Acupuncture for the treatment of diabetic peripheral neuropathy in the elderly: a systematic review and meta-analysis

Diabetic peripheral neuropathy (DPN) is one of the most common and debilitating complications of diabetes mellitus, especially in elderly patients. Characterized by functional loss of cutaneous receptors and proprioceptive sensation, it typically manifests as numbness and pain beginning in the feet and legs. This condition affects up to 50% of patients with diabetes and is often asymptomatic in the early stages, which delays diagnosis until it becomes nearly irreversible. In elderly patients, DPN represents an even greater risk, being associated with higher incidence of falls, ulcerations, and even amputations.

Age is an independent risk factor, with incidence increasing significantly with each decade of life, making patients over 60 years particularly vulnerable. Given that prolonged pharmacological treatments can increase the risk of adverse events in the elderly, there is growing interest in nonpharmacological therapies such as acupuncture.

This systematic review and meta-analysis investigated the efficacy of acupuncture in the treatment of DPN in elderly patients through a comprehensive search of six databases, including Medline, EMBASE, Cochrane, and three Chinese databases, from inception through October 2023. The researchers included only randomized clinical trials that compared acupuncture (including electroacupuncture, scalp acupuncture, warm acupuncture, and acupotomy) with pharmacological controls or other nonpharmacological interventions in patients aged 60 years or older. The primary endpoint was the clinical response rate, defined as the sum of significant improvement and effective improvement rates. Secondary endpoints included the Toronto Clinical Scoring System (TCSS), nerve conduction velocities, and blood glucose levels.

Of 4,518 studies initially identified, nine randomized clinical trials met the inclusion criteria, totaling 751 patients (383 in the acupuncture group and 368 in the control group). All included studies were published in Chinese, with sample sizes varying considerably and treatment durations between 10 days and 3 months. Most studies used traditional manual acupuncture, while one used symptom-matching acupuncture and another used warm acupuncture. Control groups mainly received conventional pharmacological treatment with mecobalamin and vitamin B, except one study that used stair training as control.

Results demonstrated consistent benefits of acupuncture across multiple parameters. The clinical response rate was significantly higher in the acupuncture group (RR = 4.49, 95% CI: 1.17-1.35, p < 0.00001), indicating that patients treated with acupuncture were more likely to experience meaningful clinical improvement. The TCSS, which assesses symptoms, signs, and nerve conduction studies, showed significant reduction in the acupuncture group (MD = -2.87, 95% CI: -5.27 to -0.48, p = 0.02), suggesting comprehensive improvement of the neuropathic condition. Nerve conduction velocities, objective indicators of neurological function, improved consistently: sensory conduction velocity of the median nerve (MD = 3.65, 95% CI: 1.60 to 5.71), motor conduction velocity of the common peroneal nerve (MD = 6.86, 95% CI: 2.52 to 11.2), and sensory conduction velocity of the common peroneal nerve (MD = 5.06, 95% CI: 3.10 to 7.03).

Additionally, acupuncture demonstrated metabolic benefits, significantly reducing fasting blood glucose (MD = -1.2, 95% CI: -2.34 to -0.07) and glycated hemoglobin (MD = -1.45, 95% CI: -2.69 to -0.21).

The clinical implications of these findings are substantial. Acupuncture emerges as a promising complementary therapy for DPN in the elderly, offering benefits that are not only symptomatic but also functional and metabolic. The favorable safety profile, evidenced by low rates of adverse events and dropouts, makes it particularly attractive for elderly populations vulnerable to medication side effects. Proposed mechanisms include improvement of blood rheology, reduction of inflammatory factors, modulation of spinal microglial response, and optimization of glycemic control.

However, several important limitations must be considered. The methodological quality of the included studies was limited, with no study adequately reporting blinding, fundamental for reducing performance bias. Significant heterogeneity among studies, reflected in differences in acupuncture protocols, study populations, and control interventions, compromises generalization of the results. The relatively small sample size and absence of long-term follow-up limit understanding of the durability of effects.

In addition, the lack of standardization in acupoint selection, stimulation techniques, and treatment duration hampers clinical replication of the most effective protocols.