Type 2 Diabetes Mellitus Patients Manifest Greater Muscle Fatigability Than Healthy Individuals During Dynamic Fatigue Protocol.

OBJECTIVE: The present study aimed to investigate the electromyographic (EMG) indices of muscle fatigue along with biochemical marker of fatigue-that is, blood lactate-during a dynamic fatigue protocol in individuals with type 2 diabetes mellitus (T2DM) vs a healthy control group. Secondarily, it aimed to examine the association between EMG indices of muscle fatigue and blood lactate in these patients. METHODS: Thirty-four participants took part in the study: 19 individuals with T2DM (age, 53.5 ± 6.85 years) and 15 age-matched healthy controls (age, 50.2 ± 3.55 years). Participants performed a dynamic fatigue protocol consisting of 5 sets of 10 repetitions each at an intensity of the 10-repetition maximum. Surface EMG of the vastus medialis and vastus lateralis muscles was recorded during the dynamic fatigue protocol, and EMG indices such as median frequency (MF), slope of MF (MFslope), Dimitrov muscle fatigue spectral index, and root-mean-square were evaluated for each contraction across all the 5 sets. Blood lactate concentrations were also assessed 3 times during the fatigue protocol. RESULTS: Findings revealed that EMG muscle fatigue indices such as MF, MFslope, and Dimitrov muscle fatigue spectral index were significantly altered in individuals with T2DM vs healthy individuals across the sets and repetitions for both the vastus medialis (P < .001) and vastus lateralis muscles (P < .001). There was a significantly greater rise in blood lactate in individuals with T2DM than in healthy individuals (P < .001), which was not found to be associated with changes in EMG indices of muscle fatigue. CONCLUSION: Findings suggest the existence of significantly greater fatigue in the knee extensor muscles of individuals with T2DM than healthy individuals.

Sensorimotor and gait training improves proprioception, nerve function, and muscular activation in patients with diabetic peripheral neuropathy: a randomized control trial.

OBJECTIVES: To examine the effect of sensorimotor and gait training on proprioception, nerve function, and muscle activation in diabetic peripheral neuropathy (DPN) patients. METHODS: Thirty-eight (25 male and 13 female) participants with DPN were selected and randomly allocated to intervention and control group. Participants in the intervention group were provided sensorimotor and gait training for eight weeks (3 days/week) along with diabetes and foot care education; participants in the control group received diabetes and foot care education only. Outcome measures involved proprioception, nerve conduction studies of peroneal and tibial nerve, and activation of lower limb muscles and multifidus while standing with eyes open and eyes closed, and treadmill walking. RESULTS: Mixed ANOVA revealed significant time effect and time×group interaction of proprioception in all four directions (p<0.05). The conduction velocity of peroneal nerve revealed significant time effect (p=0.007) and time×group interaction (p=0.022). Interaction effect was found to be significant for medial gastrocnemius and multifidus while standing with eyes open as well as with eyes closed (p≤0.004). Only multifidus showed significant group (p=0.002) and interaction effect (p=0.003) during walking. CONCLUSIONS: Sensorimotor and gait training is an effective tool for improvement of proprioception and nerve function. It benefits muscle activation around ankle and multifidus during postural control and walking in DPN patients. Clinical Trials Registry - India, National Institute of Medical Statistics (Indian Council of Medical Research): Registration Number - CTRI/2017/08/009328.

Adaptations of the Upper Body to Plyometric Training in Cricket Players of Different Age Groups.

