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Vitamin E & Vitamin C: No Impact on Cardiovascular Disease Risk; Does Lack of Sleep Increase Stroke & Heart Attack Risk in Hypertensive Patients?

Posted by doctorwascher on Sunday, November 16, 2008 9:41:48 PM
The information in this column is intended for informational purposes only, and does not constitute medical advice or recommendations by the author. Please consult with your physician before making any lifestyle or medication changes, or if you have any other concerns regarding your health.
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VITAMIN E & VITAMIN C: NO IMPACT ON CARDIOVASCULAR DISEASE RISK

Vitamin E and Vitamin C are essential vitamins with powerful antioxidant properties. These vitamins are able to neutralize toxic “free radicals,” which are normal byproducts of metabolism in our bodies. In theory, antioxidants should be able to prevent these dangerous free radicals from damaging the cells in our body, including the endothelial cells that form the interior lining of our arteries. While previous laboratory studies, typically using human cells growing in a culture dish or laboratory animals, have shown that antioxidant vitamins do indeed soak up free radicals, clinical studies of these vitamins in humans have been far less encouraging (as is often the case in medical research, unfortunately).

Now, a new long-term prospective clinical trial, involving nearly 15,000 male physicians aged 50 and above, is casting further doubt that Vitamin E and Vitamin C supplements are capable of reducing the risk of cardiovascular disease. In this 10-year study, which was conducted at Harvard University, volunteers were randomized to receive a daily Vitamin E pill (400 IU) or an identical sugar pill (placebo), as well as a daily Vitamin C pill (500 mg) or a similarly identical placebo. Unlike many previous cardiovascular disease prevention studies that have evaluated these two vitamins, the vast majority of the Physicians’ Health Study II volunteers were healthy, and had no clinical evidence of heart disease, peripheral vascular disease, or stroke upon entry into the study (only 5 percent of these volunteers had any evidence of any cardiovascular diseases at the time they joined this research study). This study appears in the current issue of the Journal of the American Medical Association.

I won’t belabor the results of this very large high quality clinical study, because the findings were very straightforward… and disappointing. There was no significant difference in the incidence of heart disease, heart attacks or strokes between the various randomized groups of male volunteers in this antioxidant vitamin study. Neither Vitamin E nor Vitamin C supplementation appeared to have any favorable impact on the incidence of cardiovascular disease in these otherwise healthy middle-aged male physicians. On the other hand, there was a 74 percent relative increase in the risk of stroke among the men who were randomized to receive Vitamin E. The type of stroke most often observed in the men taking Vitamin E was hemorrhagic (bleeding) stroke, which is not entirely surprising, as Vitamin E can cause thinning of the blood, particularly at higher doses.

In summary, this is yet another disappointing clinical research trial looking for potential health benefits associated with Vitamin E and Vitamin C supplementation. In this particular study, there appeared to be no benefit associated with Vitamin E or Vitamin C in reducing the incidence of heart disease, heart attack or stroke in healthy middle-aged men who took these vitamin supplements for an average of 8 years. Unfortunately, the results of this study mirror the similarly disappointing results of recent prospective Vitamin E and Vitamin C cancer prevention studies which have, likewise, not shown any apparent benefit in reducing the incidence of cancers. Moreover, taking regular supplements of Vitamin E, beyond the current minimum daily recommended requirement, may also increase your risk of hemorrhagic stroke.

This study joins an ever greater collection of clinical research studies that have shown no significant health benefits associated with Vitamin E and Vitamin C supplementation. For folks like me, who have long hoped for different research outcomes related to these two antioxidant vitamins, it may be time to have another look at my vitamin and supplements drawer, and to update my inventory based upon the results of this study.


DOES LACK OF SLEEP INCREASE STROKE & HEART ATTACK RISK IN HYPERTENSIVE PATIENTS?

As I sit at my computer this evening, composing this week’s column, I am struggling to stay awake after a very long week with little sleep. My head is pounding in time with my fingers as they tap on my laptop’s keys. My eyes don’t seem to want to stay in focus, either. Annoying aches in the back of my head and neck nicely round out all of my other symptoms of sleep deprivation.

It’s no secret that Americans are sleeping less and less these days. We spend more time at work, and less time in bed, than most other people around the world (we also take fewer vacations than most of the rest of the world). Bleary-eyed, chronically irritable, and perpetually dazed, we trudge through each passing day wishing we could get just an hour or two of additional sleep before being awakened by our alarms each morning. But beyond merely feeling miserable much of the time (or, on a more serious note, risking an automobile accident while driving), there may actually be significant health risks associated with chronic sleep deprivation. Indeed, recent clinical studies have suggested that, for most people, an average of 7 hours of sleep per night may be optimal for good health. Slumbering away for significantly fewer (or more) hours may, in fact, increase a person’s risk of serious illness, or even death.

