Antioxidant intervention in rheumatoid arthritis: results of an open pilot study

There is evidence that reactive oxygen species play a causal role in auto-immune diseases, such as rheumatoid arthritis (RA). Despite the supporting evidence for a beneficial effect of antioxidants on clinical characteristics of RA, the right balance for optimal effectiveness of antioxidants is largely unknown. To determine the potential beneficial effects of an antioxidant intervention on clinical parameters for RA, an open pilot study was designed. Eight non-smoking female patients with rheumatoid factor + RA and a Disease Activity Score (DAS 28) higher than 2.5 were enrolled in the study. Patients had to be receiving stable non-steroidal anti-inflammatory drug treatment and/or ‘second line’ medication for at least 3 months. The pilot group consumed 20 g of antioxidant-enriched spread daily during a period of 10 weeks. The intervention was stopped after 10 weeks and was followed by a ‘wash-out’ period of 4 weeks. At t = 0, t = 10 weeks and t = 14 weeks, patients’ condition was assessed by means of DAS. In addition, standard laboratory analyses were performed, and blood-samples for antioxidants were taken. The antioxidant-enriched spread was well tolerated. All laboratory measures of inflammatory activity and oxidative modification were generally unchanged. However, the number of swollen and painful joints were significantly decreased and general health significantly increased, as reflected by a significantly improved (1.6) DAS at t = 10 weeks. The antioxidant effect was considered beneficial as, compared to the scores at t = 0, the DAS significantly reduced at t = 10 weeks. Increase of the DAS (0.7) after the “wash-out period” at t = 14 confirmed a causal relation between changes in clinical condition and antioxidants. This open pilot study aimed to assess the clinical relevance of an antioxidant intervention as a first step in assessing potential beneficial effects of antioxidants on rheumatoid arthritis. These conclusions need to be validated in a larger controlled study population

Weight reduction is not a major reason for improvement in rheumatoid arthritis from lacto-vegetarian, vegan or Mediterranean diets

OBJECTIVES: Several investigators have reported that clinical improvements of patients with rheumatoid arthritis (RA), from participating in therapeutic diet intervention studies, have been accompanied by loss of body weight. This has raised the question whether weight reduction per se can improve RA. In order to test this hypothesis, three previously conducted diet intervention studies, comprising 95 patients with RA, were pooled. Together with Age, Gender, and Disease Duration, change during the test period in body weight, characterised dichotomously as reduction or no reduction (dichoΔBody Weight), as well as Diet (dichotomously as ordinary diet or test diet), were the independent variables. Dependent variables were the difference (Δ) from baseline to conclusion of the study in five different disease outcome measures. ΔESR and ΔPain Score were both characterised numerically and dichotomously (improvement or no improvement). ΔAcute Phase Response, ΔPhysical Function, and ΔTender Joint Count were characterised dichotomously only. Multiple logistic regression was used to analyse associations between the independent and the disease outcome variables. RESULTS: Statistically significant correlations were found between Diet and three disease outcome variables i.e. ΔAcute-Phase Response, ΔPain Score, and ΔPhysical Function. Δ Body Weight was univariately only correlated to ΔAcute-Phase Response but not significant when diet was taken into account. CONCLUSION: Body weight reduction did not significantly contribute to the improvement in rheumatoid arthritis when eating lacto-vegetarian, vegan or Mediterranean diets

An experimental study of a Mediterranean diet intervention for patients with rheumatoid arthritis

