Background: Human heredity is known to determine about 50% of heart rate variability (HRV) based on a twin study; however, genetic polymorphisms causing increased HRV in athletes are not known. Objectives: This article is aimed at studying the associations of Uncoupling protein 2 (UCP2) Ala55Val (rs660339) and UCP3-55C/T (rs1800849) polymorphisms with heart rate variability (HRV) in trained oarsmen. Methods: HRVindices (standard deviations of NNintervals (SDNN), rootmeansquare of successive differences (RMSSD), HF, LF, VLF), stroke index and cardiac index of the young oarsmen (age 17. 6 1. 6 years old, n = 23) were determined by impedance cardiography method in the supine and standing positions. Themaximumoxygen consumption (VO2max) was examined with a rower ergometer by means of a gas analyzer. Polymorphisms of the UCP2 Ala55Val and the UCP3-55T/C were genotyped by polymerase chain reaction (PCR) method and length analysis of restriction products. Results: It was found that both polymorphisms were not associated with VO2max. The UCP2 Val/Val genotype compared to the combined variant (Ala/Ala + Ala/Val) containing the 55 Ala allele, as well as the UCP3 T/T genotype compared to the combined variant (C/T + C/C) containing the-55C allele were associated with low HR and increased HRV: SDNN, RMSSD and HF vagal indices in the supine position. Moreover, the athletes with the UCP3-55T/T genotype had a pronounced increase in heart rate (ANOVA, P < 0. 001) and a decrease in stroke index (ANOVA, P = 0. 005) in response to active orthostasis compared to C/T and C/C genotypes. Conclusions: The UCP2 Val/Val and the UCP3 T/T genotypes may be genetic markers of increased HRV in the highly trained athletes, suggesting an influence of these UCP2/UCP3 polymorphisms on autonomic cardiovascular regulation.

Background: Obesity is a multifactorial metabolic disease resulting from behavioral and genetic factors. Obesity is linked to diabetes mellitus and hypertension, which are considered as major risk factors for chronic kidney disease (CKD),moreover, it has a direct effect on developing CKD and end stage renal disease (ESRD). Here was aimed to examine the association between Uncoupling protein 2 (UCP2) gene expression and obesity in CKD patients. Methods: UCP2 gene expression was analyzed by real time polymerase chain reaction (RT-PCR) in 93 participants divided into three groups. The groups included 31 non-obese CKD patients, 31 obese CKD patients, and 31 healthy, age-matched, unrelated volunteers as a control group. Results: UCP2 gene expression was significantly relevant when comparing the non-obese CKD and obese CKD groups to the control group (p< 0. 001). No significant association was found when the groups were compared by gender,Chi-square (X2) was 2. 38 and p= 0. 304. A significant negative correlation was found between UCP2 gene expression and BMI in CKD (p< 0. 05). Conclusions: These results indicate that UCP2 gene expression plays a significant role as a risk factor for obesity in CKD patients.