Giant cell arteritis in northwestern Spain: a 25-year epidemiologic study

Area of Science:

• Epidemiology
• Rheumatology
• Ophthalmology

Background:

• Giant cell arteritis (GCA) is a systemic vasculitis affecting large and medium-sized arteries, primarily in individuals over 50.
• Understanding GCA epidemiology is crucial for public health planning and resource allocation.
• Previous studies have indicated geographic variations in GCA incidence and clinical presentation.

Purpose of the Study:

• To investigate trends in the incidence of biopsy-proven GCA over a 25-year period (1981-2005) in Lugo, Spain.
• To identify any changes in the clinical spectrum of GCA, specifically focusing on visual manifestations.
• To analyze potential peaks, fluctuations, or seasonal patterns in GCA diagnosis.

Main Methods:

• Retrospective analysis of biopsy-proven GCA cases diagnosed in Lugo residents between 1981 and 2005.
• Calculation of age- and sex-adjusted annual incidence rates per 100,000 population (aged 50+).
• Statistical analysis to assess trends in incidence and clinical manifestations, including visual complications.

Main Results:

• A total of 255 biopsy-proven GCA cases were identified.
• The age- and sex-adjusted annual incidence rate was 10.13 per 100,000 population (50+).
• A progressive increase in GCA incidence was observed from 1981 through 2000 (p=0.001).
• No significant peaks or seasonal patterns in incidence were detected.
• Visual ischemic manifestations and irreversible visual loss occurred in 22.4% and 12.5% of patients, respectively.
• A significant negative trend was observed, with a decline in visual ischemic manifestations (p=0.021) and permanent visual loss (p=0.018) over the study period.

Conclusions:

• The incidence of biopsy-proven GCA has progressively increased in northwestern Spain.
• There has been a significant decline in the frequency of visual manifestations associated with GCA.
• These findings suggest a potential change in the clinical spectrum of GCA over the past 25 years.