Identification, prevalence, and treatment of painful diabetic neuropathy in patients from a rural area in South Carolina

Trends in Pain Medication Use in Patients With Type 2 Diabetes: NHANES 2005-2018

The aim of this research was to compare pain medication use trends among adults with and without type 2 diabetes in the US. This cross-sectional study used data of adults with and without (type 2) diabetes from the National Health and Nutrition Examination Survey waves 2005-2018. Use of pain medication including opioids, prescription nonsteroidal anti-inflammatory drugs, gabapentinoids, serotonin norepinephrine reuptake inhibitors, skeletal muscle relaxants, and headache treatment agents was compared by diabetes status and within select social determinants of health and clinical factors. Adults with type 2 diabetes were twice as likely to be prescribed pain medications compared to those without a diabetes diagnosis (16.2% vs 8.6%). Females and those with a history of smoking or arthritis were more likely to be on pain medications. Opioid use was the most prevalent regardless of diabetes status, and use was twice as high among those with diabetes (10.8% vs 5.5%). Patients with type 2 diabetes in the US are twice as likely to be prescribed pain medications overall as well as opioids compared with those without diabetes. Clinical guideline recommendations are necessary to find pharmacologic and nonpharmacologic nociceptive pain management specific for patients with diabetes.

Risk stratification models for predicting preventable hospitalization in commercially insured late middle-aged adults with depression

BACKGROUND

A significant number of late middle-aged adults with depression have a high illness burden resulting from chronic conditions which put them at high risk of hospitalization. Many late middle-aged adults are covered by commercial health insurance, but such insurance claims have not been used to identify the risk of hospitalization in individuals with depression. In the present study, we developed and validated a non-proprietary model to identify late middle-aged adults with depression at risk for hospitalization, using machine learning methods.

METHODS

This retrospective cohort study involved 71,682 commercially insured older adults aged 55-64 years diagnosed with depression. National health insurance claims were used to capture demographics, health care utilization, and health status during the base year. Health status was captured using 70 chronic health conditions, and 46 mental health conditions. The outcomes were 1- and 2-year preventable hospitalization. For each of our two outcomes, we evaluated seven modelling approaches: four prediction models utilized logistic regression with different combinations of predictors to evaluate the relative contribution of each group of variables, and three prediction models utilized machine learning approaches - logistic regression with LASSO penalty, random forests (RF), and gradient boosting machine (GBM).

RESULTS

Our predictive model for 1-year hospitalization achieved an AUC of 0.803, with a sensitivity of 72% and a specificity of 76% under the optimum threshold of 0.463, and our predictive model for 2-year hospitalization achieved an AUC of 0.793, with a sensitivity of 76% and a specificity of 71% under the optimum threshold of 0.452. For predicting both 1-year and 2-year risk of preventable hospitalization, our best performing models utilized the machine learning approach of logistic regression with LASSO penalty which outperformed more black-box machine learning models like RF and GBM.

CONCLUSIONS

Our study demonstrates the feasibility of identifying depressed middle-aged adults at higher risk of future hospitalization due to burden of chronic illnesses using basic demographic information and diagnosis codes recorded in health insurance claims. Identifying this population may assist health care planners in developing effective screening strategies and management approaches and in efficient allocation of public healthcare resources as this population transitions to publicly funded healthcare programs, e.g., Medicare in the US.

Safety, Tolerability and Pharmacokinetics of Single and Multiple Doses of Mirogabalin in Healthy Chinese Participants: A Randomized, Double-Blind, Placebo-Controlled Study

INTRODUCTION

Mirogabalin is a treatment option for patients with neuropathic pain; however, safety, tolerability, and pharmacokinetics (PK) data specifically for Chinese individuals are limited to a single-dose study. We aimed to assess these for both single- and multiple-dose mirogabalin in healthy Chinese participants.

METHODS

In this randomized, double-blind, placebo-controlled, phase I study, 54 healthy Chinese men and women aged 18-45 years were randomly allocated to receive single- (5, 10, or 15 mg, daily) or multiple-dose (5 mg titrated to 15 mg, twice-daily, over 22 days) oral mirogabalin or placebo. In each of three single-dose groups, 10 participants received mirogabalin and 2 received placebo; in the multiple-dose group, 14 participants received mirogabalin and 4 received placebo. The primary endpoints were PK, safety, and tolerability variables, including treatment-emergent adverse events (TEAEs), laboratory tests, and vital signs. PK data were collected for both single- and multiple-dose cohorts and evaluated by non-compartmental analysis.

