Associations of blood pressure and arterial stiffness with knee cartilage volume in patients with knee osteoarthritis

Blood pressure is associated with knee pain severity in middle-aged and elderly individuals with or at risks for osteoarthritis: data from the Osteoarthritis Initiative

BACKGROUND

Hypertension is a common comorbidity of osteoarthritis (OA). Joint pain is the main clinical manifestation of OA. Knowledge about the relationship between hypertension and OA pain is limited. This study aimed to investigate whether blood pressure parameters are associated with knee pain severity in individuals with or at risks for OA.

METHODS

Our sample consisted of 2598 subjects (60.7% female, aged 45-79 years) collected from the Osteoarthritis Initiative. Blood pressure parameters included blood pressure stage, systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP). Radiographic evaluation using Kellgren-Lawrence system and pain severity evaluation using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Numeric Rating Scale (NRS) were performed for right knee. Linear regression was used to examine the relationship between blood pressure parameters and knee pain severity.

RESULTS

For the overall sample, blood pressure stage, SBP, and PP were positively correlated with WOMAC and NRS pain scores when adjusting for age, sex, and body mass index (BMI) (p ≤ 0.024) and were inversely correlated with KOOS score (p ≤ 0.004). After further adjusting for all covariates, PP remained a positive correlation with WOMAC score (p = 0.037) while other associations between blood pressure parameters and pain scores did not reach the statistical significance. In female, higher blood pressure stage, SBP, and PP were significantly associated with increased WOMAC and NRS scores and decreased KOOS score after adjustments of age and BMI (p ≤ 0.018). When adjusting for all covariates, the correlations of PP with WOMAC, KOOS and NRS scores remained significant (p = 0.008-0.049). In male sample, SBP was positively correlated with WOMAC score when adjusting for age and BMI (p = 0.050), but other associations between blood pressure parameters and pain scores were not statistically significant. No significant correlation was observed in male when further adjusting for other covariates.

CONCLUSIONS

Increased PP is a risk factor for knee pain and mainly affects females, which suggested that controlling PP may be beneficial in preventing or reducing knee pain in females with or at risks for OA.

Assessment of aortic and peripheral arterial stiffness in patients with knee osteoarthritis by ultrasound Doppler derived pulse wave velocity

Information regarding regional arterial stiffness assessment in osteoarthritis (OA) was scarce and sometimes contradictory. We aimed to investigate the aortic, lower limb peripheral arterial stiffness and their associations with knee OA. Patients with primary knee OA and matched non-OA controls were prospectively enrolled from two medical centers in China. The carotid-femoral pulse wave velocity (cfPWV) and femoral-ankle pulse wave velocity (faPWV) were measured using a novel ultrasound technique. A total of 238 participants (including 128 patients with knee OA and 110 controls) were included. In OA patients, cfPWV was significantly higher than that of non-OA controls (9.40 ± 1.92 vs 8.25 ± 1.26 m/s, P < 0.0001). However, faPWV measurements in OA patients (12.10 ± 2.09 m/s) showed no significant difference compared with that of the controls (11.67 ± 2.52 m/s, P = 0.130). Multiple regression analysis revealed that cfPWV was independently associated with knee OA (P < 0.0001) after adjusting for the confounding factors including age, gender, smoking, mean blood pressure, body mass index, heart rate, high-sensitivity C-reactive protein and lipids profiles. In contrast, faPWV did not show independent association with knee OA (P = 0.372) when after adjusting for confounding factors. In addition, Spearman's correlation analysis showed cfPWV had a significant correlation with Kellgren-Lawrence score (rs = 0.2333, P = 0.008), but no correlation was founded between faPWV with Kellgren-Lawrence score (rs = 0.1624, P = 0.067) in OA patients. This study demonstrated that stiffening of aorta, but not lower limb arteries, was independently associated with knee OA. Our findings may call for further implementation of routine aortic stiffness assessments so as to evaluate cardiovascular risk in patients with OA.

Effects of blood pressure and antihypertensive drugs on osteoarthritis: a mendelian randomized study

BACKGROUND

Previous studies have suggested that antihypertensive drugs may play a role in the treatment of osteoarthritis, but these studies may be limited by confounding factors and lead to biased results. Therefore, we conducted a Mendelian randomization study to investigate the effects of blood pressure and antihypertensive drugs on osteoarthritis.

METHODS

We used published large-scale genome-wide association data and applied univariate and multivariate Mendelian randomization methods. The main analysis model was inverse variance weighting, and the reliability of the results was tested using MR-Egger intercept analysis, Cochran's Q test, and leave-one-out analysis. We comprehensively evaluated the relationship between systolic blood pressure, diastolic blood pressure, 12 antihypertensive drugs, and osteoarthritis. We also conducted verification in the independent queue of UK Biobank and built a simple linear regression model to obtain an independent comparison.

RESULTS

We found no evidence that systolic and diastolic blood pressure significantly affected osteoarthritis. However, among antihypertensive drugs, we observed a significant positive correlation between potassium-preserving diuretics and aldosterone antagonists and all osteoarthritis (OR: 0.560, 95% CI 0.406-0.772, P = 0.0004). Sensitivity analysis showed no horizontal pleiotropy or heterogeneity, and the leave-one-out analysis demonstrated the reliability of the results. This result was replicated with nominally statistical significance in the validation cohort and exhibited significant correlation in the linear regression analysis.

CONCLUSIONS

Our study suggested that controlling the protein targets of potassium-sparing diuretics and aldosterone antagonists may have beneficial results for osteoarthritis. These findings provide valuable medication strategies for the control of hypertension in patients with osteoarthritis.