Objective. To determine the association of obesity, defined as a body mass index (BMI) >30 or >28 kg/m 2 or by waist circumference (WC), with disease activity and severity, as well as its relationship to comorbidities in rheumatoid arthritis (RA). 9% at baseline and 15.8% at followup. In multivariable regression, BMI and obesity, defined as a BMI >30 or >28 kg/m 2 , at both inclusion and the time of the survey were independently associated with higher disease activity, fewer patients in sustained remission, higher HAQ score, more pain, and worse general health. Also, BMI and obesity independently conferred to higher odds for being diagnosed with hypertension, diabetes mellitus, and chronic pulmonary disease. Further, BMI and WC were independently associated with angina pectoris/acute myocardial infarction/coronary revascularization. In contrast, none of the examined obesity variables was associated with the prevalence of stroke or transient ischemic attack. Lifestyle changes during the observational period, such as quitting smoking or diet change, had no impact on the outcomes. Conclusion. Obesity was associated with worse RA disease outcomes and a higher prevalence of comorbidities. Body measurements are recommended to improve prediction of the disease course.

Previous studies have suggested that plasminogen activator inhibitor 1 (PAI-1) released from platelets convey resistance of platelet-rich blood clots to thrombolysis. However, the majority of PAI-1 in platelets is inactive and therefore its role in clot stabilization is unclear. Because platelets retain mRNA and capacity for synthesis of some proteins, we investigated if platelets can de novo synthesize PAI-1 with an active configuration. PAI-1 mRNA was quantified with real-time polymerase chain reaction and considerable amounts of PAI-1 mRNA were detected in all platelet samples. Over 24 hours, the amount of PAI-1 protein as determined by an enzyme-linked immunosorbent assay increased by 25% (P ‫؍‬ .001). Metabolic radiolabeling with 35 S-methionine followed by immunoprecipitation confirmed an ongoing PAI-1 synthesis, which could be further stimulated by thrombin and inhibited by puromycin. The activity of the newly formed PAI-1 was investigated by incubating platelets in the presence of tissue-type plasminogen activator (tPA).This functional assay showed that the majority of the new protein was in an active configuration and could complexbind tPA. Thus, there is a continuous production of large amounts of active PAI-1 in platelets, which could be a mechanism by which platelets contribute to stabilization of blood clots. (Blood. 2004; 104:3943-3948)

BackgroundCOMP (Cartilage oligomeric matrix protein) is a matrix protein, which is currently studied as a potential serum marker for cartilage processes in osteoarthritis (OA). The influence of physical exercise on serum COMP is not fully elucidated.The objective of the present study was to monitor serum levels of COMP during a randomised controlled trial of physical exercise vs. standardised rest in individuals with symptomatic and radiographic knee OA.MethodsBlood samples were collected from 58 individuals at predefined time points before and after exercise or rest, one training group and one control group. The physical exercise consisted of a one-hour supervised session twice a week and daily home exercises. In a second supplementary study 7 individuals were subjected to the same exercise program and sampling of blood was performed at fixed intervals before, immediately after, 30 and 60 minutes after the exercise session and then with 60 minutes interval for another five hours after exercise to monitor the short-term changes of serum COMP. COMP was quantified with a sandwich-ELISA (AnaMar Medical, Lund, Sweden).ResultsBefore exercise or rest no significant differences in COMP levels were seen between the groups. After 60 minutes exercise serum COMP levels increased (p < 0.001). After 60 minutes of rest the serum levels decreased (p = 0.003). Median serum COMP values in samples obtained prior to exercise or rest at baseline and after 24 weeks did not change between start and end of the study. In the second study serum COMP was increased immediately after exercise (p = 0.018) and had decreased to baseline levels after 30 minutes.ConclusionSerum COMP levels increased during exercise in individuals with knee OA, whereas levels decreased during rest. The increased serum COMP levels were normalized 30 minutes after exercise session, therefore we suggest that samples of blood for analysis of serum COMP should be drawn after at least 30 minutes rest in a seated position. No increase was seen after a six-week exercise program indicating that any effect of individualized supervised exercise on cartilage turnover is transient.