A normally high circulating total prolactin concentration was associated with a lower type 2 diabetes (T2D) risk within 9–10 years of follow-up since blood draw in US women, according to a recent study. These findings are consistent with experimental evidence, suggesting that among healthy women, prolactin within the biologically normal range may play a protective role in the pathogenesis of T2D. Researchers analyzed the prospective relationship between circulating prolactin concentrations and T2D risk in the Nurses’ Health Study (NHS) and NHSII with up to 22 years of follow-up. Total plasma prolactin was measured using immunoassay in 8,615 women free of T2D and cardiovascular disease at baseline blood collection (NHS 1989–1990; NHSII 1996–1999) and a subset of 998 NHS women providing a second blood sample during 2000–2002. They found:
- A total of 699 incident T2D cases were documented during 156,140 person-years of follow-up.
- Total plasma prolactin levels were inversely associated with T2D risk; the multivariable HR comparing the highest with the lowest quartile was 0.73.
- The associations were similar by menopausal status and other risk factors.
Li J, Rice MS, Huang T, et al. Circulating prolactin concentrations and risk of type 2 diabetes in US women. [Published online ahead of print October 11, 2018]. Diabetologia. doi:10.1007/s00125-018-4733-9.