Measurable deficit of autonomic and sensory nerve function in asymptomatic diabetic patients

The co-existence of sensory and autonomic neuropathy in type 1 diabetes with and without pain

AIMS

To investigate the co-existence of diabetic peripheral neuropathy (DPN), painful diabetic peripheral neuropathy (PDPN), and cardiac autonomic neuropathy (CAN) and to establish a model to predict CAN based on peripheral measurements.

METHODS

Eighty participants (20 type 1 diabetes (T1DM) + PDPN, 20 T1DM + DPN, 20 T1DM-DPN (without DPN), and 20 healthy controls (HC)) underwent quantitative sensory testing, cardiac autonomic reflex tests (CARTs), and conventional nerve conduction. CAN was defined as ≥ 2 abnormal CARTs. After the initial analysis, the participants with diabetes were re-grouped based on the presence or absence of small (SFN) and large fibre neuropathy (LFN), respectively. A prediction model for CAN was made using logistic regression with backward elimination.

RESULTS

CAN was most prevalent in T1DM + PDPN (50%), followed by T1DM + DPN (25%) and T1DM-DPN and HC (0%). The differences in prevalence of CAN between T1DM + PDPN and T1DM-DPN/HC were significant (p < 0.001). When re-grouping, 58% had CAN in the SFN group and 55% in the LFN group, while no participants without either SFN or LFN had CAN. The prediction model had a sensitivity of 64%, a specificity of 67%, a positive predictive value of 30%, and a negative predictive value of 90%.

CONCLUSION

This study suggests that CAN predominantly co-exists with concomitant DPN.

Effect of Direct Endovascular Revascularization Based on the Angiosome Model on Risk of Major Amputations and Life Expectancy in Type 2 Diabetic Patients with Critical Limb Ischemia and Foot Ulceration

BACKGROUND

We evaluated whether direct or indirect endovascular revascularization based on the angiosome model affects outcomes in type 2 diabetes and critical limb ischemia.

METHODS

From 2010 to 2015, 603 patients with type 2 diabetes were admitted for critical limb ischemia and submitted to endovascular revascularization. Among these patients, 314 (52%) underwent direct and 123 (20%) indirect revascularization, depending on whether the flow to the artery directly feeding the site of ulceration, according to the angiosome model, was successfully acquired; 166 patients (28%) were judged unable to be revascularized. Outcomes were healing, major amputation, and mortality rates.

RESULTS

An overall healing rate of 62.5% was observed: patients who did not receive percutaneous transluminal angioplasty presented a healing rate of 58.4% (P < .02 versus revascularized patients). A higher healing rate was observed in the direct versus the indirect group (82.4% versus 50.4%; P < .001). The major amputation rate was significantly higher in the indirect versus the direct group (9.2% versus 3.2%; P < .05). The overall mortality rate was 21.6%, and it was higher in the indirect versus the direct group (24% versus 14%; P < .05).

CONCLUSIONS

These data show that direct revascularization of arteries supplying the diabetic foot ulcer site by means of the angiosome model is associated with a higher healing rate and lower risk of amputation and death compared with the indirect procedure. These results support use of the angiosome model in type 2 diabetes with critical limb ischemia.

Pilot Experience on the Use of S54P4 Bioactive Glass in the Surgical Management of Diabetic Foot Osteomyelitis

To test safety and efficacy of bioactive glass, a novel material used to replace bone, able to completely bond itself to the host tissues on patients treated for osteomyelitis (OM) complicating a diabetic foot (DF). We evaluated a group of patients consecutively admitted in our department between September and December 2018, who underwent surgical DF procedures for OM and in whom the use of bioactive glass could limit the demolition phase of surgical procedure. Patients were treated with bioactive glass S53P4 on top of standard treatment directly in operating room. The patients were weekly controlled for 6 months or until complete healing. During follow-up, we analyzed primarily healing rate and secondarily time of healing, need for further debridement procedures, recurrences, and adverse or hypersensitivity reactions to study treatment. Ten DF patients were enrolled (male/female 6/4; mean age 56 ± 11 years; mean duration of diabetes 10.5 ± 4.7 years, mean hemoglobin A1c 7.2 ± 0.9%). Patients underwent surgical procedure during which, after an accurate debridement, bioactive glass was applied. A healing rate of 80% in a mean time of 34 ± 2 days, with only 1 patient who needed a second surgical look, was observed. Neither recurrences nor adverse events during follow-up were observed in treated patients. This pilot experience demonstrated that bioactive glass can be considered a useful tool for the surgical treatment of DF-related OM.

