Effect of Hypertension on Bone Mineral Density of Patients with Rheumatoid Arthritis

Abstract

Objective: Patients with rheumatoid arthritis (RA) are associated with low bone mineral density (BMD). Chronic comorbidities such as type II diabetes mellitus have shown to affect BMD parameters in patients with RA. Hypertension (HT) is a chronic disease and its coexistence with RA can alter bone health. The aim of this study was to investigate if HT affected BMD parameters in RA patients diagnosed for the first time.

Methods: Patients with the diagnosis of RA who underwent BMD studies formed the study population. Patients with HT were sorted from this population and formed a separate group. Healthy controls were drawn from subjects who came for a check-up. BMD was done with the GE Lunar DPX machine. Mean T Scores at spine, femur neck and total femur were recorded. Data from the three groups were analysed and compared. Linear regression analyses were performed.

Results: Analysis suggested that the age had inverse and BMI had direct correlation with BMD T scores in all groups. The additional diagnosis of HT in RA patients was associated with higher BMD as compared to patients with RA, but lower than controls. R² values were 0.341, 0.402 and 0.436 for mean T scores at spine, femur neck and femur total respectively. Figures from multiple regression analysis suggest that BMI alone did not explain the higher T score values in HT patients.

Conclusion: Additional morbidity of HT in RA patients negates the porotic effect of RA as judged by bone densitometry. Hence, BMD reports should be read with caution in these patients.

Keywords: T score; bone mineral density; hypertension; osteoporosis.

Figure 1.

KDE plots of T Scores versus density at different sites in controls, patients with RA and patients with RA+HT.

Figure 2.

Scatter plot of BMI versus T Scores at different sites in controls, patients with RA and patients with RA+HT