CONTEXT: Neuromuscular adaptations following exercise training are believed to enhance sports performance. While abundant research is available on adaptations of the lower body to plyometric training, little is known about adaptations of the upper body to plyometric training. OBJECTIVE: To examine the effect of plyometric training on neuromuscular adaptations in cricket players of different age groups. DESIGN: Randomized parallel group active-controlled trial. SETTING: Research laboratory, school cricket ground, and sports complex field. PARTICIPANTS: Fifty-nine cricket players were randomly assigned to either the experimental group or the control group. INTERVENTIONS: The experimental group was subjected to 8 weeks of medicine ball plyometric training held thrice per week. Neuromuscular adaptations were analyzed pretraining and posttraining in 3 age groups: <18, 18-25, and >25 years. Analysis of variance was used to ascertain the training effects between and within the 6 subgroups, that is, age group <18 years (control and experimental), age group 18-25 years (control and experimental), and age group >25 years (control and experimental). MAIN OUTCOME MEASURES: Muscle activation, upper body balance, upper body power, and muscle strength. RESULTS: Out of 59, 55 participants completed the study. Subjects aged <18 years (adolescents) showed significantly greater improvements than those from the groups 18-25 years and >25 years (adults) on upper body balance and upper body power. Significant improvements were observed in the experimental subjects of all age groups on their muscle activity of biceps brachii, upper body balance, and upper body power following medicine ball plyometric training. CONCLUSIONS: Though adolescent subjects were found to be more adaptive than adult subjects, experimental subjects showed significantly greater neuromuscular adaptations to medicine ball plyometric training than controls. These findings emphasize the need for coaches and athletic trainers to inculcate medicine ball plyometric exercises in training regimes of cricket players so as to improve their upper body performance.

Does resistance training modulate cardiac autonomic control? A systematic review and meta-analysis.

PURPOSE: To systematically evaluate the literature on the effects of resistance training (RT) on cardiac autonomic control in healthy and diseased individuals. METHODS: Electronic databases Pubmed, PEDro, and Scopus were systematically searched from their inception up to June 2018. Randomized controlled trials, quasi-experimental trials, and cross-over controlled trials investigating the effect of RT (of at least 4 weeks duration) on cardiac autonomic control assessed either by linear or non-linear measures of heart rate variability (HRV), baroreflex sensitivity, or post-exercise heart rate recovery were included. Of the studies retrieved, 28 were included in the systematic review. Meta-analysis was performed on 21 studies of the total 28 studies. RESULTS: Quality and characteristic assessment revealed fair quality evidence. The majority of literature on healthy humans suggested no change in cardiac autonomic control following RT. Standardized mean differences (SMD) showed a significant effect of RT on root mean square of successive differences between adjacent inter-beat (R-R) intervals (RMSSD) [SMD 0.96, 95% confidence interval (CI) 0.20-1.73; p = 0.01], ratio of low- to high-frequency power of HRV (LF/HF ratio; SMD -0.72, 95% CI -1.03 to -0.42; p < 0.00001), standard deviation of the instantaneous beat-to-beat variability (SD1; SMD 1.78, 95% CI 1.07-2.49, p < 0.00001), and sample entropy (SMD 1.17, 95% CI 0.36-1.97, p = 0.005) in diseased individuals. CONCLUSION: This rigorous systematic analysis revealed that RT has no or minimal effects on cardiac autonomic control of healthy individuals, but RT leads to improvement in cardiac autonomic control of diseased individuals.

Association between sleep quality and inflammatory complement components in collegiate males.

BACKGROUND: An accumulating amount of evidence has linked humoral mediators of inflammation with sleep measures. Nevertheless, important details of this association, in particular the role of the complement components in the context of chronic sleep attributes, have remained largely uncharacterized. MATERIALS AND METHODS: Fifty university students (age, 23.3 ± 3.8 years; BMI, 23.7 ± 2.9 kg/m(2)) completed the study. Four dichotomized sleep measures assessed by the Pittsburgh Sleep Quality Index (PSQI) were used in association analysis using binary logistic regression with complement component 3, 4, and complement factor I (CFI). The sleep measures were defined as sleep quality (good sleep/poor sleep; PSQI ≤5/PSQI >5), bedtime (early/late; before 00:00 h/after 0:00 h), sleep duration (short/normal ≤6 h/>6 h), and sleep onset latency (normal/disturbed; 0-1 score/2-3 score on the PSQI component of sleep latency). RESULTS: The complement component 4 was associated with sleep quality (unadjusted, OR = 1.025, p < 0.05; adjusted for age, OR = 1.025, p < 0.05; adjusted for BMI, OR = 1.027, p < 0.05) and sleep duration (unadjusted, OR = 1.041, p < 0.01; adjusted for age, OR = 1.041, p < 0.01; adjusted for BMI, OR = 1.046, p < 0.01). CFI was associated with bedtime (unadjusted, OR = 0.737, p < 0.01; adjusted for age, OR = 0.717, p < 0.01; adjusted for BMI, OR = 0.677, p < 0.01) and with sleep duration (unadjusted, OR = 0.796, p < 0.05; adjusted for age, OR = 0.796, p < 0.05). CONCLUSION: The findings indicate the importance of the role of complement components in the dynamics of sleep. Therefore, sleep should be assessed in conditions where complement components are affected.

