Researchers have discovered a gene mutation responsible for a common type of hypertension and a potential treatment for it. According to a study published in the journal Nature Genetics, a small benign nodule that occurs in around one in twenty people with hypertension is responsible for producing aldosterone, a hormone that regulates the amount of salt in the body. The gene mutation found in some of these nodules causes a massive, intermittent overproduction of aldosterone, making it difficult for clinicians to diagnose some hypertensive patients. The variation disrupts a protein known as CADM1, which prevents cells in the body from “talking” to one another and signalling that they should cease producing aldosterone. As a result, people with this gene mutation can go undetected until they receive blood testing at different times of the day, producing a variable release of aldosterone throughout the day, leading to salt overload and hypertension at its peak.
The researchers found that the key to curing this form of hypertension is unilateral adrenalectomy, the removal of one of the two adrenal glands. After the gland was removed, previously severe hypertension disappeared, requiring no treatment through several subsequent years of observation. According to the study, fewer than 1% of people with hypertension caused by aldosterone are identified because aldosterone is not routinely measured as a possible cause.
The initial patient in this study was detected by doctors who noticed a fluctuation in his hormone levels during his participation in a clinical trial of treatments for difficult hypertension. In most people with hypertension, the cause is unknown, and the condition typically requires life-long treatment with drugs. Previous research has found that between 5% to 10% of people with hypertension have a gene mutation in the adrenal glands that results in excessive amounts of aldosterone being produced.
According to Professor Morris Brown, co-senior author of the study and Professor of Endocrine Hypertension at Queen Mary University of London, “On the 900th anniversary of Barts Hospital, this story illustrates benefits from the virtuous circle of Science and Medicine. Most patients consent to our undertaking non-routine molecular analyses of their surgical samples, from which we discover how their hypertension was caused, and how to cure it in future patients.”
The researchers recommend measuring aldosterone through a 24-hour urine test instead of one-off blood measurements, which could lead to the discovery of more people living with hypertension but going undiagnosed. This study has important implications for the diagnosis and treatment of hypertension, which affects over 1 billion people worldwide.
Hypertension is a dangerous and widespread public health issue. Despite being a leading risk factor for heart disease and stroke, hypertension often goes undiagnosed until these conditions develop. In many cases, hypertension can be treated with medication, but adherence to these treatments can be challenging. The latest study highlights the importance of identifying the underlying cause of hypertension, which can lead to more effective treatments and avoidance of life-long medication. Further research will help to refine diagnostic procedures and identify alternative treatments for those with hypertension caused by aldosterone-producing nodules.
