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Objectives: To assess the distribution of blood lipids, lipoprotein and apoB/apoA-1 ratio in a multi-ethnic population of Sami, Kvens and Norwegians in Norway. Study design. A population-based cross-sectional study was carried out in 2003-2004 in an area with a mixed Sami, Kvens/Finns and Norwegian population, the SAMINOR study., Methods: A self-administrated questionnaire was distributed and total cholesterol, HDL cholesterol, triglycerides, apoB and apoA-1 counts were analysed in 6461 women and 5772 men between the ages of 36 and 79., Results: In 36-64 age group, Sami men and women had the highest apoB/apoA-1 ratio of the ethnic groups. The ethnic differences remained after adjustment for waist hip ratio, cigarette smoking, systolic and diastolic pressures, alcohol consumption, physical activity during leisure time and family history of myocardial infarction (MI). There were no significant ethnic differences in apoB/apoA-1 ratio in the older age group. Total cholesterol was significantly lower among Sami men and women, aged 65-79 years, than among the Norwegian. The opposite occurred in the 36-49 age group, with higher levels in the Sami population. We found no ethnic differences in HDL cholesterol and triglycerides., Conclusions: Middle-aged Sami women and men have increased levels of apoB/apoA-1 ratio and total cholesterol compared with Norwegians.

This study confirms a low frequency of multiple sclerosis (MS) among Sami. Only 12 Sami with a diagnosis of MS were identified in the Norwegian Sami population, which represents a significantly lower prevalence of MS in Sami (30/10(5)) compared with other Norwegians (73-164/10(5)). The clinical characteristics as well as the results of human leukocyte antigen (HLA)-DRB1 and -DQB1 typing of the Sami MS patients are reported, showing that three (27%) of the Sami MS patients carried the MS-associated HLA-DRB1*15-DQB1*06 haplotype. Interestingly, the DRB1*15-DQB1*06 haplotype had a significantly reduced frequency among Sami controls (0.086) compared with non-Sami Norwegian controls (0.163) (P(corrected) = 0.015). The low frequency of the disease-associated DRB1*15-DQB1*06 haplotype in the Sami population may contribute to the low prevalence of MS in Sami, in addition to other yet unidentified genetic and environmental factors.

Receptors for the Fc domain of IgG (Fc gammaR) play a critical role in linking cellular and humoral immunity. The various Fc gammaR genotypes may contribute to differences in infectious and immune-related diseases in various ethnic populations. The Samis are the aboriginal inhabitants of Norway and Fennoscandinavia and differ ethnically from the Norwegians. The distribution of various immune-related diseases has been reported to differ between Sami and Norwegians. This is the first study to evaluate the distribution of Fc gammaR polymorphisms in a Sami population. Two hundred Samis were genotyped for polymorphisms in the Fc gammaRIIA, Fc gammaRIIIA and Fc gammaRIIIB genes. The genotype and allele frequencies were compared with those of 272 healthy Norwegians. The Sami and Norwegian Fc gammaRIIA, Fc gammaRIIIA and Fc gammaRIIIB genotypes differed significantly. The Samis had higher frequencies of the Fc gammaRIIa-H/H131, Fc gammaRIIIa-F/F158 and Fc gammaRIIIb-NA1/NA1 genotypes. The Fc gammaR genotypes were non-randomly distributed in both populations. These findings may be important for the prevalence of autoimmune and infectious diseases in the two populations.

Thiopurine S-methyltransferase (TPMT) activity exhibits genetic polymorphism. The purpose of this investigation was to identify TPMT mutant alleles in the Saami population as a basis of developing genotyping tests for prediction of TPMT activity. The most predominant allele in Saamis (n = 194) was the TPMT*3C allele (A719G mutation) representing 92% of the mutant alleles, with an estimated allelic frequency of 3.3%. The most frequent allele in Caucasians (n = 66) living in the same geographic area was the TPMT*3A (A719G and G460A mutations) representing 91% of the mutant alleles, with an estimated allelic frequency of 3.4%. A test for one mutation, A719G, may prospectively identify more than 90% of the Saami individuals who require reduction in thiopurine dose to avoid hematopoietic toxicity. In a Norwegian population, comprising both the major Caucasian population and a minor Saami population, the same genotyping tests (eg, tests for the A719G and G460A mutations) may be used.