Objective: To investigate the efficacy of a Mediterranean diet (MD) versus an ordinary Western diet for suppression of disease activity in patients with rheumatoid arthritis (RA). Methods: Patients with well controlled, although active RA of at least two years' duration, who were receiving stable pharmacological treatment, were invited to participate. All patients were randomly allocated to the MD or the control diet (CD). To achieve good compliance with prescribed diets all patients were for the first three weeks served the MD or the CD, respectively, for lunch and dinner at the outpatient clinic's canteen. Clinical examinations were performed at baseline, and again in the 3rd, 6th, and 12th week. A composite disease activity index (DAS28), a physical function index (Health Assessment Questionnaire (HAQ)), a health survey of quality of life (Short Form-36 (SF-36)), and the daily consumption of non-steroidal anti-inflammatory drugs were used as primary efficacy variables. Results: From baseline to the end of the study the patients in the MD group (n=26) showed a decrease in DAS28 of 0.56 (p<0.001), in HAQ of 0.15 (p=0.020), and in two dimensions of the SF-36 Health Survey: an increase in "vitality" of 11.3 (p=0.018) and a decrease in "compared with one year earlier" of 0.6 (p=0.016). For the control patients (n=25) no significant change was seen at the end of the study. This difference between the two treatment groups was notable only in the second half of the trial. Conclusion: The results indicate that patients with RA, by adjusting to a Mediterranean diet, did obtain a reduction in inflammatory activity, an increase in physical function, and improved vitality

Handel av oljeterminkontrakter : En tilnærming basert på kointegrasjon

Finansmarkedet består av en rekke aktører som er på stadig søken etter potensielle investeringsmuligheter eller instrumenter som kan bidra til å redusere risiko. Oljemarkedet utgjør et av verdens største markeder. Det omsettes olje daglig, men også oljekontrakter hvor futureskontrakter er godt representert. Futureskontrakter benyttes ofte som risikoreduserende verktøy i en portefølje, eller som investeringsobjekt. Tidligere forskning har ved en rekke anledninger avdekket at det foreligger stasjonæritet mellom kontrakter for henholdsvis råolje og heating oil for ulike tidsperioder. Teorien bygger på at prisforskjellen mellom kontraktene bør utgjøre kostnader forbundet med selve raffineringsprosessen. Avvik utover dette kan da by på investeringsmuligheter, da det er grunn til å tro at tilstanden mellom kontraktene vil normalisere seg. Fenomenet omtales som spread trading, hvor prisforskjellen mellom råolje og raffinerte produkter som heating oil, utgjør en investeringsmulighet. Den første delen av vår oppgave vil fremstå som en parallellstudie til en artikkel utarbeidet av Westgaard et al (2011). De avdekket stasjonæritet for kontrakter med henholdsvis en og to måneders varighet til oppgjørsdato, men ikke 3-6 og 12. Datasamlingen ble hentet fra ICS Futures Europe fra perioden 1994 – 2009. For å avdekke regionale forskjeller benyttet vi data fra NYMEX som testes for stasjonæritet for tilsvarende periode. Kontraktene utgjør 1, 2, 3,6 og 12 måneder til oppgjør. Vårt resultat avslører at den førsteordensderiverte, LN-avkastningen, er stasjonær for alle kontraktene vi testet. Både for perioden 3/1-1994 (30/10-1995 for 12-pos) til 23/3-2012 og for perioden 1/3-2002 til 23/3-2012. Dette betyr at det vil være grunnlag for å benytte kointegrasjon til å beskrive forholdet mellom tidsseriene. Vi har også testet korrelasjon mellom avkastningen på kontrakter for lett råolje og heating oil med ulik varighet. Her er det interessant å merke seg at korrelasjonen mellom disse kontraktene på NYMEX er mye høyere enn det Westgaard et. al. (2011) fant i en lignende undersøkelse mellom Brent lett råolje og gas oil kontrakter på ICE Futures Europe. Både Engle-Granger-metoden (1987), og Johansen-metoden (1988) har blitt benyttet for å teste for kointegrasjon. Vi valgte å teste for kointegrasjon for 3 ulike tidsperioder. Perioden 3/1-1994 (30/10-1995 for 12-pos) til 23/3-2012, perioden 1/3-2002 til 23/3-2012 og perioden 1/3-2002 til 9/11-2009. Sistnevnte periode er valgt for å være en nøyaktig parallell til analysen som er gjort av Westgaard et. al (2011). Vi fikk ikke det samme resultat som Westgaard et. al (2011). For tilsvarende periode på kontraktene notert på NYMEX, fikk vi påvist stasjonæritet for alle de ulike kontrakts lengder. Ettersom vi kunne påvise kointegrasjon i dette markedet var vi for øvrig i stand til å implementere ulike handelsstrategier for å forsøke å utnytte forholdet mellom disse kontraktene. Tradingsstrategiene er inspirert av metoden Taylor (2005) beskriver rundt glidende gjennomsnitt som handelsstrategi, samt Girma & Paulson (1999) og Murat & Tokat (2009). Det var fire hovedstrategier vi benyttet. 1. Spread beregnet i absolutte USD med øvre og nedre bånd beregnet i prosent av glidende gjennomsnitt. 2. Spread beregnet i absolutte USD med øvre og nedre bånd beregnet i standardavvik av glidende gjennomsnitt. 3. Spread beregnet i prosent av lett råoljepris med øvre og nedre bånd beregnet i prosent av glidende gjennomsnitt 4. Spread beregnet i prosent av lett råoljepris med øvre og nedre bånd beregnet med standardavvik av glidende gjennomsnitt. Resultatet fra våre tester, både for prøveperioden og backtesten, indikerer at tradingmodellen gir en positiv avkastning. Det var for øvrig forskjeller mellom strategiene. Strategi 2 og strategi 4 skilte seg ut som bedre strategier enn strategi 1 og strategi 3. Både under prøveperioden og ved backtesten. Strategi 2 og strategi 4 var best på hver sine kontraktstyper, men ved å benytte risikoindikatorer som standardavvik, median og gjennomsnitt, vil strategi 4 fremstå som mest attraktiv. Det er for øvrig viktig at hver enkelt investor tar hensyn til sine risikopreferanser. Selv om både strategi 2 og strategi 4 endte opp med å produsere positiv gevinst over perioden ser vi at det er langt fra risikofritt. Testene er utført på data fra en periode hvor det var mye turbulens i markedet. Eurokrisen, Libya-krisen, den spente situasjonen i Iran, og en rekke andre internasjonale hendelser, har gjort dette til en vanskelig periode å handle i. To av handelsstrategiene klarte til tross for dette å skape en positiv gevinst for alle 5 kontraktstyper i dette klimaet. Vår oppgave, i kombinasjon med tidligere funn, indikerer at det bør være mulig å anvende strategier basert på statistisk arbitrasje og kointegrasjon til å skape en positiv avkastning over tid ved handel på bakgrunn av spread- forholdet mellom oljeterminkontrakter

