Background and Objectives: We investigated whether nutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphoycte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are associated with the presence of osteoporosis (OP) and vertebral fractures in patients with rheumatoid arthritis (RA). Materials and Methods: This retrospective cohort study included 413 postmenopausal patients with RA and 200 healthy controls who underwent dual-energy X-ray absorptiometry (DEXA) between January 2005 and December 2017. DEXA examination data were defined as the index date, and all laboratory values were measured within one month from the index date. OP was defined as a T-score < −2.5, and incident vertebral fractures were defined as the first occurrence of non-traumatic fractures after the index date. NLR, PLR, and MLR measures were dichotomized by a median split (low vs. high). Results: The median NLR, PLR, and MLR in RA patients were significantly higher than those in controls. The frequencies of OP of the lumbar spine, hip, and either site in postmenopausal patients with RA were 24.7%, 15.5%, and 32%, respectively, and were significantly higher than those in controls. After adjusting for confounding factors, a high baseline NLR was significantly associated with OP at either site (OR = 1.61, p = 0.041). In addition, high baseline NLR (OR = 2.11, p = 0.025) and PLR (OR = 2.3, p = 0.011) were related with the presence OP at hip. During the follow-up period, 53 (12.8%) patients with RA developed vertebral fractures incidentally. In multivariable Cox regression models, a high baseline NLR (HR = 4.72, p < 0.001), PLR (HR = 1.96, p = 0.024), and MLR (HR = 2.64, p = 0.002) were independently associated with a higher risk of incidental vertebral fractures. Conclusions: Our data suggest that NLR, PLR, and MLR can be used as potential markers of systemic bone loss among individuals with RA.

Background: To investigate the diagnostic performance of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in the diagnosis of rheumatoid arthritis (RA) in subjects with undifferentiated inflammatory arthritis (UIA). Methods: This retrospective cohort study investigated 201 female patients with UIA (≥1 swollen joint) and 280 age-matched, healthy female controls. “Clinical RA” was defined based on the clinical judgment of a rheumatologist and “disease-modifying anti-rheumatic drugs (DMARDs) RA” was defined as a case of initiating DMARDs treatment within 6 months after the first visit. “Classified RA” was defined as fulfilling the 2010 classification criteria for RA. Receiver operating characteristics were used to determine the optimal cut-off value. Results: UIA patients had a significantly higher NLR, PLR, and MLR than the controls. Among the 201 UIA patients, 65 (32.3%), 63 (31.3%), and 61 (30.3%) subjects were classified as clinical RA, DMARDs RA, and classified RA, respectively. At a cut-off of 0.24, MLR showed moderate accuracy for the diagnosis of DMARDs RA (sensitivity, 65.1%; specificity, 62.3%; area under the curve [AUC], 0.701; p < 0.001). However, the diagnostic accuracies of NLR and PLR were low. Conclusions: MLR may be used as a complementary diagnostic indicator for RA diagnosis in patients with UIA.

Most previous research investigating osteoporosis in rheumatoid arthritis (RA) has focused on female patients and there is a lack of data regarding clinical characteristics of osteoporosis in male patients with RA. The aim of this study was to compare the frequency of osteoporosis between male patients with RA and healthy patients, and to identify the risk factors for osteoporosis and low bone mineral density (BMD) in male patients with RA. We conducted a retrospective, cross-sectional study including 76 South Korean male patients with RA aged over 50 years and 76 age-matched male healthy individuals. BMD was measured at the lumbar spine (L1-4) and left hip (femoral neck and total hip) using dual energy X-ray absorptiometry. Osteoporosis was defined as a T-score of ≤ −2.5 according to the World Health Organization (WHO) classification. The frequency of osteoporosis at either the spine or the hip among male patients with RA was significantly higher than that among controls (22.4% vs 10.5%, P = .049) and RA patients had a significantly lower total hip BMD than healthy individuals (0.92 ± 0.14 vs 0.96 ± 0.1 g/cm2, P = .027). For male RA patients, the mean 28-joint Disease Activity Scores using erythrocyte sedimentation rate (DAS28-ESR) and body mass index (BMI) were 3.28 and 22 kg/m2, respectively. In multivariable logistic regression models, BMI ≤ 22 kg/m2 (odds ratio = 3.43, P = .043) and DAS28-ESR > 3.2 (odds ratio = 3.85, P = .032) were independent risk factors for osteoporosis at either site in male patients with RA. Our data demonstrate that male patients with RA had a 2.1 times higher risk for osteoporosis compared with healthy individuals. This suggests that appropriate management of osteoporosis in patients with RA is crucial not only for postmenopausal women but also for men aged over 50 years, especially those with low BMI and higher disease activity.