Cardiovascular Autonomic Neuropathy and Distal Symmetric Sensorimotor Polyneuropathy: These Two Diabetic Microvascular Complications do not Invariably Co-Exist

Background:

Cardiovascular autonomic neuropathy (CAN) and distal symmetrical sensorimotor polyneuropathy (DSPN) are serious microvascular complications of diabetes mellitus (DM). Their simultaneous development remains disputable. The aim of the present study was to examine the correlation between CAN and the presence/severity of DSPN in DM.

Methods:

Subjects with type 1 (group A: n=51; mean age 40.4 years) and type 2 DM (group B: n=153; mean age 64.6 years) were studied. Evaluation of DSPN was based on neuropathy disability score. Assessment of CAN was based on the battery of 4 standardized cardiovascular autonomic function tests.

Results:

In group A, patients with moderate/severe DSPN exhibited a 12-fold higher likelihood of CAN in univariate analysis (p=0.035). However, significance was lost after adjustment for gender, age, DM duration, and haemoglobin A1c. In group A, likelihood for CAN did not correlate with the presence of mild DSPN in univariate and multivariate analysis. In group B, likelihood of CAN was similar in patients with mild and in those with moderate/severe DSPN compared with patients without DSPN in univariate and multivariate analysis. In between group comparison CAN was similarly distributed in the 2 groups (p for interaction=0.367), in patients with no, mild and moderate/severe DSPN.

Conclusion:

CAN does not always co-exist with degrees of DSPN, ranging from mild to moderate/ severe and is similarly distributed in T1DM and T2DM patients with mild and moderate/severe DSPN and in patients without DSPN.

Correlation of cardiac autonomic neuropathy with small and large peripheral nerve function in type 2 diabetes mellitus

AIMS

To analyse the correlation of cardiac autonomic neuropathy (CAN), sympathetic and parasympathetic dysfunction with the different diagnostic tools for large and small peripheral nerve fibres in type 2 diabetes mellitus (T2DM).

METHODS

We included 153 T2DM subjects (92 men) with mean age of 64.4 years. CAN, as well as sympathetic and parasympathetic dysfunction were diagnosed by the Ewing's cardiovascular reflex tests. Vibration perception threshold (VPT), monofilament, Ipswich Touch test, automated sural nerve conduction study and neuropathy disability score (NDS) evaluated large and small peripheral nerve fibre function.

RESULTS

CAN (adjusted odds ratio [aOR]: 44.57), parasympathetic (aOR: 18.40) and sympathetic dysfunction (aOR: 5.50) correlated with measures of small fibre function evaluated by pinprick sensation and temperature perception. Among tools for large nerve fibres, positive correlation was shown between: (1) CAN and abnormal VPT (aOR: 16.78), (2) parasympathetic dysfunction and abnormal VPT (aOR: 39.47).

CONCLUSIONS

CAN and parasympathetic dysfunction correlate with peripheral neuropathy, especially when the latter is assessed through VPT and measures of small fibre function as evaluated by pinprick sensation and temperature perception. The latter additionally correlate with sympathetic nervous system impairment.

The Use of a Novel Super-Oxidized Solution on Top of Standard Treatment in the Home Care Management of Postsurgical Lesions of the Diabetic Foot Reduces Reinfections and Shortens Healing Time