RESULTS

Single- and multiple-dose mirogabalin was generally well tolerated with no deaths, serious TEAEs, or TEAEs leading to treatment discontinuation. Frequently reported TEAEs included dizziness, nystagmus, increased blood triglycerides, headache, and increased blood uric acid and creatine phosphokinase. Single-dose mirogabalin was rapidly absorbed (median time to maximum plasma concentration, 1.00 h) and eliminated (mean terminal elimination half-life, 2.57-3.08 h). The exposure was approximately dose-proportional. In the multiple-dose cohort, the trough plasma concentration increased dose-proportionally, and exposure and clearance were comparable to that following a single 15-mg dose. The mean cumulative amount excreted into urine up to 48 h post-dose increased in a dose-proportional manner, the mean cumulative percentage excreted into urine was 61.9%-74.3%, and renal clearance remained relatively constant.

CONCLUSION

Consistent with previous phase I studies in other populations, mirogabalin was safe and well tolerated in healthy Chinese participants at single and multiple doses of up to 15 mg twice-daily.

Characterization of Outpatient Gabapentinoid Prescribing for Pain

Two statements from national organizations outline recommended minimum effective doses of gabapentin and pregabalin for the treatment of diabetic peripheral neuropathy (DPN). However, studies of real-world gabapentinoid dosing demonstrate that the recommended dose targets are frequently not met and do not consider renal insufficiency. This study aimed to characterize gabapentinoid prescribing patterns in patients receiving primary care at two internal medicine clinics within an academic medical center. This retrospective chart review included adult outpatients who were newly initiated on gabapentin or pregabalin between October 1, 2017 and October 1, 2020 and reviewed for 12 months. A total of 1,221 patients were included in the study with 1,079 (88.4%) prescribed gabapentin and 142 (11.6%) prescribed pregabalin. Only 22.4% of patients prescribed gabapentin and 33.3% of patients prescribed pregabalin with adequate renal function met the minimum effective dosing of gabapentin 1800 mg per day and pregabalin 300 mg per day provided by the American Diabetes Association (ADA) and American Academy of Neurology (AAN). This study supports the need for optimization of gabapentinoid dosing to ensure an adequate trial at the minimum effective dose is completed.

Efficacy and safety of mirogabalin treatment in patients with diabetic peripheral neuropathic pain: A systematic review and meta-analysis of randomised controlled trials

AIM

We aimed to perform a systematic review and meta-analysis to examine the efficacy and safety of mirogabalin in patients with diabetic peripheral neuropathic pain (DPNP).

METHODS

We searched four databases from inception to 1st July 2020. We included all randomised controlled trials (RCTs) which assessed the effectiveness and safety of mirogabalin in patients with DPNP. We evaluated the quality of the included RCTs using the Cochrane risk of bias assessment tool. We pooled dichotomous outcomes as risk ratios and continuous outcomes as mean differences with 95% confidence intervals, both under the random- or fixed-effects model.

RESULTS

Three RCTs matched our inclusion criteria with a total of 1732 patients with DPNP: 1057, 534 and 141 patients received mirogabalin, placebo and pregabalin, respectively. The quality of included RCTs was marked as moderate-to-high. Mirogabalin treatment was significantly associated with a significant reduction in the average daily pain score (ADPS) compared with placebo over 7 weeks. Compared with pregabalin, mirogabalin was significantly associated with more decrease in ADPS only after 3, 4 and 5 weeks. The proportion of patients with ≥30% and ≥50% reduction in the ADPS was significantly higher in the mirogabalin vs placebo and pregabalin groups. Compared with placebo, mirogabalin was significantly associated with more adverse events of dizziness, increased weight, peripheral oedema and somnolence. The safety profile was comparable between mirogabalin and pregabalin.

CONCLUSIONS

Our systematic review and meta-analysis revealed that in patients with DPNP, mirogabalin treatment was superior to placebo and pregabalin in decreasing the ADPS over time. Besides, mirogabalin was largely safe and associated with some adverse events that could be managed conservatively.

Early Detection of Diabetic Peripheral Neuropathy: A Focus on Small Nerve Fibres

Diabetic peripheral neuropathy (DPN) is the most common complication of both type 1 and 2 diabetes. As a result, neuropathic pain, diabetic foot ulcers and lower-limb amputations impact drastically on quality of life, contributing to the individual, societal, financial and healthcare burden of diabetes. DPN is diagnosed at a late, often pre-ulcerative stage due to a lack of early systematic screening and the endorsement of monofilament testing which identifies advanced neuropathy only. Compared to the success of the diabetic eye and kidney screening programmes there is clearly an unmet need for an objective reliable biomarker for the detection of early DPN. This article critically appraises research and clinical methods for the diagnosis or screening of early DPN. In brief, functional measures are subjective and are difficult to implement due to technical complexity. Moreover, skin biopsy is invasive, expensive and lacks diagnostic laboratory capacity. Indeed, point-of-care nerve conduction tests are convenient and easy to implement however questions are raised regarding their suitability for use in screening due to the lack of small nerve fibre evaluation. Corneal confocal microscopy (CCM) is a rapid, non-invasive, and reproducible technique to quantify small nerve fibre damage and repair which can be conducted alongside retinopathy screening. CCM identifies early sub-clinical DPN, predicts the development and allows staging of DPN severity. Automated quantification of CCM with AI has enabled enhanced unbiased quantification of small nerve fibres and potentially early diagnosis of DPN. Improved screening tools will prevent and reduce the burden of foot ulceration and amputations with the primary aim of reducing the prevalence of this common microvascular complication.

