Metabolic Syndrome and Prostate Cancer Risk

Metabolic syndrome refers to a cluster of conditions that occur together. The exact definition and criteria for diagnosing metabolic syndrome may vary slightly, but it typically includes a combination of the following factors:

• Central obesity

Excess fat in the abdominal area, often measured by waist circumference. The World Health Organization defines central obesity in men as equal or more than 94 cm. However, this threshold may vary based on different populations and regions. For example, clinicians in the US may use the threshold of 102 cm, according to the National Cholesterol Education Program Adult Treatment Panel III.

• High blood pressure (hypertension)

Blood pressure equal to or greater than 130/85 mmHg or the use of blood pressure medication.

• High blood sugar (hyperglycemia)

Fasting blood sugar (glucose) level equal to or greater than 100 mg/dL or the use of diabetes medication.

• High triglycerides

Triglyceride levels equal to or greater than 150 mg/dL or the use of medication to lower triglycerides.

• Low high-density lipoprotein (HDL) cholesterol

HDL cholesterol levels less than 40 mg/dL in men or less than 50 mg/dL in women, or the use of medication to increase HDL cholesterol.

The presence of metabolic syndrome indicates an increased risk of developing certain diseases such as cardiovascular disease. Some studies have also shown a potential association between metabolic syndrome and prostate cancer although there is contradicting data in other studies. Currently, the relationship between metabolic syndrome and prostate cancer remains controversial.

Some studies on central obesity have found that it can be associated with advanced prostate cancer. However, more research is still needed to understand the mechanisms of how central obesity may affect prostate cancer risk, to be able to make clinical recommendations.

Learn more: Obesity and Prostate Cancer Risk

While there have been inconsistent findings across most studies regarding the association of hypertension and prostate cancer development, there are some studies that support this relation. Hypertension is closely linked to inflammation and inflammation has been known to be a biological mechanism that contributes to cancer development.

Unlike other conditions, hyperglycemia and diabetes tend to be inversely related to prostate cancer risk. The natural progress of persistently high blood glucose levels is an initial elevation of insulin levels, insulin resistance and then a decrease in insulin as the pancreas produces less insulin. As insulin receptors tend to be more abundant on prostate cancer cells, abnormally low insulin levels are linked to a slower prostate cancer growth, suggesting a protective factor of diabetes. However, this remains controversial due to possible detection biases such as lower prostate-specific antigen (PSA) levels in diabetic men who are less likely to be identified through PSA screening, resulting in a lower incidence rate in this group.

High triglycerides may be a potential risk factor for prostate cancer. However, studies regarding this have shown varying results, with some finding positive associations while others finding no association between the two. This may be due to confounding factors such as diabetes. The protective effects of low insulin levels may obscure the actual impacts of hypertriglyceridemia on prostate cancer risk. Other common factors, such as obesity, may also impact hypertriglyceridemia as a risk factor.

Higher HDL cholesterol has been linked to lower prostate cancer risk overall. It is hypothesized that cholesterol tends to accumulate in prostate cancer cells, increasing cell signaling that promotes carcinogenesis. A main function of HDL cholesterol is to transport cholesterol from the cells to the livers and other organs. Therefore, it is suggested that it is through this mechanism that higher HDL levels are linked to a lower prostate cancer risk. HDL also hinders oxidation and inflammation, which may also reduce prostate cancer risk. However, a study showed that HDL cholesterol induced proliferation of certain prostate cancer cells. As such, the relationship between HDL cholesterol and prostate cancer risk remains complicated.

Studies that explored the relationship between metabolic syndrome and prostate cancer have produced varying results. Some studies report that metabolic syndrome increases prostate cancer risk while others report that it decreases prostate cancer risk or has no relationship between the two. A recent meta-analysis showed that metabolic syndrome increased the incidence of high-grade prostate cancer but had no significant effect on overall prostate cancer incidence. Other studies report an association but with varying factors such as race and region. As such, more research is needed to determine the impacts of individual metabolic factors and as a group as metabolic syndrome on prostate cancer risk. Beyond this, one should note that metabolic syndrome is an important risk factor for cardiovascular disease.

If you have prostate cancer and metabolic syndrome, your treatment plan would need to account for the risks of metabolic syndrome as well.