Anti-hypertensive pills for everyone?

How about anti-hypertensive drugs as part of your daily routine? British researchers recommend that hypertensive drugs (not one but a combination) be given to everybody starting at a certain age regardless of the fact whether they actually have high blood pressure or not. The logic behind this recommended generalized prophylactic treatment is to avoid cardiovascular events caused by hypertension.

According to Dr Malcolm  Law and Dr Nicholas Wald of the Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London,

“Guidelines on the use of blood-pressure-lowering drugs can be simplified so that drugs are offered to people with all levels of blood pressure. Our results indicate the importance of lowering blood pressure in everyone over a certain age, rather than measuring it in everyone and treating it in some.”

This means that we should swallow a daily cocktail of anti-hypertensive drugs just like we are swallowing vitamins or nutritional supplements.

The researchers based their recommendations on a meta-analysis of 147 randomized trials that included a total of 958,000 people. The same researchers also supported the so-called polypill which contains 5 different cardiovascular drugs that include:

• a statin
• three anti-hypertensive drugs
• aspirin

The results of the meta-analysis showed that:

• People aged 60 to 69 benefit from taking hypertensive drugs regardless of blood pressure measurements.
• A combination of three drugs at half standard dose (as in the polypill) reduced the risk of coronary heart disease by approximately 46% and of stroke by 62%.
• A single antihypertensive agent at standard dose had about half the effect of the polypill

Currently, there are five main classes of blood-pressure-lowering drugs, namely:

• beta blockers
• thiazides
• ACE inhibitors
• angiotensin-receptor blockers
• calcium-channel blockers

All drugs except calcium-channel blockers were similarly effective in preventing cardiac events and strokes. The calcium-channel blockers seem to have a greater preventive effect against stroke compared to the other drugs.

Other health experts, however, are not so convinced about the arguments and the results of the meta-analysis. They question a lot of assumptions and as well as analytical methods that may not be valid. According to Dr. Franz Messerli of St Luke’s-Roosevelt Hospital Center, New York City

“A meta-analysis is like a sausage; only God and the butcher know what goes in it, and neither would ever eat any.”

Indeed, the idea of prescribing anti-hypertensives for everybody is hard to sell. It is true that hypertension can lead to cardiac events and strokes but there are factors aside from blood pressure play a role as well. Besides, many of the risk factors for cardiovascular disease are lifestyle, and therefore, modifiable factors.

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R-I-N-G-G-G: your blood pressure, please?

It’s not your normal phone call. It is just like having your own assistant who reminds you to check your blood pressure and refill your prescriptions except that this is all fully automated and computerized. Researchers at the University of Montreal tried a computer-based telephone program which automatically calls hypertension patients a couple of times a week to inquire for blood pressure measurements. The readings are then recorded and passed on to the patient’s health care provider who will then analyze the data and modify the treatment regime if deemed necessary.

The study included 223 hypertension patients from different primary care clinics in Laval, Quebec. 111 of the participants were assigned to the intervention group who received “an educational booklet, a digital home blood pressure monitor, a log book and access to the telephone-linked management system.” The remaining 112 received only the booklet in addition to their usual medical care program.

The study results showed that this “simple, automated feedback system made hypertension patients more aware of their potentially fatal or disabling disease and helped them significantly lower their high blood pressure.”

The reductions in blood pressure measurements in the intervention group are:

• 11.9 millimeters of mercury (mm Hg) in systolic blood pressure
• 6.6 mm Hg in diastolic pressure

The reductions in the control group are:

• 7.1 mm Hg systolic blood pressure
• 4.5 mm Hg diastolic

The success of this computer-based phone call program can be attributed to its ease and convenience but also due to the fact that there is always someone reminding the patients what to do and as well as give feedback on how well they are doing.

In addition, this is a helpful service for those patients who aren’t too mobile and tend to be forgetful.

The next step is to find out how cost-effective is this automated intervention.

According to lead author Dr. Pavel Hamet,

“The automated blood-pressure control system could be widely accepted if it is cost-effective. The healthcare system doesn’t want to increase the cost without some benefit.”

Automated services are usually more cost-effective than manned services. In addition, if further studies can confirm that this automated phone call reminder service can prevent complications of hypertension such as stroke and kidney failure that can add to health care costs, then the health authorities might just be convinced of the system’s benefits.