Polyneuropathy is inadequately treated despite increasing symptom intensity in individuals with and without diabetes (PROTECT follow-up study)

AIMS/INTRODUCTION

Despite its major clinical impact, distal symmetric polyneuropathy remains frequently undiagnosed and undertreated in clinical practice. We previously reported in the PROTECT Study that 70% of type 2 diabetes patients with distal symmetric polyneuropathy were unaware of having the latter condition.

MATERIALS AND METHODS

In the present follow up after 2.5 ± 0.7 years, 122 and 85 participants with and without type 2 diabetes, respectively, completed questionnaires to obtain information about the further course of disease and its management.

RESULTS

At follow up, 49 and 48% of the respondents with type 2 diabetes and without diabetes, respectively, reported that the intensity of paresthesia or numbness in the feet increased, whereas for burning and pain in the feet the corresponding percentages were 56 and 61%. However, 33 and 40% of the respondents with type 2 diabetes and without diabetes, respectively, reporting neuropathic symptoms at follow up did not receive any pharmacotherapy. Pharmacotherapy of neuropathic symptoms at follow up among participants with type 2 diabetes and without diabetes included mainly World Health Organization Step 1 analgesics (17% each; excluding acetylsalicylic acid), pregabalin/gabapentin (20 and 12%), vitamin B complex (13 and 22%), benfotiamine (13 and 2%), opioids (7 and 12%), antidepressants (4 and 5%) and α-lipoic acid (4 and 2%).

CONCLUSIONS

These findings point to insufficient care, inadequate treatment adherence or limited efficacy of treatments in patients with polyneuropathy, suggesting that effective measures should be implemented to correct these healthcare deficits.

Factors affecting the likelihood of a hospitalization following a diabetes-related emergency department visit: A regional and urban-rural analysis

BACKGROUND

The objective of this study is to examine place-based and individual-level predictors of diabetes-related hospitalizations that stem from emergency department (ED) visits.

METHODS

We conducted a pooled cross-sectional analysis of the National Inpatient Sample (NIS) for 2009 to 2014 to identify ED-initiated hospitalizations that were driven by the need for diabetes care. The odds of an ED-initiated diabetes-related hospitalization were assessed for the United States as a whole and separately for each census region.

RESULTS

Nationally, residents of noncore areas (odds ratio [OR] 1.10; CI 1.08, 1.12), the South (OR 8.03; CI 6.84, 9.42), Blacks (OR 2.49; CI 2.47, 2.52), Hispanics (OR 2.32; CI 2.29, 2.35), Asians or Pacific Islanders (OR 1.20; CI 1.16, 1.23), Native Americans (OR 2.18; CI 2.10, 2.27), and the uninsured (OR 2.14; CI 2.11, 2.27) were significantly more likely to experience an ED-initiated hospitalization for diabetes care. Census region-stratified models showed that noncore residents of the South (OR 1.17; CI 1.14, 1.20) and Midwest (OR 1.06; CI 1.02, 1.11) had higher odds of a diabetes-related ED-initiated hospitalization.

CONCLUSIONS

As continued efforts are made to reduce place-based disparities in diabetes care and management, targeted focus should be placed on residents of noncore areas in the South and Midwest, racial and ethnic minorities, as well as the uninsured population.

Mirogabalin for the treatment of diabetic peripheral neuropathic pain: A randomized, double-blind, placebo-controlled phase III study in Asian patients

AIMS/INTRODUCTION

This study evaluated the efficacy and safety of mirogabalin, a novel, potent, selective ligand of the α2 δ subunit of voltage-dependent Ca2+ channels, for the treatment of diabetic peripheral neuropathic pain (DPNP).

MATERIALS AND METHODS

During this double-blind, multisite, placebo-controlled phase III study, Asian patients aged ≥20 years with type 1 or 2 diabetes and DPNP were randomized 2:1:1:1 to a placebo, mirogabalin 15, 20 or 30 mg/day for up to 14 weeks, with a 1- to 2-week titration (NCT02318706). The primary endpoint was the change from baseline in average daily pain score (ADPS) at week 14, defined as a weekly average of daily pain (0 = no pain to 10 = worst possible pain, for the past 24 h).

