Cold climate could be an etiologic factor involved in Raynaud's phenomenon physiopathology. Epidemiological...

The physiopathology of Raynaud's phenomenon (RP) is not currently fully resolved. The cold seems to be not only an important factor triggering attacks, but also inducing RP. The aims of this study were to assess the prevalence of RP in Nantes urban district, and study the relationship between RP prevalence and cold climate.

Patients aged between 10 and 80 years old, consulting in five Nantes General Practices, from June 2011 and March 2012, were included. Patients presenting RP underwent a full clinical examination. Subjects not meeting Allen and Brown criteria benefited from at least a dosage of Anti-Nuclear Antibodies and a naifold Capillaroscopy. Climate data provided by French national weather agency allowed establishing an average of observed temperatures during the past five years and correlating them to the observed prevalence.

Of 954 patients included, 78 had a RP, for an overall prevalence estimated at 8.2%. The prevalence among women (8.9%) was slightly higher than men (7.3%). Secondary form represented 5.1% of RP. In the RP group, 13 patients were active smokers, mean BMI was 22.3±3.2 kg/m², and only 4 patients were treated by vasoconstrictor therapy. According to French national weather agency, between 2007 and 2011, mean temperature of January in Nantes area was 5.8 °C.

We confirmed that the lower winter temperatures a region experiences, the higher the prevalence of RP, thus raising the question of the physiopathological role of the cold in the induction or in the revelation of RP.