Restless legs syndrome: prevention with Pycnogenol® and improvement of the venoarteriolar response.

BACKGROUND: The aim of this registry study was to evaluate the preventive efficacy of Pycnogenol® (French maritime pine bark, standardized extract), an anti-inflammatory and antioxidant supplement, previously used for muscular pain and cramps, in otherwise healthy subjects with restless legs syndrome (RLS). METHODS: Two management groups were formed: one using the standard management (SM) and one using SM and Pycnogenol® 150 mg/day for 4 weeks. RESULTS: Forty-five subjects were included in the study, 21 took Pycnogenol® and 24 were in the SM group. After 4 weeks no side effects or tolerability problems were observed. Compliance was optimal. The two groups were comparable at baseline. Limb sensations were assessed with a Visual Analogue Scale Line (0 to 4). There was a statistically non-significant improvement with SM in all subjects. Improvement with Pycnogenol® supplementation was significant (P<0.05) for all assessed parameters with important clinical meanings as 19 out of 21 supplemented subjects reported a clear benefit from supplementation. Resting flux - slightly elevated at inclusion - was normalized in the supplemented group (P<0.05) as seen by a decrease in flux. The venoarteriolar response - affected at inclusion in all subjects with RLS - was improved with the supplement, indicating a better axon-axon reflex response and a lower level of subclinical neural alteration. The need for pain managements was significantly reduced (P<0.05) with supplementation after 4 weeks, as only 4/21 supplemented subjects vs. 16/24 in the SM-only group had to use analgesics. Thermography of the leg did not reveal any significant asymmetry of perfusion. Oxidative stress as plasma free radicals (PFR) was significantly improved (reduced) (P<0.05) in subjects using Pycnogenol®. Likewise, minimal edema, measured with the edema tester, was significantly decreased with Pycnogenol®. CONCLUSIONS: Pycnogenol® prevents or relieves symptoms associated with restless leg syndrome and positively affects the venoarteriolar response. Future studies in this condition, including more complex subjects may indicate the role of Pycnogenol® in this common and still obscure syndrome and in subclinical muscular and neurological alterations.