Sulfur-containing angiotensin-converting enzyme inhibitor 3-thienylalanine-ornithyl-proline activates endothelial function and expression of genes involved in Renin-Angiotensin system.

Experiments were performed to elucidate the mechanism of action of a 7-day oral administration of the sulfur-containing angiotensin-converting enzyme (ACE) inhibitor 3-thienylalanine-ornithyl-proline (TOP; 10 mg/kg/d) on endothelial dysfunction and oxidative stress compared with that of captopril (control; 40 mg/kg/d) in spontaneously hypertensive rats. The differential expression of messenger RNA by real-time reverse-transcriptase-polymerase chain reaction and protein by Western blot analysis was assessed for the markers nicotinamide adenine dinucleotide phosphate oxidase, p22phox, endothelial nitric oxide (NO) synthase, and AT1 receptor. Furthermore, TOP-induced vascular relaxation was also investigated using rat aortic rings in an organ bath. TOP significantly downregulated both messenger RNA and protein expressions of p22phox and AT1 receptor; the latter facilitates vasoconstriction through angiotensin II. In addition, TOP upregulated endothelial NO synthase, thus enhancing the production of NO. Vascular studies revealed that TOP caused endothelium-dependent vasorelaxation. In conclusion, unlike the free sulfur in captopril, the thiophene ring in TOP may act as a better scavenger of free radicals. Therefore, TOP exerted more significant antihypertensive effects than captopril, not only through angiotensin-converting enzyme inhibition but also through more effective antioxidation, because the inherent thiophene moiety resulted in the enhanced production of NO.

Impact of resistance training on muscle fatigue in type 2 diabetes mellitus patients during dynamic fatigue protocol.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is often accompanied with several neuromuscular complications of which muscle fatigue is one of the scantily studied and less-explored complication of this disease. OBJECTIVE: To investigate the effects of resistance training (RT) on muscle fatigue markers from electromyography (EMG) and capillary blood in T2DM patients. METHODS: Forty T2DM patients were randomized to either RT (n = 20) or control group (n = 20). They were assessed for EMG indices of muscle fatigue along with blood lactate (at three time points: Lactatepre, Lactatepeak, Lactatepost) during a dynamic fatigue protocol. Dynamic fatigue protocol consisted of 5 sets of leg press exercise at 10 repetition maximum intensity. RT group performed moderate intensity (65%-75% 1 repetition maximum) RT 3 times/week for 12 weeks. Control group followed usual routine. RESULTS: Findings revealed that EMG amplitude (root mean square) and Dimitrov's muscle fatigue index (FInsmk) decreased significantly while median frequency (MF) increased significantly during the dynamic fatigue protocol for both vastus medialis (Root mean square, p = .02; FInsmk, p = .001; MF, p < .001) and vastus lateralis muscle (Root mean square, p= .04,FInsmk,p = .01; MF, p < .001) post-RT. Blood lactate responses did not change after RT (Lactatepre, p = .55; Lactatepeak, p = .91; Lactatepost, p = .33). CONCLUSIONS: Findings of the present study illustrated that moderate intensity RT led to a significant reduction muscle fatigue in knee extensor muscles of T2DM patients. These results reinforce the utilization of RT in patients with T2DM.

Progressive resistance training ameliorates deteriorating cardiac autonomic dysfunction, subclinical inflammation and endothelial dysfunction in type 2 diabetes mellitus: A randomized control trial.

BACKGROUND AND AIMS: To investigate the effect of resistance training (RT) on outcomes of cardiac autonomic control, biomarkers of subclinical inflammation, endothelial dysfunction, and angiotensin II in T2DM patients with CAN. METHODS: Fifty six T2DM patients with CAN were recruited in the present study.After baseline assessment of all outcome variables, patients were randomly allocated into two groups - RT (n = 28) and Control (n = 28). The experimental group underwent 12 weeks of RT and the control group received usual care. RT was performed at an intensity of 65%-75% of 1 RM, 3 times/week for 12 weeks. RT program included 10 exercises of major muscle groups in the body. Cardiac autonomic control parameters, subclinical inflammation and endothelial dysfunction biomarkers, and serum angiotensin II concentration were assessed at baseline and after 12 weeks. RESULTS: Parameters of cardiac autonomic control showed significant improvement after RT (p < 0.05). Interleukin-6, interleukin-18 were significantly reduced while endothelial nitric oxide synthase was significantly increased post-RT (p < 0.05). CONCLUSIONS: Findings of the present study suggest that RT has the potential to enhance deteriorating cardiac autonomic function in T2DM patients with CAN. RT also seems to have an anti-inflammatory role and it may also play some role in vascular remodeling in these patients. TRIAL REGISTRATION: CTRI/2018/04/013321, Registered prospectively on 13th April 2018, Clinical Trial Registry, India.

