Peripheral Neuropathic Pain
Conditions
Keywords
gabapentin, pregabalin, Inflammatory Biomarkers, Subclinical Cardiac Dysfunction, Echocardiography, Neuropathic Pain
Brief summary
This prospective, controlled, observational cohort study will evaluate short-term changes in inflammatory biomarkers and subclinical cardiac function in adults with peripheral neuropathic pain who are prescribed gabapentin or pregabalin as part of routine clinical care. A total of 75 participants will be enrolled: 25 patients starting gabapentin, 25 patients starting pregabalin, and 25 healthy controls without peripheral neuropathy or chronic neuropathic pain. Treatment selection and dose adjustments will be determined by the treating physician and will not be assigned by the study investigators. Participants will be assessed at baseline and again after 30 ± 7 days. Assessments will include clinical information, pain severity, routine laboratory results, inflammatory biomarkers, and standard transthoracic echocardiography. No additional blood will be collected solely for research; leftover serum from routine testing will be used. The primary aim is to compare changes over time between the gabapentin and pregabalin groups, while the healthy control group will provide a reference for interpretation.
Detailed description
Peripheral neuropathic pain is a chronic condition associated with a lesion or disease of the somatosensory nervous system. Neuroimmune and inflammatory mechanisms may contribute to its development and persistence. Gabapentin and pregabalin are alpha-2-delta ligands commonly prescribed for neuropathic pain; however, whether these medications are associated with different short-term changes in inflammatory pathways and early cardiac function remains unclear.This is a single-center, prospective, controlled, observational cohort study with repeated measurements. A total of 75 adults will be enrolled in three groups: 25 patients with peripheral neuropathic pain who are prescribed gabapentin, 25 patients with peripheral neuropathic pain who are prescribed pregabalin, and 25 healthy controls without peripheral neuropathy or chronic neuropathic pain.The decision to initiate gabapentin or pregabalin, including the selected drug, starting dose, dose adjustment, continuation, or discontinuation, will be made by the treating neurosurgery physician as part of routine clinical care and independently of study participation. The investigators will not randomize participants, assign treatment, determine medication doses, or modify routine treatment decisions.Patients in the gabapentin and pregabalin cohorts will undergo baseline assessment before the first medication dose and a follow-up assessment 30 ± 7 days later. Healthy controls will undergo corresponding assessments at enrollment and after 30 ± 7 days. Clinical assessments will include demographic characteristics, neuropathic pain characteristics, pain severity measured using a 0-10 numerical rating scale, comorbidities, concomitant medications, blood pressure, heart rate, medication exposure, adherence, treatment tolerability, and adverse events.Routine laboratory findings will be recorded. No additional blood sample will be collected solely for research purposes. After completion of clinically required laboratory testing, leftover serum will be coded, aliquoted, stored at -80 °C, and used to measure the inflammatory and signaling biomarkers NLRP3, nuclear factor kappa B p65 (NF-κB p65), and signal transducer and activator of transcription 3 (STAT3), according to the manufacturers' instructions.Standard transthoracic echocardiography will be performed by a cardiologist at baseline and follow-up. Echocardiographic assessments will include left ventricular ejection fraction, left ventricular global longitudinal strain, left ventricular dimensions and wall thickness, left atrial volume index, transmitral E/A ratio, tissue Doppler e' velocity, E/e' ratio, tricuspid annular plane systolic excursion, right ventricular S' velocity, and other clinically relevant standard measurements.The primary objective is to compare changes from baseline to 30 ± 7 days in inflammatory biomarkers and subclinical cardiac function between the gabapentin and pregabalin cohorts. The primary analysis will assess the group-by-time interaction using a linear mixed-effects model. The healthy control cohort will serve as a reference group for secondary and exploratory comparisons. Additional analyses will examine associations among biomarker changes, pain severity, cardiac function, clinical characteristics, medication exposure, and treatment tolerability.De-identified clinical findings may also be integrated with publicly available, anonymous transcriptomic or genomic summary datasets for exploratory, hypothesis-generating translational analyses. No genomic sequencing will be performed on study participants, and biological samples will not be transferred outside the study institution.
Interventions
Gabapentin prescribed as part of routine clinical care for peripheral neuropathic pain. The decision to initiate treatment, as well as the starting dose, dose adjustments, continuation, or discontinuation, will be determined by the treating physician independently of study participation. The study investigators will not assign or modify treatment.
Pregabalin prescribed as part of routine clinical care for peripheral neuropathic pain. The decision to initiate treatment, as well as the starting dose, dose adjustments, continuation, or discontinuation, will be determined by the treating physician independently of study participation. The study investigators will not assign or modify treatment.
