Endogenous anandamide and self-reported pain are significantly reduced after a 2-week multimodal treatment with and without radon therapy in patients with knee osteoarthritis: a pilot study

Abstract

Multimodal therapies comprising spa applications are widely used as non-pharmaceutical treatment options for musculoskeletal diseases. The purpose of this randomized, controlled, open pilot study was to elucidate the involvement of the endocannabinoid system in a multimodal therapy approach. Twenty-five elderly patients with knee osteoarthritis (OA) received a 2-week spa therapy with or without combination of low-dose radon therapy in the Bad Gastein radon gallery. A 10-point numerical rating scale (pain in motion and at rest), WOMAC questionnaire, and the EuroQol-5D (EQ-5D) questionnaire were recorded at baseline, and during treatment period at weeks one and two, and at 3-month and 6-month follow-ups. Plasma levels of the endocannabinoid anandamide (AEA) were determined at baseline and at 2 weeks, and serum levels of several cartilage metabolism markers at all five time-points. A significant and sustained reduction of self-reported knee pain was observed in the study population, but no further significant effect of the additional radon therapy up and above base therapy. This pain reduction was accompanied by a significant reduction of AEA plasma levels during treatment in both groups. No significant differences were seen in serum marker concentrations between the groups treated with or without radon, but a small reduction of serum cartilage degradation markers was observed during treatment in both groups. This is the first study investigating AEA levels in the context of a non-pharmacological OA treatment. Since the endocannabinoid system represents a potential target for the development of new therapeutics, further studies will have to elucidate its involvement in OA pain.

Radon Improves Clinical Response in an Animal Model of Rheumatoid Arthritis Accompanied by Increased Numbers of Peripheral Blood B Cells and Interleukin-5 Concentration

“…In one of the most well-known radon spa galleries in Bad Gastein, Austria, patients receive approximately 44 kBq/m 3 radon/therapy session in the course of 10 treatment sessions, each lasting for the duration of one hour. Unlike in our experiment where we wanted to focus on only radon-induced effects, therapy includes enhanced temperature (37–41.5 °C) and humidity (70–100%) [ 1 , 8 ].…”

“…Next to the discomfort of patients that fail conventional therapies, all of these diseases bear a relatively high socioeconomic burden. Here, a therapy utilizing radon might be a useful additional therapy option, especially with regard to pain management [1,[5][6][7][8], similar to observations made in the treatment of chronic, inflammatory diseases with low doses of X-rays [9].…”

“…While it greatly contributes to the exposure from naturally occurring sources of ionizing radiation (IR) it is also widely used in the treatment of benign inflammatory and non-inflammatory diseases, in many countries. Today, it is widely accepted that the emitting alpha-particles from radon in these springs are responsible for the main dose and thus for several beneficial effects [ 1 , 2 , 3 ]. At present, the analgesic effects of radon therapies are exploited in the form of bathing in water containing radon, drinking radon-infused water or via inhalation therapy in galleries or caves with enhanced radon concentrations [ 2 , 3 , 4 , 5 ].…”

“…Various studies have shown that patients that have undergone radon therapy benefit from long-lasting pain-reducing effects [ 1 , 2 , 6 , 7 , 8 , 10 , 11 , 12 ] as reviewed by Maier et al and Falkenbach et al [ 2 , 10 ]. Next to the known analgesic effects, some hints on underlying molecular mechanisms have already been shown in pre-clinical models and patient studies.…”

Identifying Frailty in Thermal/Spa Clinical Setting: A Cross-Sectional Study

“…Thermal/spa treatments, specially water immersion, have shown to benefit cardiovascular and neuromuscular systems (4). Its use has shown to be beneficial for healthy older adults (5) as well as older people with different conditions, including Parkinson's disease (6), and constipation (7), but thermal/spa therapy are the most often used for the treatment of osteoarticular diseases in older adults (8)(9)(10)(11). A randomized controlled trial (10) showed spa therapy (including balneotherapy and jet shower), compared to etodolac treatment, improved pain, anxiety, and quality of life in older adults with generalized osteoarthritis.…”