There are still many unmet needs in the treatment of chronic wounds, especially regarding microenvironment modulation. Nexodyn is a novel super-oxidized solution capable of contrast bacterial proliferation. We aimed to evaluate if this solution, on top of standard of care, was safe and effective in improving diabetic foot outcome. We selected 50 patients admitted in our department to be submitted to surgery for acute diabetic foot infection. All patients were left open to heal for secondary intent. We divided patients into 2 groups: Group A (n = 25, male/female = 17/8, age = 67.3 ± 12.1 years, hemoglobin A1C = 7.9 ± 1.1%), patients treated with standard of care and, on top of this, Nexodyn solution, and Group B, treated only with standard of care. After discharge, patients continued Nexodyn application. We followed up patients until complete healing or up to 6 months. No differences between groups in healing rate, while time required for complete healing was significantly shorter in Group A (64.9 ± 12.1 days vs 147.4 ± 23.1 days, P < .01). During follow-up, the group treated with Nexodyn showed a reduced rate of reinfections (12 patients in Group B vs 3 patients in Group A, P < .05) and of further debridement procedures (1 patient in Group A vs 10 patients in Group B, P < .05). Nexodyn provided effective protection against reinfections in diabetic foot patients, thus reducing the necessity for debridement procedures and their healing time and presents a safety profile similar to saline solution.

Results of pancreas transplantation alone with special attention to native kidney function and proteinuria in type 1 diabetes patients

We report on our single-center experience with pancreas transplantation alone (PTA) in 71 patients with type 1 diabetes, and a 4-year follow-up. Portal insulin delivery was used in 73.2% of cases and enteric drainage of exocrine secretion in 100%. Immunosuppression consisted of basiliximab (76%), or thymoglobulin (24%), followed by mycophenolate mofetil, tacrolimus, and low-dose steroids. Actuarial patient and pancreas survival at 4 years were 98.4% and 76.7%, respectively. Relaparatomy was needed in 18.3% of patients. Restored endogenous insulin secretion resulted in sustained normalization of fasting plasma glucose levels and HbA1c concentration in all technically successful transplantations. Protenuria (24-hour) improved significantly after PTA. Renal function declined only in recipients with pretransplant glomerular filtration rate (GFR) greater than 90 ml/min, possibly as a result of correction of hyperfiltration following normalization of glucose metabolism. Further improvements were recorded in several cardiovascular risk factors, retinopathy, and neuropathy. We conclude that PTA was an effective and reasonably safe procedure in this single-center experience.

[Cardiovascular autonomous dysfunction in diabetics: the influence of disease duration, glycoregulation degree and diabetes type]

INTRODUCTION

Cardiovascular autonomous neuropathy (CAN) in diabetes has not been still defined clinically and aetiopathogenetically.

OBJECTIVE

The aim of this study was to determine the influence of disease duration, glycoregulation degree and diabetes type on damage of the cardiovascular part of the autonomous nervous system in our group of patients.

METHOD

This study included diabetics, (100 patients) the same number of patients with diabetes type I and II as well as 20 healthy individuals in the control group. Classic Ewing's cardiovascular tests were used for CAN diagnosis: (1) the cardiovascular response to Valsalva manoeuvre, (2) the cardiovascular response to deep breathing (the so-called E/I ratio), (3) the cardiovascular response to rising (the so-called 30/15 ratio), (4) the test of orthostatic hypotension and (5) the TA response to handgrip. It has been arbitrarily taken that patients, whose score of "parasympathetic" tests (Valsalva manoeuvre, E/I ratio, 30/15) is equal or bigger than 1.5 (out of possible 3), have damage of the parasympathetic part of the autonomous nervous system while patients, whose score of "sympathetic tests" (the test of orthostatic hypotension and TA response to hand-grip is equal or bigger than 1 (out of possible 2), have damage of the sympathetic part of the autonomous nervous system. The patients whose total score is equal or bigger than 2 have cardiovascular autonomous neuropathy. The glycoregulation degree is determined by the level of HbA1c.

RESULTS

There is a statistically significant, positive correlation between the values of the parasympathetic score and disease duration as well as between the total score, that is, CAN and disease duration. The connection between the sympathetic score, that is, damage of the sympathetic part of the autonomous nervous system and disease duration has not been observed. There is a positive correlation between the values of the parasympathetic score and HbA1c. The same pattern exists regarding the ratio of damage of the sympathetic part of the autonomous nervous system and the value of HbAlc, as well as the ratio of CAN, that is, the total score and HbA1c. Almost twofold, a bigger coefficient of correlation between the sympathetic score and HbA1c in relation to the coefficient of correlation of the parasympathetic score and HbA1c, points to bigger sensitivity of the sympathetic part of the autonomous nervous system to subacute deterioration of glycoregulation. The correlation between the values of autonomous scores and diabetes type has not been noted.