Effect of Whole-body Vibration on Depression, Anxiety, Stress, and Quality of Life in College Students: A Randomized Controlled Trial.

Objectives: To determine the effects of whole-body vibration (WBV) training on depression, anxiety, stress, and quality of life (QoL) in college students. Methods: The participants comprised college students who led physically inactive lifestyles as revealed by their Medical Outcomes Study Form 36 (SF-36) scores, and with elevated scores of Depression Anxiety Stress Scale (DASS) test. They were randomly allocated to two groups of 15 each: (a) the WBV group (male = 3, female = 12) and (b) the exercise group (male = 6, female = 9). The participants in the WBV group performed prescribed exercises while they stood on a vibrating platform whereas those in the exercise group performed the same exercises but without the vibrating platform. After four weeks of twice-a-week training, DASS and SF-36 were measured. The pre- and post-scores were compared between the groups. Results: Depression (p < 0.001), anxiety (p < 0.001), and stress (p < 0.001) were found to reduce significantly for the WBV group compared to the exercise group. There was also significant within-group improvement in all the components of SF-36 (p < 0.040). Conclusions: Exercising on the WBV platform may reduce depression, anxiety, and stress in college students and improve their overall QoL.

Leisure-Time Physical Activity and Glycemic Control Independently Predicts Cardiac Autonomic Neuropathy in Type 2 Diabetes Mellitus.

BACKGROUND: Though cardiac autonomic neuropathy (CAN) is a common complication of type 2 diabetes mellitus (T2DM); still, there is lack of clarity on pathophysiological correlates for its onset and progression. Therefore, the purpose of this study was to investigate the predictive ability of lifestyle and cardiometabolic risk factors for CAN in T2DM patients. METHODS: A total of 105 Indian T2DM patients were recruited in the present study. Cardiometabolic risk factors, such as glycemic control, lipids, resting heart rate, systolic and diastolic blood pressure, and lifestyle risk parameters, such as physical activity levels and sleep quality were assessed. Standard cardiovascular autonomic reflex tests were performed for diagnosing CAN by Ewing's criteria. RESULTS: Leisure-time physical activity and glycosylated hemoglobin were significant independent predictors of CAN in T2DM. Leisure-time physical activity and glycosylated hemoglobin predicted the occurrence of CAN at cutoff values ≤4.68 metabolic equivalent-hours per week (P = .007) and >7.5% (P = .002), respectively. CONCLUSIONS: The T2DM patients should be encouraged to engage in leisure-time physical activity of at least 4.68 metabolic equivalent-hours per week (equivalent to 1.2 h of walk or 0.6 h of jog per week) and therapeutic strategies for controlling hyperglycemia in T2DM should aim to reduce glycosylated hemoglobin below 7.5% to reduce CAN occurrence.

Progressive Resistance Exercises plus Manual Therapy Is Effective in Improving Isometric Strength in Overhead Athletes with Shoulder Impingement Syndrome: A Randomized Controlled Trial.

