CYP11B2 produces the hormone aldosterone, which helps conserve sodium. Through its effect on sodium, aldosterone can affect blood pressure. Also, when dysfunctional, aldosterone can contribute to the development of heart disease. That is why some CYP11B2 gene variants are associated with elevated blood pressure and heart disease risk. In this post, you will find out more about gene variants and factors that increase or decrease CYP11B2 activity.
What is CYP11B2?
This enzyme is also called aldosterone synthase (because it produces aldosterone). It is one of the cytochrome P450 monooxygenases (CYPs) [1].
CYPs eliminate toxins and drugs from the human body. However, some, like C YP11B2, are not involved in detoxification but in steroid hormone production.
Read more about different CYPs here.
Function
This enzyme produces the hormone aldosterone [2, 3]. Aldosterone helps our bodies conserve sodium and maintain blood pressure [4].
It also metabolizes steroid-based drugs spironolactone, canrenone [5], and methandienone [6].
Location
This enzyme is found in the adrenal glands [7].
The Good
This enzyme is important for maintaining aldosterone levels. Aldosterone, in turn, maintains sodium and potassium in balance and helps maintain blood pH levels.
Aldosterone deficiency due to CYP11B2 mutations can cause excessive sodium release and potassium retention, resulting in hyponatremia (low sodium), hyperkalemia (high potassium), and metabolic acidosis, which can be fatal [8].
CYP11B2 also helps maintain blood pressure.
Milder enzyme deficiency is associated with postural hypotension (low blood pressure upon standing) in adulthood [8].
The Bad
Higher enzyme activity can result in the overproduction of aldosterone.
High levels of aldosterone lead to high blood pressure (hypertension) and increase the risk of heart disease [9].
Gene Polymorphism
There are over twenty CYP11B2 gene variants [9].
Some variants increase, while others decrease aldosterone production.
RS1799998
rs1799998 (C) occurs in about 30% of African Americans and 46% of Europeans. This variant increases aldosterone levels [10].
It is associated with high blood pressure (hypertension) (479 subjects; 810 subjects; 471 subjects; meta-analysis, 29 studies, 8482 cases, and 8560 controls) [3, 4, 11, 12].
This variant is further associated with atrial fibrillation (irregular heartbeat) (meta-analysis, 11 studies, 1629 cases, and 2284 controls) [13] and increases heart disease risk in Whites and Asians (meta-analysis, 5 studies, 3687 subjects) [14].
It may also increase the risk of stroke (meta-analysis, 7 studies, 2765 cases, and 3118 controls) [15].
rs1799998 C may contribute to kidney disease (nephropathy) (meta-analysis, 5 studies, 825 cases and 910 controls) [16].
In addition, the C variant was also associated with higher BMI (290 subjects) [17].
Men with this variant are more prone to metabolic syndrome (802 couples, 640 subjects) [18, 19].
Having two Cs (C/C) contributes to an age-dependent increase in CRP, an indicator of chronic inflammation (398 subjects) [20].
C/C female carriers accumulate more fat and may be more prone to obesity (1386 subjects) [21].
On the other hand, T/T increases the risk of recurrent brain ischemia (low brain oxygen) by 1.98-fold (208 patients) [22].
The T variant and lower aldosterone levels are more often found in Himalayan people. They may help natives cope with lower oxygen levels (662 subjects) [23].
Increasing or Decreasing CYP11B2
These increase CYP11B2:
- Polychlorinated biphenyls (PCBs) [24]
- High-density lipoprotein (HDL) [7]
- Angiotensin and potassium [7]
