Cushing’s syndrome alters red blood cell profile, large study shows
Hemoglobin, hematocrit levels could be remission predictors
People with Cushing’s syndrome, marked by high levels of cortisol, had altered red blood cell profiles at diagnosis, according to a study of nearly 400 patients and 2,000 matched controls.
Among those with Cushing’s disease, a subtype of the syndrome, remission was more likely to occur in people with lower pre-treatment levels of hemoglobin, the protein that carries oxygen in red blood cells.
The study, “Impact of etiology, sex, diabetes mellitus and remission status on erythrocytic profile in patients with cushing’s syndrome: a large population database study,” was published in Pituitary.
Cushing’s syndrome is a group of conditions marked by prolonged exposure to cortisol, a stress hormone produced by the adrenal glands located above the kidneys. Common symptoms can include weight gain, round face, skin changes, muscle weakness, and extreme fatigue.
Cushing’s disease is a subtype of the syndrome in which non-cancerous tumors in the brain’s pituitary gland release adrenocorticotropic hormone (ACTH), signaling the overproduction of cortisol by the adrenal glands. Adrenal gland tumors can also release too much cortisol.
Blood cell profile changes seen in Cushing’s syndrome
Beyond the well-known signs and symptoms, Cushing’s syndrome has been associated with changes in blood cells, such as low or high counts of red and/or white blood cells.
To learn more, a team led by researchers at Tel Aviv University in Israel examined the red blood cell profiles of 397 Cushing’s syndrome patients alongside 1.970 control individuals matched by age, sex, body mass index, and socioeconomic status.
Among the evaluable patients, roughly half had Cushing’s disease (55.3%), and less than half had adrenal Cushing’s (44.7%). At diagnosis, Cushing’s patients had significantly higher rates of diabetes, high blood pressure, altered blood fats, cardiovascular disease, and chronic kidney disease.
Baseline values were calculated as a mean of test results during the year before Cushing’s syndrome diagnosis. Remission was defined as a normalization of 24-hour urinary-free cortisol following treatment, such as surgery to remove pituitary or adrenal tumors and/or medications.
Baseline blood tests revealed Cushing’s patients had significantly higher median levels of hemoglobin and hematocrit, the percentage by volume of red cells in the blood. The mean corpuscular volume, or the average volume of individual red blood cells, was also significantly higher in patients at diagnosis than controls.
Half of those with Cushing’s disease (50.3%) and the majority of adrenal Cushing’s patients (67.1%) achieved remission within one year of diagnosis.
Among those who achieved remission, hemoglobin and hematocrit levels at baseline and one year after diagnosis were generally lower than those in patients with persistent disease. Data were similar for both sexes.
Baseline predictors
Significant differences in baseline values were only seen among Cushing’s disease patients who achieved remission. In contrast, baseline values did not differ in patients with adrenal Cushing’s as a function of remission status.
“Baseline levels of hemoglobin and hematocrit could potentially act as predictors for remission in [Cushing’s disease],” the researchers wrote.
Although most Cushing’s syndrome patients with co-existing diabetes had hemoglobin levels similar to controls, their hematocrit values were significantly higher. Even so, those without diabetes still had elevated hemoglobin and hematocrit than controls. Lastly, men, but not women, with Cushing’s and diabetes who were anemic, or had low levels of hemoglobin, had a tendency towards lower urinary cortisol.
“Patients with [Cushing’s syndrome] of both pituitary and adrenal origins have elevations in hemoglobin and hematocrit,” the researchers wrote. “Interestingly, we also found that patients with [Cushing’s disease] who had lower baseline hemoglobin were more likely to attain remission.”
The researchers added that future studies “are indicated to corroborate our findings and explore changes in hemoglobin and hematocrit as potential predictors and/or markers for remission.”
About the Author
