The prevalence of childhood obesity and type 2 diabetes is a growing public health problem, so researchers in Japan sought to explore how maternal hyperglycaemia exposure during pregnancy is linked to obesity and abnormal glucose tolerance in offspring, and at which age these conditions develop.
They reviewed 20 observational studies — involving a total of 26,509 children — on the incidence of obesity and diabetes in the offspring of both non-diabetic and diabetic women, including pregnant women with gestational, type 1 and type 2 diabetes.
Diabetic type differences
They found that children born of mothers with gestational diabetes had higher BMI z-scores in childhood, while those whose mothers had type 1 diabetes had higher BMI z-scores in from pre-puberty to adolescence.
In addition, children of mothers with gestational diabetes had higher two-hour plasma glucose levels from pre-puberty to early adulthood, and those born to mothers with type 1 diabetes tended to face a higher incidence of type 2 diabetes from the time they were two to five years old until they reached early adulthood.
However, after adjusting for pre-pregnancy maternal BMI, this association was observed only in children of mothers with type 1 diabetes but not those whose mothers had gestational diabetes.
The researchers noted that among the studies reviewed, only one focused on the children of mothers with type 2 diabetes, and so evidence in this regard was scant.
Better design needed
They added that while "exposure to maternal hyperglycaemia was associated with offspring obesity and abnormal glucose tolerance", particularly in children whose mothers had type 1 diabetes, the evidence largely depended on observational studies that provided a "low quality of evidence".
They further stated that the possible association between maternal hyperglycaemia exposure during pregnancy, and obesity and abnormal glucose tolerance in offspring relies on the duration and intensity of intrauterine exposure to hyperglycaemia.
In conclusion, they wrote: "As for offspring of mothers with type 2 diabetes, we have to assess the actual status.
"To explore a causal relationship, well-designed prospective trials that consider the genetic background, timing and strength of intrauterine exposure to hyperglycaemia, other related factors, and long-term results are warranted."
Source: PLOS ONE
"Obesity and abnormal glucose tolerance in offspring of diabetic mothers: A systematic review and meta-analysis"
Authors: Maki Kawasaki, et al.