CONCLUSION

Our results show that besides disease duration, the subacute deterioration of glycoregulation also leads to the appearance of cardiovascular autonomous dysfunction in diabetes. The sympathetic nervous tissue is functionally more sensitive than the parasympathetic one to metabolic disorders in diabetes. The cardiovascular autonomous dysfunction will occur independently of the type of diabetes.

Autonomic neuropathy in mixed cryoglobulinemia

A retrospective, cross-sectional study was performed on a series of HCV-related mixed cryoglobulinemia (HCV-MC) patients to assess autonomic neuropathy (AN) and its relation to peripheral neuropathy (PN). Thirty consecutive patients affected by HCV-MC underwent clinical, neurological and electrodiagnostic examinations. Autonomic nervous system (ANS) involvement was assessed by functional cardiovascular tests and sympathetic skin response (SSR) evaluation. Sural nerve biopsy was performed in 10 patients with PN. All patients received steroids, 15 also received recombinant interferon-alpha2b (RIfn-alpha2b). PN occurred in 27 patients (90.0%) and AN in 4 (13.3 %) all with signs of PN. SSR was the autonomic test more frequently altered. Biopsy disclosed axonal degeneration more evident in the 4 patients with AN. Three out of 4 patients with AN received steroids and rIFN-alpha2b and 1 steroids alone. In our study on HCV-MC, it was concluded that AN can occur also without dysautonomic symptoms, SSR appears to be one of the optional tests to use together with dysautonomic tests to identify AN and finally PN and AN do not seem to be positively influenced by addition of rIFN-alpha2b to steroid treatment.

Does instantaneous blood glucose affect vibration perception threshold measurement using biothesiometer?

Diabetic neuropathy is a common and troublesome complication of diabetes mellitus. Vibration sensation is a measure of large fiber nerve conduction, which is very commonly affected in diabetes. The present study addresses the question of whether vibration perception threshold (VPT) measurement using a biothesiometer is reproducible under different levels of blood glucose at different hours of the day. Seventy-five diabetic patients, 31 insulin-dependent diabetes mellitus and 44 non-insulin-dependent diabetes mellitus, with mean age 50.33+/-14.22 years (21-70 years) and diabetes duration of 14.3+/-10.6 years (1-60 years) were included in the study. Forty-one patients were male and 34 were female. In conclusion, VPT was found to be reproducible under different blood glucose levels at different hours of the day, which is affected only by the height of the patient.

Hardness of plantar skin in diabetic neuropathic feet

To evaluate if skin hardness in diabetic neuropathic feet was increased and if its eventual modifications could be correlated to the severity of neuropathy, we studied a group of diabetic outpatients with and without neuropathy. Patients, selected among those who were attending their routine screening for diabetic neuropathy at our diabetologic clinic, were divided into two groups according to the presence (ND+) or absence (ND-) of diabetic neuropathy with the criteria of the S. Antonio Consensus Conference on Diabetic Neuropathy. Patients then underwent an evaluation of vibration perception threshold (VPT) by means of a biotesiometer, measurement of skin hardness (DMT) by means of a durometer, and transcutaneous oxygen tension (TcPO2) determination. VPT was determined at allux (VPT-A) and external malleolus (VPT-M), DMT was measured at heel (DMT-H), at medial (DMT-M) and lateral (DMT-L) midfoot, and at posterior midcalf (DTM-C) as a control site; TcPO2 was evaluated at dorsum (TcPO2-D) and at medial midfoot (TcPO2-M), respectively. All measurements were performed on the nondominant side with the patients supine. Patients were compared with age and gender-matched healthy volunteers (Controls), who underwent the same evaluations in the same order. ND+ patients showed higher values of VPT than ND- and Controls, both at first toe and at malleolus analysis of variance (ANOVA) p<0.01), as well of DMT in all the three sites explored (ANOVA, p<0.01). Moreover, ND+ showed no difference in DMT among the sites, while both in ND- and in controls DMT-M was significantly (p<0.05) lower than DMT-H and DMT-L. No difference among the three groups were observed in TcPO2 measurements, and no difference in DMT-C was observed either. A significant correlation was observed between DMT-H and VPT-M (r2 = 0.516) and between DMT-M and VPT-A (r2 = 0.624) in ND+ patients. Skin hardness was diffusely increased in ND+ patients, and this increase strongly correlates with the severity of neuropathy. Simple, noninvasive determination of skin hardness could identify patient at potential risk to develop neuropathic foot ulcers.

