Increased Risk of Type 2 Diabetes Among Elderly Twins.

Fetal growth restriction is more common in twins as compared to singletons because of their shared uterine environment. In addition, monozygotic (MZ) twins have a different and potentially more adverse fetal environment compared to dizygotic (DZ) twins. According to the "fetal origin hypothesis" MZ twins may be more prone to develop various metabolic abnormalities as compared to DZ twins, and twins more at risk of metabolic impairments compared to singletons. In a cohort of non-diabetic elderly twins and singletons, we have indeed demonstrated that monozygosity is associated with reduced insulin sensitivity, and that twins have increased hepatic glucose production compared to singletons. In the present population-based study we examined 298 same-sex MZ and DZ twins and 71 singleton controls (all aged 62-83 yrs) with anthropometric measures and an oral glucose tolerance test (OGTT). Data are presented as mean (SE). Twins were more abdominal obese with higher waist/hip ratio (MZ: 0.92 (0.01), DZ: 0.89 (0.01), C: 0.86 (0.01), p=0.0002), more glucose intolerant as determined by HbA1c (%) (MZ: 6.0 (0.1), DZ: 5.8 (0.1), C: 5.6 (0.0), p=0.0005) and 120 min OGTT plasma glucose (mmol/l) (MZ: 8.6 (0.5), DZ: 8.4 (0.3), C: 6.8 (0.3), p=0.0002) and insulin resistant as determined by fasting plasma insulin (pmol/1) (MZ: 52.1 (3.9), DZ: 48.3 (2.1), C: 41.3 (2.5), p=0.03 and HOMA IR index (MZ: 2.1 (0.2), DZ: 1.8 (0.1), C: 1.5 (0.1), p=0.02) as compared to singletons. Importantly, the prevalence of T2D was significantly higher in twins as compared to controls (MZ: 17.5% (CI 14.4-20.6), DZ: 15.7% (CI 13.1-18.3), C: 5.6% (CI 3.0-8.2), p=0.03). In conclusion, twin status is evidently associated to an increased risk of T2D with elderly twins exhibiting a higher degree of abdominal obesity, glucose intolerance and insulin resistance and most importantly a higher prevalence of T2D as compared to singletons. [ABSTRACT FROM AUTHOR]