RESUMO
Objective:To investigate the clinical significance of detecting serum 25-hydroxyl-vitamin D [25(OH)D] level and albumin/fibrinogen ratio (AFR) in patients with rheumatoid arthritis (RA).Methods:This retrospective study included 131 patients (95 patients with RA and 36 with arthralgia excluding autoimmune diseases), who were treated in Bozhou People′s Hospital from May 2017 to January 2020. Forty healthy controls underwent health checkups during the same period served as healthy control. RA group was divided into high (>5.1, 25 cases), medium (3.2<DAS28-CRP≤5.1), 40 cases and low (≤3.2, 30 cases) subgroups by disease activity (DAS28-CRP) based on 28 joint counts and the level of C-reactive protein(CRP). RA patients were further divided into normal (≥30 ng/ml, 17 cases), insufficient (20 ng/ml ≤ 25(OH)D<30 ng/ml, 31 cases) and deficient (<20 ng/ml, 47 cases) subgroups according to the serum 25(OH)D concentration; 4 age subgroups (≤44 years of 21 cases, 45-59 years of 43 cases, 60-74 years of 21 cases and ≥75 years of 10 cases); 2 sex subgroups (79 female and 16 male). Serum 25(OH)D, albumin and fibrinogen levels were measured in all patients and healthy controls. The general clinical and laboratory indexes were collected and analyzed. Multivariate logistic regression analyses were performed to determine the independent risk factors of RA.Results:The serum 25(OH)D concentration and albumin/fibrinogen ratio were lower ( P<0.05) in rheumatoid arthritis patients than those in other groups, and serum 25(OH)D insufficiency or deficiency was evidenced in 82.11% (78/95) rheumatoid arthritis patients. Among patients with rheumatoid arthritis, the levels of 25(OH)D were apparently different in various age groups ( P<0.05) and significantly lower in female than those in male ( P<0.05). In addition, a significant negative correlation was found between AFR and DAS28-CRP ( r=-0.497, P<0.01). Logistic regression analysis showed that 25(OH)D ( OR=0.852, 95% CI: 0.768-0.944, P=0.002) and AFR ( OR=0.626, 95% CI 0.480-0.817, P=0.001), RF-IgM ( OR=1.044, 95% CI 1.019-1.069, P<0.001) and anti-CCP antibodies ( OR=1.017, 95% CI 1.002-1.032, P=0.030) were independent risk factors for disease activity in RA patients. Conclusions:The serum 25(OH)D and AFR levels are significantly reduced and 5(OH)D insufficiency or deficiency is common in RA patients, suggesting that low levels of 25(OH)D and AFR may be the risk factors reflecting the RA disease activity.