Reduction in isometric strength of the scapulohumeral muscles is a commonly seen impairment in overhead athletes afflicted with shoulder impingement syndrome (SIS). The purpose of this study was to compare the effects of two different treatment programs: progressive resistance exercises plus manual therapy (PRE plus MT) and motor control exercises (MCE), on isometric strength of upper trapezius (UT), middle trapezius (MTr), lower trapezius (LT), serratus anterior (SA), supraspinatus (Supr.), anterior deltoid (A.D), and latissimus dorsi (LD). 80 male university-level overhead athletes clinically diagnosed with SIS were randomly allocated into either of the two groups: PRE plus MT and MCE group. Athletes in the PRE plus MT group underwent graduated exercises with resistance elastic band, stretching exercises, and mobilization of the thoracic and shoulder joints. MCE group was submitted to motor control exercises in varied planar positions. Athletes in both groups underwent management 3 times a week for 8 weeks. Isometric strength of UT, MTr, LT, Supr, A.D, SA, and LD was measured at three-time points: baseline, 4th week, and 8th week. Relative to baseline, both interventions were found to be effective in increasing and optimizing the isometric strength of muscles (p < 0.05) except for supraspinatus in the MCE group (p > 0.05). However, athletes in PRE plus MT group presented a more pronounced increase in isometric strength than those in the MCE group. Between groups analysis found the largest isometric strength improvement in PRE plus MT group for A.D, followed by Supr. and UT muscles (p < 0.05; effect size: 0.39 to 0.40). The study concluded that compared to MCE, PRE plus MT provides greater improvement in the isometric strength of scapulohumeral muscles.

Variations in cricket players' upper body dynamic balance across different levels of competition.

BACKGROUND: Balance ability has been associated with performance and injury prevention in athletes. Previous studies have investigated the differences in lower body dynamic balance abilities among male high school, collegiate and professional soccer players. OBJECTIVE: To investigate the differences on the Upper Quarter Y-Balance Test (UQYBT) in school, collegiate and employed cricket players. SUBJECTS: Dynamic balance data were collected for school (SCH; n = 22), collegiate (COL; n = 19) and employed (EMP; n = 15) cricket players of Jamia Millia Islamia, New Delhi, India using the UQYBT standardized protocol. METHODS: For the UQYBT, the participant reached with one hand in the medial, superolateral and inferolateral directions while maintaining three points of contact (other hand and both feet). The test was performed for both non-dominant and dominant hands. RESULTS: The SCH group had the least medial reach distance than the other two groups (p = 0.010). Also, SCH players tended to exhibit a lower composite reach score than the other groups, but this difference was not significant (p > 0.05). No bilateral differences were observed among the three groups in any of the reach directions. CONCLUSIONS: Upper body dynamic balance performance varied with the competition level. This may indicate that athletes' movement strategies may be different depending on the competition level and that normative values may need to be established for each competition level.

Influence of Forward Head Posture on Cervicocephalic Kinesthesia and Electromyographic Activity of Neck Musculature in Asymptomatic Individuals.

OBJECTIVE: The purpose of this study was to compare cervicocephalic kinesthesia and electromyographic (EMG) activity of neck muscles-upper trapezius (UT) and sternocleidomastoid (SCM)-between individuals with and without forward head posture (FHP) and to examine the correlation between cervicocephalic kinesthesia and craniovertebral angle (CVA). METHODS: Twenty-two asymptomatic individuals with FHP and 22 without FHP were recruited for the present study. Craniovertebral angle was measured, and those with CVA ≤53° were assigned to the FHP group, whereas those with CVA >53° were assigned to the control group. Thereafter, cervicocephalic kinesthesia and EMG activity of the neck muscles were assessed. Cervicocephalic kinesthesia was measured using a head repositioning accuracy test for all cervical spine motions. EMG activity of the UT and SCM muscles was recorded at rest and during activity. RESULTS: Position-sense error values were found to be significantly greater for all directions-ie, flexion, extension, side flexion, and rotation-in participants with FHP than those without (P < .05). EMG activity of the UT and SCM muscles was found to be significantly raised both at rest and during activity in individuals with FHP relative to the non-FHP group (P < .05). Position-sense error values showed a significant inverse correlation with CVA (P < .05). CONCLUSION: Findings of the present study suggest that cervicocephalic kinesthesia and activation patterns of the neck muscles may be significantly altered in individuals with FHP. Also, cervicocephalic kinesthesia is significantly associated with the severity of FHP.

Whole body vibration showed beneficial effect on pain, balance measures and quality of life in painful diabetic peripheral neuropathy: a randomized controlled trial.

