eGFR ranging from 35 to 60 mL/min/1.73m² who received
bisphosphonate treatments from January 2015 to December 2022. The patients were
categorized based on CrCl: <35 mL/min and ≥35 mL/min using the Cockcroft-Gault
equation.
A total of 222 patients (190 [85.6%] female; mean age 80 ± 6.54 years) were analyzed, with
109 (49.1%) patients in the CrCl <35 group and 113 (50.9%) ones in the CrCl ≥35 group.
No significant differences in overall renal function changes were observed between the
groups. However, the CrCl <35 group showed trends of increased serum creatinine (mean
difference: 0.06; 95% CI: -0.02 to 0.14; p = 0.370) and declines in eGFR (-0.41; 95% CI: -2.79
to 1.97; p = 1.000) and CrCl (-0.25; 95% CI: -1.63 to 1.13; p = 1.000). The CrCl <35 group
had higher relative risk of renal function change events with an adjusted relative risk (RR)
of 6.77 (95% CI: 1.53 to 29.88; p = 0.012) at 6 months and an adjusted RR of 3.75 (95% CI:
1.04 to 13.50; p = 0.043) at 12 months.
Calculating CrCl using the Cockcroft-Gault equation is crucial in older patients before
bisphosphonate therapy. Although no significant differences in overall renal function
changes were observed, the CrCl <35 group demonstrated trends of renal function decline
and significantly higher relative risk of renal function change events at months 6 and 12.
172 Joint Conference in Medical Sciences 2025