Impact of Vitamin D Supplementation on Arterial Vasomotion, Stiffness and Endothelial Biomarkers in Chronic Kidney Disease Patients

Background: Cardiovascular events are frequent and vascular endothelial function is abnormal in patients with chronic kidney disease (CKD). We demonstrated endothelial dysfunction with vitamin D deficiency in CKD patients; however the impact of cholecalciferol supplementation on vascular stiffness and vasomotor function, endothelial and bone biomarkers in CKD patients with low 25-hydroxy vitamin D [25(OH)D] is unknown, which this study investigated. Methods: We assessed non-diabetic patients with CKD stage 3/4, age 17–80 years and serum 25(OH)D ,75 nmol/L. Brachial artery Flow Mediated Dilation (FMD), Pulse Wave Velocity (PWV), Augmentation Index (AI) and circulating blood biomarkers were evaluated at baseline and at 16 weeks. Oral 300,000 units cholecalciferol was administered at baseline and 8-weeks. Results: Clinical characteristics of 26 patients were: age 50614 (mean61SD) years, eGFR 41611 ml/min/1.73 m2, males 73%, dyslipidaemia 36%, smokers 23% and hypertensives 87%. At 16-week serum 25(OH)D and calcium increased (43616 to 84629 nmol/L, p,0.001 and 2.3760.09 to 2.4260.09 mmol/L; p = 0.004, respectively) and parathyroid hormone decreased (10.868.6 to 7.464.4; p = 0.001). FMD improved from 3.163.3% to 6.163.7%, p = 0.001. Endothelial biomarker concentrations decreased: E-Selectin from 566662123 to 525662058 pg/mL; p = 0.032, ICAM-1, 3.4560.01 to 3.1061.04 ng/mL; p = 0.038 and VCAM-1, 54633 to 42633 ng/mL; p = 0.006. eGFR, BP, PWV, AI, hsCRP, von Willebrand factor and Fibroblast Growth Factor-23, remained unchanged. Conclusion: This study demonstrates for the first time improvement of endothelial vasomotor and secretory functions with vitamin D in CKD patients without significant adverse effects on arterial stiffness, serum calcium or FGF-23. Trial Registration: ClinicalTrials.gov NCT0200571

I am so happy cause my friend is happy for me: Capitalization, friendship, and happiness among U.S. and Turkish college students

PubMed ID: 23484350Friends usually share positive events in their lives with each other. Referred to as capitalization, this process promotes individual happiness when the discloser perceives that the responses display genuine support. Yet, the specific mechanisms explaining why capitalization is associated with happiness are not known. The present study addresses this empirical issue by testing a mediational model positing that friendship quality would mediate the relationship between capitalization and happiness among U.S. and Turkish college students. Although the psychosocial well-being of the U.S. participants was significantly higher than Turkish participants, the proposed model was supported in both groups. This suggests that part of the reason capitalization is associated with happiness is because of friendship experiences. The authors also provide suggestions for future research. © 2013 Copyright Taylor & Francis Group, LLC

Cross-sex friendship and happiness

Established research has shown that friendship is an important correlate of happiness. Yet, these studies did not directly examine the relationship between cross-sex friendship and happiness. Thus, the studies reported in this chapter aimed to investigate the association of cross-sex friendship with happiness. The first study revealed that cross-sex friendship quality and happiness are positively correlated, regardless of how happiness was assessed (e.g., affective, global). The second study showed that cross-sex friendship-happiness association is similar among emerging adults in Turkey and the U.S. The third study provided additional support for a positive relationship between cross-sex friendship quality and happiness, as it revealed that cross-sex friendship quality predicted unique variance in happiness above and beyond the role of personality for both U.S. and Turkish samples. Collectively, the studies have shown that cross-sex friendship quality is a reliable correlate of happiness. Findings were evaluated in light of theory and directions for future research were provided. © Springer Science+Business Media Dordrecht 2015

Cross-sex Friendship and Happiness

This is the first book that explicitly focuses on the relationships between various types of friendship experiences and happiness. It addresses historical, theoretical, and measurement issues in the study of friendship and happiness (e.g., why friends are important for happiness). In order to achieve a balanced evaluation of this area as a whole, many chapters in the book conclude with a critical appraisal of what is known about the role of friendship in happiness, and provide important directions for future research. Experts from different parts of the world provide in-depth, authoritative reviews on the association between different types of friendship experiences (e.g., friendship quantity, quality) and happiness in different age groups and cultures. An ideal resource for researchers and students of positive psychology, this rich, clear, and up-to-date book serves as an important reference for academicians in related fields of psychology such as cross-cultural, developmental and social