Psychosocial Factors in Painful Diabetic Neuropathy: A Systematic Review of Treatment Trials and Survey Studies

Prevalence and epidemiological characteristics of chronic pain in the Spanish population. Results from the pain barometer

BACKGROUND

Chronic pain (CP) is a public health problem worldwide.

AIM

To update the prevalence of CP and compare the clinical and social characteristics of people with CP with those with non-chronic continuous pain and a group without pain.

METHODS

An observational cross-sectional study was carried out in a representative sample of 7058 adults from the Spanish population. Sociodemographic data, the presence of CP and non-chronic continuous pain, characteristics of pain, limitations on activities of daily living (ADL), the presence and level of anxiety and depression (HADS), quality of life (SF-12v2) and social support (DUKE) were collected. Descriptive and bivariate analyses were performed.

RESULTS

The prevalence of CP was 25.9% (95% CI;24.8-26.9) and that of non-chronic continuous pain was 7.7% (95% CI;7.1-8.3). Women presented a higher prevalence of both CP (30.5% vs. 21.3%) and non-chronic continuous pain (8.8% vs. 6.6%). CP was more common in the group between 55 and 75 years old (30.6%, 95% CI = 28.6-32.6%), non-chronic continuous pain affected most the population between 18 and 34 years old (11.2%, 95% CI = 9.6-12.7%). The median duration of CP was 4 years. The lumbar was the most frequent pain site (58.1%), and 27.1% did not know the cause. A greater frequency of limitations on ADL, more anxiety and depression, and worse quality of life were shown among the subjects with CP.

CONCLUSION

CP affects one in four Spanish people and impairs the mental, physical and social health. Differences exist by sex and age in its frequency. Identifying subjects with non-chronic continuous pain is fundamental to prevent their pain from becoming chronic.

SIGNIFICANCE STATEMENT

Indicating the main aspects where this work adds significantly to existing knowledge in the field, and if appropriate to clinical practice. Due to its high prevalence and impact on quality of life, chronic pain has become one of the main health problems nowadays. Attention must be paid to it both from a clinical and social perspective, trying to raise awareness among the population of its possible causes and consequences. In routine clinical practice, greater consideration is given to groups of people with a higher prevalence of chronic pain, such as women and people with middle age, and with no chronic pain to prevent the appearance of chronic pain.

Topical Nigella sativa L. product: a new candidate for the management of diabetic peripheral neuropathy

BACKGROUND

Diabetic neuropathy is one of the most common complications of diabetes. The synthetic drugs available in the market have side effects and limitations for diabetic patients, the vast majority of whom are in the upper age group. In this regard, based on Persian medicinal sources, Nigella sativa (N. sativa) has proved to have beneficial effects on neuropathic pain and neurological disorders. In this study, the effect of N. sativa is investigated topically in patients with diabetic neuropathy.

METHODS

This study was performed as a double-blind clinical trial on 120 neuropathic patients. The patients were divided into three groups. The first group received a topical N. sativa product as an ointment, the second group was given a topical placebo, and the third received 300 mg gabapentin capsules. The blindness was done in first and second groups. Diabetic neuropathy was assessed before the study using the Michigan Neuropathy Screening Instrument (MNSI). In addition, neuropathy symptoms were evaluated after the trial using the MNSI questionnaire.

RESULTS

The data were elicited from the patients' answers to a number of questions in the Michigan questionnaire. There were statistically significant differences between the group that received the topical N. sativa product and the other two groups in terms of legs and feet numbness (p value = 0.001), burning pain in feet or legs (p value = 0.001), muscle cramps in feet or legs (p value = 0.001), prickling fleeing in feet or legs (p value = 0.001), hurting of the skin when the bed covers touch it (p value = 0.005), aggravated symptoms at night (p value = 0.001) and hurting feelings in the legs when walking (p value = 0.032). However, the three studied groups were not statistically different in distinguishing hot water from cold water.

CONCLUSION

According to the results of this study, the topical use of N. sativa, compared to the current drugs, has acceptable improving effects on diabetic neuropathic patients.

Deteriorated sleep quality and associate factors in patients with type 2 diabetes mellitus complicated with diabetic peripheral neuropathy

Objectives

To understand the sleep quality and its influencing factors in patients with type 2 diabetes mellitus (T2DM) who suffered diabetic peripheral neuropathy (DPN), and provide evidence for clinicians to carry out comprehensive intervention measures to improve the sleep quality of patients.

Methods

Patients who were admitted to the Endocrinology Department of Affiliated Hospital of Zunyi Medical University were recruited from May to December 2022, and the investigation were conducted by face-to-face interview. The questionnaires included PSQI questionnaire and influencing factors, such as lifestyle and health status.

Results

Among the 193 patients, 40.4% of the patients never took physical examination, 56.5% of the patients had duration of illness greater than 5 years, 61.7% of the patients had had an operation, 10.4% of the patients had bad dietary status, and 55.4% of the patients had physical pain. In addition, the PSQI general score was 8.34 ± 3.98, the occurrence rate of poor sleep quality (PSQI ≥ 8) was 54.4%, and the results showed that sleep quality of the physical pain group was worse than the no pain group. Moreover, the results of multivariate analysis revealed that the factors affecting sleep quality were lower frequency of exercise, bad dietary status, lower frequency of physical examination, longer duration of illness, and smoking, and the OR and 95% CI were [1.40, 1.04∼1.89], [3.42, 1.86∼6.29], [1.49, 1.01∼2.20], [1.78, 1.09∼2.92], [2.38, 1.17∼4.88], respectively.

Conclusion

Patients with DPN have higher risk of poor sleep quality. Moreover, there were many risk factors associated with poor sleep quality, clinicians and health policymakers should timely detect and effectively intervene in these factors to improve the sleep quality, which is important to enhance the quality of life of T2DM patients complicated with DPN.

