New research shows that in patients with benign prostatic hyperplasia, elevated aldosterone levels may relate to lower vitamin D levels.
Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate gland that may block the flow of urine through the urethra. The precise cause of BPH is not yet fully known. About 90% of men aged 80 years and older have BPH.
Aldosterone is a steroid hormone secreted by the adrenal gland that acts on the kidneys to increase the reabsorption of ions and water. This increases blood volume, which leads to an increase in blood pressure. It is part of the renin-angiotensin system (RAS), which is a hormone system that regulates blood pressure and fluid balance. Overproduction of aldosterone is thought to be involved in the pathogenesis of BPH.
Vitamin D has recently been identified as a regulator of the RAS. Since the prostate gland is part of the RAS, and dysfunction of the RAS is implicated in the disease process of BPH, researchers hypothesize that low vitamin D levels may contribute to risk of BPH and elevated aldosterone levels through its role in RAS regulation.
Previous epidemiological studies show an association between BPH and vitamin D deficiency. However, epidemiological studies are greatly affected by confounding variables that limit the impact of their results.
This led researchers out of Turkey to conduct a case-control study to reduce the number of confounders and lend more evidence to the case for a causal role of vitamin D in BPH.
They compared the vitamin D and aldosterone levels of 25 BPH patients with 30 volunteer healthy controls.
They then gave each participant a general questionnaire that included questions about age, socioeconomic status, origin of ancestors, physical activity status, smoking, alcohol consumption and detailed medical history. This was done to control for any extraneous variables that may have affected the results of the previous epidemiological studies.
After controlling for confounding variables, the researchers’ analyses revealed:
- Aldosterone levels were significantly higher in BPH patients than in the control group.
- Vitamin D levels were significantly lower in patients with BPH (13.2 ng/ml) compared to healthy controls (17.3 ng/ml).
- Median vitamin D levels in both groups were lower than the limit used to designate vitamin D sufficiency (20 ng/ml).
These findings confirm results from epidemiological studies.
This study prevents a novel finding of high aldosterone levels in conjunction with low vitamin D levels in individuals with BPH. There is likely a link between vitamin D deficiency and overproduction of aldosterone. Vitamin D levels have been found to be inversely associated with levels of another hormone in the RAS called renin. An increase in renin concentrations ultimately leads to an increase in aldosterone levels.
This study is limited by its observational design which means that we can’t know for sure if vitamin D plays a role in regulating aldosterone levels.
Future research should include large cohort studies that follow participants for long periods of time to determine vitamin D’s role in chronically elevated aldosterone levels and the development of BPH. It will then be important to conduct randomized controlled trials to see if vitamin D has an effect on BPH and aldosterone levels.