Validity of reported energy expenditure and reported intake of energy, protein, sodium and potassium in rheumatoid arthritis patients in a dietary intervention study

Validity of reported energy expenditure and reported intake of energy, protein, sodium and potassium in rheumatoid arthritis patients in a dietary intervention study. Hagfors L, Westerterp K, Skoldstam L, Johansson G. Department of Food and Nutrition, Umea University, Umea, Sweden. [email protected] OBJECTIVES: The aim of the study was to validate a diet history interview (DHI) method and a 3-day activity registration (AR) with biological markers. SUBJECTS AND STUDY DESIGN: The reported dietary intake of 33 rheumatoid arthritis patients (17 patients on a Mediterranean-type diet and 16 patients on a control diet) participating in a dietary intervention study was assessed using the DHI method. The total energy expenditure (TEE), estimated by a 3-day AR, was used to validate the energy intake (EI). For nine subjects the activity registration was also validated by means of the doubly labelled water (DLW) method. The excretion of nitrogen, sodium and potassium in 24-h urine samples was used to validate the intake of protein, sodium and potassium. RESULTS: There was no significant difference between the EI and the TEE estimated by the activity registration or between the intake of protein, sodium and potassium and their respective biological markers. However, in general, the AR underestimated the TEE compared to the DLW method. No significant differences were found between the subjects in the Mediterranean diet group and the control diet group regarding the relationship between the reported intakes and the biological markers. CONCLUSION: The DHI could capture the dietary intake fairly well, and the dietary assessment was not biased by the dietary intervention. The AR showed a bias towards underestimation when compared to the DLW method. This illustrates the importance of valid biological markers