Mortality trends in patients with early rheumatoid arthritis over 20 years: results from the Norfolk Arthritis Register

OBJECTIVE

To examine mortality rates in UK patients with early rheumatoid arthritis (RA) from 1990-2011 and compare with population trends.

METHODS

The Norfolk Arthritis Register (NOAR) recruited adults with ≥2 swollen joints for ≥4 weeks: cohort 1 (1990-1994), cohort 2 (1995-1999), and cohort 3 (2000-2004). At baseline, serum rheumatoid factor and anti-citrullinated protein antibody were measured and the 2010 American College of Rheumatology/European League Against Rheumatism RA classification criteria were applied. Patients were followed for 7 years, until emigration or death. The UK Office for National Statistics notified the NOAR of the date and cause of deaths, and provided mortality rates for the Norfolk population. All-cause and cardiovascular-specific standardized mortality ratios (SMRs) were calculated. Poisson regression was used to compare mortality rate ratios (MRRs) between cohorts and then, with cubic splines, to model rates by calendar year. Analyses were performed in patients 1) with early inflammatory arthritis, 2) classified as having RA, and 3) autoantibody positive.

RESULTS

A total of 2,517 patients were included, with 1,639 women (65%) and median age 55 years, and 1,419 (56%) fulfilled the 2010 RA criteria. All-cause and cardiovascular-specific SMRs were significantly elevated in the antibody-positive groups. There was no change in mortality rates over time after accounting for changes in the population rates. In RA patients, all-cause MRRs, compared to cohort 1, were 1.13 (95% confidence interval [95% CI] 0.84-1.52) and 1.00 (95% CI 0.70-1.43) in cohorts 2 and 3, respectively.

CONCLUSION

Mortality rates were increased in patients with RA and SMRs were particularly elevated in those who were autoantibody positive. Compared to the general population, mortality rates have not improved over the past 20 years.

Assessing fitness to drive in brain tumour patients: a grey matter of law, ethics, and medicine

BACKGROUND

Neurocognitive deficits from brain tumours may impair the ability to safely operate a motor vehicle. Although certain jurisdictions in Canada legally require that physicians report patients who are unfit to drive, criteria for determining fitness are not clearly defined for brain tumours.

METHODS

Patients receiving brain radiotherapy at our institution from January to June 2009 were identified using the Oncology Patient Information System. In addition to descriptive statistics, details of driving assessment were reviewed retrospectively. The Fisher exact test was used to determine factors predictive of reporting a patient to the Ontario Ministry of Transportation (mto) as unfit to drive. A logistic regression model was constructed to further determine factors predictive of reporting.

RESULTS

Of the 158 patients available for analysis, 48 (30%) were reported to the mto, and 64 (41%) were advised to stop driving. With respect to the 53 patients with seizures, a report was submitted to the mto for 30 (57%), and a documented discussion about the implications of driving was held with 35 (66%). On univariate analysis, younger age, a central nervous system primary, higher brain radiotherapy dose, unifocal disease, and the presence of seizures were predictive of physician reporting (p < 0.05). On logistic regression modelling, the presence of seizures (odds ratio: 3.9) and a higher radiotherapy dose (odds ratio: 1.3) remained predictive of reporting.

INTERPRETATION

Physicians frequently do not discuss the implications of driving with brain tumour patients or are not properly documenting such advice (or both). Clear and concise reporting guidelines need to be drafted given the legal, medical, and ethical concerns surrounding this public health issue.

Stage I-II non-small-cell lung cancer treated using either stereotactic ablative radiotherapy (SABR) or lobectomy by video-assisted thoracoscopic surgery (VATS): outcomes of a propensity score-matched analysis

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) lobectomy and stereotactic ablative radiotherapy (SABR) are both used for early-stage non-small-cell lung cancer. We carried out a propensity score-matched analysis to compare locoregional control (LRC).

PATIENTS AND METHODS

VATS lobectomy data from six hospitals were retrospectively accessed; SABR data were obtained from a single institution database. Patients were matched using propensity scores based on cTNM stage, age, gender, Charlson comorbidity score, lung function and performance score. Eighty-six VATS and 527 SABR patients were matched blinded to outcome (1:1 ratio, caliper distance 0.025). Locoregional failure was defined as recurrence in/adjacent to the planning target volume/surgical margins, ipsilateral hilum or mediastinum. Recurrences were either biopsy-confirmed or had to be PET-positive and reviewed by a tumor board.

RESULTS

The matched cohort consisted of 64 SABR and 64 VATS patients with the median follow-up of 30 and 16 months, respectively. Post-SABR LRC rates were superior at 1 and 3 years (96.8% and 93.3% versus 86.9% and 82.6%, respectively, P = 0.04). Distant recurrences and overall survival (OS) were not significantly different.

CONCLUSION

This retrospective analysis found a superior LRC after SABR compared with VATS lobectomy, but OS did not differ. Our findings support the need to compare both treatments in a randomized, controlled trial.

