Friday, November 9, 2018

‘Eye Health’ Supplements

To help clinicians guide patients, this article provides a practical overview on three of the most common ocular conditions for which supplements and dietary factors may play a role.

Macular Degeneration – The Age-Related Eye Disease Study (AREDS) and the Age-Related Eye Disease Study 2 (AREDS2) are two of the largest and most rigorous clinical trials that have investigated the effects of nutritional supplementation on the progression dry age-related macular degeneration (AMD) to wet AMD. Observational trial also have assessed the impact of diet and supplements on the development and progression of AMD.

Results - Patients without AMD did not benefit from taking the AREDS formulation. Patients with mild or borderline AMD did not benefit from taking either the AREDS or AREDS2 formulation. Both formulations slightly lowered the risk for AMD progression in those patients with intermediate or advanced AMD. Patient who smoke should take the AREDS2 formulation to avoid the beta-carotene in the AREDS formulation, which can increase the risk for lung cancer. Lutein, zeaxanthin, and omega-3 fatty acids were included in the AREDS2 formulation but did not decrease the risk for AMD progression. The Blue Mountains Eye Study found that the consumption of vegetables and dietary lutein and zeaxanthin was associated with a reduced risk for AMD. Patients with intermediate or advanced AMD should be encouraged to take the AREDS or AREDS2 formulation as a nutritional supplement. Smoking is a risk factor for the development and progression of AMD and should be discouraged. Physical activity should be encouraged, as it has been demonstrated to have a modest protective effect. A diet consisting of fish, fruits, leafy greens, and nuts has been shown to be beneficial in some studies.

Wednesday, November 7, 2018

Wisdom Wednesday: Levothyroxine

Up to 7% of the general population has hypothyroidism, which is corrected with thyroid hormone treatment. The general goals of thyroid hormone replacement are to provide resolution of patient symptoms and hypothyroid signs, including biological and physiologic markers of hypothyroidism; achieve normalization of serum thyroid-stimulating hormone (TSH) concentrations with improvement in circulating thyroid hormone concentrations; and avoid overtreatment (eg, iatrogenic thyrotoxicosis), especially in elderly persons.

Levothyroxine, a synthetically made thyroxine (T4), is the predominant form of thyroid hormone replacement used on patients with hypothyroidism. In healthy and iodine-sufficient individuals, the majority of thyroid hormone produced is T4, synthesized exclusively by the thyroid gland, with a smaller amount of T3, which is produced by the thyroid and in peripheral tissues via diodination of the circulating T4.

In the setting of fluctuating T4 levels, deiodinase activity is tightly regulated to maintain normal T3 levels at the various target tissues. In hypothyroidism, the 5’ deiodinase is activated to allow greater conversion of T4 to the bioactive form of thyroid hormone, T3.
Given the high prevalence of hypothyroidism in the general population, levothyroxine has consistently been the most frequently prescribed medication in the United States over the past several years. In 2016, approximately 123 million prescriptions for levothyroxine were dispensed.

Monday, November 5, 2018

Common Blood Pressure Drugs Tied to Increased Lung Cancer Risk

Angiotensin-converting-enzyme (ACE) inhibitors are associated with increased lung cancer risk compared with angiotensin-receptor blockers (ARBs), an observational study in The BMJ suggests.

Using a U.K. primary care database, researchers identified over 900,000 adults who began treatment with a new antihypertensive drug class from 1995 through 2015. Those with histories of cancer were excluded.

During a mean 6 years' follow-up, lung cancer was diagnosed in 0.8% of the cohort. After adjustment for smoking and other confounders, ACE inhibitor use was associated with significantly increased lung cancer risk relative to ARB use (1.6 vs. 1.2 per 1000 person-years). The increased risk didn't appear until after 5 years of ACE inhibitor use, and then increased with increasing duration of use.

The authors note that ACE inhibitors lead to accumulation of bradykinin in the lungs, which "may directly stimulate growth of lung cancer." An editorialist, meanwhile, concludes, "In an individual patient, concerns about the long term risk of lung cancer should be balanced against gains in life expectancy associated with use of [ACE inhibitors]."

My Take:
ACE inhibitors are one of the three antihypertensive medications I mentioned in last Friday’s blog. Remember that I also mentioned that these drugs cause fluid retention in the lungs and legs (congestive heart failure). Bradykinin is a peptide produced in the kidneys that causes vasodilatation thus lowering blood pressure. When the body is in homeostasis, bradykinin is short lived. However, ACE inhibitors cause this peptide to build up in the lungs, along with the edema, where it acts as a carcinogen.

Friday, November 2, 2018

Study Questions Whether Treating Mild Hypertension Benefits Patients

For low-risk patients with mild hypertension, starting antihypertensive drug treatment might not reduce mortality, according to a JAMA Internal Medicine study. The American College of Cardiology and American Heart Association currently recommend that all patients with systolic blood pressure at or above 140 mm Hg or diastolic BP at or above 90 mm Hg receive antihypertensive therapy.

Using U.K. electronic medical records, researchers matched 19,000 adults with mild hypertension (140/90-159/99 mm Hg) and low cardiovascular risk who received antihypertensive medication to another 19,000 who weren't treated. During a median 6 years' follow-up, rates of mortality and cardiovascular disease were similar between the groups. Antihypertensive treatment was, however, associated with higher risk for hypotension, syncope, electrolyte abnormalities, and acute kidney injury.