               

Why African Americans are prone to hypertension

African Americans are more susceptible to stroke and other cardiovascular diseases than any other ethnic group in the US.  According to recent statistics from the American Stroke Association

• Blacks have almost twice the risk of first-ever strokes compared to whites.
• Blacks have higher death rates for stroke compared to whites.
• The prevalence of high blood pressure in African Americans in the United States is the highest in the world.
• Among non-Hispanic blacks age 20 and older, 62.9 percent of men and 77.2 percent of women are overweight or obese.
• In 2001, 27.7 percent of black or African-Americans only, used any tobacco product. Heavy cigarette smoking approximately doubles a person’s risk for stroke when compared to light smokers.
• Black women have higher prevalence rates of high blood pressure, obesity, physical inactivity, and diabetes than white women.

This recent research at the Medical College of Georgia may give us a clue to this ethnic group’s susceptibility. It seems that a natural mechanism that regulates blood pressure is missing in many African Americans who are otherwise perfectly healthy. High blood pressure is a major risk factor for cardiovascular disease. Blood pressure can be increased by stress. However, the human body has a built-in mechanism that brings down the blood pressure. This system works by excreting more salt into the urine.

According to researcher Dr. Matthew Diamond

“The way it’s supposed to work is the higher your blood pressure goes, the system is supposed to be suppressed so you urinate out more sodium and the blood pressure goes down in response.”… The renin-angiotensin-aldosterone system helps regulate blood pressure, prompting the kidneys to hold onto more salt - and fluid - if it’s too low and to get rid of salt when it’s high.

However this mechanism that regulates blood pressure does not seem to work properly in about 1 in 3 adolescent African Americans. The study looked at 168 participants aged 15 to 18 years of age. The participants were healthy, non-obese, with normal blood pressure, and were placed on diets with controlled sodium and potassium. The researchers monitored their blood pressure, urine and blood samples while the participants were exposed to environmental stress through playing video games. The results showed that the renin-angiotensin-aldosterone system worked perfectly well in adolescents who were white but was improperly suppressed in about a third of black participants.

The reason for this dysfunction cannot be easily explained but may have some genetic explanation. The researchers are now planning to “screen participants for a genetic mutation that has been linked to hypertensive kidney disease to see if that’s a factor that can be used to help identify those at risk for hypertension and kidney disease.”

May is National High Blood Pressure Education Month in the US. The results of this study may just be the key understanding why African Americans are prone to hypertension and cardiovascular disease.

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Depressed? Check your blood pressure!

The link between depression and cardiovascular health is well-known although the mechanism behind the relationship is not well-understood.

A study by Dutch researchers may just give us an idea of the complexity of that link. For one thing, contrary to the common perception that depression can lead to hypertension, depression, is, in fact, associated with low blood pressure. However, medications against depression - the so-called anti-depressants can increase blood pressure. In particular, tricyclic antidepressants (TCAs) can increase the risk for hypertension.

According lead author Carmilla Licht

“Doctors should at least be aware of a potential blood-pressure rise that could be linked to TCA use, especially for patients with cardiovascular disease or high blood pressure or others who are at risk for hypertension…They may consider meticulously monitoring these patients’ blood pressure when they prescribe one of these antidepressants or consider prescribing another antidepressant medication.”

The results of the study are somewhat controversial because they contradict the current “depression-hypertension theory.”

The study was part of the Netherlands Study of Depression and Anxiety, and followed up 2618 participants aged 18 to 65 years old. The study participants were divided into 3 groups:

• Control group without history of anxiety or depression
• Patient group with a major depressive disorder (MDD) but not on antidepressants
• Patients with MDD and on antidepressants

Patients were monitored for systolic blood pressure (SBP) and diastolic blood pressure (DBP) and distinction was made between different types of antidepressants, e.g. selective serotonin-reuptake inhibitors (SSRIs) vs tricyclic antidepressants (TCAs).

The study also observed that a typical patient with psychiatric disorder “were a little older, more likely to be female, less educated, less physically active, smoked more, and had a higher body-mass index and more diseases.”

The study results showed that compared with health controls, MDD patients have significantly lower blood pressure. However, MDD patients on TCA had significant higher blood pressure. The use of SSRIs doesn’t seem to be associated with blood pressure measurements.

So the next question is

Is it the depression that lowers the blood pressure or is it the low blood pressure that causes the depression?

