Heritability and familiality of type 2 diabetes and related quantitative traits in the Botnia Study

Abstract

Aims/hypothesis To study the heritability and familiality of type 2 diabetes and related quantitative traits in families from the Botnia Study in Finland. Methods Heritability estimates for type 2 diabetes adjusted for sex, age and BMI are provided for different age groups of type 2 diabetes and for 34 clinical and metabolic traits in 5,810 individuals from 942 families using a variance component model (SOLAR). In addition, family means of these traits and their distribution across families are calculated. Results The strongest heritability for type 2 diabetes was seen in patients with age at onset 35-60 years (h 2 =0.69). However, In contrast, physical activity showed rather low heritability (0.16-0.18), whereas smoking showed strong heritability (0.57-0.59). Family means of these traits differed two-to fivefold between families belonging to the lowest and highest quartile of the trait (p<0.00001). Conclusions/interpretation To detect stronger genetic effects in type 2 diabetes, it seems reasonable to restrict inclusion of patients to those with age at onset 35-60 years. Sequencing of families with extreme quantitative traits could be an important next step in the dissection of the genetics of type 2 diabetes.

Association between the Interleukin‐6 Gene −572 C/G Polymorphism and the Risk of Type 2 Diabetes Mellitus: A Meta‐Analysis of 11,681 Subjects

“…T2DM is a complex disease with various involved factors (Mathias et al, 2009). Previous studies have reported that the preva-lence rates of T2DM vary substantially throughout the world (International Diabetes Federation, 2012), and relatives of T2DM patients are at greater risk for developing the disease than the general population (Newman et al, 1987;Mathias et al, 2009;Almgren et al, 2011). Newman et al found that 58% of monozygotic co-twins of diabetic twins were themselves diabetic compared with an expected prevalence of 10% (Newman et al, 1987).…”

The Correlation between LDL-C and Non-HDL-C Levels and Cardiovascular Events in Patients with Metabolic Syndrome

“…In current study we ascertained that the weakest factors of Cardiovascular morbidity were decreased level of HDL-C and also type 2 diabetes. In the Botnia Study [33] which was a large family study of subjects with type 2 diabetes and their relatives in western Finland, the presence of the metabolic syndrome was associated with a 6-fold increase in CVD mortality during the 6.9-year follow-up [34]. In persons with MetS who do not have diabetes, increased risks of CVD and CHD mortality remain.…”

Many ways to die, one way to arrive: how selection acts through pregnancy

“…Given the inverse correlation between traditional consumption of dietary components increasing GDM risk and current incidence of GDM, high glycemic foods and dairy may have acted as selective agents on metabolism during pregnancy. Since GDM is very likely to have a genetic basis --67% of the risk of type 2 diabetes for adults younger than 60 is heritable [38], and women with GDM have 7--12x elevated risk for type 2 diabetes [39,40] --natural selection can act on its underlying risk factors. Therefore, any population environmentally at risk for GDM without access to C--sections should experience selection against genetic risk factors for GDM.…”