The Samis are an ethnic minority living in the Northern region of Norway, Sweden, Finland and Russia. Traditionally the Samis made their living from reindeer herding with some fishing and agriculture. Earlier studies have shown that their diet consisted of large amounts of reindeer meat, some fish and wild berries with low intakes of other fruits, vegetables and dairy products. Due to the introduction of technical improvements like snowmobiles and terrain vehicles which makes moving with the herd less necessary, their lifestyle has changed. There is little documentation how this has affected their dietary habits. In this study, the dietary pattern and nutrient intake of a group of Samis (n = 75) living in traditional reindeer herding areas of North Norway were investigated and compared with that of a group of Norwegians (n = 65). Dietary information was obtained through an interview by a nutritionist using the dietary history method. The findings indicate that nutrient content of the Sami diet is adequate except for folic acid. Calcium and iron intake was slightly below recommended levels for Sami females. There seems to be some difference between the diet of the Samis and Norwegians. The Samis consume more meat, fat, table sugar and coffee and less fruits and vegetables. The dietary pattern of the Samis seems, however, to be changing toward a more typically Norwegian diet.

The Finnmark Health Survey of 1987-88 showed that there was no significant difference in the prevalence of coronary heart disease between a Sámi population and a Norwegian population. Among men 40-59 years of age, a prevalence of myocardial infarction or angina pectoris or both, of 5.5%, was found both in Norwegians and in the predominantly Sámi population of Inner Finnmark. Among women, a prevalence of 3.1% and 3.3% was found among Norwegians and Sámis, respectively. The difference in results between males and females was less among Sámis than Norwegians, despite Sámi women having a lower risk factor level than Norwegian women. A clinical follow-up study done in 1992-93 showed no significant differences in serum lipid concentrations between the Sámi and the Norwegian population. Sámis had a lower familial occurrence of coronary heart disease than Norwegians. Waist to hip ratio was higher among Sámis than Norwegians.

The mitochondrial DNA of 62 Saami from the north of Norway was analyzed in the D loop hypervariable region I and II and sequences were compared to other gene pools. Two major (lineage 1 and 2) and two minor (lineage 3 and 4) maternal lineage clusters were found. Lineage 1 (56.9% of all hitherto analyzed Saami samples) contains a substantial number of branching haplotypes which are unknown in European gene pools. Lineage 2 (31.5%) and lineage 4 (3.6%) have few branching points and are present at a low rate throughout European gene pools. Lineage 3 (4.7%) has polymorphisms characteristic of circumpolar lineages.

A number of metabolic pathways are subject to both genetic polymorphism and interethnic differences. A catabolic pathway of 6-mercaptopurine, red blood cell (RBC) thiopurine methyltransferase (TPMT) activity showed genetic polymorphism in Caucasians, but variation according to ethnicity has not been studied. We investigated if red blood cell thiopurine methyltransferase was subject to interethnic variation in a Saami (Lappish; n = 36) and a Caucasian population (n = 50). The Saami population sample had 29% higher thiopurine methyltransferase activity, 17.0 +/- 3.3 U/ml red blood cell compared with the Caucasian population sample, 13.1 +/- 2.9 U/ml red blood cell (p much less than 0.001). Probit plots and frequency distribution histograms supported bimodality consistent with genetic polymorphism in both study populations. Differences in chronic diseases, drug consumption, age, or gender could not explain the interethnic difference in red blood cell thiopurine methyltransferase activity. The higher red blood cell thiopurine methyltransferase activity in the Saami population group indicates that these subjects may require higher dosages of thiopurine drugs than Caucasians.

This study investigated the relationship of serum selenium to its dietary sources in a group of Lappish men and a control population. Lappish men had higher serum selenium concentrations than non-Lappish men (1.79 vs 1.58 mumol/1; p = 0.003). Serum selenium correlated positively with consumption of reindeer meat, age and cholesterol. In linear regression models, however, being Lappish was the most significant predictor of high serum selenium. Lappish men ate more reindeer meat (p = 0.001) and less fish (p = 0.013) than men in the control group. Consumption of reindeer meat was also correlated with higher serum cholesterol levels. We conclude that high serum selenium concentrations in Lappish men may be important since low mortality from cancer is reported in this group.