Increased responses to the actions of fibroblast growth factor 21 on energy balance and body weight in a seasonal model of adiposity

The present study aimed to investigate the actions of fibroblast growth factor 21 (FGF21) on energy balance in a natural model of relative fatness, the Siberian hamster. Hamsters were studied under long days (LD) to promote weight gain, or short days to induce weight loss, and treated with rhFGF21 (3 mg/kg/day) via s.c. minipumps for 14 days. On days 7-9, detailed assessments of ingestive behaviour, metabolic gas exchange and locomotor activity were made. FGF21 caused substantial (P < 0.0001) weight loss in the fat LD state but not in the lean SD state: at the end of the study, FGF21-treated hamsters in LD lost 18% of body weight compared to vehicle controls, which is comparable to the natural body weight loss observed in SD. Epididymal fat pads, a correlate of total carcass fat content, were reduced by 19% in FGF21 treated hamsters in LD, whereas no difference was found in SD. Body weight loss in LD was associated with a reduction in food intake (P < 0.001) and a decreased respiratory exchange ratio (P < 0.001), indicating increased fat oxidation. Treatment with FGF21 maintained the normal nocturnal increase in oxygen consumption and carbon dioxide production into the early light phase in hamsters in LD, indicating increased energy expenditure, although locomotor activity was unaffected. These data suggest a greater efficacy of FGF21 in hamsters in LD compared to those in SD, which is consistent with both the peripheral and possibly central actions of FGF21 with respect to promoting a lean phenotype. The observed differences in FGF21 sensitivity may relate to day length-induced changes in adipose tissue mass.

A composite computational model of liver glucose homeostasis. II. Exploring system behaviour

Using a composite model of the glucose homeostasis system, consisting of seven interconnected submodels, we enumerate the possible behaviours of the model in response to variation of liver insulin sensitivity and dietary glucose variability. The model can reproduce published experimental manipulations of the glucose homeostasis system and clearly illustrates several important properties of glucose homeostasis-boundedness in model parameters of the region of efficient homeostasis, existence of an insulin sensitivity that allows effective homeostatic control and the importance of transient and oscillatory behaviour in characterizing homeostatic failure. Bifurcation analysis shows that the appearance of a stable limit cycle can be identified.

A composite computational model of liver glucose homeostasis. I. Building the composite model

A computational model of the glucagon/insulin-driven liver glucohomeostasis function, focusing on the buffering of glucose into glycogen, has been developed. The model exemplifies an 'engineering' approach to modelling in systems biology, and was produced by linking together seven component models of separate aspects of the physiology. The component models use a variety of modelling paradigms and degrees of simplification. Model parameters were determined by an iterative hybrid of fitting to high-scale physiological data, and determination from small-scale in vitro experiments or molecular biological techniques. The component models were not originally designed for inclusion within such a composite model, but were integrated, with modification, using our published modelling software and computational frameworks. This approach facilitates the development of large and complex composite models, although, inevitably, some compromises must be made when composing the individual models. Composite models of this form have not previously been demonstrated.

Short-days induce weight loss in Siberian hamsters despite overexpression of the agouti-related peptide gene

Many vertebrates express profound annual cycles of body fattening, although it is not clear whether these represent differential activity of the central pathways known to mediate homeostatic control of food intake and energy expenditure, or whether the recent discovery of a major role for pars tuberalis-ependymal signalling points towards novel mechanisms. We examined this in the Siberian hamster (Phodopus sungorus) by using gene transfection to up-regulate a major orexigenic peptide, agouti-related peptide (AgRP), and then determined whether this increased anabolic drive could prevent the short-day induced winter catabolic state. Infusions of a recombinant adeno-associated virus encoding an AgRP construct into the hypothalamus of hamsters in the long-day obese phase of their seasonal cycle produced a 20% gain in body weight over 6 weeks compared to hamsters receiving a control reporter construct, reflecting a significant increase in food intake and a significant decrease in energy expenditure. However, all hamsters showed a significant, prolonged decrease in body weight when exposed to short photoperiods, despite the hamsters expressing the AgRP construct maintaining a higher food intake and lower energy expenditure relative to the control hamsters. Visualisation of the green fluorescent protein reporter and analysis of AgRP-immunoreactivity confirmed widespread expression of the construct in the hypothalamus, which was maintained for the 21-week duration of the study. In conclusion, the over-expression of AgRP in the hypothalamus produced a profoundly obese state but did not block the seasonal catabolic response, suggesting a separation of rheostatic mechanisms in seasonality from those maintaining homeostasis of energy metabolism.

Effects of the thyromimetic agent diiodothyropropionic acid on body weight, body mass index, and serum lipoproteins: a pilot prospective, randomized, controlled study

CONTEXT

Widespread thyroid hormone actions offer the possibility of developing selective thyromimetic analogs with salutary metabolic properties. Consequently, effects of diiodothyropropionic acid (DITPA) on body weight, serum lipoproteins, and bone metabolism markers were studied in a prospective, controlled, double-blind 24-wk trial, which was primarily designed to assess treatment of stable chronic heart failure.

DESIGN

Eighty-six patients (aged 66 +/- 11 yr, mean +/- sd) were randomized (1:2) to placebo or an escalating DITPA dose (90 to 180, 270, and 360 mg/d) over 8 wk until serum TSH was less than 0.02 mU/liter. Patients were studied at 2, 4, 6, 8, 16, and 24 wk and after 4 wk off study drug. Only 21 DITPA-treated and 27 placebo patients completed the full 24 wk of therapy.

RESULTS

DITPA therapy lowered serum TSH levels and, to a lesser extent, serum T(3) and T(4), but there were no differences in clinical manifestations of thyrotoxicosis or hypothyroidism. Serum total and low-density lipoprotein cholesterol levels both decreased on DITPA; there was a transient decrease in triglycerides and no change in high-density lipoprotein cholesterol. DITPA therapy was associated with significant reduction in body weight, 12.5 lb at 24 wk. Increases in serum osteocalcin, N-telopeptide, and deoxypyridinoline levels were consistent with increased bone turnover on DITPA.

CONCLUSION

This investigation of DITPA actions demonstrated its efficacy in reducing body weight and lowering total and low-density lipoprotein cholesterol levels. However, DITPA's adverse effects at doses used resulted in a high dropout rate and potentially dangerous skeletal actions were observed.