PURPOSE: The aim of the study was to determine the efficacy of whole body vibration (WBV) therapy on pain, neuropathy disability score, balance, proprioception and quality of life (QOL) in patients with painful diabetic peripheral neuropathy (PDPN). METHODS: Twenty-six (16 males and 10 females) patients with PDPN were selected on the basis of inclusion and exclusion criteria. Subjects were randomly allocated to an experimental group (n = 13, age = 60.69 ± 5.08) and a control group (n = 13, age = 59.54 ± 4.25). The experimental group was given WBV therapy for six weeks (3 days/week) in addition to standard medical care, dietary advice and lifestyle modifications. Control group was provided only standard medical care, dietary advice and lifestyle modifications. Outcome measures included numeric pain rating scale (NPRS), Leeds assessment of neuropathic symptoms and signs (LANSS), vibration perception threshold (VPT), neuropathy disability score (NDS), proprioception, single-leg stance test (SLST), timed up and go test (TUGT) and short form 36 questionnaire (SF-36). RESULTS: NPRS, LANSS, NDS, SLST and TUGT showed significant time effect (p ≤ 0.022) and time×group interaction (p ≤ 0.007), whereas group effect was found to be significant only in LANSS (p = 0.001). VPT showed significant group effect (p ≤ 0.045) and time×group interaction (p ≤ 0.007) at great toe, metatarsal head and total average score. SF-36 was found to be significant time effect (p ≤ 0.024) in all domains except limitations due to physical health (p = 0.461). SF-36 average score was found be significant for group effect (p = 0.002) and time×group interaction (p < 0.001). CONCLUSION: WBV improves sensory sensations like pain and vibration perception, neuropathy disability score, balance measures and health-related QOL in PDPN.

Electromyographic Activity of Hip Musculature During Functional Exercises in Participants With and Without Chronic Ankle Instability.

OBJECTIVE: The main objective of the present study was to investigate the electromyographic (EMG) activity of gluteus medius (Gmed) and gluteus maximus (Gmax) muscles during functional exercises in subjects with chronic ankle instability (CAI) vs healthy controls. METHODS: Seventeen subjects (age, 24.4 ± 2.03 years) with CAI and 17 healthy controls (age, 24.6 ± 2.57 years) were recruited for the present study. For all participants, after testing maximum voluntary isometric contraction of the Gmed and Gmax muscle, EMG activity of these muscles was recorded during functional exercises, such as the Y Balance Test and the single-leg squat with and without Swiss ball. RESULTS: EMG activity of Gmed and Gmax was found to be significantly (P < .05) reduced during all functional exercises in subjects with CAI when compared with healthy controls. No significant differences (P > .05) were observed in the EMG activity of both muscles across different functional exercises. CONCLUSION: Our findings indicate that EMG activity of hip muscles is significantly reduced in CAI subjects, which might give an indication regarding the inclusion of hip muscle strengthening (Gmax and Gmed) in the rehabilitation of CAI. Moreover, Gmed and Gmax muscle activity did not vary during the different functional exercises within each group, which might indicate that activation pattern of these muscles are not sensitive to the type of functional task.

Cardioprotective Efficacy of Coriandrum sativum (L.) Seed Extract in Heart Failure Rats Through Modulation of Endothelin Receptors and Antioxidant Potential.

The present study aimed to evaluate the therapeutic and prophylactic potential of Coriandrum sativum extract in isoproterenol-induced heart failure (HF) in Wistar rats. Two weeks after the isoproterenol administration, rats developed severe impairment in left ventricular functions, reduced baroreflex sensitivity, and significant alteration in hemodynamic parameters and lipid profile. HF rats also exhibited enhanced lipid peroxidation and increased expression of endothelin receptors (ETA and ETB). Therapeutic and prophylactic treatment with C. sativum extract significantly (p < .05) improved the left ventricular functions and hemodynamic parameters and increased baroreflex sensitivity. It also inhibited lipid peroxidation, improved lipid profile, and downregulated the expression of endothelin receptors. Simvastatin treatment showed a similar cardioprotective effect. Our results suggest that C. sativum extract provides significant protection from heart failure possibly due to its ability to improve left ventricular functions and baroreflex sensitivity, attenuate lipid peroxidation, and modulate the expression of endothelin receptors.

Sleep duration is a significant predictor of cardiac autonomic neuropathy in type 2 diabetes mellitus.

