International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Northern Epidemiology

OBJECTIVES: Giant Cell Arteritis (GCA) has predilection for certain racial and northern geographic distributions. In the U.S. most patients with GCA share northern European ancestry, with low incidence in Hispanics and Asians. Contrarily, Alaska Natives share similar susceptibilities to genetically-influenced diseases with their Pacific Rim neighbors. We surveyed the Alaska Native population for GCA incidence.

STUDY DESIGN: Retrospective review.

METHODS: All Alaska Natives are served exclusively by a network of affiliated hospitals which has maintained a computerized diagnostic database for the last twenty years. Retrospective review of medical diagnostic codes for GCA, temporal artery biopsy and acute anterior ischemic optic neuropathy was done for biopsy-proven GCA.

RESULTS: A total of 3 patients had positive biopsies out of twenty biopsies that were performed on Alaska Natives in 20 years. All presented with new onset headache and other systemic complaints and had elevated Westergren sedimentation rates. There were two women and one man. The average age was 71. Only one patient presented with visual symptoms and lost vision. Patients responded well to standard therapy. All have subsequently died from causes unrelated to GCA. These cases all came from coastal areas of Alaska where intermarriage with people of European ancestry was common. No cases were found from more isolated central and northern population centers. The calculated incidence of GCA in Alaska Natives is 1/100,000 in those over 50 years old. The 15% positive biopsy rate in our survey is typical for other surveys done for GCA, indicating a routine degree of clinical suspicion for the disease.

CONCLUSION: This is the first widespread, long-term study of a native American population for the incidence of GCA. The results indicate that GCA is essentially nonexistent in genetically-isolated Alaska Natives, but does occur in more diverse coastal populations with greater intermarriage. The low incidencee of GCA in Alaska Natives is similar to that reported for Japan and other Pacific Rim countries, which share a common genetic heritage; it contrasts with the high incidence reported for European countries of similar northern latitudes. The calculated incidence of 1/100,000 in those over 50 years is similar to that of Asian populations.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)