Prostate enlargement is often considered a condition that is inevitable with aging. Abundant evidence, however, indicates that it is rather another consequence of Insulin Resistance.
BPH is increasingly common with age
Benign Prostatic Hypertrophy (BPH) is a non-cancerous enlargement of the prostate gland that can lead to difficulties with urination, classically resulting in frequent nighttime urination, increased urinary frequency, urinary hesitancy, weak urine stream, and incomplete bladder emptying.
BPH is the most common non-malignant condition of the prostate in men. Among men over the age of 50 years, about 60% of them have evidence of BPH, and for men over the age of 70 years, that increases to 80%.
What causes BPH?
While BPH is certainly
more common with age, there is clearly more to the story than just aging. Much research has focused on testosterone as a potential cause, however it now appears that testosterone plays only a permissive role – it is necessary for, but not sufficient for, the development of prostatic enlargement. (ref) Men castrated before puberty who do not receive androgen supplementation never develop BPH, indicating that testosterone is indeed a necessary factor. However, despite decreasing testosterone levels with age, prostates continue to increase in size. That finding suggests that there are other factors responsible for the prostatic enlargement.
Epidemiologic data indicates a higher incidence of BPH in those with the following conditions, all of which are markers of insulin resistance:
- Metabolic Syndrome (ref)
- Abdominal obesity (ref)
- Increased insulin levels (ref, ref, ref, ref)
- Increased fasting glucose levels (ref, ref, ref)
- Diabetes (ref, ref)
- Low HDL cholesterol (ref, ref)
How does Insulin contribute to BPH?
Insulin is an anabolic (growth promoting) hormone. Insulin resistance is a state of decreased response to the effects of insulin, necessitating higher levels of insulin to achieve the same effect.
There are many postulated theories regarding the mechanisms behind insulin resistance and prostate enlargement. (ref, ref)
- Increased sympathetic tone
- Insulin stimulation of tissue growth
- Altered sex hormone expression
- Induction of inflammation and oxidative stress
Even without a diagnosis of diabetes, insulin resistance consistently appears to be an independent risk factor for BPH. (ref)
Supportive evidence
- The higher the insulin level, the faster the growth rate of the prostate. (ref, ref)
- Hyperinsulinemia causes enlargement of the prostate in rats. (ref)
- Furthermore, when a low insulin state is created by a toxin targeting the insulin-producing cells of the pancreas, the pancreas undergoes a dramatic decrease in size. (ref)
Prostate cancer
There are several lines of evidence indicating a role of insulin in the development of prostate cancer. (ref) From a clinical standpoint, high insulin levels are associated with increased mortality from prostate cancer, as well as treatment failure. Metabolic Syndrome, another name for the syndrome of insulin resistance, is associated with shorter survival from prostate cancer.
Summary
Prostate enlargement is not an inevitable complication of aging. Rather, it is another manifestation (another symptom) of insulin resistance. Despite no strong evidence of causation, there is consistent data linking BPH with multiple markers of insulin resistance.
