Climatic factors such as heat and humidity that lead to dehydration can signal a future attack for gout sufferers, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Washington DC.
Gout, caused by deposits of monosodium uric crystals, causes severe pain and swelling of the joints. The attacks, which typically affect one joint over a period of a few days, most often the big toe, can also generate fever, chills, a general feeling of malaise and rapid heartbeat. Depleting the body of fluids through perspiration has been long considered a potential trigger for recurrent gout attacks.
To test the suspected effects of humidity and temperature on the chances of recurrent attacks, researchers recruited 197 individuals who had experienced a gout attack within the past year. Participants were asked to log onto a study Web site when they experienced a gout attack and complete a questionnaire on the risk factors they had experienced the two days prior (known as the hazard period). They also were asked to complete the same questionnaire on experiences over a two-day control period. Climatic data on temperature, barometric pressure, humidity and precipitation for each participant's zip code, obtained from the National Oceanic and Atmospheric Administration, was then compared between hazard period and control period with adjustments made for alcohol consumption, purine intake and diuretic use.
Results indicated that high temperature and high humidity were strongly associated with increased risk of a recurrent gout attack. The risk of recurrent attacks increased by almost two-fold when the maximum daily temperature increased from 0-53° F to 87-105° F. A similar magnitude of increased risk also was found when the humidity increased from the dew point of 4-32°F to 64-77°F. Barometric pressure and precipitation appeared to have no influence.
"Our data indicate that both high temperature and high humidity are associated with an increased risk of recurrent gout attacks," explains Yuquing Zhang, D.Sc., Professor of Medicine and Epidemiology, Boston University School of Medicine; Boston, Massachusetts and an investigator in the study. "Thus, when it's hot and humid, those with gout should consider drinking more fluids to avoid potentially painful gout attacks."
Gout afflicts about 1 in 100 people and as many as 6 - 7 percent of older men. This condition and its complications occur more often in men, women after menopause, and people with kidney disease. Gout is strongly associated with obesity, hypertension, hyperlipidemia and diabetes. Because of genetic factors, gout tends to run in some families.