visfatin ( also known as nicotinamide phosphoribosyltransferase and pre - b cell 
 colony - enhancing factor ) is a multifunctional protein . visfatin has been reported to be 
 involved in several biological processes in the type 2 diabetes mellitus system1,2,3,4 . visfatin is also upregulated by 
 hypoxia , inflammation , and hypoglycemia , and downregulated by insulin2 . as the distribution of body fat , particularly visceral 
 abdominal fat , might be even be more relevant than the total amount of stored fat , 
 scientists have tried , with limited success , to identify the differences between these 
 topographically distinct depots in order to understand what makes the intra - abdominal depot 
 so deleterious5 . plasma visfatin has a stronger relationship to intra - abdominal ( visceral ) fat than to 
 subcutaneous fat . in addition , similar to the action of insulin , visfatin may play a role in 
 insulin resistance6 . however , because 
 several other studies have shown that visfatin levels are not correlated to fat mass , these 
 relationships must continue to be investigated1,2,3,4 , 7 . even if insulin 
 is normally secreted , it has an impaired ability to remove glucose from the bloodstream to 
 control blood sugar concentrations and results in high blood sugar levels8 . sedentary individuals and individuals with lower percentages of lean body mass have higher 
 prevalence rates of insulin resistance . regular exercise improves these factors , which 
 relate to insulin resistance6 , and reduces 
 the risk of comorbid conditions such as cardiovascular disease9 . given the role of exercise in the improvement of insulin 
 resistance , and the potential role of visfatin in insulin resistance , exercise could 
 potentiate a change in visfatin as insulin resistance is improved . many studies that report visfatin levels simply rely on the relationship of visfatin to anthropometric variables or 
 to the diagnosis of diabetes , but fail to account for the role of physical activity on these 
 levels . another feature of type ii diabetic patients is the failure of the functionality and 
 decreased numbers of -cells . the damage in the -cell function , which reduces insulin 
 secretion and inhibits the proper control of blood sugar levels , is explained as a crucial 
 feature of the occurrence of chronic uncontrolled type ii diabetes . several studies have examined the relationship between visfatin expression levels and 
 homeostasis model assessment of insulin resistance ( homa - ir ) index in response to exercise 
 training10 , 11 . however , the potential relationship between exercise training and 
 changes in visfatin level and homa - ir index related to obesity , type 2 diabetes , and 
 cardiovascular diseases has not been analyzed . in addition , while several research studies 
 have used the homa - ir index as a parameter of diabetic risk , research studies that use the 
 homa -cell index are less common12 . 
 preclinical changes and mediation of these variables utilizing lifestyle behavior 
 modifications such as exercise have potential to alleviate the progression to diagnosed 
 obesity - related disease such as diabetes and cardiovascular disease . in order to establish 
 this potential mediation , first this study examined not only the relationship between adipocytokines such as visfatin and 
 homa - ir index in response to exercise training in overweight college - aged women . furthermore , the primary objective of this study was to establish the relationship between 
 visfatin , pancreatic endocrine hormones , homa - ir index , and homa -cell index by using a 
 12-week hydraulic resistance exercise program . the subjects were sedentary female overweight college students aged 2026  years who had not 
 been previously diagnosed with abnormal glucose metabolism or other health problems , and had 
 body fat percentages greater than 25% . the subjects were randomly assigned to an exercise 
 group ( n = 15 ) and a control group ( n = 12 ) . the characteristics of the subjects are shown 
 in table 1table 1.characteristics of the subjects ( mean  sd)variablesexercise group(n = 15)control group(n = 12)age ( years)21.6  1.620.8  1.7height ( cm)162.1  6.0162.1  5.9weight ( kg)62.0  10.061.9  6.8body mass index ( kg / m)23.5  2.723.5  1.7muscle mass ( kg)40.1  6.139.2  4.3body fat ( % ) 31.3  3.931.0  3.0 . this study was approved and reviewed by the institutional review board of the human care 
 and use committee of the society of sport research institute of dongguk university . written 
 consent was obtained from all of the subjects . the subjects were scheduled to participate in 
