Читать книгу Handbook of Diabetes - Rudy Bilous - Страница 68

A link between low birthweight and later development of type 2 diabetes in a UK population has led to a hypothesis linking foetal malnutrition to impaired β cell development and insulin resistance in adulthood. Abundant adult nutrition and consequent obesity would then expose these problems, leading to IGT and eventually type 2 diabetes. This has been called the thrifty phenotype hypothesis (Figure 7.15).

A meta‐analysis of 31 populations involving 152,084 individuals from varying ethnic groups and 6090 cases of diabetes was published in 2008. This confirmed a negative association between birthweight and diabetes in 23, but found a positive association in eight studies. The combined odds ratio for type 2 diabetes was 0.8 (95% CI 0.72–0.89) for each 1 kg increase in birthweight. This relationship was strengthened if macrosomic (birthweight >4 kg) and offspring of mothers with known type 2 diabetes were excluded (odds ratio (OR) 0.67, 95% CI 0.61–0.73). Notably there was a tendency for a positive relationship in North American populations largely due to higher rates of maternal obesity and gestational diabetes. Adjustment for socio‐economic status had no effect, but adjustment for achieved adult BMI attenuated the relationship.

With increasing maternal obesity and gestational diabetes mellitus (GDM), it is conceivable that the relationship will change to the pattern currently seen in Native Americans which is more U‐shaped. However, it is still unclear whether low birthweight is a causative factor or a sign of other potential mechanisms which may predispose to later diabetes.