Factors associated with circulating concentrations of irisin in the general population cohort of the ABCD study.

OBJECTIVE: Animal studies have shown that irisin is a myokine secreted following physical exercise, and that it induces the remodeling of white adipose tissue toward brown adipose tissue. Therefore, a protective role of irisin against obesity, diabetes, and other metabolic and cardiovascular conditions has been hypothesized. However, data in humans are contradictory and few data are available concerning the general population. DESIGN: We aimed to evaluate the association between serum irisin concentrations and habitual physical activity, as well as other metabolic and cardiovascular factors in a general population in a Mediterranean area. METHODS: We considered 858 consecutive individuals included in the ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340), a longitudinal observational single-center study of a cohort representative of the general population of Palermo, Sicily. Irisin serum concentrations (Phoenix Europe, Germany), habitual physical activity (HPA) level, and other blood and clinical variables were measured. RESULTS: The irisin serum concentrations were not normally distributed in the cohort (Shapiro-Wilk test=0.94; P<0.001). A significant association between irisin concentrations and HPA was observed (P<0.001). Irisin concentrations were higher in women than in men (P<0.01), and significantly correlated with serum concentrations of HDL-cholesterol (P<0.05) and hs-C-reactive protein (hs-CRP; P<0.05). Binary logistic regression analysis demonstrated that high (⩾ median value) irisin serum concentrations were significantly associated with female gender (OR=1.63; 95% CI=1.16-2.28), high serum hs-CRP concentrations (OR=1.61; 95% CI=1.02-2.54) and the HPA level (OR=1.42; 95% CI=1.02-1.96). CONCLUSIONS: Our study confirms, in a cohort of a general population, that irisin concentrations gradually increase with the usual level of habitual physical activity.

Renal function and carotid atherosclerosis in adults with no known kidney disease.

BACKGROUND AND AIMS: A high prevalence of atherosclerotic lesions characterizes patients with chronic kidney disease, though there is little data on the relationship between kidney function and atherosclerotic changes in the healthy population or in people with no known renal impairment. The aim of our study was to analyze, in a comprehensive general population with no known kidney disease, the relationship between renal function and subclinical carotid atherosclerotic damage. METHODS AND RESULTS: A general real-life population of 611 participants (233 males and 378 females; age ≥18 years) with no known kidney failure was selected for the study. The glomerular filtration rate (GFR) was estimated according to the CKD-EPI equation. Carotid intima-media thickness (c-IMT) and plaques were assessed by duplex Doppler ultrasonography of the carotid vessels. The main laboratory and metabolic parameters were evaluated in all participants. When we divided the overall study population into tertiles according to GFR values (I tertile <85; II tertile: 85-99; III tertile >99 ml/min/1.73 m2), the c-IMT mean values and the prevalence of carotid plaques decreased with the increasing tertile of GFR. On univariate analysis, c-IMT was significantly correlated with eGFR (r = -0.33; p < 0.001), serum creatinine (r = 0.17; p < 0.001), and other variables such as age, systolic blood pressure, waist circumference, fasting or random glycemia, and glycated hemoglobin (HbA1c). On multiple regression analysis, serum creatinine was associated with c-IMT (ß = 0.069; p = 0.017), independent of other covariates. CONCLUSION: Our study seems to suggest the importance of early identification of people with near normal or mildly decreased renal function due to its association with carotid atherosclerosis.

Influence of a new bicycle crank design on aerobic parameters of non-cyclists.

AIM: A well known problem in conventional cycling crank systems is the pedalling dead spot when the crank arms are in vertical position. The pedalling dead spot mitigates the power output during the propulsion phase of pedalling. The aim of this study was to verify the effects of a new design of crank system on aerobic parameters of performance in healthy non-cyclists. The mechanical concept of the new system is based on the theory that crank arms should never be perpendicularly aligned to the ground at dead spot. METHODS: The maximal aerobic capacity (VO2 max) and different parameters of cycling efficiency were measured in 14 (mean±SD of age: 26±5) non-obese (body mass index: 26.0±3.0 kg/m2) healthy men in two different occasions at intervals of 2 days using alternately and in randomized order both the traditional crank system and the system without dead spot respectively. RESULTS: The workload performed was significantly higher with the new crank system as suggested by the higher exercise duration (12.89 ±2.36 vs. 13.33±2.30 min; P=0.032). CONCLUSION: The favourable results obtained in this study using the new chainring may be in consequence of a more efficient biomechanics of pedalling that does not reflect changes in O2 consumption and CO2 produced. However, it is not possible to exclude that involuntary motivational factors may have induced the difference in the time test since it was not possible to blind subjects about the two crank systems. Further investigations are necessary to confirm the results of this exploratory study and give a more exhaustive explanation about the mechanisms that allow the possible better performance with this new chainring system.

Obtaining family consent for participation in Alzheimer's research in a Cuban-American population: strategies to overcome the barriers.

Cultural values and beliefs affect family attitudes toward participation in research. Significant resistance to allowing their elders with dementia to participate in clinical research was encountered in Cuban-American families. These families expressed concern about disturbing the elder's comfort (tranquilidad) and solitude (soledad). Furthermore, most believed that intervention would be futile. Feelings of guilt associated with nursing home placement may have been exacerbated by the suggestion that active intervention could be effective. Strategies to overcome these barriers included reduced emphasis on the potential superiority of the intervention to be tested, reassurance that contact with research staff was usually appreciated by participants, arrangements to talk with the family as a group about the study, and increased use of Spanish-language consent forms.

Development of a disease management program.

Changes in reimbursement, new regulatory guidelines, and other issues impacting the healthcare industry have forced providers to examine new models of healthcare delivery. One of those models is disease management or disease-state management. This article presents issues involved in developing such a program using the experiences of a Florida-based health system as an example.