Stimulated by Huang et al 2020.
PD –Parkinson’s Diseasekey to acronyms
LHID – Longitudinal Health Insurance Database (Taiwan)
NHIRD – National Health Insurance Research Database (Taiwan)
NHI – National Health Insurance (Taiwan)
This is one of two papers from Taiwan I am highlighting on the blog this week (2 separate blog posts). It is another of the large retrospective observational cohort studies. I summarised the details of these at the start of a previous blog: Reducing TKR surgery.
Until I read the title of this paper I did not know that there was any association between depression and PD, but apparently the risk of developing PD is increased 3 fold in patients with depression.[2,3] Some of this increased risk may be related to use of antidepressant medication, but it is also possible that depression could be part of the natural history of PD.
Using acupuncture to treat depression may therefore have more than one plausible mechanism. First it may preclude the use of drugs associated with an increased risk of PD, and second, the recognised neuroprotective effect of acupuncture may improve resilience in those parts of the brain that are affected.
This study identified just under 50 thousand patients with a diagnosis of depression between 1996 and 2013 from the LHID 2000, comprising a random sample of 1 million patients from the larger NHIRD. The latter covers more than 98% of the population of Taiwan. The sample was narrowed to those diagnosed with depression within the years 2000 to 2012, of which just over 10k had treatment with acupuncture and just over 14k had not. These groups were matched in a 1:1 ratio by propensity score (year of diagnosis, index date, age, sex, area, income, urbanisation, comorbidities and medications), and that left 9189 in each group.
The use of acupuncture was associated with a 61% lower incidence of PD. That is almost back to the incidence of PD in the normal population. The average number of acupuncture visits per patient recorded in the NHIRD was 7.2 – this would not include any acupuncture paid for directly by the patient, but since the authors tell us that the NHI program allows up to 15 acupuncture sessions per month, I’m not sure that would be an issue.
The use of steroids and statins were also independently associated with a reduction in the incidence of PD, although not to the same degree as that associated with acupuncture. Interestingly, steroids were not associated with a significantly reduced incidence of PD in patients who received acupuncture, but statins were, which might suggest that any mechanisms involved overlap less between acupuncture and statins than between acupuncture and steroids. Since there is more data on the anti-inflammatory effects of acupuncture than any lipid altering effects, I guess this makes sense.
1 Huang C-H, Lin M-C, Hsieh C-L. Acupuncture Treatment Reduces Incidence of Parkinson’s Disease in Patients With Depression: A Population-Based Retrospective Cohort Study in Taiwan. Front Aging Neurosci 2020;12:591640. doi:10.3389/fnagi.2020.591640
2 Schuurman AG, van den Akker M, Ensinck KTJL, et al. Increased risk of Parkinson’s disease after depression: a retrospective cohort study. Neurology 2002;58:1501–4. doi:10.1212/wnl.58.10.1501
3 Gustafsson H, Nordström A, Nordström P. Depression and subsequent risk of Parkinson disease: A nationwide cohort study. Neurology 2015;84:2422–9. doi:10.1212/WNL.0000000000001684
4 Alonso A, Rodríguez LAG, Logroscino G, et al. Use of antidepressants and the risk of Parkinson’s disease: a prospective study. J Neurol Neurosurg Psychiatry 2009;80:671–4. doi:10.1136/jnnp.2008.152983