To investigate glucose regulation in young adults with very low birth weight (VLBW; <1500 g) in an Asian population.
Cross-sectional observational study.
A general hospital in Hamamatsu, Japan.
111 young adults (42 men and 69 women; aged 19–30 years) born with VLBW between 1980 and 1990. Participants underwent standard 75 g oral glucose tolerance test (OGTT).
Primary and secondary outcome measures
The primary outcomes were glucose and insulin levels during OGTT and risk factors for a category of hyperglycaemia defined as follows: diabetes mellitus, impaired glucose tolerance (IGT), impaired fasting glycaemia (IFG) and non-diabetes/IGT/IFG with elevated 1 h glucose levels (>8.6 mmol/l). The secondary outcomes were the pancreatic β cell function (insulinogenic index and homeostasis model of assessment for beta cell (HOMA-β)) and insulin resistance (homeostasis model of assessment for insulin resistance (HOMA-IR)).
Of 111 young adults with VLBW, 21 subjects (19%) had hyperglycaemia: one had type 2 diabetes, six had IGT, one had IFG and 13 had non-diabetes/IGT/IFG with elevated 1 h glucose levels. In logistic regression analysis, male gender was an independent risk factor associated with hyperglycaemia (OR 3.34, 95% CI 1.08 to 10.3, p=0.036). Male subjects had significantly higher levels of glucose and lower levels of insulin during OGTT than female subjects (p<0.001 for glucose and p=0.005 for insulin by repeated measures analysis of variance). Pancreatic β cell function was lower in men (insulinogenic index: p=0.002; HOMA-β: p=0.001), although no gender difference was found in insulin resistance (HOMA-IR: p=0.477). In male subjects, logistic regression analysis showed that small for gestational age was an independent risk factor associated with hyperglycaemia (OR 33.3, 95% CI 1.67 to 662.6, p=0.022).
19% of individuals with VLBW already had hyperglycaemia in young adulthood, and male gender was a significant independent risk factor of hyperglycaemia. In male young adults with VLBW, small for gestational age was associated with hyperglycaemia.
Neonatal intensive care has improved the survival rate for very low birth weight infants (VLBW; birth weight <1500 g) in recent decades, and the first generation of VLBW infants have only recently reached young adulthood.
Only a few studies have shown that VLBW (or preterm) is associated with glucose intolerance in Caucasian young adults, while glucose regulation in Asian young adults with VLBW is still uncertain.
The present study investigated glucose regulation in young adults with VLBW in an Asian population and determined the factors associated with hyperglycaemia.
Of 111 young adults with VLBW, 19% of individuals already had hyperglycaemia (type 2 diabetes, impaired glucose tolerance (IGT), impaired fasting glycaemia (IFG) and non-diabetes/IGT/IFG with elevated 1 h glucose levels).
Male gender was a significant independent risk factor of hyperglycaemia in young adults with VLBW.
Small for gestational age was associated with hyperglycaemia particularly in male young adults with VLBW.
Strengths and limitations of this study
This is the first study assessing the glucose regulation in young adults with VLBW in an Asian population.
This study does not provide information on postnatal growth patterns, which have been shown to be associated with later hyperglycaemia in previous studies.
The study design with no control subjects makes it impossible to address the delayed impact of VLBW itself on glucose regulation.