The authors speculate that three things might influence the depression-low blood pressure link.

• Use of anti-hypertensive drugs
• Common causes of depression and low blood pressure, e.g. fluctuations in metabolites, hormones or neurotransmitters
• Low blood pressure can cause depressive symptoms, e.g. fatigue, dizziness, low tolerance to cold temperatures, and concentration problems.

While depression is associated with low blood pressure, the study shows that anxiety is linked to high blood pressure. This, the authors say, might be due to continuous stress associated with anxiety.

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When relationships go bad, women’s heart suffer most

Tension. Stress. Anger. Anxiety. These are what you get in a relationship gone bad. Unfortunately, the emotional distress that comes with a strained relationship can translate into physiological problems that in turn lead to conditions like high blood pressure, heart problems, and obesity.

These health problems have been reported for both men and women although the latter seems to be more susceptible to health issues caused by bad relationships, according to a study by researchers at the University of Utah.

For the study, [the researchers] recruited 276 couples married an average of two decades, in which men and women were between 40 and 70 years old. Participants filled out questionnaires that covered positives, such as emotional warmth and mutual support; and areas of tension, such as frequency of arguments and extent of disagreements over issues like sex, kids, and money. (Source: WebMD).

The participants were also monitored for blood chemistry, blood pressure and waist circumference.

The study showed that the health effects of a discordant relationship on women’s health include:

• Depressive symptoms, more likely to be reported by women.
• Metabolic syndrome symptoms (which would include increased blood sugar levels, increased levels of bad cholesterol and triglycerides) more likely to be reported by women.
• Weight gain and increased waist circumference, also more likely to be reported by women.
• Depressive symptoms reported by men not related to metabolic syndrome.

This is not the first study to explore the effect of relationships on health outcomes.

A large body of research shows that divorce is associated with coronary calcification in both men and women. However, the current study clearly indicates that the relationship between emotional distress caused by a bad relationship and cardiovascular health is stronger in men than women.

In another study, researchers found out that the quality of a marriage relationship can have an influence on recovery rates of women with breast cancer.

Corollary to this, another study on stroke victims and their spouses showed that, depending on coping skills, caregiving can cause depression and put a strain on relationships.

But why are women more susceptible? According to the researchers:

“Women seem to be more relationship oriented. We know by research that women tend to base their self-concept on relationships, how they are doing, how things are going for them. And we think that’s the reason we’ve shown that negative relationship issues seem to take a greater toll on women emotionally and physically.”

               

High BP trends among America’s children

The latest statistics from the US National Health and Nutrition Examination Surveys (NHANES) are out and the numbers do not look too good for American children and teenagers.

NHANES are surveys conducted by National Center for Health Statistics, Centers for Disease Control and Prevention (CDC) which provide “cross-sectional, nationally representative health examination data on the US civilian, noninstitutionalized population.”

CDC researchers, in collaboration with colleagues from Wake Forest University School of Medicine Department of Epidemiology and Prevention, North Carolina, conducted an analysis of NHANES data from the following years: 1988 to 1994, 1999 to 2002, and 2003 to 2006. These are data of children and adolescents in the age range of 8 to 17 years old. The researchers specifically looked at the elevated blood pressure (BP) and estimates of BP before reaching elevated levels.

BP was measured and classified based on the update guidelines in the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. The results of the data analysis showed that overweight and obese children and adolescents are more likely to suffer from elevated BP.

Hypertension or above normal BP is common among adults. However, there is increasing indication that elevated BP is also becoming a problem among children as well. This is troubling because other research studies have shown that high BP tracks through life, and that “BP levels measured in childhood and adolescence are also associated with elevated BP in adulthood.”

Hypertension is well-known risk factor for chronic health conditions such as cardiovascular disorders (e.g. heart attack, heart failure, stroke) and kidney disease. However, hypertension can be managed with lifestyle change strategies.

High BP in children has been also linked to other health conditions.

Sleep breathing disorder is a condition “characterized by short periods of upper airway obstructions that are complete (apnea) or partial (hypopnea), or a longer period of insufficient air movement (obstructive hypoventilation).” This sleep disturbance leads to restless sleep, snoring and daytime sleepiness. Sleep breathing disorder, which seems to cause hypertension, has been associated with obesity and enlarged nostrils.

Other studies have linked high BP to lack of physical activity among children and adolescents, as reported by British researchers. The study was part of the Avon Longitudinal Study of Parents and Children.