My Take:
The controversy over treating borderline hypertension escalated when the two organizations noted above reduced the systolic and diastolic levels at which medication should be prescribed. They recommended a full cardiac workup for these patients as well.

Mild hypertension responses well to simple lifestyle changes – exercise, weight loss, and healthier eating habits. Supplementation of vitamin B2 and B3, magnesium or Co Q10 can also be effective. Sometimes something as simple as increasing the quality or quantity of sleep will lower BP to normal levels.

Hypertension medication is a slippery slope. It is, in fact, how most people begin taking prescription medication. Once it starts, it rarely stops and additional medications soon follow.

Wednesday, October 31, 2018

Wisdom Wednesday: ‘Good’ Cholesterol Might Be Bad Too

HDL cholesterol may be known as the “good” kind, but a new study suggests high levels of it are not always a good thing for women after menopause.

The study, of nearly 1,400 postmenopausal women, found that those with higher HDL levels were more likely to show “plaques” in their carotid arteries. Those arteries supply blood to the brain, and plaque buildup there signals an increased risk of both stroke and heart disease.

“We used to think, the higher the better,” said Dr. Karol Watson, director of the Women’s Heart Health Program at the University of California at Los Angeles. “But we’ve been rethinking HDL in recent years.” Watson, who was not connected to the study said “everyone agrees” that low HDL – below 40 mg/dL – is bad. But studies have also found that very high HDL is liked to trouble, too. For example, a 2016 study of over 630,000 people found that women and men with very high HDL – above 90 mg/dL – were more likely to die (of noncardiovascular causes) during the study period than those whose HDL was in the middle of the pack.

HDL is known as the “good” cholesterol because it does positive things, including clearing fat from the arteries and ushering it to the liver to be removed. But, Watson said, research suggests that HDL function can go awry when its environment is not ideal – such as when a person is obese or has diabetes or other health conditions causing chronic inflammation in the blood vessels. “HDL seems to be like a chameleon, changing based on its surroundings,” Watson explained.

Monday, October 29, 2018

Higher Intake of Organic Foods Tied to Lower Cancer Risk

Higher intake of organic foods is associated with lower risk for breast cancer and lymphomas, a JAMA Internal Medicine study suggests.

Nearly 70,000 French adults reported how often they consumed 16 types of organic products (e.g., fruits, vegetables, dairy items) and then were followed for roughly 5 years. During that time, over 1300 new cancers were diagnosed. After adjustment for overall diet and other confounders, cancer risk decreased as organic food consumption increased. In particular, adults with the highest intake of organic foods had a 24% lower risk for cancer than those with the lowest organic intake.

When examined by cancer type, the risk reduction was limited to postmenopausal breast cancer and lymphomas.

Commentators point to numerous study limitations and urge caution in interpreting the findings. They write, "For overall health, current evidence indicates that the benefits of consuming conventionally grown produce are likely to outweigh the possible risks from pesticide exposure. Concerns over pesticide risks should not discourage intake of conventional fruits and vegetables, especially because organic produce is often expensive and inaccessible to many populations."

My Take:
I couldn’t disagree more with the commentator’s conclusions. However, going 100% organic is not feasible for most of us.

Friday, October 26, 2018

Herpes May Account for 50 Percent of Alzheimer's Cases

The herpes virus could account for at least half of Alzheimer's cases, according to a new review of the findings of three recent studies examining links between Alzheimer's and herpes.

The new paper, published in the Frontiers in Ageing Neuroscience journal, also suggests that antiviral drugs may reduce the risk of senile dementia — which is mostly caused by Alzheimer's disease — among people who have severe cases of herpes. Herpes simplex virus 1 (HSV1) is the type of herpes that results in cold sores. HSV1 is a common virus, and the majority of people will have contracted it by the time they reach old age. However, the virus remains permanently in the body and cannot be decisively removed either by the body's natural defense mechanisms or by drugs.

The virus is inactive most of the time, but when a person has HSV1, they may find that flare-ups occur when they are stressed or sick, resulting in characteristic blisters. Medical News Today have reported on several studies this year alone that have provided evidence of a connection between Alzheimer's and herpes. In June, we looked at a study in which postmortem tests on brain tissue support a mechanistic link between Alzheimer's and the herpes viruses HHV-6A and HHV-7. And in July, we brought you news on a study that found the use of antiherpetic medication may dramatically reduce dementia risk.

Study author Professor Ruth Itzhaki, from the University of Manchester in the United Kingdom, found in previous studies that cold sores caused by HSV1 are more prevalent among people that carry a gene variant called APOE-e4, which may increase a person's risk of developing
Alzheimer's. "HSV1 could account for 50 percent or more of Alzheimer's disease cases," she states. Our theory is that in APOE-e4 carriers, reactivation is more frequent or more harmful in HSV1-infected brain cells, which as a result accumulate damage that culminates in development of Alzheimer's."

For this review, she looked at three recent studies on the relationship between Alzheimer's and herpes or chickenpox that analyzed population data from Taiwan, a country which enrolls almost all citizens in the National Health Insurance Research Database.