Original Research

The prevalence of diabetes mellitus among Sami and non-Sami inhabitants of Northern Norway – the SAMINOR 1 Survey (2003–2004) and the SAMINOR 2 Clinical Survey (2012–2014)

AUTHORS

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Ali Naseribafrouei
1 MD, PhD student in epidemiology., PhD student *

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Bent-Martin Eliassen
2 PhD, Postdoctoral fellow, Postdoctoral fellow

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Marita Melhus
3 Master of Science, senior engineer, Master of Science, senior engineer

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Johan Svartberg
4 MD, PhD, Head of division and professor

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Ann Ragnhild Broderstad
5 MD, PhD, MD, PhD, Academic director

AFFILIATIONS

1, 2, 3 Centre for Sami Health Research, Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromso, Norway

4 Division of Internal Medicine, University Hospital of North Norway, Tromso, Norway; and Tromso Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromso, Norway

5 Centre for Sami Health Research, Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromso, Norway; and Department of Medicine, University Hospital of Northern Norway, Harstad, Norway

ACCEPTED: 16 October 2018


early abstract:

Introduction:This study aimed to compare the prevalence of diabetes mellitus (DM) between Sami and non-Sami inhabitants of Northern Norway participating in the SAMINOR 1 Survey and the SAMINOR 2 Clinical Survey, and to track DM prevalence over time.

Methods:SAMINOR 1 (2003–2004) and SAMINOR 2 (2012–2014) are cross-sectional, population-based studies that each recruited Sami and non-Sami inhabitants. The data used in this paper were restricted to participants aged 40–79 years in 10 municipalities in NorthernNorway. Participants completed self-administered questionnaires and underwent clinical examination and blood sampling. Both questionnaire information and non-fasting/random plasma glucose levels were used to ascertain DM. The study included 6288 and 5765 participants with complete data on DM and outcomes, i.e., 54.6% and 46.3% of the invited samples, respectively.

Results:No difference in the prevalence of DM between Sami and non-Sami participants was observed, in either survey. Women had a statistically significantly lower DM prevalence than men in SAMINOR 2. Mean waist-to-height ratio and waist circumference increased substantially in both sexes; mean body mass index increased only slightly in men and remained unchanged in women. The total, age-standardized DM prevalence in SAMINOR 1 and 2 was 10.0% (95% confidence interval [CI]: 9.2–10.7) and 11.2% (95% CI: 10.4–12.0), respectively, and the proportion of self-reported (i.e., known) DM increased from 49.2% to 73.0%. In almost the same time span (2004–2015), the use of oral glucose-lowering agents increased.

Conclusion:Overall, no ethnic difference was observed in DM prevalence. Overall DM prevalence was high, but did not change significantly from SAMINOR 1 to SAMINOR 2. The percentage of known versus unknown cases of DM increased, as did the prescription of medication for DM between 2004 and 2015.