A single family has been described in which obesity results from a mutation in the leptin-receptor gene (LEPR), but the prevalence of such mutations in severe, early-onset obesity has not been systematically examined. We sequenced LEPR in 300 subjects with hyperphagia and severe early-onset obesity, including 90 probands from consanguineous families, and investigated the extent to which mutations cosegregated with obesity and affected receptor function. We evaluated metabolic, endocrine, and immune function in probands and affected relatives. Of the 300 subjects, 8 (3%) had nonsense or missense LEPR mutations — 7 were homozygotes, and 1 was a compound heterozygote. All missense mutations resulted in impaired receptor signaling. Affected subjects were characterized by hyperphagia, severe obesity, alterations in immune function, and delayed puberty due to hypogonadotropic hypogonadism. Serum leptin levels were within the range predicted by the elevated fat mass in these subjects. Their clinical features were less severe than those of subjects with congenital leptin deficiency. The prevalence of pathogenic LEPR mutations in a cohort of subjects with severe, early-onset obesity was 3%. Circulating levels of leptin were not disproportionately elevated, suggesting that serum leptin cannot be used as a marker for leptin-receptor deficiency. Congenital leptin-receptor deficiency should be considered in the differential diagnosis in any child with hyperphagia and severe obesity in the absence of developmental delay or dysmorphism.
Cardiovascular disease (CV) is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). This is the result of an accelerated atherosclerotic process. Adequate CV risk stratification has special relevance in RA to identify patients at risk of CV disease. However, current CV risk screening and management strategies underestimate the actual CV risk in RA. Consequently, the search for additional tools that may help to identify those patients at high CV risk has become a key objective in the last years. In this regard, non-invasive surrogates, such as carotid ultrasonography, have been found to be excellent predictors of future CV events. In addition, several studies have revealed the relevance of a genetic component in the development of CV disease in RA patients. Besides an association with HLA-DRB1* shared epitope alleles other gene polymorphisms located inside and outside the HLA seem to influence the risk of cardiovascular disease in RA. Moreover, serum levels of some metabolic syndrome-related biomarkers, adipokines such as adiponectin and biomarkers of endothelial cell activation and inflammation such as Osteoprotegerin and Asymmetric dimethylarginine have recently been found useful for the prediction of CV disease in these patients. An update of the current knowledge on these potential markers, especially focused on new genetic and serological biomarkers is shown in this review.
Insulin resistance is an essential feature of the metabolic syndrome that has been linked to rheumatoid arthritis (RA). Understanding how inflammation arising in one tissue affects the physiology and pathology of other organs remains an unanswered question with therapeutic implications for chronic conditions including obesity, diabetes mellitus, atherosclerosis, and RA. Adipokines may play a role in the development of atherogenesis in patients with RA. Biologic therapies, such as TNF-αantagonists, that block proinflammatory cytokines have beneficial effects on the insulin resistance that is often observed in patients with RA.
Objectives. The aims of this study were to study physical activity (PA) in patients with RA by accelerometry and to determine to what degree their mobility is affected by disease activity. Methods. A group of 50 RA patients, without lower limb clinical disease, and 50 age- and sex-matched healthy controls were included in this cross-sectional study. PA was assessed by accelerometry and with the International Physical Activity Questionnaire (IPAQ). We performed multiple regression analysis not only to compare PA between groups, but also to explore the relation between RA features, including disease activity and cardiovascular risk parameters, and PA. In a randomized group of 30 RA patients a test–retest study was carried out in order to determine the correlation between variations in disease activity and PA. Results. The number of minutes of moderate and vigorous activity per day, as evaluated by accelerometry, was significantly lower in RA patients than in healthy controls. In RA patients, accelerometry and IPAQ demonstrated concordance to a moderate degree [quadratic weighed kappa index 0.27 (0.06–0.48), P = 0.02]. HAQ negatively correlated with both IPAQ and accelerometry data. The 28-joint DAS using CRP (DAS28-CRP) was also inversely related with IPAQ. Framingham score and metabolic syndrome were inversely associated with PA in RA patients. Interestingly, variations in PA by accelerometry inversely correlated with changes in RA disease activity (r = −0.42, P = 0.02). Conclusion. In RA patients, accelerometry is a reliable technique to evaluate PA. This study not only showed that RA patients spend less time doing moderate and vigorous PA than healthy controls, but also PA, as assessed by accelerometry, was sensitive to any changes in disease activity.
The purpose of this study was to determine whether long-term modulation of inflammatory activity by tumor necrosis factor (TNF)-α inhibitors has some influence on insulin resistance (IR). 16 active rheumatoid arthritis (RA) patients without CV risk factors treated with anti-TNF-α agents were included in this study. RA activity by disease activity score 28, IR by HOMA2-IR, body composition by impedance analysis, physical activity by accelerometry, abdominal fat distribution by magnetic resonance imaging, and serum level of key adipokines by ELISA were measured at baseline and during a 1-year follow-up period. Patient body mass index increased significantly (26.94±3.88 vs. 28.06±4.57 kg/m2, p=0.02) after 1 year of treatment. Body composition, in terms of fat and fat-free mass, remained unchanged except for a significant elevation in body cell mass (25.50±4.60 vs. 26.60±3.17 kg, p=0.02). Basal levels of IR in the RA patients included in this study were significantly higher than healthy controls (1.6±0.8 vs. 1.11±0.56, p=0.011) but did not change during the follow-up. Nor did basal concentrations of adiponectin, visfatin, leptin, ghrelin, resistin, and apelin in response to anti-TNF-α treatment; only retinol-binding protein 4, showed a significant increase (51.7±32.7 vs. 64.9±28.4 μg/ml, p=0.03) at the end of the study. IR, adiposity distribution, and serum levels of most adipokines are not significantly affected by long-term inhibition of TNF-α in RA patients. Our data suggest that although systemic blockade of TNF-α exerts an anticachectic effect in RA patients, it does not seem to play a major role in IR.
1 August 2014 in Seminars in Arthritis and Rheumatism
Last recommendations regarding cardiovascular risk (CVR) in rheumatoid arthritis (RA) patients were developed by the EULAR group in 2010. The aim is to update evidence-based recommendations about this worrying health problem. We assembled a multidisciplinary workgroup (rheumatologists, endocrinologist, cardiologist, and epidemiologist) and a panel of 28 expert rheumatologists. The study was carried out in two big phases: identifying key areas in the prevention and management of CVR and developing a set of recommendations based on a review of the available scientific evidence and use of the Delphi consensus technique. All this has been developed according to an updating process of evidence-based recommendations. Overall, 25 recommendations were made addressing three complementary areas: CVR assessment tools, patient eligibility for assessment, and treatment strategies for control of CVR. The grade of the recommendations was not substantially modified compared to the original EULAR recommendations, except in two of them, which were upgraded from C to B. These two recommendations are the ones related to the use of corticosteroids and smoking cessation. The new developed recommendations address these two areas: CVR assessment and treatment strategies for control of CVR. There are substantial gaps in the current knowledge that do not allow classifying properly RA patients based on their actual CVR and to accurately identify those patients who would benefit from CVR assessment. Consequently, studies designed to determine the causal effects of RA disease characteristics on cardiovascular morbidity/mortality and to identify patients at high risk of cardiovascular disease are still needed.
About Me
Iván Ferraz-Amaro is a rheumatologist who is interested in cardiovascular disease and rheumatic diseases.
Iván Ferraz-Amaro is a rheumatologist who is interested in cardiovascular disease and rheumatic diseases.