Now, a new study from Japan, where people also tend to get by on much less sleep than the rest of the world does, suggests that chronic sleep deprivation may substantially increase your risk of stroke, heart attack and death due to cardiac events, especially if your blood pressure tends to increase at night while you sleep. This prospective clinical research study, just published in the Archives of Internal Medicine, evaluated 1,255 healthy older adults with uncomplicated high blood pressure. The average age of the volunteers in this study was 70 years (range: 33 to 97 years), and the average duration of patient follow-up was 4 years. Continuous blood pressure readings were performed on these patient volunteers for 24-hour periods at home, on a weekly basis, and all patients were closely followed for signs of heart attack (fatal or non-fatal) and stroke over the duration of the research study. All patient volunteers also maintained a “sleep diary” on the evenings when their blood pressure was being monitored.

In this study of hypertensive patients, a nightly sleep duration of less than 7.5 hours was associated with nearly twice the risk of experiencing a cardiovascular event (i.e., stroke, non-fatal heart attack, or fatal heart attack) when compared to hypertensive patients who reported more than 7.5 hours of sleep per night.

Other studies, looking primarily at younger and healthier patients, have also noted an increased risk of death (from any cause) when the average nightly duration of sleep drops below 7 hours. This particular study is unique in that the patient volunteers all had high blood pressure, and all of them underwent 24-hour continuous monitoring of their blood pressure. This latter feature is important because nocturnal rises in blood pressure have previously been linked with an increased risk of cardiovascular events, but blood pressure increases at night have not previously been studied in combination with duration of sleep.

When the researchers in this study looked specifically at those patients who experienced a rise in their blood pressure at night, the risk of cardiovascular events associated with sleeping less than 7.5 hours per night increased dramatically. When this group of patient volunteers was compared to patients who slept more than 7.5 hours per night and who had the normal pattern of stable or decreased blood pressure at night, the risk of serious cardiovascular events was more than 4 times as common in the patients with rising blood pressure and sleep durations of less than 7.5 hours. Thus, among older patients with hypertension, increased nocturnal blood pressure and decreased duration of sleep, when combined, were associated with a very high risk of heart attack, death from heart attack, and stroke.


There are some important limitations in this study that should be considered. First of all, none of the patient volunteers in this study were observed in sleep lab, and so the sleep durations reported by the patients are subject to a great deal of inaccuracy. (The most accurate method of determining if patients are asleep or awake is to perform a formal sleep lab study, including the use of continuous EEG recordings of brainwave activity). Secondly, because the study volunteers were not observed by the researchers at night, it is not possible for this research study to determine if the rise in nocturnal blood pressure was, in some way, directly and solely responsible for the increase in cardiovascular events observed in the “blood pressure risers” who slept less than 7.5 hours per night. In fact, multiple health-related factors are known to cause elevated blood pressure at night, including sleep apnea, some medications, alcohol, obesity, diabetes, and nightmares, among others, and some of these same factors are, themselves, directly associated with an increased risk of cardiovascular events. For example, there is a well-known pattern of nocturnal heart attacks, and many experts believe that sleep apnea is the likely culprit in many such cases. According to this theory, the periods of decreased oxygen flow to the heart that occur when patients with sleep apnea momentarily stop breathing may give rise to heart attacks when coexisting coronary artery disease is also present. (Patients with sleep apnea typically have multiple and asymptomatic “apneic” episodes throughout the night, and oxygen levels within the blood and vital organs can drop precipitously during these brief spells when breathing stops.)

Therefore, in order to validate the conclusions of this study, the study would have to be repeated under conditions requiring that all patient volunteers undergo formal sleep lab testing in addition to continuous blood pressure monitoring. Nonetheless, there is ample previous research data suggesting that chronic sleep deprivation is associated with a higher risk of serious illness, and with an increased risk of death. So, on that note, I’m calling it a night, and I’m off to bed now to try and catch some much-needed sleep.

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Dr. Wascher is an oncologic surgeon, professor of surgery, a widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center:

http://www.sbhcs.com/hospitals/newark_beth_israel/mservices/oncology/surgical.html

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Send your feedback to Dr. Wascher at: rwascher@doctorwascher.net

_______________________________________________________________________________________________________
To read more of Dr. Wascher’s Health Report columns, please visit his website at: http://doctorwascher.com

_______________________________________________________________________________________________________

Copyright 2008. Robert A. Wascher, MD, FACS.

