Proinflammatory cytokines and the novel myokine irisin, a cleavage product of FNDC5, have been found to play a role in obesity and type 2 diabetes mellitus (T2DM). Irisin has been shown to increase browning of adipose tissue, thermogenesis, energy expenditure, and insulin sensitivity, yet its association with inflammatory markers is still limited. Circulating irisin has been found to be increased in obesity, while in adult subjects with T2DM decreased levels have been found. However, data establishing the association of circulating irisin in children and adolescents with T2DM has not been described in the literature. The objective of this study was to determine irisin plasma concentration and its association with metabolic and adiposity markers and with hs-CRP, a surrogate marker of inflammation used in clinical practice, in a pediatric population with T2DM. A cross-sample of 40 Mexican children and adolescents aged 7-17 were recruited, 20 diagnosed with T2DM and 20 healthy controls. Plasma irisin levels were found to be lower in the T2DM group compared with controls, which could be attributed to a reduced PGC-1α activity in muscle tissue with a consequent decrease in FNDC5 and irisin expression. Irisin concentration was found to be positively correlated with HDL-c, LDL-c, and total cholesterol, while negatively correlated with BMI, waist circumference, and triglycerides. However, after multiple regression analysis, only HDL-c correlation remained significant. hs-CRP was higher in the T2DM group and positively associated with adiposity markers, unfavorable lipid profile, insulin levels, and HOMA-IR, but no association with irisin was found. Given the favorable metabolic effects attributed to irisin, the low plasma levels found in children and adolescents with T2DM could exacerbate the inflammatory and metabolic imbalances and the intrinsic cardiovascular risk of this disease. We propose an “irisin-proinflammatory/anti-inflammatory axis” to explain the role of irisin as a metabolic regulator in obesity and T2DM.

The growing elderly population of HIV-infected patients is leading to a significant epidemiological transition and HIV infection has been proposed as a premature and accelerated aging model rending the individual more susceptible to premature disability. However, the determinants of disability among this emergent population are still lacking. Therefore, the aim of this study is to determine the correlates of prevalent disability in adults ≥50 years with HIV infection. A cross-sectional study of 184 HIV-infected adults receiving ambulatory care in an HIV clinic of a tertiary care, university-affiliated hospital in Mexico City was conducted. Disability for instrumental (IADL) and basic activities of daily living (ADL) was established. Sociodemographic factors, clinical variables, current CD4(+) cell count, and HIV viral load (VL) were tested as potential determinants of disability. Multivariate logistic regression analyses were used to identify the correlates of both types of disability. The mean age was 59.3 years. All participants were receiving highly active antiretroviral therapy. Of participants 17.9% had disability for IADL and 26.1% for ADL. Multivariate logistic regression analyses indicated that being older; having a lower CD4(+) cell count, and having a detectable HIV VL were independently associated with both types of disability. In addition, educational level was also independently associated with ADL disability. Age, educational level, low CD4(+) cell count, and detectable HIV VL were independently associated with disability. Whether effective and timely antiretroviral therapy will reduce the risk of disability in HIV-infected elderly patients needs to be evaluated.

The prevalence of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) has increased in the pediatric population. Irisin, an adipomyokine, is involved in white adipose tissue browning, energy expenditure, insulin sensitivity, and anti-inflammatory pathways. Data on the associations among circulating irisin levels, soluble cell adhesion molecules (sCAMs), and inflammatory cytokines is scarce in children and adolescents with MetS and T2DM. Subjects aged 6-16 years were grouped into T2DM, MetS, and healthy controls. Serum irisin levels were significantly lower in the MetS (6.6 [2.8-18.0] ng/mL) and T2DM (6.8 [2.2-23.2] ng/mL) groups compared with controls (30.3 [24.6-57.1] ng/mL). Negative correlations between irisin and the BMI percentile (R=−0.358), WC percentile (R=−0.308), and triglycerides (R=−0.284) were identified, while positive associations with TC (R=0.287), HDL-c (R=0.488), and LDL-c (R=0.414) were observed. Significant negative correlations were found between irisin and sNCAM (R=−0.382), sICAM-2 (R=−0.300), sVCAM-1 (R=−0.292), MCP-1 (R=−0.308), and IFN-α2 (R=−0.406). Of note, lower concentrations of most sCAMs (sICAM-1, sPSGL-1, sP-selectin, sEpCAM, sICAM-2, sALCAM, sPECAM-1, sCD44, sVCAM-1, sICAM-3, sL-selectin, and sNCAM) were shown in T2DM subjects compared with MetS patients. Lower irisin levels induce a lack of inhibition of oxidative stress and inflammation. In T2DM, higher ROS, AGEs, glucotoxicity, and inflammation trigger endothelial cell apoptosis, which downregulates the sCAM expression as a compensatory mechanism to prevent further vascular damage. In opposition, in subjects with MetS that have not yet developed T2DM and its accompanying stressors, the upregulation of the sCAM expression is ensued.

Background: The phenotype of frailty proposed by Fried et al has shown to predict several adverse health-related outcomes in elderly populations worldwide; however, the description of such associations in Latin America is still scarce. Objective: To describe the association between frailty and recent hospitalization, disability for basic (ADL) and instrumental activities of daily living (IADL). Design, Setting and Participants:Cross-sectional study of 1,124 community-dwelling adults aged 70 and older participating in the Coyoacán cohort. Measurements: Frailty was defined by the presence of at least three of the following criteria: weight loss, exhaustion, low physical activity, slowness, and weakness. Multiple regression analyses were used to test the association between frailty and the outcomes of interest, adjusting for potential confounders. Results: Mean age was 78.2 (SD ±6.1) years. Prevalence of frailty was 14.1%. Adjusted multivariate models showed that frail status was associated with ADL disability (OR 3.06, 95%CI 1.52-6.17), IADL disability (OR 17.02, 95%CI 6.16-47.01), and recent hospitalization (OR 3.21, 95%CI 1.31-7.8). Conclusion: Among Mexican community-dwelling elderly, frailty is associated with ADL and IADL disability as well as with recent hospitalizations. Moreover, frailty’s prevalence in this population appears to be greater compared to what has been reported elsewhere. Social and cultural traits should be further studied as correlates of frailty in diverse populations.