Effect of 8 Weeks Exercise on Irisin in Obese Women

ABSTRACT BACKGROUND ː The prevalence of obesity and type2 diabetes is escalating at an alarming rate in many developed as well as developing countries. Irisin is a novel muscle and adipose drived chemokine that is, proteolytically processed from the product of the FNDC5 (fibronectin type ш domain containing 5) gene. The purpose of this study is to examine the effect of three kind of training on irisin in sedentary obese women. METHODS3ː3 obese women (medium age: 37.99 ± 3.7 year, height: 1.55 ± 0.03 meter, BMI: 34.6 ± 5.07 kg/m) participated in the study, on three groups, including endurance, resistance and concurrent. RESULTS ː After 8 weeks exercise we did not find significant differences in fasting glucose, insulin, HOMA-IR and irisin between the groups (P>0.05), but glucose and insulin in resistance groups and irisin in all groups had significant changes (P<0.05). CONCLUSIONS ː In summery in this study in contrast to hypothesis there were no difference between groups of training. It can be hypothesise that the increase of irisin in obese people is one of the preventing ways against of obesity's side effects. Exercise could improve the signaling pathways and consume the fat accumulations, therefore at the end of exercise duration, irisin decreased. DOI : 10.14302/issn.2381-862X.jwrh-17-1750


Introduction
Discovery of myokines has emphasized the role of muscle as an important source of exercise-induced hormones to communicate information and interact with other tissues, including fat, the liver, and the pancreas, to alter metabolism (1).
Metabolic diseases such as obesity and diabetes are undoubtedly some of the most challenging health issues of our times (2).The prevalence of obesity and type 2 diabetes is escalating at an alarming rate in many developed as well as developing countries and is basically a consequence of imbalance between energy intake and energy expenditure (3,4).Obesity on itself could be the source of other disease like type2 diabetes.
The prevalence of obesity among the women is more than the men that may be because of the lowest knowledge and lack of exercise and sport facilities in some countries (5,6).The health benefits of regular exercise are undisputed, thereby reduce the risk of lifestyle-related diseases, such as obesity but the molecular mechanisms are not completely understood (7).
Irisin is a novel muscle and adipose drived chemokine that is, proteolytically processed from the product of the FNDC5 (fibronectin type ш domain containing 5) gene.Both exercise and the PGC1α (peroxisome proliferator-activated receptor gamma coactivator 1 α) induce irisin expression.Irisin induces the browning of adipocytes and thermogenesis by increasing of UCP1 (uncoupling protein 1) level (8,9,10,11,12).It is mentioned that irisin could orchestrate many metabolic pathways (13,14,15,16,17,18), for example irisin has gained great interest as a potential new target to combat obesity and its associated disorders, such as type 2 diabetes mellitus (10).

Results
At the beginning, there were not different among groups in blood (P>0.05)(Table 4).After 8 weeks exercise we did not find significant differences in fasting glucose, insulin, HOMA-IR and irisin between the groups (P>0.05),but glucose and insulin in resistance groups and irisin in all groups had significant changes inner the groups (P<0.05)(Fig 1,2,3,4).

Discussion
Irisin is a novel muscle and adipose derived chemokine that is, proteolytically processed from the product of the FNDC5 (fibronectin type ш domain containing 5) gene.Both exercise and the PGC1α (peroxisome proliferator-activated receptor gamma coactivator 1 α) induces the browning of adipocytes and thermogenesis by increasing of UCP1 (uncoupling protein 1) level (8,10,11,12).Although Bostrom et al observed increase of irisin after endurance training ( 8), but a significant increase in irisin was not found after exercise therapy in non-obese individuals, and no significant changes in irisin occurred in obese patients after 8 week endurance training and 12 week strength and endurance training (30).Previous studies pointed to different results, these conflicting reports may be because of differences between duration and intensity of exercise, time of blood samplings, age and health problem of population of studies and the difference of measurement assays and kits (12,22,23,24,25,26).
In summery in this study in contrast to hypothesis there were no difference between groups of training.It just observed that irisin was significantly decreased in all three groups of obese women.Some studies indicated that circulating irisin correlated positively with increased risk of metabolic syndrome and insulin resistance as assessed with these kinds of findings it has been  Moreno et al found that irisin was higher in subjects with low activity than in those with average or high activity (37).Huh et al showed that irisin was highest in obese prediabetic patients, followed by obese patients and non -obese individuals, and lowest in athletes (10).The ) and time of completion.At the end their cardiovascular fitness was evaluated.During the exercise, the subjects were encouragement to finish their duration of work.Participants were instructed not to change their eating habits in the course of the study.The participants report -day-dietary record during pre-and posttraining.One weekend day was comprised for each three-day-dietary record.The result of food intake was presented as the amount of total kcal per day.The influences of training groups (endurance, resistance and concurrent) and the two time points (pre and post) on serum samples concentration were evaluated by twoway repeated-measure ANOVA, followed by Bonferroni correction.Normal distribution of data was determined using Shapiro-wilk's test.All analyses were performed using SPSS version 18 and figures were produced using Prism 5.04.