Cognitive Benefits of Sodium-Glucose Co-Transporters-2 Inhibitors in the Diabetic Milieu

Patients with diabetes are at higher risk of cognitive impairment and memory loss than the normal population. Thus, using hypoglycemic agents to improve brain function is important for diabetic patients. Sodium-glucose cotransporters-2 inhibitors (SGLT2i) are a class of therapeutic agents used in the management of diabetes that has some pharmacologic effects enabling them to fight against the onset and progress of memory deficits. Although the exact mediating pathways are not well understood, emerging evidence suggests that SGLT2 inhibition is associated with improved brain function. This study reviewed the possible mechanisms and provided evidence suggesting SGLT2 inhibitors could ameliorate cognitive deficits.

Quality of life of persons with painful diabetic neuropathy: How can we improve it?

Painful diabetic neuropathy (PDN) is difficult to treat, with pharmacological treatments providing only partial pain relief that is limited by medication side effects. This necessitates a holistic approach to pain control,with pharmacological treatments supplemented by the management of psychosocial aspects of pain experience. Pain catastrophising and psychological flexibility are among the psychological constructs impacting persons' adaptation to PDN. While the former increases disability and reduces quality of life (QoL), the latter leads to less functional impairment and depression. Specific fears, and in particular, fear of falling, are significantly associated with pain-related disability and reduced QoL. The role of secondary parameters ofpain experience, including sleep and mood disturbancesas the potential guides to the selection of pharmacological treatmentsis yet to be established. Over the past decade there has been a steady increase in studies testing psychological interventions, including cognitive behavioural therapy and its several modifications, to manage pain in DN sufferers.Thesepilot and feasibility studies demonstrated the potential beneficial effects on pain severity and pain interference, depression and QoL in adults with PDN.Adequately powered trials are needed to confirm the effectiveness of these interventions in terms of pain experience and their impact on QoL.

Usability and Acceptability of a Videoconference Program for the Treatment of Depression in Adults With Peripheral Neuropathy

Peripheral neuropathy is a debilitating neurological disorder affecting 13% to 14% of the US population. Estimates for co-occurring mood disorders in individuals with neuropathy range from 30% to 47%, but sparse evidence exists regarding depression treatment for adults with neuropathy. A cognitive-behavioral treatment, Acceptance and commitment therapy, is known to reduce depression in people with chronic pain, but little is known about its effectiveness in adults with neuropathy, particularly when the treatment is provided via videoconference. Acceptability and usability of this therapeutic treatment provided via videoconference was assessed in participants with peripheral neuropathy and symptoms of depression. Participants completed pre- and post-self-report outcome measures: the nine-item depression scale of the Patient Health Questionnaire and the 36-item Short-Form Health Survey. They also completed the Acceptability e-Scale and Post-Study System Usability Questionnaire after treatment. Depression decreased significantly, with scores declining from an average of 9.2 to 5.1 on the Patient Health Questionnaire ( P < .05). The Short-Form Health Survey indicated significant improvement post-treatment on the "Energy/Fatigue" and "Emotional Well Being" subscales. The intervention was rated by participants as acceptable and demonstrated high usability. This initial therapeutic treatment via videoconference offers promise to treat depression in older adults with neuropathy.

The association of self-reported symptoms of central sensitization and sleep disturbances in neuropathic pain

Introduction

Patients with neuropathic pain (NP) report a higher impairment of quality of life and sleep than patients with chronic pain without neuropathic characteristics. These include somatosensory peculiarities like allodynia, a surrogate marker for central sensitization.

Objectives

This study aimed to investigate the relation between symptoms of central sensitization and sleep disturbances in patients with NP.

Methods

Within this cross-sectional study, data sets of 3339 patients with chronic NP syndromes (painful diabetic polyneuropathy, n = 543; postherpetic neuralgia, n = 1480) or complex regional pain syndromes (CRPS, n = 1316) were analyzed. Neuropathic pain symptoms were assessed with the painDETECT questionnaire (PD-Q), depression with the Patient Health Questionnaire-9, and sleep impairment with items of the Medical Outcomes Study Sleep Scale in 4 subscales. The association of demographic/clinical data, somatosensory phenotype, depression, and pain intensity with sleep impairment was assessed by unadjusted Spearman correlation analyses and multivariable regression analyses.

Results

Sleep impairment was observed in all pain aetiologies although with some significant differences in the single sleep items. The intensity of the individual PD-Q items differed to some extent between the 3 pain entities, whereas the PD-Q sum score was similar. Thermal hyperalgesia and burning assessed by the PD-Q were significantly associated with sleep disturbance, adequacy, and quantity but not with sleep somnolence. Only depression and self-reported allodynia had a significant relation to all 4 sleep elements.

Conclusion

Beside depression, allodynia as a surrogate marker hints to a possible impact of central sensitization on the sleep disruption of patients with NP.

Painful Diabetic Peripheral Neuropathy - A Survey of Patient Experiences

Purpose

An online survey was conducted in the USA to obtain information about the knowledge and experiences of patients with painful diabetic peripheral neuropathy (pDPN).

Patients and Methods

506 adults with diabetes and pDPN affecting the feet for ≥6 months, for which pain medication had been prescribed for ≥6 months, completed an online survey questionnaire in March 2021.

Results

79% of respondents had type 2 diabetes, 60% were male, 82% were Caucasian and 87% had comorbidities. Pain was significant to severe in 49% of respondents, and 66% had disability due to nerve pain. Anticonvulsants, over-the-counter pills and supplements were the most commonly used medications. Topical creams/patches were prescribed in 23% of respondents. 70% had tried multiple medications for their pain. 61% of respondents had to see ≥2 doctors before receiving a correct diagnosis of pDPN. 85% of respondents felt that the doctor understood their pain and its impact on their life. 70% had no difficulty finding the information they wanted. 34% felt insufficiently informed about their condition. A medical professional was the primary, and most trusted, source of information. Frustration, worry, anxiety and uncertainty were the most commonly reported emotions. Respondents were generally eager to find new medications for pain relief and desperate for a cure. Lifestyle changes because of nerve pain were most commonly associated with physical disabilities and sleep disturbance. Better treatments and freedom from pain were the overriding perspectives when considering the future.