AIM: To investigate the association between sleep quality outcomes and measures of cardiac autonomic function and to assess the predictive ability of sleep quality outcomes for cardiac autonomic neuropathy (CAN) in type 2 diabetes mellitus (T2DM). METHODS: Fifty patients with T2DM (age, 51.3±7.01years; glycemic control, 8.4±1.65%) completed the study. Patients were diagnosed for CAN using the standard clinical autonomic test battery and were also assessed for heart rate variability (HRV) under resting conditions. Sleep quality was examined using the Pittsburg Sleep Quality Index (PSQI). RESULTS: Sleep duration, sleep onset latency, sleep efficiency, daytime dysfunction and global PSQI score showed significant correlations with measures of cardiac autonomic control (p<0.05). At an optimal cut-off of≤5.83h (area under the curve: 0.76, p=0.0003; sensitivity: 50%; specificity: 94.4%), sleep duration predicted occurrence of CAN (odds ratio, confidence interval: 0.18, 0.04-0.70; p=0.01) in T2DM after adjusting for various clinical confounders. CONCLUSION: Findings of the present study suggest that subjective sleep outcomes such as sleep duration, sleep onset latency, sleep efficiency, daytime dysfunction and overall sleep quality are associated with the indices of cardiac autonomic function in T2DM. Moreover, short sleep duration may be considered a predictor in the occurrence of CAN in these patients. Considering the role of sleep in the pathophysiology of CAN, sleep should be routinely examined in patients with T2DM and appropriate therapeutic interventions should be implemented particularly in case of reduced sleep duration.

Subclinical inflammation and endothelial dysfunction are linked to cardiac autonomic neuropathy in type 2 diabetes.

PURPOSE: The present study aimed to examine association between inflammatory and endothelial function biomarkers and indices of cardiac autonomic control in T2DM patients. METHODS: 50 T2DM patients were recruited for this study. For cardiac autonomic function, cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV) analysis was performed. Blood samples were collected for evaluating inflammatory and endothelial function biomarkers. Multivariable linear regression analysis adjusted for diabetes duration, glycemic control, waist circumference, hypertension, dyslipidemia, metformin, and statins was performed to examine the association between the biomarkers and cardiac autonomic function parameters. RESULTS: Interleukin-6 was inversely related to total power (p = .009) and low frequency power (p = .04). Interleukin-18 and high sensitivity C-reactive protein inversely correlated with measures of cardiac vagal control (p < .05). Both nitric oxide and endothelial nitric oxide synthase were positively linked with cardiac vagal control indices (p < .05) whereas endothelin-1 did not show any independent association with cardiac autonomic function parameters. CONCLUSIONS: Biomarkers of inflammation and endothelial function are associated with measures of cardiac vagal control and global HRV which suggest that there is some pathophysiological link between subclinical inflammation, endothelial dysfunction and cardiac autonomic dysfunction in T2DM.

Diagnostic performance of resting and post-exercise heart rate variability for detecting cardiac autonomic neuropathy in type 2 diabetes mellitus.

BACKGROUND: Post-exercise recovery phase is associated with clustering of various cardiovascular events and, therefore, monitoring of cardiac autonomic control via heart rate variability (HRV) during this phase may allow identification of autonomic alterations that are not evident under resting conditions in type 2 diabetes mellitus (T2DM) patients. PURPOSE: To investigate and compare the diagnostic performance of resting and post-exercise HRV for detecting cardiac autonomic neuropathy (CAN) in T2DM patients. METHODS: Forty-two T2DM patients were categorized as CAN-positive and CAN-negative based on standard cardiovascular autonomic reflex tests (CARTs). Short-term resting and post-exercise HRV after a graded exercise test were evaluated for each participant. Diagnostic performance of both resting and post-exercise HRV measures was computed using standard statistical procedures. RESULTS: Diagnostic testing yielded superior diagnostic performance of post-exercise HRV than resting HRV measures. Root mean square of successive differences (RMSSD) between adjacent R-R intervals (p = 0.01), percentage of consecutive N-N intervals that vary by >50 ms (pNN50) (p = 0.03) and total power (TP) (p = 0.01) were significantly better diagnostic indicators of CAN under post-exercise conditions than at rest. Predictive ability of these post-exercise HRV measures for CAN was maintained after adjusting various clinical confounders to cardiac autonomic function. CONCLUSION: Post-exercise HRV measures such as TP, RMSSD and pNN50 were found to be more accurate diagnostic tests for detecting CAN than resting HRV. Hence, monitoring of the HRV measures proposed here during exercise testing protocols may provide important diagnostic information regarding CAN in T2DM.