Estimated 8-year cumulative incidence of diabetes mellitus among Sami and non-Sami inhabitants of Northern Norway - The SAMINOR Study.

BACKGROUND: The aim of the study was to estimate and compare the 8-year cumulative incidence of diabetes mellitus (DM) among Sami and non-Sami inhabitants of rural districts in Northern Norway. METHODS: Longitudinal study based on linkage of two cross-sectional surveys, the SAMINOR 1 Survey (2003-2004) and the SAMINOR 2 Clinical Survey (2012-2014). Ten municipalities in rural Northern Norway were included in the study. DM-free participants aged 30 and 36-71 years in SAMINOR 1 were followed from 2 years after SAMINOR 1 to attendance in SAMINOR 2. The average follow-up time was 8.1 years. Of 5875 subjects who had participated in SAMINOR 1 and could potentially be followed to SAMINOR 2, 3303 were included in the final analysis. Self-reported DM and/or HbA1c ≥ 6.5% were used to identify incident cases of DM. RESULTS: At baseline, body mass index (BMI) and waist-to-height ratio (WHtR) were higher among Sami than among their non-Sami counterparts. After 8 years of follow-up, 201 incident cases of DM were identified (6.1% both Sami and non-Sami subjects). No statistically significant difference was observed in the cumulative incidence of DM between the Sami and non-Sami. CONCLUSIONS: No statistically significant difference in the 8-year cumulative incidence of DM among Sami and non-Sami was observed, although Sami men and women had higher baseline BMI and WHtR.

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).

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 article were restricted to participants aged 40-79 years in 10 municipalities in Northern Norway. 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, ie 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 (ie 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.

Prevalence of pre-diabetes and type 2 diabetes mellitus among Sami and non-Sami men and women in Northern Norway - The SAMINOR 2 Clinical Survey.

The aim of this study was to determine and compare the prevalence of pre-diabetes and type 2 diabetes mellitus (T2DM) among Sami and non-Sami men and women of rural districts in Northern Norway. The SAMINOR 2 Clinical Survey is a cross-sectional population-based study performed in 2012-2014 in 10 municipalities of Northern Norway. A total of 12,455 Sami and non-Sami inhabitants aged 40-79 years were invited to participate and 5878 were included in the analyses. Participants with self-reported T2DM and/or a glycated haemoglobin (HbA1c) result ≥6.5% were categorised as having T2DM. Those with 5.7%≤HbA1c<6.5% were categorised as pre-diabetics. In men, the total age-standardised prevalence of pre-diabetes (37.9% vs 31.4%) and T2DM (10.8% vs 9.5%) were higher in Sami compared with non-Sami; the ethnic difference was statistically significant for both pre-diabetes (OR 1.42, p < 0.001) and T2DM (OR 1.31, p = 0.042). In women, pre-diabetes (36.4% vs 33.5%) and T2DM (8.6% vs 7.0%) were also more common in Sami than non-Sami; the differences in both pre-diabetes (OR 1.20, p = 0.025) and T2DM (OR 1.38, p = 0.021) were also statistically significant. The observed ethnic difference in the waist-to-height ratio (WHtR) was a plausible explanation for the ethnic difference in the prevalence of pre-diabetes and T2DM.

Ethnic difference in the prevalence of pre-diabetes and diabetes mellitus in regions with Sami and non-Sami populations in Norway - the SAMINOR1 study.

OBJECTIVE: The aim of this study was to measure the prevalence of pre-diabetes and diabetes mellitus in rural populations of Norway, as well as to explore potential ethnic disparities with respect to dysglycaemia in Sami and non-Sami populations. DESIGN: Cross-sectional population-based study. METHODS: The SAMINOR1 study was performed in 2003-2004. The study took place in regions with both Sami and non-Sami populations and had a response rate of 60.9%. Information in the SAMINOR1 study was collected using two self-administered questionnaires, clinical examination and laboratory tests. The present analysis included 15,208 men and women aged 36-79 years from the SAMINOR1 study. RESULTS: Age-standardised prevalence of pre-diabetes and diabetes mellitus among Sami men was 3.4 and 5.5%, respectively. Corresponding values for non-Sami men were 3.3 and 4.6%. Age-standardised prevalence of pre-diabetes and diabetes mellitus for Sami women was 2.7 and 4.8%, respectively, while corresponding values for non-Sami women were 2.3 and 4.5%. Relative risk ratios for dysglycaemia among Sami participants compared with non-Sami participants were significantly different in different geographical regions, with the southern region having the highest prevalence of pre-diabetes and diabetes mellitus among Sami participants. CONCLUSION: We observed a heterogeneity in the prevalence of pre-diabetes and diabetes mellitus in different geographical regions both within and between different ethnic groups.