Figure 1 .Figure 2 . 6 Figure 3 .Figure 4 .
Figure 1._Irisin in different groups higher irisin in obese persons is due to compensation for metabolic homeostasis, and this suggests that irisin should be decreased by body weight reduction due to discontinuation of compensatory action(14).Due to the difference in metabolism in obese and non-obese individuals, there are disturbances and differences in the signaling processes and intramuscular stimuli of these individuals.Recent investigates suggested that probably irisin has effects on gluconeogenesis and glycogenesis via PI3K/ populations.Irisin secretion in response to adipose and insulin resistance probably enhanced metabolic homeostasis in a compensatory way by altering lipid metabolism via browning of white adiposities(37).Therefore, with regard to one of the important sources of irisin secretion, the adipose tissue, it seems that in this study, the high levels of irisin in obese individuals who did not have a metabolic disorder would have a protective and supportive role in obstructing the complications of obesity, so obese people are less likely to suffer from obesity.In these people, physical activity could decrease the complications of obesity by improving the glucose signaling pathways and other routes, as well as the higher body fat intake, thus reducing Irisin by the end of the period.In general, the present study did not show a significant difference in the effect of different types of training on the Irisin of sedentary and obese women.This study is not without limitations.We did not any lean control group, however all subjects completed the study in random order then served as their own controls.Also by finding of receptor(s) of irisin in different part of body would open the door to better understand of its role and its mechanisms.Additional researches are needed to elucidate the potential and hidden interaction of irisin and exercise by different intensity and duration in several populations.ConclusionsWith regard to one of the important sources of irisin secretion, the adipose tissue, it seems that in this study, the high levels of irisin in obese individuals who did not have a metabolic disorder would have a protective and supportive role in obstructing the complications of obesity, so obese people are less likely to suffer from obesity.In these people, physical activity could decrease the complications of obesity by improving the glucose signaling pathways and other routes, as well as the higher body fat intake, thus reducing Irisin by the end of the period.In general, the present study did not show a significant difference in the effect of different types of training on the Irisin of sedentary and obese women.

Table 1 : subject characteristic in three exercised groups.
).In diabetic mice, persistent subcutaneous perfusion of irisin into endurance, resistance and concurrent exercise training groups on base of obesity.Some of subjects failed during the study and could not complete it.Lastly 33 obese and sedentary women participate in this study (endurance n=10, resistance n=12 and concurrent n=11).Subject characteristics are shown in table 1.The inclusion criteria required a BMI>25 kg/m 2 or a body fat percentage ≥ 30%.Subjects with a history of disease such as major cardiovascular disease, hemodialysis, asthma and other problems were excluded.This study was approved by the ethics committee of IR.TBZMED.REC.1395.927.Informed written consent was obtained from each subject.Participants were evaluated before and after the exercise training in all of the measurement (physiologic like irisin, insulin, glucose, HOMA-IR and anthropometric like BMI, Fat% and etc.).BMI (kg/m 2 ) and body composition was determined.Bio-impedance body composition analyzer was used.Also skeletal Freely Available Online www.openaccesspub.org| JWRH CC-license DOI : 10.14302/issn.2381-862X.jwrh-17-1750Vol-2 Issue 1 Pg.no.-3 er.Serum insulin and irisin were measured using an enzyme linked-immunosorbent assay (ELISA) commercial kit (Demeditec Insulin Elisa DE2935-Germany and Human Irisin Elisa Kit E3253Hu, Shanghai Crystal day Biotech Co., Ltd.With assay range: 0.2 ng/ml-60 ng/ml and Sensitivity: 0.095 ng/ml and intra-Assay: CV<8%, Inter-Assay: CV<10%).The homestasis model assessment of insulin resistance (HOMA-IR) was calculated as the product of fasting serum insulin (mU/l) and FG (mg/dl) concentrations, divided by 405 (11, 18, 26, 30) .The exercise program was executed mum (1RM) testing which was performed at baseline.According to table 3.Each exercise was performed in the moderate contraction velocity (~1 s concentric, ~1 s eccentric).The resting interval between sets was near 1 minute.And the concurrent training program was include of both endurance and resistance programs in way that in odd sessions subjects done endurance training and in even sessions subjects done resistance training (31,32,33,34,35,36).Rackport VO2max test was used for testing of the subject's cardiovascular fitness.After a brief warm up, the subjects walk as briskly as possible for one mile (1609 meters) with a heart rate monitor.Tester records heart rate (beats per minute