Comorbidity in multiple sclerosis is associated with diagnostic delays and increased mortality.

OBJECTIVE: To investigate the effect of chronic comorbidity on the time of diagnosis of multiple sclerosis (MS) and on mortality in MS. METHODS: We conducted a population-based, nationwide cohort study including all incident MS cases in Denmark with first MS symptom between 1980 and 2005. To investigate the time of diagnosis, we compared individuals with and without chronic comorbidity using multinomial logistic regression. To investigate mortality, we used Cox regression with time-dependent covariates, following study participants from clinical MS onset until endpoint (death) or to the end of the study, censuring at emigration. RESULTS: We identified 8,947 individuals with clinical onset of MS between 1980 and 2005. In the study of time of diagnosis, we found statistically significant odds ratios for longer diagnostic delays with cerebrovascular comorbidity (2.01 [1.44-2.80]; <0.0005), cardiovascular comorbidity (4.04 [2.78-5.87]; <0.0005), lung comorbidity (1.93 [1.42-2.62]; <0.0005), diabetes comorbidity (1.78 [1.04-3.06]; 0.035), and cancer comorbidity (2.10 [1.20-3.67]; 0.009). In the mortality study, we found higher hazard ratios with psychiatric comorbidity (2.42 [1.67-3.01]; <0.0005), cerebrovascular comorbidity (2.47 [2.05-2.79]; <0.0005), cardiovascular comorbidity (1.68 [1.39-2.03]; <0.0005), lung comorbidity (1.23 [1.01-1.50]; 0.036), diabetes comorbidity (1.39 [1.05-1.85]; 0.021), cancer comorbidity (3.51 [2.94-4.19]; <0.0005), and Parkinson disease comorbidity (2.85 [1.34-6.06]; 0.007). CONCLUSIONS: An increased awareness of both the necessity of neurologic evaluation of new neurologic symptoms in persons with preexisting chronic disease and of optimum treatment of comorbidity in MS is critical.

Inverse comorbidity in multiple sclerosis: Findings in a complete nationwide cohort.

BACKGROUND: Inverse comorbidity is disease occurring at lower rates than expected among persons with a given index disease. The objective was to identify inverse comorbidity in MS. METHODS: We performed a combined case-control and cohort study in a total nationwide cohort of cases with clinical onset of MS 1980-2005. We randomly matched each MS-case with five population controls. Comorbidity data were obtained from multiple, independent nationwide registries. Cases and controls were followed from January 1977 to the index date, and from the index date through December 2012. We controlled for false discovery rate and investigated each of eight pre-specified comorbidity categories: psychiatric, cerebrovascular, cardiovascular, lung, and autoimmune comorbidities, diabetes, cancer, and Parkinson's disease. RESULTS: A total of 8947 MS-cases and 44,735 controls were eligible for inclusion. We found no inverse associations with MS before the index date. After the index date, we found a decreased occurrence of chronic lung disease (asthma and chronic obstructive pulmonary disease) (HR 0.80 (95% CI 0.75-0.86, p<0.00025)) and overall cancer (HR 0.88 (95% CI 0.81-0.95, p=0.0005)) among MS-cases. CONCLUSION: This study showed a decreased risk of cancers and pulmonary diseases after onset of MS. Identification of inverse comorbidity and of its underlying mechanisms may provide important new entry points into the understanding of MS.

Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice: an observational study from the DANBIO registry and the Copenhagen Osteoarthritis Study.

BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking. In this study, we aimed to: 1) establish reference values for normal hand bone mass (bone mineral density measured by digital x-ray radiogrammetry (DXR-BMD)); and 2) examine whether HBL is normalised in rheumatoid arthritis patients during treatment with tumour necrosis factor alpha inhibitors (TNFI). METHODS: DXR-BMD was measured from hand x-rays in a reference cohort (1485 men/2541 women) without arthritis randomly selected from an urban Danish population. Sex- and age-related HBL/year was estimated. DXR-BMD was measured in rheumatoid arthritis patients (n = 350: at start of TNFI, and ~2 years after TNFI start), of which 135 patients had three x-rays (~2 years prior to TNFI, at start of TNFI, and ~2 years after TNFI start). Individual HBL/year prior to and during TNFI was calculated and compared to reference values. RESULTS: Estimated HBL/year varied strongly with age and sex. Compared to the reference values, 75 % of 135 patients had increased HBL prior to TNFI treatment and 59 % had increased HBL during TNFI treatment (p = 0.17, Chi-squared). In 38 % (38/101) of patients with increased HBL, HBL was normalised during TNFI treatment, whereas 47 % (16/34) of patients with normal HBL prior to TNFI had increased HBL during TNFI treatment. In the 350 patients, increased HBL during TNFI was associated with time-averaged 28-joint disease activity score (odds ratio 1.69 (95 % Confidence Interval 1.34-2.15)/unit increase, p < 0.001), and patients in time-averaged remission had lower HBL than patients without remission (0.0032 vs. 0.0058 g/cm(2)/year; p < 0.001, Mann-Whitney). CONCLUSIONS: We established age- and sex-specific reference values for DXR-BMD in a large cohort without arthritis. HBL was increased in the majority of rheumatoid arthritis patients initiating TNFI in clinical practice, and only normalised in a minority during TNFI.