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Your blood pressure and the weather

The temperatures are going down, but your blood pressure is going up. Is this logical?

It is, according to a French research study which observed that blood pressure varies with the season. The data of the study is based on measurements on 8,801 French adults older than 65 years and followed up for more than two years.

The study results show “that blood pressure in elderly people varies significantly with the seasons, with rates of high blood pressure readings rising from 23.8% in summer to 33.4% in winter. Blood pressure increases were seen in both the systolic (top) and diastolic (bottom) numbers.” The average systolic blood pressure was 5 mmHg higher in the winter months than in the summer months.

What is more disturbing is that the temperature-related effects on high blood pressure become more pronounced with age, and as observed in this study, in people older than 80 years.

The mechanism behind this seasonal variation is not clear but “possible explanations of the cold weather effect include activation of the sympathetic nervous system (which helps control how the body responds to stress) and release of the hormone catecholamine, which may increase blood pressure by speeding the heart rate and decreasing the responsiveness of blood vessels.”

The findings of the study help shed light on the well-documented seasonal variations in illness and death caused by stroke and aneurysms or rupture of the blood vessels. According to the American Stroke Association, stroke is the number 3 cause of mortality in the US, after heart disease and cancer.

And now that it is winter time in the northern hemisphere, people, especially the elderly should closely monitor their blood pressure. However, the increase in blood pressure in winter time should not actually discourage people from venturing outdoors. The American Stroke Association and American Heart Association encourage physical activity such as walking - even in winter time through the Start! Heart Walk. Connect with other walkers (sole-mates!) in your area using the My Start! Community. Track your walking progress using the free online tool My Start! Online Tracker. The brochure Start! Walking This Winter can give you some basic tips on how to enjoy the winter outdoors without endangering your health.

 

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Can vitamin C lower your BP?

Many studies have evaluated the effect of vitamin C (ascorbic acid) on cardiovascular health, with disappointing results. That is why the report of Dr Gladys Block and her colleagues at the University of California, Berkeley was met with surprise, and well, scepticism.

The Berkeley researchers report in the Nutritional Journal that the concentration of vitamin C in the plasma is inversely linked to blood pressure. This means that the higher the vitamin C levels in the plasma, the lower is the blood pressure. This association was observed among 242 young women aged 18 to 21 years old who were participants in the 10-year National Heart, Lung, and Blood Institute Growth and Health Study on adolescent obesity.

The author notes:

“It appears that the BP is less likely to rise if people have a good level of plasma vitamin C…This study suggests that vitamin C may be an important factor in BP regulation even among healthy young adults and that further study is warranted.”

The possible mechanism for this blood pressure lowering properties might be that vitamin C significantly decreases the levels of 2 substances: F2-isprostane, which is a marker of oxidative stress, and C-reactive protein (CRP), which is a marker of inflammation. Both inflammation and oxidative stress play a role in cardiovascular disorders, including hypertension.

Many experts do not believe that vitamin C can have some cardiovascular benefits. For one thing, the data was criticized as poor, being based only on women who are overweight or obese. In cases like this, comparative studies just simply give more credibility.

Hypertension expert Dr Franz Messerli of St Luke’s Roosevelt Hospital, New York comments at heartwire:

“To my way of thinking, plasma vitamin-C level in this population could be simply a good biomarker for intake of fruit and vegetables. Thus, the more fruits and vegetables these young women ate (ie, the healthier their diet), the lower their salt intake and not surprisingly, the lower their blood pressure… Vitamin C is a powerful antioxidant in vitro, and in some animal studies it has been shown to act as a vasodilator, possibly by enhancing the bioavailability of nitric oxide. But a recent study has failed to show an effect of the acute oral ingestion of vitamin C on oxidative stress, arterial stiffness, or blood pressure in healthy subjects.”

Despite the criticisms and scepticism, Dr. Block is planning to further investigate the vitamin C - blood pressure link in a large-scale randomized study.

Regardless whether vitamin C can lower blood pressure or not, the fact remains that eating fresh fruit and vegetables is beneficial to our health. And eating vitamin C-rich fruit such as oranges and other citrus fruits cannot hurt anybody.

               

Your job and your blood pressure

Increase in blood pressure has been associated with psychological and emotional stress. But how does stress in the job affect blood pressure? This has been the subject of numerous research studies over the years but the results are conflicting. In this post, I am reviewing 3 studies on 3 different types of workers in Japan.

