Prolactin Linked to Diastolic Dysfunction in Men With Type 2 Diabetes
Higher prolactin levels track with poorer diastolic function and worse heart failure severity among men diagnosed with type 2 diabetes, according to a cross-sectional analysis published online on October 21, 2026, in Endocrine Connections. Researchers found that this hormonal association exists in men but does not appear in women.
Led by Jesper Krogh of the Department of Medicine at Zealand University Hospital in Region Zealand, Denmark, the multicentre cohort study evaluated 937 patients with type 2 diabetes between 2011 and 2013. The participants had a mean age of 65.5 years, with men making up 66% of the cohort. The mean duration of diabetes among the studied group stood at 12.1 years.
Patient Evaluation and Hormone Measurement Methods
Investigators measured plasma prolactin levels using a two-step immunoassay. The established reference range spans 40 to 400 mIU/L in men and 35 to 600 mIU/L in women. Across the study population, median prolactin levels registered at 121 mIU/L in men and 126 mIU/L in women.
The primary outcome examined systolic function through left ventricular ejection fraction, analyzed as a continuous variable. Secondary outcomes included global longitudinal strain as an additional marker of left ventricular performance. Diastolic function was evaluated via lateral E/e′, where a value of 14 or higher signifies diastolic dysfunction. Researchers also utilized the New York Heart Association functional class, ranging from I to IV, to gauge heart failure severity, alongside tracking A1c levels and lipid profiles.
Statistical Associations in Male Patients
In the adjusted statistical model, each unit increase in the log-transformed prolactin level corresponded to an increase of 2.43 in E/e’ among men, with a 95% confidence interval of 0.9 to 3.9 and a significant P value of .001. Conversely, women showed no such statistical association, registering a P value of .13.
Higher prolactin concentrations also correlated positively with worse New York Heart Association functional classes in men, yielding a P value below .001. Male patients assigned to New York Heart Association class I showed a median prolactin level of 117 mIU/L. In contrast, men categorized under class III or IV exhibited a median prolactin level of 142 mIU/L. Female patients demonstrated no parallel trend, with a P value of .82.
Evaluated Markers Showing No Correlation
Prolactin levels demonstrated no association with left ventricular ejection fraction or global longitudinal strain in either male or female participants. The analysis uncovered no significant links between prolactin concentrations and A1c, low-density lipoprotein, high-density lipoprotein, or triglyceride levels in either sex.
The study findings call for intervention studies to support or reject a causal role for prolactin in diastolic dysfunction in patients with type 2 diabetes,
the authors wrote.
Potential Limitations and Study Design Constraints
The cross-sectional design of the investigation introduces the possibility of reverse causation. Researchers noted that despite multivariate adjustments, residual confounding cannot be completely excluded from the findings.
Plasma prolactin levels were captured through a single measurement per patient. Investigators acknowledged that acute stress experienced during the evaluation period may have influenced individual hormone values. Funding for the study was provided by Skibsreder Per Henriksen, R og Hustrus Fond, and the authors reported no relevant conflicts of interest.
Frequently Asked Questions About Prolactin and Diabetes
What was the primary finding regarding men with type 2 diabetes?
Researchers found that higher prolactin levels were associated with poorer diastolic function, marked by an increase in E/e’, and a worse New York Heart Association functional class in men.
Did female participants show the same cardiac associations?
No, women with type 2 diabetes showed no significant association between prolactin levels and diastolic function or heart failure severity.
How were prolactin levels measured in the cohort?
Plasma prolactin was evaluated using a two-step immunoassay, yielding median levels of 121 mIU/L in men and 126 mIU/L in women.
What factors showed no link to prolactin concentrations?
Prolactin showed no association with systolic function, left ventricular ejection fraction, global longitudinal strain, A1c levels, or lipid profiles in either sex.