Conclusion

Patients with pDPN are generally well informed about their pain and trust their doctor but remain unsatisfied with their current treatment and struggle to find a lasting solution for their pain. Early identification and diagnosis of pain in diabetics, and education about treatments, is important to minimize the impact of pain on quality of life and emotional well-being.

Neuropathy in paediatric type 1 diabetes mellitus - clinical characterization and analysis of risk factors in the diabetes prospective follow-up registry DPV (Diabetes-Patienten-Verlaufsdokumentation)-registry

OBJECTIVES

Data on the prevalence, clinical features and risk factors associated with paediatric diabetic neuropathy (DN) are scarce.

METHODS

We retrospectively analysed data from the DPV registry, including patients under 20 years of age, treated for type 1 diabetes mellitus (T1D) between 2005 and 2021. Patients with non-diabetic neuropathy were excluded. Data came from centres in Austria, Germany, Luxembourg and Switzerland.

RESULTS

1,121 of the 84,390 patients included had been diagnosed with DN. Univariate analysis showed patients with DN to be older and predominantly female, with a longer duration of T1D, higher insulin dosages per kg and day, lower rates of insulin pump therapy, higher postprandial glucose-, higher HbA_1c-and higher cholesterol levels, and higher diastolic and systolic blood pressure values. There was also a larger proportion of smokers and higher prevalence of diabetic retinopathy. Median duration of diabetes at diagnosis of DN was 8.3 years. Multivariable analysis, adjusted for demographics revealed an increased risk for DN among female patients and those who were older, underweight (BMI-SDS), smoked cigarettes or had a longer duration of T1D or higher levels of HbA_1c and postprandial blood glucose. The presence of retinopathy and higher cholesterol levels were also linked to increased risk while not-using insulin pump therapy was not.

CONCLUSIONS

DN can develop after just a short duration of T1D. Prevention may be achieved by a lowering of HbA_1c-and postprandial glucose levels through improved glycaemic control. This warrants further investigation. The slight female predominance suggests further hormonal and genetic etiological factors.

Diabetic Peripheral Neuropathy Associated with Foot Ulcer: One of a Kind

Significance: Diabetic peripheral neuropathy (DPN) associated with a diabetic foot ulcer (DFU) is likely to be complicated with critical factors such as biofilm infection and compromised skin barrier function of the diabetic skin. Repaired skin with a history of biofilm infection is known to be compromised in barrier function. Loss of barrier function is also observed in the oxidative stress affected diabetic and aged skin. Recent Advances: Loss of barrier function makes the skin prone to biofilm infection and cellulitis, which contributes to chronic inflammation and vasculopathy. Hyperglycemia favors biofilm formation as glucose lowering led to reduction in biofilm development. While vasculopathy limits oxygen supply, the O2 cost of inflammation is high increasing hypoxia severity. Critical Issues: The host nervous system can be inhabited by bacteria. Because electrical impulses are a part of microbial physiology, polymicrobial colonization of the host's neural circuit is likely to influence transmission of action potential. The identification of perineural apatite in diabetic patients with peripheral neuropathy suggests bacterial involvement. DPN starts in both feet at the same time. Future Directions: Pair-matched studies of DPN in the foot affected with DFU (i.e., DFU-DPN) compared with DPN in the without ulcer, and intact skin barrier function, are likely to provide critical insight that would help inform effective care strategies. This review characterizes DFU-DPN from a translational science point of view presenting a new paradigm that recognizes the current literature in the context of factors that are unique to DFU-DPN.

Effect of Cognitive-Behavioral Therapy or Mindfulness Therapy on Pain and Quality of Life in Patients with Diabetic Neuropathy: A Systematic Review and Meta-Analysis

OBJECTIVES

This study aimed to evaluate the effectiveness of cognitive behavioral therapy (CBT) and mindfulness therapy (MT) for pain relief and quality of life (QOL) in patients with diabetic neuropathy.

REVIEW/ANALYSIS METHODS

Four databases were systematically searched from their respective inception dates to 29 June 2021. Relevant randomized controlled trials (RCTs) were screened and assessed for risk of bias. Eight RCTs evaluating CBT or MT were included. Statistical analysis was performed using Review Manager 5.4.

RESULTS

Eight RCTs involving 384 patients with painful diabetic neuropathy (PDN) tested psychological interventions, including three CBT and five MT studies. The results showed that patients' pain severity (standardized mean difference [SMD] = -0.60, 95% confidence interval [CI; -0.93 to -0.27], P = .0003) and QOL (SMD = -0.43, 95% CI [-0.83 to -0.04], p = .03) were improved immediately after treatment. Besides, the pain intensity (SMD = -0.67, 95% CI [-1.37 to 0.03], p = .06), pain interference (SMD = -0.75, 95% CI [-1.20 to -0.30], p = .001) and depressive symptoms (SMD = -0.62, 95% CI [-0.96 to -0.28], p = .0003) were superior to the control group after follow up. The subgroup analysis results of different intervention type showed that the CBT group could immediately improve pain (SMD = -0.44, 95% CI [-0.78 to -0.10], p = .01) after treatment. However, there was no statistically significant difference in the CBT group after follow-up (SMD = -0.15, 95% CI [-0.52 to 0.22], p = .42).

CONCLUSIONS

Cognitive behavioral therapy or MT is effective for treating pain in patients with diabetic peripheral neuropathy, improving the QOL, and reducing depressive symptoms. However, large-scale, multi-centre, rigorously designed RCTs are needed to further verify the long-term effects.

