Research Article Vitamin D Insufficiency Is Associated with Lower Physical Function in Patients with Heart Failure and Diabetes M. R. Lopes, 1 Paula A. B. Ribeiro, 2,3 Priscila Ledur, 1 Gabriela C. Souza, 4,5 Nadine Clausell, 2,4,5 and Beatriz D. Schaan 1,2,4,6 1 Endocrinology Post-Graduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil 2 Cardiology Post-Graduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil 3 Hospital de Cl´ ınicas de Porto Alegre, Porto Alegre, RS, Brazil 4 Department of Internal Medicine, Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil 5 Cardiology Division, Hospital de Cl´ ınicas de Porto Alegre, Porto Alegre, RS, Brazil 6 Endocrinology Division, Hospital de Cl´ ınicas de Porto Alegre, Servic ¸o de Endocrinologia, Rua Ramiro Barcelos 2350, Pr´ edio 12, 4 ∘ Andar, 90035-003 Porto Alegre, RS, Brazil Correspondence should be addressed to Beatriz D. Schaan; beatrizschaan@gmail.com Received 22 June 2014; Accepted 11 August 2014; Published 25 August 2014 Academic Editor: Francesco Chiarelli Copyright © 2014 M. R. Lopes et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Vitamin D defciency is frequent among patients with heart failure (HF) and diabetes, disorders associated with exercise intolerance and muscle weakness. Tis study aims to search for associations between vitamin D sufciency and physical function indexes in patients with HF and diabetes. A cross-sectional study of 146 HF patients, 39.7% with diabetes, at a Brazilian tertiary outpatient clinic was performed. Patients underwent clinical evaluation, 6-minute walk test (6MWT), handgrip strength, physical activity level (IPAQ), and biochemical evaluations including serum 25-hydroxyvitamin D. Classifcation was done according to vitamin D status (≥30 ng/dL, sufcient) and presence/absence of diabetes in vitamin sufcient, no diabetes (DS-C,  = 25), vitamin sufcient, diabetes (DS-DM,  = 18), vitamin defcient, no diabetes (DD-C,  = 63), and vitamin defcient, diabetes (DD-DM,  = 40). Patients age was 55.4 ± 8 yrs; 70.5% had vitamin D defciency. Clinical characteristics were similar among groups. Total time expended in physical activity was similar among groups ( = 0.26). DS-C covered higher distances in the 6 MWT (392 ± 60 m) versus DD-DM (309 ± 116 m);  = 0.024. Handgrip strength was similar among groups but tended to lower levels in DD-DM ( = 0.074) even afer being adjusted to physical activity ( = 0.069). Vitamin D defciency can infuence physical function in HF diabetic patients. 1. Introduction Congestive heart failure is a major cause of morbidity and mortality, with high costs to society [1]; its consequences are even worse when associated with diabetes mellitus. Heart failure incidence in patients with diabetes mellitus is much higher than in the general population [2] and is related to lower survival and lower responsiveness to treatments [3]. Patients with heart failure can develop a wasting process in which neurohormones and proinfammatory cytokines contribute to a catabolic process. Malabsorption from the gut as a result of bowel wall edema and decreased bowel perfusion also plays an important role, contributing to the progression of nutritional defciency [4]. Importantly, the long-term prognosis is considerably worse once cardiac cachexia has been diagnosed [5]. Vitamin D defciency has been associated with type 2 diabetes [6], hypertension [7], acute myocardial infarction [8], and heart failure [9], and its prevalence is rising around the world [10]. Tese are observational data, and association between vitamin D and those conditions can be confounded by factors such as general health status, exercise tolerance, obesity, and exposure to sunlight [11]. Vitamin D also plays a key role in muscle contraction [12] and has been related to muscle pain and weakness, fatigue, and performance, derangements that can be reversed by its oral supplementa- tion [13]. Diabetes, especially when poorly controlled and of Hindawi Publishing Corporation Journal of Diabetes Research Volume 2014, Article ID 320930, 9 pages http://dx.doi.org/10.1155/2014/320930