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

Relationships between metabolic markers and obesity measures in two populations that differ in stature-The SAMINOR Study

Background

The relationships between metabolic markers and obesity measures may differ by ethnicity, sex, and height. Questions have been posed whether these relationships differ by ethnicity in the population in Northern Norway, but this has not been explored yet.

Objectives

Investigate the relationships between metabolic markers and obesity measures in Sami and non‐Sami and explore the impact of stature.

Methods

In total, 13 921 men and women aged 30 and 36 to 79 years (22.0% Sami) from a population‐based cross‐sectional survey in Norway, the SAMINOR 1 Survey (2003‐2004, 57.2% attendance), were included. Relationships between triglycerides, high‐density lipoprotein cholesterol, glucose, systolic/diastolic blood pressure (BP), metabolic syndrome and diabetes mellitus as outcomes, and body mass index (BMI), waist circumference (WC), and waist‐to‐height ratio (WHtR), respectively, were modelled using fractional polynomial regression. Appropriate interaction analyses and adjustments were made.

Results

The non‐Sami were approximately 6 cm taller than the Sami. No interactions were found between ethnicity and obesity. At the same levels of WC, BMI, or WHtR, levels of lipids and BP differed marginally between Sami and non‐Sami, but these were eliminated by height adjustment, with one exception: At any given WC, BMI, or WHtR, Sami had approximately 1.4 mmHg (95% CI, −2.1 to −0.7) lower systolic BP than non‐Sami (P values < .001).

Conclusions

Height explained the marginal ethnic differences in metabolic markers at the same level of obesity, except for systolic BP, which was lower in Sami than in non‐Sami at any given BMI, WC, or WHtR.

Dietary patterns of adults and their associations with Sami ethnicity, sociodemographic factors, and lifestyle factors in a rural multiethnic population of northern Norway - the SAMINOR 2 clinical survey

Background

Few population-based studies have assessed dietary behaviors in the rural multiethnic population of Northern Norway. The present study determined dietary patterns and investigated their association with Sami ethnicity, sociodemographic factors, and lifestyle factors in a multiethnic population in rural Northern Norway.

Methods

This cross-sectional study included 4504 participants of the SAMINOR 2 Clinical Survey (2012–2014) aged 40–69 years. All participants completed a lifestyle and food frequency questionnaire. Dietary patterns were determined using principal component analysis. Associations between food patterns and ethnicity, sociodemographic factors, and lifestyle factors were examined by multiple linear regression.

Results

Six dietary patterns were identified that accounted for 28% of the variability in food intake in the study sample: ‘processed meat/westernized’, ‘fish/traditional’, ‘fruit/vegetables’, ‘reindeer/traditional’, ‘bread and sandwich spreads’, and ‘sweets and bakery goods’. The ‘reindeer/traditional’ pattern was most common among the inland Sami population. The ‘fish/traditional’ pattern was most common among costal multiethnic Sami and least common among inland Sami and among women independent of ethnicity. The ‘fish/traditional’ pattern was also positively associated with older age, high education level, small household size, and smoking. Adherence to the ‘processed meat/westernized’ pattern was lower among inland Sami than inland/coastal non-Sami; no ethnic differences in adherence to this pattern were found between costal multiethnic Sami and inland/coastal non-Sami. Unhealthy lifestyle factors, like low physical activity level and smoking, and younger age were mainly associated with the ‘processed meat/westernized’ pattern, whereas socioeconomic factors like low education, low gross annual household income, and large household size were related to the ‘sweets and bakery goods’ pattern. Male gender, low education level, and smoking were associated with the ‘bread and sandwich spreads’ pattern. The ‘fruit/vegetables’ pattern was characterized by healthy dietary choices and a health-conscious lifestyle, and was more common in women with a high education level and income.

Conclusions

Adherence to the six identified dietary patterns was characterized by different sociodemographic and lifestyle factors. Ethnicity, in combination with geographical region of residence, was associated with dietary behaviors. This study provides knowledge that will be useful in future studies on dietary patterns related to chronic diseases in the rural population of Northern Norway.

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.

Change in prevalence and severity of metabolic syndrome in the Sami and non-Sami population in rural Northern Norway using a repeated cross-sectional population-based study design: the SAMINOR Study

OBJECTIVE

To examine the change in both the prevalence and severity of metabolic syndrome (MetS) in the Sami and non-Sami in Northern Norway due to a lack of knowledge regarding the development of MetS in this population.

DESIGN

Repeated cross-sectional study.

SETTING

The study is based on data from the SAMINOR 1 Survey (2003-2004, n=6550) and the SAMINOR 2 Clinical Survey (2012-2014, n=6004), conducted in 10 municipalities in Northern Norway.

PARTICIPANTS

Men and women aged 40-79 years were invited. We excluded participants not handing in the questionnaire and with missing information concerning ethnicity questions or MetS risk factors resulting in a final sample of 6308 (36.0% Sami) subjects in SAMINOR 1 and 5866 (40.9% Sami) subjects in SAMINOR 2.

OUTCOME MEASURES

MetS prevalence was determined using the harmonised Adult Treatment Panel III (ATP-III) criteria, and severity was assessed with the MetS severity Z-score. Generalised estimating equations with an interaction term (survey × ethnicity) were used to compare prevalence and severity between the two surveys while accounting for partly repeated measurements.

RESULTS

The overall, age-standardised ATP-III-MetS prevalence was 31.2% (95% CI: 29.8 to 32.6) in SAMINOR 1 and 35.6% (95% CI: 34.0 to 37.3) in SAMINOR 2. Both the ATP-III-MetS prevalence and the mean MetS severity Z-score increased between the surveys in all subgroups, except the ATP-III-MetS prevalence in non-Sami women, which remained stable. Over time, Sami men showed a slightly larger increase in MetS severity than non-Sami men (p<0.001): the score increased by 0.20 (95% CI: 0.14 to 0.25) and 0.06 (95% CI: 0.01 to 0.10) in Sami and non-Sami men, respectively. Abdominal obesity increased markedly between the surveys in all subgroups.

CONCLUSION

The prevalence and severity of MetS increased over time in rural Northern Norway. Abdominal obesity appeared to drive the increase in ATP-III-MetS prevalence. Sami men had a slightly larger increase in severity than non-Sami.