 the hydraulic resistance exercise training at dongguk university fitness center in 
 gyeong - ju , south korea . during the 12-week intervention , the subjects in the hydraulic resistance exercise group 
 were trained 5 days per week ( from monday to friday ) , 70 minutes per day . the subjects in 
 both the control and exercise intervention groups were instructed to maintain their current 
 dietary intake and physical activity patterns for the duration of the study , and compliance 
 with this instruction was assessed via physical activity and food frequency questionnaires 
 administered at the beginning and end of the study . visfatin concentration was measured by using an eia reader ( e - max precision , molecular 
 devices , usa ) . insulin concentration was measured by using modular analytics ( e170 , roche , 
 germany ) . glucagon concentrations were measured by using a -counter ( cobra-5010 quantum , 
 packard , usa ) . glucose concentrations were measured by using the automated analyzer ( advia 
 1650 , usa ) . a human visfatin enzyme - linked immunosorbent assay kit ( biovision , usa ) , insulin ( roche ) , 
 double antibody glucagon ( siemens , usa ) , and glucose ( bayer , usa ) were used to determine the 
 concentrations of visfatin ( ng / ml ) , insulin ( iu / ml ) , glucagon ( pg / ml ) , and glucose ( mg / dl ) , 
 respectively . by using the analyzed insulin and glucose concentration level in the blood , 
 homa - ir , which is the indicator of insulin resistance , was estimated and homa -cell index , 
 the indicator for insulin secretion level , was also assessed13 . all of the subjects in the exercise group were asked to perform the same stretching routine 
 prior to ( warm up , 10  min ) and after ( cool down , 10  min ) each training session . they 
 performed a 50-min main exercise program that included a 50-min resistance training using 
 hydraulic resistance exercise equipment ( neocean , korea ) . exercise intensity was monitored 
 during the training sessions by using a polar real - time system ( polar s610 , finland ) . the 
 hydraulic resistance exercise training programs are shown in table 2table 2.the hydraulic resistance exercise program14classificationtype of exercise%hrmax ( rating of perceived exertion)noteadaptationimprovementmaintenanceweeks 1 and 2weeks 311week 12warm - upstretching ( 5 or 6 kinds)40% ( 11)40% ( 11)40% ( 11)810  minhydraulic resistance trainingpectoral fly / rear deltoid leg press shoulder press squat upright 
 row biceps / triceps abdominal / low back inner / outer thigh rotary torso 
 glute / hamstrings chest press leg curl4060% ( 1114)5080% ( 1316)6575% ( 1415)4550  min speed : max time : 1  min / each 12  min/1 set rest time 20 
 sec / between each machine 5  min / between setcool downstretching ( 5 or 6 kinds)4050% ( 1113)4050% ( 1113)4050% ( 1113)810  min . all of the descriptive data were expressed in terms of mean  standard deviation . independent t tests were performed to examine differences in the baseline characteristics of 
 the subjects between the 2 groups . two - way repeated analysis of variance was used to 
 evaluate significant changes in dependent variables in the exercise group before and after 
 the exercise program and to compare these values with those for the control group before and 
 after the study period . the pearson correlation was calculated to examine the relationship 
 between visfatin and other variables such as insulin , glucagon , glucose , homa - ir index , and 
 homa -cell index . all of the analyses were performed by using spss version 18.0 ( spss , 
 chicago , il , usa ) . the subjects baseline characteristics did not significantly differ between the groups ( p 
 > 0.05 ) . the changes in body composition , visfatin level , pancreatic endocrine hormone 
 level , homa - ir index , and homa -cell index after hydraulic resistance exercise for 12 weeks 
 are shown in table 3table 3.the change in body composition , visfatin , pancreatic endocrine hormones , homa - ir , 
 homa cell after hydraulic resistance exercise for 12 weeksexercisepre - exercisepost - exerciseweight ( kg)exercise62.0  10.061.4  10.4*control61.9  6.862.5  6.9bmi ( kg / m)exercise23.5  2.723.2  2.8*control23.5  1.723.9  1.5muscle mass ( kg)exercise40.1  6.140.6  6.0control39.2  4.338.9  4.3body fat ( % ) exercise31.3  3.929.6  4.7***control31.0  3.032.0  3.2visfatin ( ng / ml)exercise2.3  1.51.9  0.9*control1.8  0.72.6  1.5insulin ( iu / ml)exercise9.1  3.34.9  2.8***control6.1  2.57.8  1.7glucagon ( pg / ml)exercise85.3 6.755.4  13.2control87.9  5.769.5  11.3glucose ( mg / dl)exercise85.3  7.784.9  6.2control87.9  5.791.3  5.8homa - irexercise1.9  0.81.1  0.6***control1.3  0.61.8  0.4homa -cellexercise153.0  48.582.4  43.8***control89.8  33.3103.1  28.8 . the interaction effects ( time  group ) on weight ( p = 0.04 ) , body mass index 
