Pregnancy-associated plasma protein-A tied to third-trimester insulin sensitivity

Early concentrations of pregnancy-associated plasma protein-A were linked to third-trimester insulin sensitivity, gestational diabetes and hypertension, according to researchers in the United Kingdom.

“A number of studies have found associations between reduced circulating [pregnancy-associated plasma protein-A] concentrations in early pregnancy and the subsequent development of gestational diabetes, although these are not uniform occurrences,” Clive J. Petry, PhD, of the department of pediatrics at the University of Cambridge, and colleagues wrote. “Where such associations have been found, studies have tended not to investigate mechanisms that may be underpinning these associations.”

Petry and colleagues collected serum samples from 821 women enrolled in the Cambridge Baby Growth Study, an ongoing prospective longitudinal study. All women participated in the study between 2001 and 2009. The researchers compared serum samples collected at week 15 of pregnancy with results from oral glucose tolerance tests at week 28.

Increased concentrations of pregnancy-associated plasma protein-A were associated with a lower risk for gestational diabetes, the researchers reported (OR = 0.623; P = 3.5 x 10^-3), as well as a reduction in mean arterial blood pressures (β = -0.202 to -0.177; P = 1.7-6.9 x 10^-3). Petry and colleagues also reported a negative association between pregnancy-associated plasma protein-A and both week 28 fasting glucose concentrations (β = -0.149; P = 6.6 x 10^-4) and 60-minute glucose concentrations (β = -0.188; P = 1.5 x 10^-5).

There were strong associations between increased pregnancy-associated protein-A at week 15 and decreased insulin resistance at week 28, the researchers wrote (HOMA IR: β = -0.319; P = 1.7 x 10^-13). Increased pregnancy-associated protein-A concentrations were also linked to increased insulin secretion relative to insulin sensitivity (P = 6.5 x 10^-6).

“In summary, we confirmed associations between circulating [pregnancy-associated plasma protein-A] concentrations in week 15 of pregnancy and the future development of [gestational diabetes] and high blood pressure,” the researchers wrote. “Underpinning these associations was an even stronger association with insulin sensitivity… Further studies on the effect of [insulin-like growth factors] on insulin sensitivity in pregnancy would therefore appear warranted.” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosures.