Ethnic differences in the prevalence of general and central obesity among the Sami and Norwegian populations: The SAMINOR study

Aims: To estimate the prevalence of general (body mass index) and central (waist circumference and waist/hip ratio) obesity in an area with a mixed Sami and Norwegian population. Methods: A cross-sectional population-based study carried out in 2003 2004, the SAMINOR study. The attendance rate was 60.6%. A total of 7,301 men and 7,841 women, aged 36-79, were included in the analyses. Height, weight, waist and hip circumference were measured, body mass index (BMI) calculated and information concerning lifestyle was collected by questionnaire. Results: The prevalence of general obesity (BMI >= 30 kg/m(2)) in participants who had Sami as their home language for three generations (Sami I) and Norwegian participants was 38.7% and 24.3% for women respectively; and for men 26.9% and 23.4% respectively. More than 40% of the women had central obesity (waist circumference >= 88 cm), and the highest prevalence was found in Sami I women (45%). The highest prevalence of central obesity (waist circumference >= 102 cm) was found in Norwegian men (24.2%). The ethnic differences persisted after adjustment for age, education, physical activity in leisure time, and smoking habits. Conclusions: The prevalence of obesity was high in this population and central obesity was most pronounced in women, particularly in Sami women. Sami men were less obese than Norwegian men. Further studies are necessary to examine a possible explanation for these findings, especially to elaborate on the impact of diet.