Growth differences between North American and European children at risk for type 1 diabetes

AIM: To evaluate the relationships between early growth and regional variations in type 1 diabetes (T1D) incidence in an international cohort of children with familial and genetic risk for T1D. METHODS: Anthropometric indices between birth to 5 yr of age were compared among regions and T1D proband in 2160 children participating in the Trial to Reduce Insulin-dependent diabetes mellitus in the Genetically at Risk study. RESULTS: Children in Northern Europe had the highest weight z-score between birth to 12 months of age, while those in Southern Europe and U.S.A. had the lowest weight and length/height z-scores at most time points (p < 0.005 to p < 0.001). Few differences in z-score values for weight, height, and body mass index were found by maternal T1D status. Using International Obesity Task Force criteria, the obesity rates generally increased with age and at 5 yr were highest in males in Northern Europe (6.0%) and in females in Canada (12.8%). However, no statistically significance difference was found by geographic region. In Canada, the obesity rate for female children of mothers with and without T1D differed significantly at 4 and 5 yr (6.0 vs. 0.0% and 21.3 vs. 1.9%, respectively; p < 0.0125) but no differences by maternal T1D status were found in other regions. CONCLUSIONS: There are regional differences in early childhood growth that are consistent with the higher incidence of T1D in Northern Europe and Canada as compared to Southern Europe. Our prospective study from birth will allow evaluation of relationships between growth and the emerging development of autoimmunity and progression to T1D by region in this at-risk population of childre

Improved environmental status : 50 years of declining fish mercury levels in boreal and subarctic Fennoscandia

Temporally (1965–2015) and spatially (55°–70°N) extensive records of total mercury (Hg) in freshwater fish showed consistent declines in boreal and subarctic Fennoscandia. The database contains 54 560 fish entries (n: pike > perch ≫ brown trout > roach ≈ Arctic charr) from 3132 lakes across Sweden, Finland, Norway, and Russian Murmansk area. 74% of the lakes did not meet the 0.5 ppm limit to protect human health. However, after 2000 only 25% of the lakes exceeded this level, indicating improved environmental status. In lakes where local pollution sources were identified, pike and perch Hg concentrations were significantly higher between 1965 and 1990 compared to values after 1995, likely an effect of implemented reduction measures. In lakes where Hg originated from long-range transboundary air pollution (LRTAP), consistent Hg declines (3–7‰ per year) were found for perch and pike in both boreal and subarctic Fennoscandia, suggesting common environmental controls. Hg in perch and pike in LRTAP lakes showed minimal declines with latitude, suggesting that drivers affected by temperature, such as growth dilution, counteracted Hg loading and food web exposure. We recommend that future fish Hg monitoring sampling design should include repeated sampling and collection of pollution history, water chemistry, fish age, and stable isotopes to enable evaluation of emission reduction policies

Two insulin gene single nucleotide polymorphisms associated with type 1 diabetes risk in the Finnish and Swedish populations

We have developed high-throughput tests for the detection of the insulin gene region SNPs -23HphI and -2221MspI. The potential of these markers to enhance the efficiency of type I diabetes risk screening was then evaluated by analyzing them in Finnish and Swedish populations. Blood spots on filter paper were analyzed using PCR followed by sequence- specific hybridization and time-resolved fluorometry reading. Distribution of the genotypes at both positions differed significantly among the affected children compared to the controls. The risk genotypes (CC, AA) were significantly more common in Finland than in Sweden, both among patients and controls. The VNTR genotype homozygous for the protective class III alleles showed a significantly stronger protective effect than the heterozygote (p = 0.02). Analyzing both SNPs enabled the detection of VNTR class III subclasses IIIA and IIIB. The observed significance between effects of the protective genotypes was due to the strong protective effect of the IIIA/IIIA genotype. IIIA/IlIA was the only genotype with significant discrepancy between protective effects compared to the other class III genotypes. These observations suggest that heterogeneity between the protective IDDM2 lineages could exist, and analyzing both -23HphI and -2221MspI would thus potentially enhance the sensitivity and specificity of type I diabetes risk estimation