Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus and can lead to serious complications. Therapeutic strategies for pain control are available but there are few approaches that influence neurological deficits such as numbness.
This study investigated the effectiveness of acupuncture on improving neurological deficits in patients suffering from type 2 DPN.
The acupuncture in DPN (ACUDPN) study was a two-armed, randomized, controlled, parallel group, open, multicenter clinical trial. Patients were randomized in a 1:1 ratio into two groups: The acupuncture group received 12 acupuncture treatments over 8 wk, and the control group was on a waiting list during the first 16 wk, before it received the same treatment as the other group. Both groups received routine care.
Outcome parameters were evaluated after 8, 16 and 24 wk. They included:
- neurological scores, such as an 11-point numeric rating scale (NRS) for hypesthesia,
- neuropathic pain symptom inventory (NPSI),
- neuropathy deficit score (NDS),
- neuropathy symptom score (NSS);
- nerve conduction studies (NCS) as assessed with a handheld point-of-care device.
Sixty-two participants were included. The NRS for numbness showed a difference of 2.3 (P < 0.001) in favor of the acupuncture group, the effect persisted until week 16 with a difference of 2.2 (P < 0.001) between groups and 1.8 points at week 24 compared to baseline. The NPSI was improved in the acupuncture group by 12.6 points (P < 0.001) at week 8, the NSS score at week 8 with a difference of 1.3 (P < 0.001); the NDS and the TNSc score improved for the acupuncture group in week 8, with a difference of 2.0 points (P < 0.001) compared to the control group. Effects were persistent in week 16 with a difference of 1.8 points (P < 0.05). The NCS showed no meaningful changes. In both groups only minor side effects were reported.
The authors concluded that acupuncture may be beneficial in type 2 diabetic DPN and seems to lead to a reduction in neurological deficits. No serious adverse events were recorded and the adherence to treatment was high. Confirmatory randomized sham-controlled clinical studies with adequate patient numbers are needed to confirm the results.
That “acupuncture may be beneficial” has been known before and presumably was the starting point of the present study. So, why conduct an open, under-powered trial with non-blind assessors and without defining a primary outcome measure?
Could the motivation be to add yet another false-positive study to the literature of acupuncture?
False-positive, you ask?
Yes, let me explain by having a look at the outcome measures:
- NRS = a subjective endpoint.
- NPSI = a subjective endpoint.
- NDS = a subjective endpoint.
- NSS = a subjective endpoint.
- NCS = the only objective endpoint.
And what is remarkable about that?
- Subjective endpoints are likely to respond to placebo effects.
- Objective endpoints are not likely to respond to placebo effects.
In other words, what the authors of this study have, in fact, confirmed with their study is this:
acupuncture is a theatrical placebo!
Interesting!
What this study demonstrates again:
Beware of misinterpreting the p-value as a “truth value” for evidence.