Low birth weight ups type 2 diabetes risk: study

People born with a low birth weight due to genetic factors may have an increased risk of developing type 2 diabetes, a new study has found.

Researchers from Tulane University in the US conducted the study on 3,627 type 2 diabetes cases and 12,974 controls of European ancestry. They created a genetic risk score (GRS) based on five low birth weight-related genetic variations known as single nucleotide polymorphisms (SNPs).

The analysis showed that for each one point increase in GRS (with the score ranging from 1-10), the risk of developing type 2 diabetes increased by six per cent, researchers said.

Using a statistical technique called Mendelian randomisation, they further found evidence that the low birth-weight was actually causing the excess risk in type 2 diabetes.

This type of analysis, is, researchers said, a new approach for establishing causal relationships in studies of this nature.

"Evidence from both population and experimental studies has suggested that restricted early life development has long-term structural and functional influence on individuals'



predisposition to an increased risk of metabolic diseases such as type 2 diabetes," researchers said.

"However, to our knowledge, this study is the first to investigate the potential causal relation between low birth-weight and risk of type 2 diabetes," they added.

Since low birth-weight represents restricted intrauterine growth (foetal growth), it cannot be ruled out that it is in fact the risk factors for this restricted growth that are causing the low birth-weight and in turn causing type 2 diabetes to develop, researchers said.

Risk factors for restricted intrauterine growth include malnutrition, anaemia, infections and placental insufficiency, they said. Researchers found that a genetically lowered birth weight was associated with increased susceptibility to type 2 diabetes.

Our findings support a potential causal relation between birth weight and risk of type 2 diabetes, providing novel evidence to support the role of intrauterine exposures in the pathogenesis of type 2 diabetes," researchers said.

The findings were published in the journal Diabetologia.