 ( bmi ; p = 0.02 ) , and body fat ( p < 0.001 ) were observed in body composition . however , the 
 interaction effect ( time  group ) on muscle mass ( p = 0.086 ) was not observed in body 
 composition . the interaction effects ( time  group ) on visfatin ( p = 0.04 ) , insulin ( p < 
 0.001 ) , homa - ir ( p < 0.001 ) , and homa -cell index ( p < however , 
 the interaction effects ( time  group ) on glucagon and glucose were not observed between the 
 exercise and control groups ( p > 0.05 ) . the correlations of visfatin to insulin level , 
 glucagon level , glucose level , homa - ir index , and homa -cell index are shown in table 4table 4.correlation of visfatin level with pancreatic endocrine hormone level , homa - ir 
 index , and homa -cell indexcategoryvisfatin in hydraulic resistance ( n = 
 15)visfatin in control ( n = 12)prepostprepostrrrrinsulin0.240.060.270.26glucagon0.010.230.380.41glucose0.010.010.380.40homa ir0.190.070.190.15homa -cell0.250.080.470.30 . in the  all subjects  dataset , visfatin was not significantly correlated with 
 any of the subjects ( p > 0.05 ) . obesity is the main factor of diabetic and cardiovascular diseases and their complications . 
 in south korea , changes in diet and physical activity that occur in women aged 2030  years 
 marks this as a crucial stage for intervention , but often they do not have prevalent signs 
 or symptoms of disease and still appear to be physically fit . thus , the interest in 
 investigating the impact of exercise has been low . however , the impact of exercise on 
 preclinical measures demands further elucidation within this age group . this study focused on the effectiveness of 12 weeks of hydraulic resistance exercise 
 training on potential changes in body composition , visfatin level , insulin level , glucagon 
 level , glucose level , homa - ir index , homa -cell index , and the relationship between these 
 variables . a significant decrease in visfatin level was observed , and visfatin level was not 
 significantly correlated with the aforementioned variables in any of the subjects . traditionally , as aerobic exercise is associated with greater energy expenditure than 
 resistance exercise , it is considered to be more effective in reducing body weight and fat 
 mass15 . however , many studies have 
 reported that resistance exercise is more effective in increasing fat - free mass ( fm)13 . malina16 reported that the correlation between bmi and fm in young college 
 students was high . although the obese subjects in this study had high bmi , they also had 
 higher fm than that reported for adults . in our study , hydraulic resistance exercise 
 significantly decreased the weight , bmi , and body fat but did not increase the muscle 
 mass . some plurality exists in the literature regarding the relationship of visfatin level , 
 adiposity , and the effects of exercise on visfatin level . furthermore , lee et al . reported 
 that 12 weeks of aerobic exercise training with an energy expenditure of 300400  kcal / d 
 decreased plasma visfatin levels in obese adolescents11 . meanwhile , berndt et al . reported that they did not observe any 
 significant relationship between visfatin levels and visceral adipose tissue as assessed by 
 using computed tomography16 . furthermore , 
 ghanbari - niaki et al . reported that plasma visfatin levels increased after short bouts of 
 high - intensity exercise17 . one potential explanation for the variance in study results is the relationship between 
 visfatin and insulin levels . however , opinions vary even on this point18 . in particular , the relevance studies of visfatin level and homa - ir 
 index reported many differing results4 , 18 , 19 . moreover , the relationship between exercise training and exhibited 
 increases or decreases in plasma visfatin levels remains controversial . some efforts have 
 been made to demonstrate the relationship between exercise - induced changes in visfatin and 
 changes in glucose and lipid metabolisms . however , research has not yet explained the 
 mechanism thereby exercise is related to visfatin20 . the results of this study show that hydraulic resistance exercise training decreased plasma 
 visfatin levels in overweight college students . this study , however , did agree with previous research 
 demonstrating that 12 weeks of combined exercise reduced both visfatin and insulin secretion 
 levels in obese female college students21 . based on the results shown in table 3 , a 
