Retrospective Analysis of Use of Angiotensin Receptor Blockers and Patellar Cartilage Volume Among Patients with Knee Osteoarthritis
Authors: Kale Vijay , Jackson Kendra 
Published: May 2022

PurposeWe reported Losartan reduces loss of patellar cartilage in patients with knee osteoarthritis (Kale & Jackson FASBEBJ, 35(S1) and using animal model (Osteoarthritis and Cartilage, 2019, 27; 676‐686). This retrospective study explores whether the patellar cartilage volume loss reduction in patients with knee osteoarthritis is class effect of Angiotensin Receptor Blockers (ARBs) or it is confined to losartan.MethodsData for this study was used from Osteoarthritis Initiative (OAI) publicly available database. A total of 4796 men and women aged 45‐79 years were into the study primarily consisting of those with knee OA and those at high risk for developing knee OA. Our study focused on the progression sub cohort, which consisted of 1390 subjects with knee OA. This study used three measurement periods; baseline, 12 months and 24 months. Patients with missing data for entire series or part missing data were excluded from analysis. Patients’ data then divided into losartan group, control group (patients without losartan, and without other ARBs) and patients with other ARBs (excluding losartan). Specific data sets for the analysis included of demographics such age, sex, race (Clinical_FNOH, Enrollees), patient drug usage (MIF00), Magnetic Resonance Imaging (MRI) data sets on cartilage volume were used from KMRI_FNIH_Qcart_Biomediq00 (baseline), KMRI_FNIH_Qcart_Biomediq01 (12 months), and KMRI_FNIH_Qcart_Biomediq03 (24 months). The patellar cartilage volume variables were V00PatellarCartilage (baseline), V01PatellarCartilage (12 months) and V03PatellarCartilage (24 months). Additional protocol details are published and available on the internet (https://oai.epi‐ucsf.org/datarelease/docs/StudyDesignProtocol.pdf).ResultsOur analysis of the progression sub cohort included a total of 582 patients with symptomatic knee OA. For identifying effects of losartan as reported previously, our analysis of the progression sub cohort included a total of 85 (44 %) were men and 108 (56 %) women with symptomatic knee OA. Average age of the participants for this group was 59.6 years (SD, 8.7 years; range, 45–78 years). Most of the participants in this group were Caucasian (n=142; 73.6 %) and African American (n=42; 21.8 %). Of the 193 patients included in analysis for effect of losartan, 30 patients were taking losartan and remaining 163 patients were placed into control group. Average age of the participants was 59.6 years (SD, 8.7 years; range, 45–78 years).Our analysis show that there was no significant loss of cartilage volume with patients on losartan over baseline at 12 months (5 %) and 24 months (8 %) post enrollment. Patients without losartan showed significantly higher cartilage loss at 24 months post enrollment over baseline (~15 %, p≤ 0.05, Student’s t‐test assuming unequal variances).For the ARBs group, preliminary analysis showed that there are 478 patients taking ARBs excluding losartan. Among the 478 patients, 77 patients have complete patellar cartilage volume data for three time points which we will use for our analysis.ConclusionThis study suggests that losartan reduces loss of patellar cartilage in patients with knee osteoarthritis. Analysis of other ARBs and their effects on cartilage volume is in progress.