All rights reserved.
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Statin Drugs Decrease Heart Attacks Even with Normal Cholesterol; Statins & PSA Levels

Posted by doctorwascher on Saturday, November 15, 2008 9:58:04 AM
The information in this column is intended for informational purposes only, and does not constitute medical advice or recommendations by the author. Please consult with your physician before making any lifestyle or medication changes, or if you have any other concerns regarding your health.
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STATINS CUT HEART ATTACK RISK EVEN WITH NORMAL CHOLESTEROL LEVELS

The cholesterol-lowering statin drugs have become one of the most commonly prescribed classes of medications in the world, and nearly 20 million patients have been prescribed statins in the United States alone. The statins block a critical enzyme (HMGCoA reductase) that is required for the manufacture of cholesterol in our bodies. An extensive body of clinical research has shown that statins can significantly reduce the risk of heart attack and stroke in patients with high levels of the “bad cholesterol,” LDL. There is also some research evidence that patients with LDL levels in the high-normal range may benefit from statin medications as well (it should be remembered that nearly half of all heart attacks and strokes occur in patients who have normal LDL cholesterol levels). Now, a new study, published online in the New England Journal of Medicine, strongly suggests that statin drugs may also significantly decrease the risk of coronary artery disease, heart attack, stroke, and death from all of these diseases, in at least some patients with completely normal LDL cholesterol levels.

This newly published prospective, randomized, placebo-controlled research study, and referred to as the JUPITER study, enrolled nearly 18,000 adults in the United States and in other countries, and was supposed to have lasted for 5 years. Because the study’s researchers noted such striking benefits during a recent interim analysis of the study’s data, the JUPITER study was prematurely terminated in March of this year, only 2 years after the study was initiated.

There are several unique and clinically important aspects of this clinical study to be considered. First unlike many of the previously published clinical studies looking at statins, the JUPITER study included large numbers of women, African-Americans and Hispanics, and the study confirmed that all of these groups appeared to benefit from treatment with statin drugs. The other important difference in this study is that the volunteer patients participating in this clinical study all had normal total cholesterol and LDL cholesterol levels in their blood. However, these patients also had abnormally high levels of C-reactive protein (CRP) in their blood.

CRP is a protein that is manufactured primarily in the liver, and is a marker of both acute and chronic inflammation. Many cardiovascular disease experts believe that coronary artery disease, peripheral vascular disease and some types of stroke are all associated with chronic inflammation occurring within diseased blood vessels. CRP has been shown, in some research studies, to act as a marker for cardiovascular disease, especially in patients with elevated cholesterol levels (although elevated LDL cholesterol levels are thought to be more predictive of cardiovascular disease risk than elevated CRP levels).

In the JUPITER study, volunteer patients were randomized to receive either Crestor, a relatively new statin drug, or a placebo (sugar pill). Neither the patient volunteers nor the researchers knew which pill each patient was randomized to receive. (Randomized “double-blinded” prospective studies, such as this one, are generally accepted as the most accurate way of validating the effects of new treatments.)

At the point when this study was prematurely halted, the collected data revealed that the patients receiving the statin drug Crestor, when compared to the patients receiving a placebo, experienced a 55 percent reduction in the risk of heart attack and a 48 percent decrease in the risk of stroke. Overall, the risk of experiencing a major heart attack, stroke, or death from any cardiovascular disease was reduced by 47 percent in the group of volunteer patients who received Crestor. The patients who were randomized to receive Crestor experienced, on average, a 50 percent reduction in LDL cholesterol blood levels and a 37 percent reduction in CRP blood levels. It is very important to point out that the JUPITER study’s patient volunteers better represented the general population in terms of age, gender and race than most of the previously published statin studies, and all of these various subgroups of patients appeared to benefit equally from statin therapy.

The results of this study are likely to significantly change the existing guidelines for the use of statins in cardiovascular disease prevention, as many of the patients in the JUPITER trial who appeared to benefit from statin therapy would be considered, by current guidelines, to be at relatively low risk for cardiovascular disease (e.g., based upon their age, weight, smoking history, family history, cholesterol levels, and the presence or absence of high blood pressure). Indeed, many of the JUPITER study patients would not be candidates for statin medications under the current clinical guidelines for the use of these potent drugs.

At the present time, CRP is not routinely used to screen for cardiovascular disease in the asymptomatic population. Thus, this study raises the additional question as to whether or not CRP levels should be regularly measured, in addition to cholesterol and triglyceride levels, as part of routine cardiovascular disease screening. Certainly, the results of this study would suggest that CRP levels should probably be checked more frequently, particularly in patients who do not have other apparent risk factors for cardiovascular disease, such as advanced age, a history of smoking, obesity, diabetes, hypertension, sedentary lifestyle or elevated levels of total and LDL cholesterol. Based upon the entry criteria for the JUPITER study, men at or above the age of 50 and women at or above the age of 60 who have a CRP blood level greater than 2.0 milligrams per liter should at least be considered for statin therapy, even if their cholesterol levels are within the normal range. (It should also be noted that CRP levels can become elevated at any single point in time for a variety of reasons, including periods of acute illness and infection, and so single measurements of CRP may therefore not accurately reflect an individual’s risk of cardiovascular disease over the long-term.)