Indirect Comparison of 10 kHz Spinal Cord Stimulation (SCS) versus Traditional Low-Frequency SCS for the Treatment of Painful Diabetic Neuropathy: A Systematic Review of Randomized Controlled Trials

Spinal cord stimulation (SCS) is increasingly used to treat painful diabetic neuropathy (PDN). At the time of a recent meta-analysis in this field, data were only available from randomized controlled trials (RCTs) of traditional low-frequency SCS (LF-SCS). However, outcomes from high-frequency 10 kHz SCS treatment are now available. Our study aimed to systematically review the contemporary evidence for SCS in patients with lower limb pain due to PDN and include an indirect comparison of the high- and low-frequency modalities. We searched the PubMed/CENTRAL databases up to 18 August 2022, for peer-reviewed RCTs of SCS that enrolled PDN patients with lower limb pain symptoms. The quality of the evidence was assessed with the Cochrane Risk of Bias tool. Using SCS treatment arm data from the RCTs, we indirectly compared the absolute treatment effect of 10 kHz SCS and LF-SCS. Results are presented in tables and forest plots. This systematic review was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines. Three RCTs met our eligibility criteria, including the recent 10 kHz SCS RCT (N = 216, 90 implanted) and 2 others that examined LF-SCS (N = 36, 17 implanted; N = 60, 37 implanted). Our analysis of 6-month data found clinically meaningful pain relief with each SCS modality. However, significantly greater pain reduction was identified for 10 kHz SCS over LF-SCS: average pain reduction in the 10 kHz SCS cohort was 73.7% compared with 47.5% in the pooled LF-SCS group (p < 0.0001). In the permanent implant subset, the 50% pain reduction responder rate was 83.3% in the 10 kHz SCS cohort versus 63.0% in the pooled LF-SCS group (p = 0.0072). The overall risk of bias of each included RCT was deemed high, mainly due to the absence of patient blinding. Our analysis indicates that paresthesia-free 10 kHz SCS can provide superior pain relief and responder rate over LF-SCS for managing PDN patients refractory to conventional medical management.

Mindfulness-Based Interventions: Focus on Pediatric Type 1 and Type 2 Diabetes

PURPOSE OF REVIEW

Mindfulness-based interventions (MBIs) focus on promoting nonjudgmental, purposeful awareness of the present experience, and they include specific components such as body scan, meditation, and breathing techniques for healthier coping with stress and reduced negative affect. In adult populations with chronic illness (e.g., type 1 diabetes [T1D], type 2 diabetes [T2D], overweight), MBIs have been shown to improve psychosocial outcomes with some improvements in health outcomes as well. Youth with T1D/T2D frequently experience heightened depression as well as diabetes distress, which are associated with less frequent blood glucose monitoring, insulin administration, and nutrition oversight. Thus, MBIs have potential to alleviate psychosocial distress in youth with T1D/T2D and also improve health outcomes. This paper is a review of the literature on potential psychosocial and health benefits of MBIs for youth with T1D/T2D.

RECENT FINDINGS

Among youth with T1D/T2D, MBIs have been shown to reduce symptoms of depression and diabetes distress. Improvements in health outcomes, such as A1c, have been inconsistent across studies. Although research on the efficacy of MBIs to improve psychosocial and health outcomes in youth with T1D/T2D is promising, this area of study is in its early stages. Future investigation of MBIs in youth with T1D and T2D is warranted, recognizing that these are heterogeneous groups with potential benefit of specifically tailored interventions.

Factors related to cognitive function in type-2 diabetes and neuropathic pain patients, the role of mood and sleep disorders in this relationship

To compare cognitive function in patients with diabetes mellitus type-2 (T2DM) both with and without diabetic neuropathic pain (DNP). To analyse the relationship between mood and sleep disorders, quality of life and cognitive function in patients with DNP. Cross-sectional study conducted in patients with T2DM and neuropathy. The presence of DNP, cognitive function, mood status, sleep quality, health-related quality of life, pain intensity and phenotype of pain were measured. Descriptive, bivariate and multivariate analyses were performed. A total of 149 patients (71 with DNP) were included. Patients with and without DNP presented similar scores on the TYM (41.46; SD = 6.70 vs. 41.97; SD = 5.50) and those with DNP had a slightly higher frequency of cognitive impairment (TYM score ≤ 41: 40.8% vs. 43.6%). The patients without DNP performed better in the verbal fluency dimension (mean = 3.53; SD = 0.98 vs. mean = 3.82; SD = 0.66). Being older (B = − 0.258) and under treatment with insulin (B = − 2.919) were related with greater cognitive impairment. Obesity (OR = 17.277) and a longer duration of diabetes (OR = 1.317) were also related to greater risk of cognitive impairment. Impaired cognitive function in patients with DNP is more related to T2DM factors than pain factors. The presence of depression and a worse quality of life were related to a greater risk of cognitive impairment. Identifying and controlling these factors should be an essential intervention for maintaining the cognitive function in patients with T2DM and DNP.

Emergence of Ectopic Adrenal Tissues-What are the Probable Mechanisms?

Ectopic adrenal tissue, defined as the formation of adrenal tissue in an abnormal anatomical location, is not a rare entity and may have clinical significance. Even though the mechanism for their emergence has not been fully understood, numerous cases of ectopic adrenal tissue have been reported, mostly in the vicinity of the original location of adrenal gland, such as in kidneys and gonads. In these cases, most authors attributed their emergence to a probable migration defect. However, this mechanism does not simply explain the ectopic tissues in remote locations, such as in the hypophysis or lungs. This review summarizes these reports, describing many different locations in which ectopic adrenal tissues were encountered, together with their suggested mechanisms.

