***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Obesity and type 2 diabetes ( T2D ) are associated with abnormal cardiovascular autonomic function and increased risk for cardiac complications , especially after exercise . Since improvements at rest are not always observed after training , we investigated changes in resting and post-exercise autonomic function in obese women with and without T2D after16-week of walking training .  Heart rate ( HR ) variability ( HRV ) and baroreflex sensitivity ( BRS ) were measured at rest and 20 min after a 20 min bout of treadmill exercise at 65 % VO2 peak in obese women with ( n = 8) and without T2D ( n = 12 ) before and after training . HRV was analyzed by frequency-domain [ high- ( HF ) power and low-frequency ( LF ) ] and BRS by the sequence method . Exercise training induced similar significant changes in VO2 peak , resting systolic blood pressure ( SBP ) and post-exercise autonomic function in both groups . Training increased VO2 peak ( 6 % ; P < 0.01 ) and decreased resting SBP ( 8 % ; P < 0.001 ) . Increased post-exercise HR recovery ( 5 % ; P < 0.001 ) , HF power ( 14 % ; P < 0.05 ) , LF power ( 14 % ; P < 0.05 ) and BRS ( 86 % ; P < 0.001 ) were also observed . Resting autonomic function and post-exercise SBP were not altered after training . In conclusion , endurance training reduced blood pressure without changes in HRV and BRS at rest , but training increased HRV and BRS during the recovery of acute endurance exercise indicating an improved post-exercise autonomic modulation of HR , which was similar in obese women with and without T2D Aims /hypothesisGait characteristics and balance are altered in diabetic patients . Little is known about possible treatment strategies . This study evaluates the effect of a specific training programme on gait and balance of diabetic patients . Methods This was a r and omised controlled trial ( n = 71 ) with an intervention ( n = 35 ) and control group ( n = 36 ) . The intervention consisted of physiotherapeutic group training including gait and balance exercises with function-orientated strengthening ( twice weekly over 12 weeks ) . Controls received no treatment . Individuals were allocated to the groups in a central office . Gait , balance , fear of falls , muscle strength and joint mobility were measured at baseline , after intervention and at 6-month follow-up . Results The trial is closed to recruitment and follow-up . After training , the intervention group increased habitual walking speed by 0.149 m/s ( p < 0.001 ) compared with the control group . Patients in the intervention group also significantly improved their balance ( time to walk over a beam , balance index recorded on Biodex balance system ) , their performance-oriented mobility , their degree of concern about falling , their hip and ankle plantar flexor strength , and their hip flexion mobility compared with the control group . After 6 months , all these variables remained significant except for the Biodex sway index and ankle plantar flexor strength . Two patients developed pain in their Achilles tendon : the progression for two related exercises was slowed down . Conclusions /interpretationSpecific training can improve gait speed , balance , muscle strength and joint mobility in diabetic patients . Further studies are needed to explore the influence of these improvements on the number of reported falls , patients ’ physical activity levels and quality of life . Trial registration : Clinical Trials.gov NCT00637546 Funding : This work was supported by the Swiss National Foundation ( SNF ) : Objective : The objective of this study was to eluci date whether the degree of autonomic modulation is associated with the degree of microvascular complications in patients with type 1 diabetes . Methods : A total of 290 type 1 individuals with diabetes were r and omly recruited during normal visits to outpatient clinics at 4 Danish hospitals . The degree of autonomic modulations was quantified by measuring  heart rate variability ( HRV ) during passive spectral analysis and active tests ( valsalva ratio [ VT ] , response to st and ing [ RT ] , and deep breathing [ E : I ] ) . To describe possible associations between severity of microvascular complications and measures of autonomic modulation , multivariate analysis was performed . Results : After adjusting for diabetes duration , sex , age , pulse pressure , heart rate , and smoking , autonomic dysfunction remained significantly correlated with severity of retinopathy , nephropathy , and peripheral neuropathy in individuals with type 1 diabetes patients . Conclusions : Autonomic dysfunction is present in early