 Managers

In Japan, the number of managerial employees suffering from cardiovascular disease is said to be higher than any other type of employee. A study of Japanese employed managers and retired managers showed that these people in the management suffer from masked hypertension. The disadvantage of masked hypertension as compared to sustained hypertension is that it often goes undiagnosed so that the people affected are not taking preventive measures or early treatment.

The author concludes that

“job stress seemed to be one of the main causes of masked hypertension…that more frequent measurements of  [blood pressure] at the work place are necessary to identify subjects with masked hypertension.”

Factory workers

This study looked at 352 male factory workers in Japan to evaluate the relationship between “job strain and subclinical indicators of arteriosclerosis.” Subclinical indicators are early indicators before the actual symptoms are actually observed in the clinical setting. The researchers measured these in cerebral artery, the aorta, and the carotid artery. The results show that job strain was associated with the indicators but the association was not significant.

Shift workers

This study which looked at Japanese male employees suggests that shift work may elevate both systolic and diastolic blood pressure - in other words increased risk for hypertension.

That’s what industrialization is all about - 24-hour, non-stop operations in factories and manufacturing plants. To keep companies running, employees have to work in shifts day and night. It is estimated that about a quarter of Japanese companies operate on shifts.

The researchers studied 3963 day workers and 2748 alternating shift workers working in a Japanese steel company. All the workers were male and had annual health check ups between 1991 and 2005.

Looking at the relative increases in blood pressure, the researchers reported that alternating shift workers have significantly higher systolic and diastolic blood pressure than their colleagues working during normal day hours.

The authors conclude that

“[the] study in male Japanese workers revealed that alternating shift work was a significant independent risk factor for an increase in blood pressure. Moreover, the effect of shift work on blood pressure was more pronounced than other well-established factors, such as age and body mass index.”

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Risk factors for hypertension: men vs women

The National Heart Lung and Blood Institute and MayoClinic list the following as the most common risk factors for hypertension:

• Older age
• Race or ethnicity
• Overweight or obesity
• Gender
• Stress
• Lack of physical activity
• Use of tobacco
• Family history of hypertension
• High alcohol consumption
• High sodium in the diet
• Low vitamin D levels
• Low potassium in the diet

This latest study by Chinese researchers reports that risk factors can contribute differentially to the developing hypertension depending on individual’s gender. The researchers studied 834 men and 835 women aged 15 to 84 years old in an ethnically isolated group and assessed their risk factors by collecting data on lifestyle, diet, and demographics as well as performing blood tests, genotyping, and blood pressure measurements.

The differences they observed were as follows:

Prevalence of hypertension	lower in women
Awareness	lower in women
Treatment	lower in women
Mean blood pressure	lower in women (116/72 vs 119/75)

Lifestyle risk factors

As expected, age is a common risk factor both gender that cannot be altered. However, several lifestyle risk factors seem to be strongly linked to males.

Lifestyle risk factors which are specific for males are:

• Physical activity
• Alcohol consumption
• Body weight and body mass index (BMI)
• Waist circumference

A lifestyle risk factor which is specific for females is calcium intake in the diet.

Other lifestyle risk factors common to both males and females are:

• education level
• plasma lipid profile (e.g. cholesterols and triglycerides)
• dietary intakes of energy, fat, sodium, and potassium

Genetic risk factors

Gene markers also varied between males and females. Genetic polymorphisms affecting the following genes encoding:

• calpastatin
• lipoprotein lipase
• thyrotropin-releasing hormone receptor
• Willebrand factor

are specific for women.

Conversely, polymorphisms in the genes encoding the following:

• angiotensin-converting enzyme
• aldehyde dehydrogenase
• hepatic lipase

 are specific for men.

Since this study was conducted on an ethnically isolated group of people and it is not clear how the results can be extrapolated to the general population. The researchers themselves are a bit cautious with the interpretation of the data and conclude that

“Sex differences in the prevalence of hypertension in the Hei Yi Zhuang population may be mainly attributed to the differences in dietary habits, lifestyle choices, sodium and potassium intakes, physical activity level, and some genetic polymorphisms.”

Whatever future studies will show, they wouldn’t change the fact that an unhealthy lifestyle is a strong factor in getting hypertension - whether you are male or female!

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