MedicalResearch.com Interview with:
Paras Karmacharya, MD
Internal Medicine Reading Health System
West Reading, PA 19611
Co-Authors: Ranjan Pathak MD, Madan Raj Aryal MD,
Smith Giri MD, Anthony A Donato MD MHPE
Medical Research: What is the background for this study?
Studies describing seasonal variations in acute gouty arthritis note a seasonal trend, but disagree on timing, with most showing a peak in spring months while others showing peaks later in the year. However, serum uric acid (SUA) levels seem to peak in the summer months. This disparity has led to the hypothesis that the flares might be related to factors other than elevated serum uric acid levels. Various theories on the effects of weather and immune system changes on the chronobiology of the equilibrium and precipitation of monosodium urate crystals have been proposed. We aimed to shed light on this question by examining the seasonal variation in the incidence of acute gouty arthritis in the US using a large inpatient database.
Medical Research: What are the main findings?
We used the Nationwide Inpatient Sample (NIS) database, a large national database that represents 20% of all hospital admissions, to identify adult patients with a primary diagnosis of acute gouty arthritis from 2009-2011 during their hospitalization. A total of 28,172 hospitalizations with primary diagnosis of acute gouty arthritis were reported from 2009-11. The peak incidence of acute gout was seen in the month of November (peak/low ratio 1.34, 95% CI 1.29-1.38, p<0.05) (Figure 1). The highest number of hospitalizations was observed in autumn months, while the lowest incidence was observed in spring (28.12% vs. 23.13%, p<0.001).
Medical Research: What should clinicians and patients take away from your report?
Unlike previous studies, our analysis found the peak incidence of acute gout in the fall with its peak in the month of November. Various environmental (temperature, humidity, diet, physical activity) and biochemical factors (low cortisol levels, high absolute neutrophil counts and plasminogen activator inhibitor-1) have been implicated for the seasonal variation, but the data on this is conflicting. Whether our findings are reflective of purine and alcohol intake over the US holidays in November and December is a hypothesis that requires further testing.