Which factors influence radiographic progression during treatment with tumor necrosis factor inhibitors in clinical practice? Results from 930 patients with rheumatoid arthritis in the nationwide Danish DANBIO registry.

OBJECTIVE: To investigate baseline characteristics associated with radiographic progression and the effect of disease activity, drug, switching, and withdrawal on radiographic progression in tumor necrosis factor (TNF) inhibitor-naive patients with rheumatoid arthritis (RA) followed for about 2 years after anti-TNF initiation in clinical practice. METHODS: DANBIO-registered patients with RA who had available radiographs (anti-TNF initiation and ∼2 yrs followup) were included. Radiographs were scored, blinded to chronology with the Sharp/van der Heijde method and linked with DANBIO data. Baseline characteristics were investigated with univariate regression and significant variables included in a multivariable logistic regression analysis with ± radiographic progression [Δ total Sharp score (TSS) > 0] as dependent variable. Effect of time-averaged C-reactive protein (CRP), 28-joint Disease Activity Score with CRP (DAS28-CRP), and treatment status at followup were investigated with univariate regression analysis. RESULTS: The study included 930 patients. They were 75% women, 79% positive for IgM-rheumatoid factor (IgM-RF), median age was 57 yrs (range 19-88), disease duration 9 yrs (1-59), DAS28-CRP 5.0 (1.4-7.8), TSS median 15 [3-45 interquartile range (IQR)] and mean 31 (SD 40). Patients started treatment with infliximab (59%), etanercept (18%), or adalimumab (23%). At followup (median 526 days, IQR 392-735), 61% were treated with the initial anti-TNF, 29% had switched TNF inhibitor, and 10% had withdrawn. Twenty-seven percent of patients had progressed radiographically. ΔTSS was median 0.0 [0.0-0.5 IQR/mean 0.6 (SD 2.4)] units/year. Higher TSS, older age, positive IgM-RF, and concomitant prednisolone at baseline were associated with radiographic progression. Time-averaged DAS28-CRP and time-averaged CRP, but not type of TNF inhibitor, were associated with radiographic progression. Patients who stopped/switched during followup progressed more than patients who continued treatment. CONCLUSION: High TSS, older age, IgM-RF positivity, and concomitant prednisolone were associated with radiographic progression during 2 years of followup of 930 anti-TNF-treated patients with RA in clinical practice. High disease activity and switching/stopping anti-TNF treatment were associated with radiographic progression.

Impact of tumour necrosis factor inhibitor treatment on radiographic progression in rheumatoid arthritis patients in clinical practice: results from the nationwide Danish DANBIO registry.

OBJECTIVES: To compare radiographic progression during treatment with disease-modifying antirheumatic drugs (DMARD) and subsequent treatment with tumour necrosis factor α inhibitors (TNF-I) in rheumatoid arthritis (RA) patients in clinical practice. METHODS: Conventional radiographs (x-rays) of hands and wrists were obtained ∼2 years before start (prebaseline), at baseline and ∼2 years after start (follow-up) of TNF-I. Clinical data were obtained from the DANBIO registry and the patient files. x-Rays were scored blinded to chronology according to the Sharp/van der Heijde method. Annual radiographic progression rates during the DMARD (prebaseline to baseline x-ray) and TNF-I (baseline to follow-up x-ray) periods were calculated. RESULTS: 517 RA patients (76% women, 80% IgM rheumatoid factor positive, 65% anticyclic citrullinated peptide positive, 40% current smokers, age 54 years (range 21-86), median disease duration 5 years (range 0-57)) were included. Patients were treated with infliximab (61%), etanercept (15%) or adalimumab (24%). During the DMARD period 85% of patients received methotrexate, 51% sulphasalazine and 78% prednisolone. The median DMARD period was 733 days (IQR 484-1002) and the median TNF-I period was 562 days (IQR 405-766). The median radiographic progression rate decreased from 0.7 (IQR 0-2.9) total Sharp score units/year (dTSS) in the DMARD period to 0 (0-0.9) units/year in the TNF-I period (p<0.0001, Wilcoxon). Corresponding mean dTSS values were 2.1 (SD 3.7) versus 0.7 (SD 2.3) units/year (p<0.0001, paired t test). 305 patients progressed (dTSS >0) in the DMARD period compared with 158 patients in the TNF-I period (p<0.0001, χ(2)). CONCLUSION: This nationwide observational study of RA patients documented significantly reduced radiographic progression during TNF-I treatment compared with the previous period of DMARD treatment.