Introduction: A growing body of evidence is supporting a beneficial impact of breastfeeding on maternal metabolism and overall cardiovascular risk. The aim of this study was to evaluate the association between prolactin levels and metabolic parameters as well as indices of subclinical atherosclerosis, in a sample of premenopausal women with normal levels of prolactin.
Patients and Methods: This cross-sectional study included a total of 64 non-lactating premenopausal women. We evaluated anthropometric parameters and obtained blood samples for hormonal and biochemical assessments. Sonographical evaluation included indices of structural vascular disease (carotid intima media thickness, IMT) as well as pulse wave velocity (PWV).
Results: Lower levels of IMT were observed in cases with higher levels of prolactin (carotid IMT 5.87±0.78 mm vs 6.47±1.24 mm, P-value=0.023), an association that remained significant even after adjusting for age and BMI. Measures of PWV did not exhibit a significant difference between high vs low levels of prolactin; instead, we confirmed a direct linear independent association (PWV, b-coefficient=0.370, P-value=0.013) in a model adjusted for age, BMI, pulse pressure, HOMA-IR and lipids. Higher levels of prolactin were associated with lower levels of glucose (78.9±6.2 mg/dl vs 85.2±9.5 mg/dl, P-value=0.025), almost significantly lower values of HOMA-IR (1.17±0.29 vs 1.56±0.70, P-value=0.058). Women with prolactin levels in the 4th quartile vs 1st quartile presented with higher levels of HDL-cholesterol (69.0±11.8 mg/dl vs 60.13±9.80 mg/dL, P-value=0.027) and almost significantly lower levels of LDL-cholesterol (93.2±25.3 mg/dL vs 113.8±32.8 mg/dL, P-value=0.056).
Conclusions: High levels of prolactin within the normal range in non-lactating pre-menopausal women are associated with a beneficial impact on carotid IMT and an adverse effect on arterial stiffness. Moreover, higher levels of prolactin are also associated with improved levels of insulin resistance and blood lipids.
18 - 21 May 2019
European Society of Endocrinology