 significant decrease was observed for insulin , homa - ir index , and homa -cell index . however , no significant improvement was observed in the levels of glucagon and glucose after 
 the hydraulic resistance exercise . several studies also showed decreased insulin 
 concentration22 , 23 . without changes in blood glucose levels , reduced insulin 
 concentrations would indicate that the speed and effectiveness of glucose clearance have 
 improved and that insulin sensitivity increased through exercise training as expected24 . furthermore , regular exercise training 
 including combined exercise might improve the ability of insulin to stimulate translocation 
 of glucose transporter 4 ( glut 4 ) to the muscle membrane after exercise25 . in addition , the result of homa - ir index - related research 
 revealed improvement in the reduction in the homa - ir index through exercise26 . however , there is still the issue of which between insulin resistance and homa -cell 
 precedes the occurrence of diabetes . in the case where insulin resistance is argued to be 
 the primary cause , decline in the function of -cell is the later response to the gradual 
 increase in insulin secretion due to the insulin resistance . however , those who argue that 
 the malfunction of -cell as the primary cause of diabetes state that the reduction in the 
 insulin secretion is the reason that normal blood sugar levels would increase27 . in addition , the homa - ir index seems to 
 reflect insulin resistance , but there is still room for discussion regarding the correlation 
 between homa -cell index and the -cell function of the pancreas . results show that -cell malfunction is a powerful indicator , predictive of diabetes when 
 the -cell function is evaluated in terms of considering insulin resistance . this outcome is 
 consistent with that of the study of haffnet et al , in which they stated that the -cell 
 malfunction is the primary cause of diabetes . through regular exercise , less insulin can 
 carry the same amount of glucose to muscles and the liver . therefore , -cells in the 
 pancreas do not have to excessively secrete insulin , resulting in decreased homa - ir and homa 
 -cell indexes28 . it was therefore believed that the effect of exercise would be beneficial to overweight 
 women . this led to the present research that demonstrated the positive effect of hydraulic 
 resistance exercise on overweight university students in their twenties with respect to 
 visfatin , insulin , homa - ir , and homa -cell measures . the focus on young overweight women in their twenties was an advantage of this study , in 
 contrast to previous studies that focused on middle - aged or older adults . twelve weeks of 
 supervised hydraulic resistance exercise did indeed affect weight , bmi , body fat , visfatin 
 level , insulin level , homa - ir index , and homa -cell index . however , it did not affect the 
 muscle mass , glucagon level , and glucose level of our sample of overweight women . . however , 
 visfatin did not demonstrate a relationship with insulin , glucagon , and glucose levels , and 
 homa - ir and homa -cell indexes .
[ purpose ] this study aimed to examine the correlation of visfatin level to pancreatic 
 endocrine hormone level , homeostasis model assessment of insulin resistance ( homa - ir ) 
 index , and homa -cell index in hydraulic resistance exercise . 
 furthermore , it 
 investigated the relationship between visfatin level and other variables affected by 
 exercise in overweight women . 
 [ subjects and methods ] the exercise group trained for 12 
 weeks , 70 minutes / day , 5 days / week . 
 visfatin level , pancreatic endocrine hormone level , 
 homa - ir index , and homa -cell index were measured before and after the intervention . 
 based on the blood insulin and glucose concentrations , homa - ir index , the indicator of 
 insulin resistance , and homa -cell index , the indicator of insulin secretion level , were 
 assessed . 
 [ results ] interaction effects on visfatin level , insulin level , homa - ir index , 
 and homa -cell index were observed . 
 interaction effects on glucagon and glucose levels 
 were not observed between the intervention groups . 
 the correlations of visfatin level to 
 insulin , glucagon , and glucose levels , and homa - ir and homa -cell indexes were not 
 significant for any of the subjects . 
 [ conclusion ] therefore , the 12-week resistance 
 exercise affected body composition , visfatin level , insulin level , homa - ir index , and homa 
 -cell index . finally , visfatin was not related to insulin , glucagon , and glucose levels , 
 and homa - ir and homa -cell indexes .