Whether or not everyone should be considered for statin therapy is unclear at this time, and another large scale prospective, randomized, placebo-controlled, double-blinded study, like the JUPITER study, will be necessary to answer this question. It should also be remembered that statins, like most drugs, are associated with a small but significant risk of potentially serious side effects. In a small percentage of patients, statin drugs have been associated with serious liver, muscle and kidney toxicity, and all patients who are started on statin drugs must be carefully followed by their physicians for any evidence of these potential complications of statin therapy.

Finally, it is important to note that this study was funded by the manufacturer of Crestor (AstraZeneca). As I have previously warned, clinical research studies that are conducted with funding from “interested parties” must always be viewed with a critical eye. As this is an increasingly more common phenomenon, however, as government sources of research funding continue to shrink, it has become impossible to simply reject the findings of all “industry-sponsored” research studies. In the case of the JUPITER study, the authors have filed disclosures indicating that AstraZeneca was completely excluded from all data collection and data analysis, and from the writing of the study’s soon-to-be published manuscript.



STATINS & PSA LEVEL

As the previous study indicates, the clinical role of statin drugs has grown tremendously over the past few years as, increasingly, clinical research studies continue to reveal their potential to reduce death and disability from life-threatening cardiovascular diseases. However, some experts have proposed that statins may possess other potential health benefits beyond the reduction of cardiovascular diseases alone. While the data on statins as cancer prevention drugs has been very contradictory thus far, some (but not all) studies have suggested that statins might also reduce the risk of prostate cancer. Now, a new clinical study, just published in the Journal of the National Cancer Institute, suggests yet another possible prostate-related effect of statin drugs.

In this study, more than 1200 male veterans, all of whom were taking statin drugs for elevated LDL cholesterol, were followed between 1990 and 2006 at the Durham, North Carolina, Veterans Affairs Medical Center. At the time of their entry into this study, none of these men, with an average age of 60 years, had a history of any previous prostate gland diseases, including prostate cancer. All of the men underwent testing of their blood prostate-specific antigen (PSA) levels both prior to and following the initiation of statin therapy.

On average, LDL cholesterol levels decreased by 28 percent after beginning treatment with statin drugs. Interestingly, PSA levels also declined after these men began taking statins and, moreover, the greatest reductions in PSA levels were observed in the men who also had the largest reductions in their LDL cholesterol levels. Among the men who experienced the largest reduction in LDL cholesterol levels, after initiating statin therapy, a 17 percent reduction in blood PSA levels was observed.

Currently, the measurement of blood PSA levels is an important part of routine screening for prostate cancer, and elevated levels of this protein generally indicate the need to perform biopsies of the prostate gland to rule-out cancer. The results of this study, therefore, raise the concern that early cases of prostate cancer might conceivably be missed in men who are taking statins, as mildly-to-moderately elevated levels of PSA might be suppressed by long-term statin use. Whether or not statin-associated reductions in PSA levels might actually be associated with a lower risk of prostate cancer was beyond the scope of this study, and so further prospective randomized clinical trials with statin drugs and placebos must be completed before any claims can be made that statins reduce the risk of prostate cancer. For now, however, the results of this limited observational research study suggest the need for caution when interpreting PSA results in men who are taking statins. Certainly, men with a family history of prostate cancer (and at an early age, in particular), and African-American men, should advise their physicians about the results of this research study if they are currently taking statin drugs, and these high-risk men should be carefully monitored for other signs and symptoms of prostate cancer, in addition to PSA levels. In such cases, a low threshold to perform biopsies of the prostate gland should at least be considered.

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Dr. Wascher is an oncologic surgeon, professor of surgery, a widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center:

http://www.sbhcs.com/hospitals/newark_beth_israel/mservices/oncology/surgical.html

_______________________________________________________________________________________________________
Send your feedback to Dr. Wascher at: rwascher@doctorwascher.net

_______________________________________________________________________________________________________
To read more of Dr. Wascher’s Health Report columns, please visit his
website at: http://doctorwascher.com

_______________________________________________________________________________________________________
Copyright 2008. Robert A. Wascher, MD, FACS.
All rights reserved.
_______________________________________________________________________________________________________








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