Early autonomic dysfunction in patients with diabetes mellitus assessed by spectral analysis of heart rate and blood pressure variability

Patients with diabetes mellitus (DM) often have alterations of the autonomic nervous system (ANS), even early in their disease course. Previous research has not evaluated whether these changes may have consequences on adaptation mechanisms in DM, e.g. to mental stress. We therefore evaluated whether patients with DM who already had early alterations of the ANS reacted with an abnormal regulatory pattern to mental stress. We used the spectral analysis technique, known to be valuable and reliable in the investigation of disturbances of the ANS. We investigated 34 patients with DM without clinical evidence of ANS dysfunction (e.g. orthostatic hypotension) and 44 normal control subjects (NC group). No patients on medication known to alter ANS responses were accepted. The investigation consisted of a resting state evaluation and a mental stress task (BonnDet). In basal values, only the 21 patients with type 2 DM were different in respect to body mass index and systolic blood pressure. In the study parameters we found significantly lower values in resting and mental stress spectral power of mid-frequency band (known to represent predominantly sympathetic influences) and of high-frequency and respiration bands (known to represent parasympathetic influences) in patients with DM (types 1 and 2) compared with NC group (5.3 +/- 1.2 ms2 vs. 6.1 +/- 1.3 ms2, and 5.5 +/- 1.6 ms2 vs. 6.2 +/- 1.5 ms2, and 4.6 +/- 1.7 ms2 vs. 6.2 +/- 1.5 ms2, for resting values respectively; 4.7 +/- 1.4 ms2 vs. 5.9 +/- 1.2 ms2, and 4.6 +/- 1.9 ms2 vs. 5.6 +/- 1.7 ms2, and 3.7 +/- 2.1 ms2 vs. 5.6 +/- 1.7 ms2, for stress values respectively; M/F ratio 6/26 vs. 30/14). These differences remained significant even when controlled for age, sex, and body weight. However, patients with DM type 2 (and significantly higher body weight) showed only significant values in mental stress modulus values. There were no specific group effects in the patients with DM in adaptation mechanisms to mental stress compared with the NC group. These findings demonstrate that power spectral examinations at rest are sufficiently reliable to diagnose early alterations in ANS in patients with DM. The spectral analysis technique is sensitive and reliable in investigation of ANS in patients with DM without clinically symptomatic autonomic dysfunction.

Factors associated with impaired vibration perception in Mauritians with normal and abnormal glucose tolerance. Mauritius NCD Study Group

Vibration perception threshold (VPT) was measured in 1185 Indian, Creole, and Chinese men and women in Mauritius, where the current prevalence of diabetes mellitus in adults aged 25-74 years is estimated to be 13%. Vibration perception threshold was measured using a biothesiometer, at seven sites in the hand, wrist, foot, and ankle, during a population survey in 76% of 574 known diabetic patients (KDM), 79% of 525 newly diagnosed diabetic patients (NDM), 18% of 1121 subjects with impaired glucose tolerance (IGT), and in 127 normal subjects. The association of VPT with glucose tolerance and other risk factors was assessed in order to identify individuals most at risk of foot ulceration and to determine whether risk factors and normal levels for VPT in these ethnic groups were consistent with those reported for Caucasians. After adjusting for age and height, geometric mean VPT at six of seven sites increased significantly with worsening glucose tolerance and increasing duration of diabetes in both men and women, VPT also increased significantly with level of fasting plasma glucose in men, but not women. Smoking and alcohol consumption had no effect on VPT, and body-mass index (BMI) was positively associated only at some sites. Chinese subjects had lower VPTs than Indians or Creoles. In multiple linear regression models, age, male gender, duration of diabetes, ethnic group, and height (lower extremity sites) were significantly associated with VPT among diabetic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)