Evaluation of Mindfulness Training Combined with Aerobic Exercise on Neurological Function and Quality of Life in Patients with Peripheral Neuropathy Type 2 Diabetes Mellitus

Objective. To investigate the effect of mindfulness training on neurological function and quality of life in patients with type 2 diabetic peripheral neuropathy. Methods. This study selected 120 patients with type 2 diabetic peripheral neuropathy and randomly divided them into three independent subgroups according to different training methods: mindfulness meditation group (MM), aerobic exercise group (AE), and mindfulness combined with aerobic exercise group. (MMAE). The three groups were analyzed for SNCV and MNCV velocities, MAAS and TCSS scores, neurological symptom scores, neurological sign scores, and quality of life. Results. Before treatment, SNCV and MNCV were not significantly significant ( $P>0.05$ ), but after treatment, SNCV and MNCV were significantly higher, and the MMAE group changed more significantly ( $P<0.05$ ); before treatment, MAAS and TCSS scores were not significant ( $P>0.05$ ), but after treatment, MAAS scores were significantly higher, TCSS scores were significantly lower, and more significantly in MMAE; the difference was significant ( $P<0.05$ ); before treatment, there was no statistical significance of the neurological signs score ( $P>0.05$ ); after treatment, the neurological symptoms score and neurological signs score were significantly reduced, and the changes in the MMAE group were statistically significant ( $P<0.05$ ); there was no significant difference in the quality of life score before treatment ( $P>0.05$ ), and the quality of life score in the MMAE group was significantly increased ( $P<0.05$ ). Conclusion. Mindfulness training combined with aerobic exercise has an ideal therapeutic effect on patients with type 2 diabetic peripheral neuropathy, and has a very important role in improving the neurological function and quality of life of the patients. It is a safe and effective treatment method. Therefore, mindfulness training combined with aerobic exercise is worthy of promotion and application.

Small Fiber Neuropathy

PURPOSE OF REVIEW

This narrative review aims to summarize advances in the field of small fiber neuropathy made over the last decade, with emphasis on novel research highlighting the distinctive features of SFN.

RECENT FINDINGS

While the management of SFNs is ideally aimed at treating the underlying cause, most patients will require pain control via multiple, concurrent therapies. Herein, we highlight the most up-to-date information for diagnosis, medication management, interventional management, and novel therapies on the horizon. Despite the prevalence of small fiber neuropathies, there is no clear consensus on guidelines specific for the treatment of SFN. Despite the lack of specific guidelines for SFN treatment, the most recent general neuropathic pain guidelines are based on Cochrane studies and randomized controlled trials (RCTs) which have individually examined therapies used for the more commonly studied SFNs, such as painful diabetic neuropathy and HIV neuropathy. The recommendations from current guidelines are based on variables such as number needed to treat (NNT), safety, ease of use, and effect on quality of life.

ViphyllinTM, a Standardized Black Pepper Extract Exerts Antihyperglycemic Effect and Improves Sciatic Nerve Conduction in High Fat Diet/Streptozotocin-Induced Diabetic Model Rats

PURPOSE

Research on plant-based formulations has drawn considerable attention in the management of diabetic neuropathy (DN) for having lesser side effects than the synthetic counterparts. Here, we have investigated for the first time the therapeutic effects of a standardized Piper nigrum L., (black pepper) seed extract, Viphyllin^TM in mitigating hyperglycemia and neuropathic pain of type 2 diabetes model rats.

METHODS

Type 2 diabetes was induced in male Wistar rats using high fat diet and a single dose of streptozotocin (60 mg/kg i.p.). The diabetic rats were orally administered with Viphyllin containing not less than 30% β-caryophyllene (BCP), at 25 mg, 50 mg and 100 mg/kg/day doses for 6 weeks. Changes in body weight, fasting blood glucose (FBG), glucose tolerance, and blood biochemical parameters were measured. The nociceptive response to thermal stimulus (tail flick test) and sciatic nerve conduction velocity (NCV) were recorded at the end of study.

RESULTS

Viphyllin treatment markedly improved the body weight and glucose tolerance in diabetic rats. Also, the extract could significantly reduce the diabetes-induced elevation in FBG, liver and kidney indices. Further, Viphyllin dose-dependently increased the nociception latency in tail flick test compared to untreated diabetic rats (p<0.05). Viphyllin at 100 mg/kg significantly increased the NCV (44.12±1.91*** m/s vs diabetic control 25.80±1.88 m/s). The antioxidant enzyme activities in sciatic nerve tissue were considerably increased in Viphyllin-treated groups compared to diabetic control. A 6-week treatment with Viphyllin markedly reversed the pathological manifestations of diabetes in vital organs such as liver, kidney and pancreas.

CONCLUSION

The study concludes that Viphyllin exerts antidiabetic effects and improves nerve conduction to mitigate neuropathic pain.

Peoples' experiences of painful diabetic neuropathy: are pain management programmes appropriate?

OBJECTIVE

Painful diabetic neuropathy (PDN) is a painful complication of diabetes. This study aimed to explore: (1) strategies used by participants to manage impacts of PDN and (2) their perspectives on whether strategies from pain management programmes (PMPs) had applicability for PDN.

DESIGN

Participants were recruited through local National Health Service (NHS) diabetes and PDN clinics, and nationally from a diabetes support charity. One-to-one interviews were conducted. The transcribed data were analysed using inductive thematic analysis.

RESULTS

Twenty-three people were interviewed who had PDN symptoms for mean 10 years. Four themes emerged from the data: seeking help and advice, pragmatic approach to management, perspectives on physical activity and perspectives on psychological coping strategies.

CONCLUSION

Some participants were open to the strategies advised by PMP strategies. There were also strong opinions that no exercise or psychological approach could help with diabetes-related pain. It is possible PMPs as currently delivered need to be adapted to maximise engagement from people with PDN. Research is required to understand the healthcare priorities of people with PDN and whether these priorities can be mapped to existing management strategies.

Psychological Backgrounds of Medically Compromised Patients and Its Implication in Dentistry: A Narrative Review

The number of medically compromised dental patients is increasing every year with the increase in the super-aged population. Many of these patients have underlying psychiatric problems and diseases, which need to be recognized by dental professionals for better treatment outcomes. The aim of this narrative review article is to summarize the psychological and psychiatric backgrounds of medically compromised patients who are frequently visited and taken care of by dentists using findings from recent systematic reviews and meta-analyses. Anxiety and symptoms of depression, post-traumatic stress disorders, panic disorders, poor cognitive functions, and poor quality of life were some of the common psychological backgrounds in medically compromised patients. Additionally, the consequences of these psychological problems and the considerations that need to be taken by the dentist while treating these patients have been discussed. Dental professionals should be aware of and recognize the different psychological backgrounds of medically compromised dental patients in order to provide appropriate dental treatment and to prevent oral conditions from worsening.

