Chronic alcoholism and associated magnesium and potassium deficiencies may cause a condition, called pseudo-Cushing’s syndrome, a recent case report from Japan shows.
The research, “Hypokalemia associated with pseudo-Cushing’s syndrome and magnesium deficiency induced by chronic alcohol abuse,” was published in the journal CEN Case Reports.
Chronic alcoholism is often associated with hypokalemia and hypomagnesemia, which means low blood levels of potassium and magnesium, respectively. One frequent finding in patients with hypokalemia is increased concentration of potassium in the urine, which may be induced by magnesium deficiency.
The research team presented the case of a 63-year-old man with potassium and magnesium deficiency associated with pseudo-Cushing’s syndrome caused by chronic alcoholism. Of note, pseudo-CS refers to individuals with laboratory and physical manifestations similar to Cushing’s syndrome (CS), but whose hormonal imbalance is not caused by problems in the hypothalamic-pituitary-adrenal axis.
The patient first came to the hospital with recurrent potassium deficiency during episodes of muscle weakness, a condition known as hypokalemic periodic paralysis. The patient also revealed blood magnesium deficiency, undetectable urinary magnesium, and sodium levels on the upper limit of the normal range.
The patient then received potassium infusions for 16 days, which improved his deficiency. However, the levels decreased again to the initial values at seven days after stopping infusions. Conversely, excretion of potassium in his urine increased.
Physical examinations revealed features related to CS, including muscle weakness or mild abdominal obesity, but no moon face or “buffalo hump” behind the neck, which are other typical CS characteristics.
He had been drinking alcohol excessively for more than 40 years and suffered from occasional diarrhea. He ate limited amounts of soy products, seafood, and seaweed, which are sources of magnesium and potassium.
Besides the deficient levels of potassium associated with muscle weakness, the patient also received treatment for hypertension and for excessive blood levels of uric acid. Besides the chronic alcoholism, he also had been a heavy smoker for four decades.
As in CS, the patient’s urine cortisol and adrenocorticotropin (ACTH) levels were higher than normal. These alterations could not be corrected with dexamethasone, a corticosteroid. He was diagnosed with ACTH-dependent CS, though an imaging test revealed no evidence of pituitary adenoma (tumor).
The clinicians hypothesized that his high cortisol levels promoted the magnesium deficiency-induced excessive urine levels of potassium. This led to a treatment regimen with daily infusions of magnesium and potassium (both 20 mmol/day), which improved the blood potassium level, as well as measurements of kidney transport and excretion of potassium nine days later.
Magnesium infusions were then stopped with no change in the restored potassium levels and the patient was discharged. He then received weekly infusions of magnesium (20 mmol/day) for five months, which maintained blood potassium within the normal range.
Because the clinicians thought the excessive alcohol consumption led to the high cortisol levels, they limited alcohol intake to 20 grams (about seven ounces) per day after discharge. After six months, examinations revealed normal urinary cortisol level, as well as improved ACTH values. The patient’s blood pressure was under control and his muscle weakness and abdominal obesity had disappeared.
“The reduction of alcohol intake appeared to have restored deranged cortisol regulation and we made a diagnosis of pseudo-[CS] due to chronic alcohol abuse,” the researchers wrote.
Magnesium infusions were stopped. The patient’s blood potassium level remained normal over another five months. However, he then increased his alcohol consumption to pre-treatment levels, which deteriorated the potassium level. Finally, one month infusion with magnesium (20 mmol/week) improved the patient’s potassium deficiency again.
Overall, “it is necessary to consider alcohol-induced pseudo-[CS] in patients with chronic alcoholism who have clinical features associated with [CS],” the investigators considered.
However, the potential contribution of lifestyle factors, such as alcohol abuse or low intake of potassium, rather than a pseudo-CS condition, cannot be discarded as the primary cause of deficient levels of magnesium and potassium, they observed.