Sami patients in northern Norway experience longer symptoms duration before psoriatic arthritis diagnosis and have more axial involvement.

OBJECTIVES

To compare Sami and non-Sami patients with PsA in northern Norway, where both the human antigen HLA-B27 and psoriasis are prevalent, particularly among the Sami population.

METHODS

A total of 536 adult PsA patients were recruited from the Norwegian Arthritis Registry and hospitals in northern Norway. All participants met the Classification Criteria for Psoriatic Arthritis. A questionnaire from the SAMINOR (a study in regions with Sami and Norwegian populations) was used to identify Sami and non-Sami patients. Demographic, clinical and laboratory parameters were compared between these groups. Binary logistic regression was used to adjust for age and gender differences.

RESULTS

The 60 Sami and 476 non-Sami patients identified were comparable in demographic characteristics and disease activity measurements. Sami patients experienced a longer duration of symptoms before diagnosis compared with non-Sami patients (4 years 2 years,  = 0.045), with a more pronounced delay among Sami men (5 years 1 year,  = 0.003). Sami men also had higher scores for back and/or pelvis pain (42 mm 31 mm,  = 0.034). Axial involvement was more frequent among Sami than non-Sami patients (30% 18%,  = 0.029), even after adjusting for gender and age (odds ratio 1.91,  = 0.041). Among patients with axial involvement, HLA-B27 was positive in 47.1% of Sami patients compared with 37% of non-Sami patients ( = 0.461).

CONCLUSIONS

Sami patients face longer symptom durations before diagnosis and more frequent axial involvement than non-Sami patients. Sami men also report higher back/pelvic pain levels, though no differences between the cohorts in demographics or disease activity were observed.