Abstract:
Background: Several studies have suggested that abnormal glucose
metabolism, caused by the easy availability of calories and
an increasingly sedentary lifestyle, is a cause of infertility. Indeed,
specific foods have been shown to affect fertility by influencing related
signaling pathways. Excess insulin has been shown to induce
hormonal imbalances, which in turn can disrupt ovulation, egg quality,
and conception, and women exhibiting insulin resistance often
develop polycystic ovarian syndrome (PCOS). Similarly, a majority
of diabetic individuals also suffer from infertility. Recently, our understanding
of the relationship between glucose metabolism and
fertility has greatly improved.
Methods: The published literature was systematically reviewed for
case-controlled and cohort studies investigating infertility and glucose
metabolism. A meta-analysis was then performed on all studies
meeting well-defined selection criteria, as determined by two
independent reviewers. The studies were critically evaluated using
the Newcastle-Ottawa scale for non-randomized studies, before
data were pooled and analyzed.
Main findings: Twenty-one articles were included in the final analysis,
all of which provided the age, BMI, and ovulatory status of the
subjects. A significant association between impaired glucose metabolism
and infertility was observed. Additionally, impaired glucose
metabolism was significantly more likely to occur where subjects
were over 30 years of age, had a BMI of over 25 kg/m2, or had
metabolic syndrome. Impaired glucose metabolism was also associated
with PCOS and infertility in women.
Conclusion: We have systematically pooled the available evidence,
and we find a convincing causative link between altered
glucose metabolism and serious fertility complications.