Reduced microvascular reactivity in patients with diabetic neuropathy

BACKGROUND

Neurogenic regulation is involved in the development of microcirculation response to local heating. We suggest that microvascular reactivity can be used to estimate the severity of diabetic polyneuropathy (DPN).

OBJECTIVE

To evaluate the prospects for using the parameters of skin microvascular reactivity to determine the severity of DPN.

METHODS

26 patients with diabetes mellitus were included in the study (patients with retinopathy (n = 15), and without retinopathy (n = 11)). The severity of DPN was assessed using Michigan Neuropathy Screening Instrument (MNSI) and Norfolk QOL-DN (NQOLDN). Skin microcirculation was measured by laser Doppler flowmetry with local heating test.

RESULTS

There were revealed moderate negative correlations between microvascular reactivity and the severity of DPN (for MNSI (Rs = -0.430), for NQOLDN (Rs = -0.396)). In patients with retinopathy, correlations were stronger than in the general group (for MNSI (Rs = -0.770) and NQOLDN (Rs = -0.636)). No such correlations were found in patients without retinopathy.

CONCLUSION

Correlation of the microvascular reactivity and DPN was revealed in patients with registered structural disorders in microvessels (retinopathy). The lack of such correlation in patients without retinopathy may be explained by the intact compensatory mechanisms of microvessels without severe disorders.

The Predictors of Painful Diabetic Neuropathy and Its Effect on Quality of Life

BACKGROUND

Knowing the prevalence and predictors of neuropathic pain and its impacts on the quality of life (QoL) using measurement tools is important for good diabetes management. In Turkish society, neuropathic pain, its predictors and its impact on the quality of life of diabetics are not considered enough.

OBJECTIVES

This study examined the prevalence and predictors of neuropathic pain and its impacts on the quality of life in diabetics in Rize Province, Turkey.

DESIGN

This study was designed as a cross-sectional, correlational study.

SETTING

Data collected through face-to-face interviews. The sample size was determined using the formula [n= N t²pq / d² (N-1) + t²pq].

PARTICIPANT

The sample of the study consisted of 122 people with diabetes who visited the diabetes outpatient clinic of the hospital.

METHODS

A Personal Information Form, Douleur Neuropathique en 4 questions (DN4), and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were used to collect data. Pain intensity was measured using Visual Analogue Scale (VAS) RESULTS: The prevalence of the diagnosed painful diabetic polyneuropathy (PDPN) was found to be 22.9%. On the other hand, the prevalence of the undiagnosed PDPN was found to be 44.3% according to DN4 and 27.9% according to LANSS. The VAS pain score was determined as 1.99±1.20 (range: 1-5). In the people with PDPN, nephropathy was seen 4.514 times more frequently according to DN4 and 7.217 times more frequently according to LANSS. Painful diabetic peripheral neuropathy had negative effects on all dimensions of QoL except for social function and mental health (p <0.05).

CONCLUSIONS

It is important for nurses to determine the prevalence and predictive factors of PDPN in their region and to evaluate the effect of pain on the quality of life of diabetics. Nurses should attempt to increase the quality of life of people with diabetes by reducing the predictors affecting pain.

Prevalence and incidence of diabetic peripheral neuropathy in Latin America and the Caribbean: A systematic review and meta-analysis

AIMS

The objective of this systematic review and meta-analysis is to estimate the prevalence and incidence of diabetic peripheral neuropathy (DPN) in Latin America and the Caribbean (LAC).

MATERIALS AND METHODS

We searched MEDLINE, SCOPUS, Web of Science, EMBASE and LILACS databases of published observational studies in LAC up to December 2020. Meta-analyses of proportions were performed using random-effects models using Stata Program 15.1. Heterogeneity was evaluated through sensitivity, subgroup, and meta-regression analyses. Evidence certainty was performed with the GRADE approach.

RESULTS

Twenty-nine studies from eight countries were included. The estimated prevalence of DPN was 46.5% (95%CI: 38.0-55.0) with a significant heterogeneity (I2 = 98.2%; p<0.01). Only two studies reported incidence, and the pooled effect size was 13.7% (95%CI: 10.6-17.2). We found an increasing trend of cumulative DPN prevalence over time. The main sources of heterogeneity associated with higher prevalence were diagnosis criteria, higher A1c (%), and inadequate sample size. We judge the included evidence as very low certainty.

CONCLUSION

The overall prevalence of DPN is high in LAC with significant heterogeneity between and within countries that could be explained by population type and methodological aspects. Significant gaps (e.g., under-representation of most countries, lack of incidence studies, and heterogenous case definition) were identified. Standardized and population-based studies of DPN in LAC are needed.

A systematic review and meta-analysis of the serum lipid profile in prediction of diabetic neuropathy

