Breast cancer risk doubles with calcium channel blockers for hypertension
Breast cancer risk assessment must take into consideration chronic inflammation, which comes to the fore in light of a study just published in JAMA Internal Medicine (formerly Archives of Internal Medicine) offering evidence that use use of calcium channel blockers double the risk for breast cancer. The authors observe:
"Antihypertensive agents are the most commonly prescribed class of medications in the United States. Evidence regarding the relationship between different types of antihypertensives and breast cancer risk is sparse and inconsistent..."
So they investigated different types of blood pressure medication for an association with invasive breast cancers among a group of 2,763 postmenopausal women in the Seattle area. Their data for the risk of invasive ductal and invasive lobular breast cancers shows a strong link to calcium-channel blockers:
"Current use of calcium-channel blockers for 10 or more years was associated with higher risks of ductal breast cancer (odds ratio [OR], 2.4; 95% CI, 1.2-4.9) and lobular breast cancer (OR, 2.6; 95% CI, 1.3-5.3). This relationship did not vary appreciably by type of calcium-channel blocker used (short-acting vs long-acting, dihydropyridines vs non-dihydropyridines). In contrast, use of diuretics, β-blockers, and angiotensin II antagonists were not associated with risk."
That's a 240% and 260% (more than double) increase in risk for ductal and lobular breast cancer respectively.Clinical note: Neuromuscular excitability, including innervation of the smooth muscles that line the arteries, is controlled by the balance of calcium and magnesium ions. Hyperexcitability results with an excess of calcium in relation to magnesium can result in vasoconstriction that increases blood pressure. Calcium-channel blockers diminish the effect of calcium on the blood vessel but without increasing the relative deficit of magnesium ('nature's calcium-channel blocker' and one of the most common deficiencies). Magnesium also supports the parasympathetic nervous system's anti-inflammatory effect. A number of studies have associated suboptimal magnesium with chronic inflammation, and the link between the increased risk factor for cardiovascular disease with calcium supplementation is thought to be associated with calcium's opposition to magnesium. It would be prudent to not only avoid calcium-channel blockers in the treatment of hypertensive postmenopausal women, but to carefully assess them for evidence of suboptimal magnesium levels.