Are clinical measures influenced by various ethnic origins in Iranian patients with ankylosing spondylitis?A pilot study.
BACKGROUND
Ankylosing spondylitis (AS) may manifest with heterogeneous patterns according to ethnic origins. The purpose of this study was to describe the influence of various Iranian ethnic origins on clinical measures in patients with AS.


METHODS
0ne hundred sixty-three AS patients diagnosed by modified New York 1984 criteria were enrolled consecutively. The patients were classified into Fars, Turk, Kord, Lor and other ethnic origins. Several clinical measures were described and compared between the ethnic origins.


RESULTS
The highest and the lowest finger to floor distance was observed for Fars ethnicity (20.4±14.8) and other ethnicities (5.9±8.1), respectively (P=0.04). The frequency of severe decrease in cervical slope was significantly different between various ethnicities (P=0.025). The most and the least frequency of severe decrease in cervical slope was observed in Fars patients (61.3%) and other ethnicities (20%), respectively. The frequency of severe thoracic kyphosis was significantly dissimilar between various ethnicities (P=0.006). The most and the least frequency of severe increase in thoracic kyphosis was observed in Fars (68.8%) and Lor patients (25%), respectively. A significant relationship was seen only between other ethnicities and finger to floor distance, lateral lumbar flexion, chest expansion and BASDAI (P<0.05).


CONCLUSIONS
Clinical expression variations in AS disease might be influenced by various Iranian ethnic origins. A larger sample size with other Iranian ethnicities (Baluch, Arab, etc) is required to clear the definite relationship between Iranian ethnicities and clinical expression.
Internal Medicine Division, Baharloo Hospital, Tehran University of Medical Sciences, International Campus (TUMS-IC),Tehran, Iran. ; Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Sasan
S
Fallahi
Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Ahmad Reza
AR
Jamshidi
Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Mahdi
M
Mahmoudi
Department of Public Health, Alborz University of Medical Sciences, Karaj, Iran. ; Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
Mostafa
M
Qorbani
Ankylosing spondylitis; Clinical features; Ethnicity; Iranian