stages of retinopathy , nephropathy , and peripheral neuropathy in patients with type 1 diabetes BACKGROUND Diabetes is the most important cause of peripheral neuropathy ( DPN ) . No definitive treatment for DPN has been established , and very few data on the role of exercise training on DPN have been reported . AIM OF THE STUDY We sought to examine the effects of long-term exercise training on the development of DPN in both Types 1 and 2 diabetic patients . PARTICIPANTS AND METHODS Seventy-eight diabetic patients without signs and symptoms of peripheral DPN were enrolled , r and omized , and subdivided in two groups : 31 diabetic participants [ 15 f , 16 m ; 49+/-15.5 years old ; body mass index ( BMI ) = 27.9+/-4.7 ] , who performed a prescribed and supervised 4 h/week brisk walking on a treadmill at 50 % to 85 % of the heart rate reserve ( exercise group : EXE ) , and a  control group of 47 diabetic participants ( CON ; 24 f , 23 m ; 52.9+/-13.4 years old ; BMI = 30.9+/-8.4 ) .  Vibration perception threshold ( VPT ) , nerve distal latency ( DL ) , nerve conduction velocity ( NCV ) , and nerve action potential amplitude ( NAPA ) in the lower limbs were measured . RESULTS We found significant differences on Delta ( delta ) in NCV for both peroneal and sural motor nerve between the EXE and CON groups during the study period ( P<.001 , for both ) . The percentage of diabetic patients that developed motor neuropathy and sensory neuropathy during the 4 years of the study was significantly higher in the CON than the EXE group ( 17 % vs. 0.0 % , P<.05 , and 29.8 % vs. 6.45 % , P<.05 , respectively ) . In addition , the percentage of diabetic patients who developed increased VPT ( 25 V ) during the study was significantly higher in the CON than the EXE group ( 21.3 % vs. 12.9 % , P<.05 ) . Change on Hallux VPT from baseline to the end of the study was significantly different between the EXE and CON groups ( P<.05 ) ; no significant change in Malleolus VPT between the two groups occurred . CONCLUSIONS This study suggests , for the first time , that long-term aerobic exercise training can prevent the onset or modify the natural history of DPN Background Low heart rate variability ( HRV ) is associated with a higher risk of death in patients with heart disease and in elderly subjects and with a higher incidence of coronary heart disease ( CHD ) in the general population . Methods and Results We studied the predictive value of HRV for CHD and death from several causes in a population study of 14 672 men and women without CHD , aged 45 to 65 , by using the case-cohort design . At baseline , in 1987 to 1989 , 2-minute rhythm strips were recorded . Time-domain  measures of HRV  were determined in a r and om sample of 900 subjects , for all subjects with incident CHD ( 395 subjects ) , and for all deaths ( 443 subjects ) that occurred through 1993 . Relative rates of incident CHD and cause-specific death in tertiles of HRV were computed with Poisson regression for the case-cohort design . Subjects with low HRV had an adverse cardiovascular risk profile and an elevated risk of incident CHD and death . The increased risk of death could not be attributed to a specific cause and could not be explained by other risk factors . Conclusions Low HRV was associated with increased risk of CHD and death from several causes . It is hypothesized that low HRV is a marker of less favorable health Heart rate ( HR ) variability has been extensively studied in patients surviving an acute myocardial infa rct ion ( AMI ) . The majority of studies have shown that patients with reduced or abnormal HR variability/turbulence have an increased risk of mortality within few years after an AMI . Various measures of HR dynamics , such as time-domain , spectral , and non-linear measures of HR variability , as well as HR turbulence , have been used in risk stratification of post-AMI patients . The prognostic power of various measures , except of those reflecting rapid R – R interval oscillations , has been almost identical , albeit some non-linear HR variability measures , such as short-term fractal scaling exponent , and HR turbulence , have provided somewhat better prognostic information than the others . Abnormal HR variability predicts both sudden and non-sudden cardiac death after AMI . Because of remodeling of the arrhythmia substrate after AMI , early measurement of HR variability to identify those at high risk should likely be repeated later in order to assess the risk of fatal arrhythmia events . Future r and omized trials using HR variability/turbulence as one of the pre-defined inclusion criteria will show whether routine measurement of HR