Weather may impact patients’ tolerance to pain
A recent analysis appeared to substantiate the widely held notion that weather affects pain, the study authors noted.
“Few existing studies neither have had sufficient power to address possible nonlinear associations nor did they use methodologies that could address the issue of nonlinearity,” Erlend Hoftun Farbu, a PhD student at The Arctic University of Norway, and colleagues wrote in Pain. “Another problem is that the effect of weather likely depends on the preceding weather.”
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Farbu and colleagues reviewed data from a survey of adults aged older than 40 years who lived in Tromsø Norway, a municipality north of the Arctic Circle where the yearly temperature ranges from a mean of -3.3C in February to a mean of 12.3C in July.
The researchers gauged pressure pain tolerance (PPT) among 18,987 adults based on how much pressure they could tolerate on each leg until the pain was unbearable or 100 kPa of pressure had been applied, whichever came first. The survey also assessed cold pain tolerance (CPT) of 18,285 adults who “submerged their open and relaxed dominant hand and wrist” in 3C water until the pain was either unbearable or 2 minutes had elapsed, whichever came first.
“We created 3-day moving averages for PPT and the daily measures of CPT with the seasonality removed and used cross-correlation to investigate the possible association between pain tolerance and meteorological variables,” Farbu and colleagues wrote.
The results showed a “clear seasonal variation” in CPT, the researchers wrote. Specifically, the rate of the adults removing their hand from the CPT test was up to 75% higher during the warmer times of the year compared with some of the coldest times of the year.
Although there was no seasonal variation in PPT, the researchers wrote that there was “a clear autocorrelation for daily mean PPT, meaning the PPT on one day was correlated with the observations from preceding days.” This autocorrelation had a mean lifetime of 5.1 days (95% CI, 4-7.2). This falls “within the range of mean lifetime for the meteorological anomalies,” which the researchers said varied from 2.6 days (95% CI, 1.9-4) for precipitation to 6.2 days (95% CI, 5.5-7.2) for barometric pressure. After the researchers extracted seasonality from the variables, there was no autocorrelation for daily CPT.
“One limitation of our study is that PPT and CPT were measured only once,” the researchers wrote. “Thus, we studied the average pain tolerance of a population and were unable to include possible individual variation or adaptation over time.”
The impact of other limitations — including patients’ hand temperatures prior to completing the test and their structured attendance — was partially offset by the additional analyses, according to the researchers.
“Although observational, these findings suggest that weather has a causal, non-linear, dynamic effect on pain tolerance,” Farbu said in a press release. “But it remains unclear if the link between weather and pain involves physiological or psychological factors, or a combination of factors.
“If we are correct that the relationship is dynamic and non-linear, it might very well explain why many studies find small effects and conflicting results,” he added.
References
Brittanica.com. Tromsø. https://www.britannica.com/place/Tromso. Accessed Nov. 4, 2021.
Farbu EH, et al. Pain. 2021;doi:10.1097/j.pain.0000000000002437.
Weather can affect pain tolerance, reports study in Pain. https://www.newswise.com/articles/weather-can-affect-pain-tolerance-reports-study-in-pain. Published Sept. 21, 2021. Accessed Nov. 4, 2021.
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I experienced multiple fractures and nerve damage in an accident when my car was hit by an 18-wheeler, thrown up against the median and burst into flames. Since then, I know that weather can trigger pain.
In some instances, like neuropathy, the pain some patients experience when it’s cold outside may stem from their already-tense muscles feeling extra pressure from impinging on a nerve and thus, tense further from the cold. In arthritis, it’s the joints that feel the extra pressure. However, I also have patients who tell me they do not experience weather-related changes.
Relationships like the ones explored by Farbu and colleagues might stem from the fact that certain people are much more connected to their body and feel things in a greater way than other people do.
Lutherville, Maryland
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We cannot quite get to the point of causality with studies such as the one by Farbu and colleagues, but we can get an association.
We see patients experience weather-related pain all the time. Most classically, the type of pain associated with arthritis seems to predict the weather. This study shows what we see in the clinic, and the old wives’ tales and wisdom over the years has shown to be the case.
The true mechanism is still an area of ongoing research. Several hypotheses exist. Firstly, there is thought that the factors associated with weather (barometric pressure, temperature, humidity) influence the swelling and contraction of tendons and ligaments associated with joint pain. Other theories suggest there is an association between chemical hormones in the brain (eg, serotonin) that alter the perception of pain. In much the same way as we turn up the volume on the radio, these chemicals can increase or attenuate the perception of pain at the level of the brain and spinal cord.
Patients who experience weather-related pain can sometimes plan activities and engagement around the weather. However, there are some people who find themselves naturally gravitating toward places where the weather does not have such fluctuations.
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