Declining hemoglobin levels may serve as a marker for disease duration in male macroprolactinoma: a proof-of-concept retrospective study

Y. Rudman*^a (Dr), H. Duskin-Bitan^a (Dr), I. Richter^a (Dr), G. Tsvetov^a (Dr), H. Masri-Iraqi^a (Dr), A. Akirov^a (Prof), I. Shimon^a (Prof)

^a Rabin Medical Center, Petah-Tikva, ISRAEL

* rudman.yaron@gmail.com

Introduction:

Men harboring macroprolactinoma frequently suffer from central hypogonadism and secondary anemia.

We hypothesized that a decrease in hemoglobin (HB) levels prior to prolactinoma diagnosis, in otherwise healthy male patients with macroprolactinoma, may signal the appearance of hyperprolactinemia and estimate disease duration.

Materials and Methods:

We retrospectively evaluated the pre-diagnosis HB curves (HB measurements over time) of 106 male patients with macroprolactinoma.

Men without hypogonadism, patients that received testosterone treatment prior to diagnosis, patients with other causes of anemia, and those with insufficient data were excluded. The HB curve was regarded “informative” if the patient had 2 previous normal (“baseline”) HB measurements that were at least 1.0 g/dL above the HB measured later, at diagnosis.

Patient’s demographic, clinical and biochemical parameters, sellar MRI and visual fields were obtained.

Results:

Out of 106 patients, 91 men (86%) presented with hypogonadism, and 55 men (52%) had HB levels lower than 13.5 g/dL at diagnosis.

We identified 18 male patients with “informative” HB curves (median follow-up of 14.3 years). These 18 men (age, 45.2±14.7 years) presented with a mean prolactin of 1545±1615 ng/mL, mean total testosterone levels of 1.2±0.8 ng/mL, and adenoma diameter of 22.7±9.6 mm.
The median low HB duration (from the first below-baseline HB measurement to hyperprolactinemia diagnosis) was 5.4 years (IQR, 2.7-8.9).
The mean HB decrement from pre-diagnosis baseline (14.5±0.3 g/dL) to diagnosis nadir (13.0±0.6 g/dL) was 1.5±0.5 g/dL.
We found no correlation between low HB duration and baseline prolactin levels, testosterone levels or adenoma size. We discovered a correlation between low HB duration and patient-reported sexual dysfunction duration (N=11, Pearson’s R=0.63, p=0.04).

Discussion:

Over 50% of male patients with macroprolactinoma exhibit low HB levels at diagnosis. In our cohort of otherwise healthy men with macroprolactinoma and hypogonadism, we found a marked decrease in Hb levels that preceded prolactinoma diagnosis by a median of 5.4 years.
We found that pre-diagnosis low HB duration correlated well with patient-reported sexual dysfunction duration.
These results support our hypothesis that pre-diagnosis low HB duration may serve as a marker for disease duration in a subset of hypogonadal male patients diagnosed with macroprolactinoma.

The author has declared no conflict of interest.