Transcutaneous Application of Gaseous CO ₂ Improves Diabetic Distal Symmetrical Polyneuropathy in Patients with and Without Chronic Wounds

The study explores the effects of non-invasive transcutaneous CO₂ therapy on diabetic symmetrical peripheral polyneuropathy (DSPN). Overall, we included 120 patients with diabetes: 40 patients with DSPN (group A) and 40 patients with DSPN and diabetic foot ulceration (DFU) (group B), both receiving 20 sessions of CO₂ therapy; 40 DSPN patients not receiving treatment (group C). Outcomes were assessed using the Semmes-Weinstein monofilament test, 128 Hz tuning fork vibration sensation, hallux temperature, wound dimensions, and adverse effects. There was a significant improvement in protective sensation for the CO₂-treated groups. Group A exhibited a 53% improvement, while Group B improved by 34% (p = .002). In Groups A, B vibration sensation improvement was 30% and 23%, respectively. Hallux temperature increased more in Group A (5.10 °C) compared with Group B (3.89 °C). Improvement in monofilament sensation was observed in both CO₂ treated groups, regardless of ankle-brachial index (ABI), with best results in patients having borderline ABI (67.5% in Group A and 53.1% in Group B). In conclusion, CO₂ therapy effectively alleviated DSPN symptoms in patients with/without DFUs, with normal or insufficient circulation, and it was well-tolerated without adverse effects.