Whether the lipid profile in diabetic patients is associated with diabetic neuropathy (DN) development remains ambiguous, as does the predictive value of serum lipid levels in the risk of DN. Here, we performed the first meta-analysis designed to investigate the relationship between DN and the serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL). Candidate studies were comprehensively identified by searching PubMed, Embase, Cochrane Library and Web of Science databases up to May 2020. Observational methodological meta-analysis was conducted to assess the relationships of TG, TC, HDL, and LDL levels with DN. Changes in blood lipids were used to estimate the effect size. The results were pooled using a random-effects or fixed-effects model. Potential sources of heterogeneity were explored by subgroup analysis. Various outcomes were included, and statistical analyses were performed using STATA (Version 12.0). Mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. The Newcastle–Ottawa Scale (NOS) was applied to assess the methodological quality. I2 statistics were calculated to evaluate statistical heterogeneity. Funnel plots were utilized to test for publication bias. A sensitivity analysis was performed by omitting each study one by one. Thirty-nine clinical trials containing 32,668 patients were included in the meta-analysis. The results demonstrated that DN patients showed higher TG and lower HDL levels (MD = 0.34, 95% CI: 0.20–0.48 for TG; MD = -0.05, 95% CI: -0.08–-0.02, I² = 81.3% for HDL) than controls. Subgroup analysis showed that patients with type 1 diabetes mellitus (T1DM) neuropathy had elevated TG levels in their serum (MD = 0.25, 95% CI: 0.16–0.35,I² = 64.4% for T1DM). However, only patients with T1DM neuropathy had reduced serum HDL levels, and there was no significant difference in serum HDL levels between patients with T2DM neuropathy and controls (MD = -0.07, 95% CI: -0.10–-0.03, I² = 12.4% for T1DM; MD = -0.02, 95% CI: -0.07–0.03, I² = 80.2% for T2DM). TC and LDL levels were not significantly different between DN patients and controls (MD = -0.03, 95% CI: -0.14–0.09, I² = 82.9% for TC; MD = -0.00, 95% CI: -0.08–0.08, I² = 78.9% for LDL). In addition, compared with mild or painless DN patients, those with moderate or severe pain DN pain had significantly reduced serum TC and LDL levels (MD = -0.31, 95% CI: -0.49–-0.13, I² = 0% for TC; MD = -0.19, 95% CI: -0.32–-0.08, I² = 0% for LDL). TG levels and HDL levels did not vary considerably between patients with mild or painless DN and those with moderate or severe DN pain patients (MD = 0.12, 95% CI: -0.28–0.51, I² = 83.2% for TG; MD = -0.07, 95% CI:-0.14–0.01, I² = 58.8% for HDL). Furthermore, people with higher TG and LDL levels had higher risk of DN (OR = 1.36, 95% CI: 1.20–1.54, I² = 86.1% for TG and OR = 1.10, 95% CI: 1.02–1.19, I² = 17.8% for LDL). Conversely, high serum HDL levels reduced the risk of DN (OR = 0.85, 95% CI: 0.75–0.96, I² = 72.6%), while TC levels made no significant difference with the risk of DN (OR = 1.02, 95% CI: 1.00–1.04, I² = 84.7%). This meta-analysis indicated that serum lipid profile changes are among the biological characteristics of DN. Lipid levels should be explored as routine laboratory markers for predicting the risk of DN, as they will help clinicians choose appropriate therapies, and thus optimize the use of available resources.

Advances in Screening, Early Diagnosis and Accurate Staging of Diabetic Neuropathy

The incidence of both type 1 and type 2 diabetes is increasing worldwide. Diabetic peripheral neuropathy (DPN) is among the most distressing and costly of all the chronic complications of diabetes and is a cause of significant disability and poor quality of life. This incurs a significant burden on health care costs and society, especially as these young people enter their peak working and earning capacity at the time when diabetes-related complications most often first occur. DPN is often asymptomatic during the early stages; however, once symptoms and overt deficits have developed, it cannot be reversed. Therefore, early diagnosis and timely intervention are essential to prevent the development and progression of diabetic neuropathy. The diagnosis of DPN, the determination of the global prevalence, and incidence rates of DPN remain challenging. The opinions vary about the effectiveness of the expansion of screenings to enable early diagnosis and treatment initiation before disease onset and progression. Although research has evolved over the years, DPN still represents an enormous burden for clinicians and health systems worldwide due to its difficult diagnosis, high costs related to treatment, and the multidisciplinary approach required for effective management. Therefore, there is an unmet need for reliable surrogate biomarkers to monitor the onset and progression of early neuropathic changes in DPN and facilitate drug discovery. In this review paper, the aim was to assess the currently available tests for DPN's sensitivity and performance.

Sleep Characteristics in Diabetic Patients Depending on the Occurrence of Neuropathic Pain and Related Factors

This study aims to compare the sleep characteristics (structure and quality) in patients with type-2 diabetes mellitus with and without diabetic neuropathic pain (DNP), and to investigate the relationship of sensory phenotypes, anxiety, and depression with sleep quality in DNP patients. A cross-sectional study was performed in patients with type-2 diabetes mellitus and neuropathy. Patients were classified into two groups-with or without neuropathic pain-according to the "Douleur Neuropathique-4 (DN4)" scale. Sleep characteristics and quality (Medical Outcomes Study-MOS-sleep), pain phenotype (Neuropathic Pain Symptom Inventory-NPSI), mood status (Hospital Anxiety and Depression scale-HADS), pain intensity (Visual Analogue Scale-VAS), and quality of life (SF-12v2) were measured. The sample included 130 patients (65 with DNP). The mean scores in all the dimensions of the MOS-sleep scale were higher (more disturbances) in the DNP patients. Higher scores in anxiety or depression, greater intensity of pain or a higher score in the paroxysmal pain phenotype were associated with lower sleep quality in DNP patients. A shorter duration of the diabetes and lower levels of glycated hemoglobin were also associated with lower sleep quality. The results show the relationship between DNP and sleep quality, and the importance of assessing sensory phenotypes and mental comorbidities in these patients. Taking these factors into consideration, to adopt a multimodal approach is necessary to achieve better clinical results.

Online Acceptance and Commitment Therapy for People with Painful Diabetic Neuropathy in the United Kingdom: A Single-Arm Feasibility Trial

OBJECTIVE

This study aimed to assess the feasibility of online Acceptance and Commitment Therapy for painful diabetic neuropathy in the United Kingdom and to determine if a larger randomized controlled trial testing treatment efficacy is justified.

METHODS

Participants with painful diabetic neuropathy were recruited online and from hospital services. This was a single-arm study in which all participants received online Acceptance and Commitment Therapy. Participants completed questionnaires at baseline and three months post-treatment. Primary feasibility outcomes were recruitment, retention, and treatment completion rates. Secondary outcomes were pre- to post-treatment effects on pain outcomes and psychological flexibility.

