The pain experienced by people with diabetes is a symptom of diabetic neuropathy. The impact on quality of life is significant. Pain makes walking difficult, sleep troublesome, and eventually contributes to a decrease in social interaction.1
Many have suggested that diabetic neuropathy is just another symptom of the poor circulation which occurs in other organs of diabetic patients, leading to retinopathy, nephropathy, coronary artery disease and gastroparesis.2 Thus, anything that increases circulation to organs or the limbs experiencing pain should be of immeasurable help to patients.
Infrared light therapy is a type of medical device cleared by the FDA for increasing circulation and reducing pain. We currently use one of these devices on our diabetic patients who have pain as one of their symptoms of neuropathy.
| ABSTRACT OBJECTIVE The purpose of this case report is to evaluate the effect of near-infrared treatments on pain, one of the symptoms of diabetic peripheral neuropathy (DPN). Treatments using the identical protocol were conducted at five separate locations in Southern California. METHODS Severity of neuropathic pain was assessed in 235 subjects in five clinics. Pain (VAS), was used to determine the severity of pain. Then, following a mean of 30 light therapy treatments (20 minutes /treatment, three times / week) on the lower extremities, the pain was reassessed. Site-specific initial pain, final pain and change in pain were evaluated with analysis of variance. Data are presented as mean ± standard deviation. RESULTS Baseline pain was 8.1 ± 1.8. Following treatments, pain decreased to 1.8 ± 2.4 (P < 0.0001). Initial pain and final pain were virtually identical at each location. CONCLUSIONS Pain significantly improves during NIR treatments in diabetic subjects with neuropathy. There was a wide range of treatment times, but on average 30 treatments were required. This is likely due to the complexity of type 2 diabetes and comorbidities. Light therapy devices may decrease pain, one of the symptoms of DPN, and thereby improve quality of life. |
Methods
Subjects (n = 235) who presented to our clinics with symptoms of neuropathy were given a complete physical. A thorough medical history was obtained; if the person was diabetic (HgA1c >5.5), a Pain Self-Assessment Form was completed (Visual Analogue Scale: 0-10).
Subjects were then offered treatment with an FDA-cleared near-infrared LED device. The treatment protocol was explained and informed consent was obtained. Treatments were performed on the foot and calf of each leg for 20 minutes, three times a week.
Statistics
To determine if the baseline, post-treatment, or change in pain from baseline differed by study site, an analysis of variance was done for each variable with site as a factor in the model.
Results
Approximately 50 patients per location, each with diabetic lower extremity pain, were treated at the five study sites. The number of treatments varied by patient, but the median was 30 visits for NIR treatment. Summary statistics for baseline pain, post-treatment pain, and change from baseline pain are presented in the table below by study site and overall.
Discussion
NIR treatments are effective in reducing pain, one of symptoms of neuropathy in patients with diabetes. The reason may lie in improved oxygen and glucose delivery to nerves, resulting in an increase in ATP, which is needed to regulate ion channels. The net effect of increased circulation would be a decrease in ischemic pain.3
Most of the patients who came to our clinic had significant pain, averaging between 7-8/10. Initial pain scores were virtually identical at each of the five locations.
Over about 10 weeks (approximately 30 treatments), pain decreased to between 1.5 and 3.0. Our protocol of three treatments per week was adopted because it is difficult for patients to come to our clinics more often. Using this protocol, we found that diabetic patients treated at any of our sites with NIR were virtually equally likely to experience a meaningful and significant reduction in their neuropathic pain.
| SUMMARY OF BASELINE, POST-TREATMENT, AND CHANGE FROM BASELINE PAIN AFTER TREATMENT | ||||
| Data Source |
Baseline Pain (Average) |
Post-Treatment Pain (Average) |
Change from Baseline (Average) |
Average Number of Visits |
| All Sites (235 total patients) |
8.179 | 1.791 | -6.387 | 23.03 |
Acknowledgements: Statistical analysis conducted by Richard P. Chiacchierini, PhD, R.P. Chiacchierini & Associates, Rockville, Md. The author has no financial interests to disclose.
References
- Diabetic Neuropathy – Symptoms. Mayo Clinic, Feb. 24, 2015.
- Diabetic Neuropathy – Causes. Mayo Clinic, Feb. 24, 2015.
- Lohr NL, Keszler A, Pratt P, et. al. Enhancement of nitric oxide release from nitrosyl hemoglobin and nitrosyl myoglobin by red/near infrared radiation: potential role in cardioprotection. J Mol Cell Cardiol, 2009;47:256-63.
Dr. Philip Straw's mission is to save as many seniors as possible from the crippling effects of peripheral neuropathy and the conditions associated with it. His practices exclusively treat patients with neuropathy and diabetes. In 2014 Dr. Straw published Neuropathy: How to Relieve Foot Numbness, Tingling, Burning and Cramping Without Drugs or Surgery, the A-to-Z handbook for neuropathy sufferers.