Sponsors
Study design
Eligibility
Inclusion criteria
* Patient Cohorts:Age 18 years or older.A clinical diagnosis of peripheral neuropathic pain based on medical history, physical and neurological examination, and, when available, electrophysiological testing or imaging.A determination, following routine clinical evaluation, that initiation of gabapentin or pregabalin is clinically appropriate.Ability to complete baseline assessments before the first dose.Ability and willingness to provide written informed consent.Healthy Controls:Age 18 years or older.Attendance at the cardiology department for a routine health examination or check-up.No peripheral neuropathy, chronic neuropathic pain, gabapentin or pregabalin use, or clinically significant cardiovascular disease based on standard clinical screening.Eligibility, as far as possible, for frequency matching with the patient cohorts by age, sex, and body mass index.Ability and willingness to provide written informed consent.
Exclusion criteria
* Known or newly identified heart failure.2. Clinically significant valvular heart disease, cardiomyopathy, significant cardiac arrhythmia, previous acute coronary syndrome, or other significant structural heart disease.3. Active or recent acute infection.4. Active autoimmune or systemic inflammatory disease.5. Active malignancy.6. Recent major surgery, severe trauma, or acute cardiovascular event.7. Current systemic corticosteroid or immunosuppressive treatment.8. Advanced renal or hepatic dysfunction.9. Uncontrolled thyroid disease.10. Pregnancy or breastfeeding.11. Any acute clinical condition likely to substantially affect baseline biomarker measurements.12. Current use of gabapentin or pregabalin at baseline.13. Inability to complete baseline measurements before the first dose of gabapentin or pregabalin.14. Any other condition that, in the investigator's judgment, would prevent safe or appropriate participation in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Serum NLRP3 Concentration | Baseline and 30 ± 7 days after treatment initiation | Serum NLRP3 concentration will be measured using an enzyme-linked immunosorbent assay (ELISA) in coded leftover serum obtained after completion of routine clinical laboratory testing. Measurements will be performed before the first dose of gabapentin or pregabalin and at the follow-up visit. Change will be calculated as the follow-up value minus the baseline value. The primary comparison will evaluate the group-by-time interaction between the gabapentin and pregabalin cohorts. |
| Change From Baseline in Serum NF-κB p65 Concentration | Baseline and 30 ± 7 days after treatment initiation | Serum nuclear factor kappa B p65 (NF-κB p65) concentration will be measured using an enzyme-linked immunosorbent assay (ELISA) in coded leftover serum obtained after completion of routine clinical laboratory testing. Measurements will be performed before the first dose of gabapentin or pregabalin and at the follow-up visit. Change will be calculated as the follow-up value minus the baseline value. The primary comparison will evaluate the group-by-time interaction between the gabapentin and pregabalin cohorts. |
| Change From Baseline in Serum STAT3 Concentration | Baseline and 30 ± 7 days after treatment initiation | Serum signal transducer and activator of transcription 3 (STAT3) concentration will be measured using an enzyme-linked immunosorbent assay (ELISA) in coded leftover serum obtained after completion of routine clinical laboratory testing. Measurements will be performed before the first dose of gabapentin or pregabalin and at the follow-up visit. Change will be calculated as the follow-up value minus the baseline value. The primary comparison will evaluate the group-by-time interaction between the gabapentin and pregabalin cohorts. |
| Change From Baseline in Left Ventricular Global Longitudinal Strain | Baseline and 30 ± 7 days after treatment initiation | Left ventricular global longitudinal strain (LV-GLS) will be assessed by standard transthoracic echocardiography and reported as a percentage. Measurements will be performed before the first dose of gabapentin or pregabalin and at the follow-up visit, using the same echocardiography system and analysis software whenever possible. Change will be calculated as the follow-up value minus the baseline value. The primary comparison will evaluate the group-by-time interaction between the gabapentin and pregabalin cohorts. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Neuropathic Pain Intensity | Baseline and 30 ± 7 days after treatment initiation | Neuropathic pain intensity will be assessed in the gabapentin and pregabalin cohorts using an 11-point numerical rating scale ranging from 0 (no pain) to 10 (worst imaginable pain). Change will be calculated as the follow-up score minus the baseline score |
| Change From Baseline in Left Ventricular Ejection Fraction | Baseline and 30 ± 7 days after baseline | Left ventricular ejection fraction will be measured by standard transthoracic echocardiography using the biplane Simpson method and reported as a percentage. Change will be calculated as the follow-up value minus the baseline value. |
| Change From Baseline in Left Atrial Volume Index | Baseline and 30 ± 7 days after baseline | Tricuspid annular plane systolic excursion (TAPSE) will be measured by transthoracic echocardiography and reported in millimeters as an indicator of right ventricular systolic function. Change will be calculated as the follow-up value minus the baseline value. |