RESULTS

Of 225 potentially eligible participants, 30 took part in this study. Regarding primary feasibility outcomes, the treatment completion and follow-up questionnaire completion rates were 40% and 100%, respectively. Generally, at baseline those who completed the treatment, compared with those who did not, had better daily functioning and higher psychological flexibility. With respect to secondary outcomes, results from the completers group showed clinically meaningful effects at post-treatment for 100% of participants for pain intensity and pain distress, 66.7% for depressive symptoms, 58.3% for functional impairment, 41.7% for cognitive fusion, 66.7% for committed action, 58.3% for self-as-context, and 41.7% for pain acceptance.

CONCLUSIONS

This preliminary trial suggests feasibility of recruitment and follow-up questionnaire completion rates, supporting planning for a larger randomized controlled trial. However, treatment completion rates did not achieve the prespecified feasibility target. Changes to the treatment content and delivery may enhance the feasibility of online Acceptance and Commitment Therapy for people with painful diabetic neuropathy on a larger scale.

The Effectiveness of Acceptance and Commitment Therapy on Pain Acceptance and Pain Perception in Patients with Painful Diabetic Neuropathy: A Randomized Controlled Trial

INTRODUCTION

Neuropathic pain is a complex phenomenon in patients with diabetes. These patients have many problems, such as psychological problems, high-level pain perception, and pain acceptance. This study aimed to evaluate the effectiveness of acceptance and commitment therapy on pain acceptance and pain perception in patients with painful diabetic neuropathy.

METHODS

This study was performed according to the clinical trial method. The sample size was 50 participants. In this study, participants were divided into interventional and control groups. According to the diagnosis of neurologists, all participants received conventional medications to manage neuropathic pain. The intervention group received acceptance and commitment therapy for eight sessions. The results in the three phases of pre-test, post-test, and follow-up were evaluated. After completing the study, to comply with ethical standards, the control group received psycho-education. The tools used were the McGill Pain Questionnaire (MPQ) and the Chronic Pain Acceptance Questionnaire (CPAQ). Statistical analysis includes mean, standard deviation, and repeated-measures (ANOVA) conducted by SPSS software version 22.

RESULTS

The results demonstrated that in the post-test and follow-up phases, acceptance and commitment therapy could improve pain acceptance and reduce pain perception in the intervention group compared to the control group (P < 0.01).

CONCLUSION

The results indicated that acceptance and commitment therapy could be used as a psychological intervention besides pharmacotherapy to improve pain acceptance and reduce pain perception in patients with painful diabetic neuropathy.

CLINICAL TRAIL REGISTRATION

This study was registered at the Iranian Registry of Clinical Trials (IRCT20180205038630N4).

Relationship between diabetic neuropathic pain and comorbidity. Their impact on pain intensity, diabetes complications and quality of life in patients with type-2 diabetes mellitus

OBJECTIVE

To compare cognitive function, mood and sleep status in patients with and without diabetic neuropathic pain (DNP) and their relationship with pain intensity, diabetes complications, and quality of life. To determine whether these relationships differ depending on the sensorial phenotype.

METHODS

Cross-sectional study performed on patients with type-2 diabetes-mellitus and neuropathy. Presence of DNP, pain intensity and phenotype, mood status, sleep characteristics and quality of life were measured.

RESULTS

A total of 130 patients (65 with DNP) were included. DNP was related to poor sleep quality (OR = 1.03;CI95%:1.02-1.05), pain treatment (OR = 3.00,CI95%:1.24-7.29) or previous anxiety (OR = 2.70,CI95%:1.05-6.99). Patients with specific phenotypes or depression (=0.82,CI95%:-0.02-1.67) referred more severe pain. More complications were related to older age (OR = 1.40,CI95%:1.12-1.66), higher pain intensity (OR = 1.51,CI95%:1.00-2.28), lower cognitive performance (OR = 1.25,CI95%:1.09-1.43), previous anxiety (OR = 10.48,CI95%:1.46-75.24) and insulin treatment (OR = 124.50,CI95%:6.64-2335.06). Decrease in mental quality of life was associated with sleep disorders (β = -0.33,CI95%:-0.48,-0.23), physical comorbidities (β = -9.73,CI95%:-18.15, -1.31) and previous anxiety (β = -7.91,CI95%:-13.04, -2.77). Lower scores in physical quality of life were related to sleep disorders (β = -0.12,CI95%:-0.21, -0.18), obesity (β = -8.35,CI95%:-13.16, -3.55), longer time since diagnosis (β = -0.72,CI95%:-1.44;0.01) and disability (β = -14.58,CI95%:-24.69; -4.48).

CONCLUSIONS

The results support the idea that mental comorbidity and sleep disorders are factors associated with DNP and greater pain intensity, more diabetes complications and lower quality of life. Moreover, they highlight the relationship between sensorial phenotypes and pain intensity, and lower cognitive performance and diabetes complications.

New Perspective in Diabetic Neuropathy: From the Periphery to the Brain, a Call for Early Detection, and Precision Medicine

Diabetic peripheral neuropathy (DPN) is a common chronic complication of diabetes mellitus. It leads to distressing and expensive clinical sequelae such as foot ulceration, leg amputation, and neuropathic pain (painful-DPN). Unfortunately, DPN is often diagnosed late when irreversible nerve injury has occurred and its first presentation may be with a diabetic foot ulcer. Several novel diagnostic techniques are available which may supplement clinical assessment and aid the early detection of DPN. Moreover, treatments for DPN and painful-DPN are limited. Only tight glucose control in type 1 diabetes has robust evidence in reducing the risk of developing DPN. However, neither glucose control nor pathogenetic treatments are effective in painful-DPN and symptomatic treatments are often inadequate. It has recently been hypothesized that using various patient characteristics it may be possible to stratify individuals and assign them targeted therapies to produce better pain relief. We review the diagnostic techniques which may aid the early detection of DPN in the clinical and research environment, and recent advances in precision medicine techniques for the treatment of painful-DPN.