variability/turbulence will become a routine clinical tool for risk stratification of post-AMI patients BACKGROUND Heart rate variability ( HRV ) reflects autonomic nervous system modulation of cardiac activity . There is a relationship between degrees of physical activity , HRV changes and the risk of cardiovascular disease . AIM To study the effect of a supervised integrated exercise programme on HRV in type 2 diabetes mellitus ( DM ) . METHODS The study group consisted of 48 patients ( 27 males , mean age 62+/-7 years ) with type 2 diabetes , of whom 28 underwent a special exercise programme whereas the remaining 20 did not and served as the control group . The supervised integrated exercise programme was applied for a period of 9 months .  Deep breathing time domain HRV ( difference between the shortest and the longest R-R interval over one minute ) was measured at baseline and after 3 , 6 and 9 months . RESULTS A significant improvement in the HRV values was observed with increasing duration of exercise ( 13.03+/-1.08 beats/min at baseline versus 16.5+/-1.11 beats/min at 9 months , p < 0.001 ) whereas HRV decreased in the control group ( 14.85+/-1.15 beats/min at baseline vs. 14.30+/-1.75 at 9 months , p < 0.05 ) . Favourable changes in HRV in the exercise group were gender-dependent and were significant in males ( 12.4+/-1.76 beats/min at baseline vs. 16.18+/-1.91 at 9 months , p < 0.001 ) whereas in females only a trend towards HRV improvement was observed . The HRV changes were also age-dependent and were more pronounced in younger patients than in the elderly . The metabolic parameters of diabetes control ( blood glucose and glycosylated haemoglobin levels ) significantly improved in the exercise group and significantly worsened in the control group . CONCLUSIONS Regular supervised integrated exercise significantly improves HRV  in patients with type 2 DM , which may favourably influence their long-term prognosis [ Purpose ] This study evaluated the effects of 12 weeks combined aerobic and resistance exercise on heart rate variability in patients with Type 2 diabetes mellitus . [ Subjects and Methods ] The subjects were 16 female patients with Type 2 diabetes mellitus selected among the participants of a chronic disease management exercise class at C Region Public Health Center in South Korea . Subjects were r and omly assigned to the exercise group ( n=8 ; age , 55.97 ± 7.37 ) or the control group ( n=8 ; age , 57.53 ± 4.63 ) The exercise group performed aerobic and resistance exercises for 60 minutes per day , 3 times per week for 12 weeks . Anthropometric measurements , biochemical markers , physical fitness , and heart rate variability were examined . [ Results ] After 12 weeks of  exercise , weight , body fat percentage , waist circumference , blood glucose , insulin resistance , glycated hemoglobin level , systolic blood pressure , and diastolic blood pressure significantly decreased and cardiorespiratory fitness and muscular strength significantly increased in the exercise group . Although heart rate variability measures showed favorable changes with the exercise program , none were significant . [ Conclusion ] Although the exercise program did not show notable changes in heart rate variability in patients with Type 2 diabetes within the timeframe of the study , exercise may contribute to the prevention and control of cardiovascular autonomic neuropathy Autonomic neuropathy in diabetes leads to impaired regulation of blood pressure and heart rate variability ( HRV ) , which is due to a shift in cardiac autonomic balance towards sympathetic dominance . Lower HRV has been considered a predictor of cardiac mortality and morbidity . Deep breathing test is a simple method to measure HRV and it provides a sensitive measure of cardiac autonomic function . The effect of long-term physical activity on HRV in type-2 diabetes mellitus is inconclusive . We aim ed to evaluate the effects of regular physical exercise on HRV with 
    Output:
    
Physical exercise has become a therapy for T2DM , because it improves physical fitness and functional capacity , enhances metabolic control and insulin sensitivity , reduces inflammatory markers and neuropathy symptoms and can increase the regenerative capacity of cutaneous axons , slowing or preventing neuropathy progression .
However , it is not clear to what extent physical exercise can improve HRV in this population .
Weekly frequency might be the most important factor to improve HRV .
These aspects could help to design better programs based in scientific evidence , incorporating HRV as an important variable associated with diabetic neuropathy and mortality