RESULTS

Of 834 randomized patients, 330, 164, 165 and 165 received placebo, mirogabalin 15, 20 or 30 mg/day, respectively, and were included in analyses (modified intention-to-treat population, n = 824); 755 (90.5%) completed the study. At week 14, the least squares mean average daily pain score change from baseline was -1.31, -1.34, -1.47 and -1.81, respectively, showing statistical significance for mirogabalin 30 mg/day versus placebo (P = 0.0027). The treatment-emergent adverse events observed were mostly mild-to-moderate in all mirogabalin doses, and the most frequent treatment-emergent adverse events were nasopharyngitis, somnolence, dizziness, peripheral edema and weight increase.

CONCLUSIONS

Mirogabalin relieved DPNP in a dose-dependent manner; mirogabalin 30 mg/day showed statistically significant pain relief (vs placebo) in Asian DPNP patients. All doses of mirogabalin tested were well tolerated.

Diabetes-related hospital mortality in the U.S.: A pooled cross-sectional study of the National Inpatient Sample

AIMS

Despite advancements in the diagnosis and treatment of diabetes in the U.S., place-based disparities still exist. The purpose of this study is to determine place-based and other individual-level variations in diabetes-related hospital deaths.

METHODS

A pooled cross-sectional study of the 2009-2015 National Inpatient Sample was conducted to examine the odds of a diabetes-related hospital death. The main predictors were rurality and census region. Individual-level socio-demographic factors were also examined.

RESULTS

Approximately 1.5% (n = 147,069) of diabetes-related hospitalizations resulted in death. In multivariable analysis, the odds of diabetes-related hospital deaths increased across the urban-rural continuum, except for large fringe metropolitan areas, with the highest odds of such deaths occurring among residents of micropolitan (OR = 1.16, 95% C.I. = 1.14, 1.18) and noncore areas (OR = 1.21, 95% C.I. = 1.19, 1.24). Compared to residents of the Northeast, residents in the South, West and Midwest regions were significantly more likely to experience a diabetes-related hospital death. Asian or Pacific Islanders, Medicaid-covered patients and the uninsured were also more likely to die during a diabetes-related hospitalization.

CONCLUSIONS

Place-based disparities in diabetes-related hospital deaths exist. Targeted focus should be placed on the control of diabetic complications in the South, West and Midwest census regions, and among rural residents.

NYX-2925, A Novel N-methyl-D-aspartate Receptor Modulator: A First-in-Human, Randomized, Double-blind Study of Safety and Pharmacokinetics in Adults

NYX‐2925, a new chemical entity, acts as a co‐agonist to glutamate at the N‐methyl‐D‐aspartate receptor (NMDAR). At low concentrations of endogenous agonists (glycine/D‐serine), NYX‐2925 partially activates NMDARs, modulating neural pathways relevant for chronic pain. NYX‐2925 is being developed for the treatment of chronic pain conditions, including painful diabetic peripheral neuropathy and fibromyalgia. In this first‐in‐human, phase I, single‐ascending dose (50–1,200 mg) and multiple‐ascending dose (150–900 mg) study, the safety, tolerability, and pharmacokinetics (PKs) of NYX‐2925 were evaluated in 84 healthy adult volunteers. No safety concerns emerged, including no dissociative side effects. NYX‐2925 exhibited dose‐proportional PKs and minimal accumulation following once‐daily dosing for 7 days. Cerebrospinal fluid (CSF) measurements confirmed that NYX‐2925 crosses the blood brain barrier, with maximum CSF concentrations approximating 6–9% of maximum plasma concentrations at the same dose level. NYX‐2925 was safe and well‐tolerated in healthy volunteers, and the study results support the continued clinical development for chronic pain conditions.

The H-Reflex as a Biomarker for Spinal Disinhibition in Painful Diabetic Neuropathy

PURPOSE OF REVIEW

Neuropathic pain may arise from multiple mechanisms and locations. Efficacy of current treatments for painful diabetic neuropathy is limited to an unpredictable subset of patients, possibly reflecting diversity of pain generator mechanisms, and there is a lack of targeted treatments for individual patients. This review summarizes preclinical evidence supporting a role for spinal disinhibition in painful diabetic neuropathy, the physiology and pharmacology of rate-dependent depression (RDD) of the spinal H-reflex and the translational potential of using RDD as a biomarker of spinally mediated pain.

RECENT FINDINGS

Impaired RDD occurs in animal models of diabetes and was also detected in diabetic patients with painful vs painless neuropathy. RDD status can be determined using standard neurophysiological equipment. Loss of RDD may provide a clinical biomarker of spinal disinhibition, thereby enabling a personalized medicine approach to selection of current treatment options and enrichment of future clinical trial populations.