Winter 2024 - Vol. 19, No. 4 DIAGNOSING PRIMARY ALDOSTERONISM¹
In approximately 6% of cases of hypertension, primary aldosteronism is the underlying cause, yet only 2% of these patients are formally diagnosed. Case detection means testing patients with a first-degree relative with primary aldosteronism, resistant hypertension, hypokalemia, an adrenal nodule, atrial fibrillation, obstructive sleep apnea, or a family history of early cerebrovascular accident.

Testing involves using the aldosterone-renin ratio; ratios of >30 indicate independent aldosterone secretion (i.e., aldosteronism). Confirmatory testing should then be performed using either the captopril challenge, oral or intravenous salt loading, or fludrocortisone suppression; persistently high aldosterone levels yield the diagnosis.

Following these, adrenal computed tomography and adrenal vein sampling help differentiate unilateral from bilateral adrenal aldosterone production. Treatment of unilateral primary aldosteronism includes adrenalectomy; bilateral disease may be treated with mineralocorticoid receptor antagonists, such as spironolactone or eplerenone.

ENDOCRINE SOCIETY ADVISES AGAINST VITAMIN D TESTING
New Endocrine Society guidelines call for limiting vitamin D supplementation beyond the daily recommended intake to specific risk groups and advises against routine 25-hydroxyvitamin D [25(OH)D] testing in healthy individuals.

The guidelines are based on evidence presented in June at the Endocrine Society annual meeting and simultaneously published in the Journal of Clinical Endocrinology and Metabolism.² The evidence suggests that the following may benefit from vitamin D supplementation:

1. Children ages 1-18 years, to prevent rickets and potentially lower the risk for respiratory tract infections.
2. Pregnant people, to lower the risk for maternal and fetal or neonatal complications.
3. Adults older than 75 years, to lower the risk for mortality.
4. Adults with prediabetes, to lower the risk for type 2 diabetes.

In those groups, the recommendation is for daily, rather than intermittent, empiric vitamin D supplementation of more than what was recommended in 2011 by the National Academy of Medicine, then called the Institute of Medicine: 600 IU/d for those ages 1-70 years and 800 IU/d for those older than 70 years.

The Endocrine Society acknowledges that the optimal dose for these populations isn’t known. The guidelines recommend against testing for blood vitamin D levels in the general population, including those with obesity or darker complexions.

Those with established osteoporosis or osteopenia are not covered by this guideline, nor are patients with several diseases, such as chronic kidney disease or inflammatory bowel disease. There remain more questions than answers about who to test, who to supplement, and to what long-term benefit.

MOST ADULTS WITH HEART DISEASE CONSUME TOO MUCH SODIUM
Individuals with heart disease, on average, consume more than twice the recommended daily sodium intake, according to a study presented at the Annual Scientific Session of the American College of Cardiology (ACC) in April.

Current U.S. Department of Agriculture guidelines recommend that most adults limit their sodium intake to less than 2,300 mg/day; for individuals with cardiovascular disease, the limit is even lower at 1,500 mg/day, according to guideline recommendations from the ACC and the American Heart Association.

The study found that among a sample of more than 3,100 people with heart disease, 89% consumed more than the recommended daily maximum of 1,500 mg of sodium and, on average, study participants consumed more than twice this amount.

Researchers estimated sodium intake based on questionnaires in which participants were asked to report everything they had consumed in 24 hours, and study participants with cardiovascular disease consumed an average of 3,096 mg of sodium per day, compared to the national average of 3,400 mg/day reported by the Centers for Disease Control and Prevention. Socioeconomics, gender, race, nor age seemed to play a role in these outcomes.

Patients can lower their sodium intake by preparing more meals at home and reading food labels, keeping in mind that a serving of any food should have less than or equal to 140 mg of sodium.

Researchers further suggest continued and better education about the benefits of limiting sodium.

COMMON BLOOD PRESSURE DRUG MAY INCREASE RISK OF BLEEDING
People with an irregular heart rhythm taking diltiazem may be at a greater risk of serious bleeding, according to a recent study in JAMA.³

Atrial fibrillation, the most common type of irregular heart rhythm, can lead to blood clots or stroke if left untreated. To prevent complications, people with atrial fibrillation are often prescribed anti-clotting medications and medications to control heart rate.

The study reviewed health records from 2012 and 2020, looking at Medicare beneficiaries ages 65 years or older with atrial fibrillation who started taking apixaban or rivaroxaban in addition to their diltiazem or metoprolol. Patients receiving diltiazem were 20% more likely to experience bleeding-related hospitalization and death. Risks seemed to be increased in those taking higher doses of medications. There were no significant differences in rates of stroke, systemic embolism, or hemorrhaging.

These results are significant because they show that while there are some benefits to using diltiazem over metoprolol, and vice versa, differences in metabolism may introduce some increased risks of bleeding in those taking diltiazem.

The research group will continue to investigate what causes different reactions to the same medications and identify ways to potentially monitor drug levels. “Genetic differences can impact how different people metabolize medications,” said Eli Zimmerman, MD, a neurology professor at Northwestern Medicine and a co-author of the study.
 

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Originally published in the Winter 2012 issue of JLGH in conjunction with the American Board of Internal Medicine's now-complete Choosing Wisely campaign, this edited reprint is offered to remind physicians of the importance of talking with patients about what tests, treatments, and procedures are needed — and which ones are not.
 

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