Does Climate Affect Arthritis Pain? Studies Say it Depends

According to John Hopkins Medicine, two recent studies conducted in Cordoba City, Argentina, and Florida came to different conclusions about the climate's affect on arthritis pain. The studies involved more than 300 individuals suffering from arthritis and fibromyalgia, as well as some 32 non-suffers.

A brief summary of the three illnesses studied is necessary to set the stage.

Osteoarthritis is the most common form of arthritis. For people over age 65, it's the primary cause of limited movement and physical disabilities. According to the Osteoarthritis Initiative (OAI), 35 million Americans fall within the 65-and-over age category, and more than half of them have at least the beginnings of osteoarthritis in one or more joints.

Rheumatoid arthritis is a chronic illness that can strike at any age. It occurs when the body's immune system wrongly attacks its own tissues, causing inflammation of the joints and the tissue around the joints. With rheumatoid arthritis the cause of pain and stiffness is tissue inflammation around the joint, which can also lead to severely deformed joints.

Fibromyalgia is another chronic illness that can cause disabling pain and stiffness in the muscles, connective tissues and joints. It differs from rheumatoid arthritis in that there is no tissue inflammation causing the pain; neither does fibromyalgia lead to joint deformities. The illness primarily affects women of middle age.

In one study, 151 people with one of the aforementioned illnesses kept a detailed daily journal of their disease-related pain for a year; 32 people without disease also kept journals. These study participants all lived in Cordoba City, Argentina, where the average daily temperature is between 52 and 75 degrees. Researchers compared the daily journal reports with the daily weather conditions, including temperature, barometric pressure and relative humidity.

Not surprisingly, those individuals without disease were unaffected by the weather. Those with disease had increased pain affected by weather conditions as follows:

Rheumatoid arthritis: affected by high humidity and high barometric pressure

Osteoarthritis: affected only by high humidity

Fibromyalgia: affected by only high barometric pressure

Participants in all three groups had more disease-related pain on those days when the temperature was lowest. Although the findings are interesting, the researchers concluded that they were not significant enough to say definitively that pain can predict weather, or vice versa.

In another study, 154 people with an average age of 72 participated in a similar study for up to two years. These individuals all lived in Florida, where the average daily temperature generally ranges in the mid-50s to the mid-80s. All study participants were osteoarthritis sufferers. The relationship between the weather - in this case researchers looked at temperature, barometric pressure and precipitation - and pain was:

Except for a slight increase in hand pain in women when the barometric pressure rose, researchers found no significant association between osteoarthritis pain and weather conditions.

The John Hopkins report says there is some evidence that arthritis sufferers who live in warm, dry climates have fewer episodes of arthritis pain. However, they conclude that the course of arthritis itself is not affected by the climate where one lives.

Resources:

John Hopkins Medicine; http://www.hopkinsreport.com/arthritis/

OAI; http://www.oai.ucsf.edu/datarelease/StudyOverview.asp