Shanghai Health: Blood Pressure, How Low Should You Go?

Shanghai Living

Despite the progress made in treatment and prevention, hypertension affects over one billion people globally. It has been known for decades as the ‘silent killer’ and is one of the leading risk factors for coronary heart disease, stroke, and kidney failure. Its overall prevalence in the populations of United States, Europe, and China is approximately 30%, 40%, and 20% respectively, and according to a study published in 2005 in the journal Lancet, the number of adults with hypertension is expected to increase 60% globally by 2025. The global economic burdens associated with these epidemic rates make control and, more importantly, prevention one of the top health priorities of governments worldwide.

When most people think about hypertension, they think about a blood pressure of 140/90 and above — anything above means it’s time to see your doctor while numbers below this are considered ‘normal’. However, it’s not so simple.

In 2003, the threshold for what was considered ‘normal’ blood pressure was lowered to 120/80 and a new diagnostic category called ‘pre-hypertension’ was established.

Pre-hypertension is when a person’s blood pressure is above normal but not high enough to be considered hypertension. This relatively new diagnosis is based on a studies showing that people who have blood pressures in the pre-hypertension range are at increased risk for developing cardiovascular disease (CVD) compared to people who do not. On the other hand, studies have also shown that even seemingly trivial reductions in blood pressure can result in a significant reduction in CVD. Therefore, persons with repeated blood pressure measurements indicating pre-hypertension should not ignore these readings given the known associated health risks.

So does this mean we should all be shooting for a blood pressure of less than 120/80, regardless of the means? Not really.

Surprisingly, unlike hypertension, studies have not demonstrated an overall benefit in treating blood pressures in the pre-hypertension range with medications. Luckily, the same does not hold true for healthy life-style changes. This is because, in most cases, elevated blood pressure is often a symptom of other underlying cardiovascular risk factors including overweightobesity, smoking, sleep apnea, stress, physical inactivity, and unhealthy dietary choices.

Adopting healthy patterns of living can provide the unique benefit of simultaneously reducing those risk factors, resulting in an across the board risk reduction.

Even as early as 1983, the World Health Organization recommended the use of nonpharmacologic approaches as primary and adjunctive treatment for hypertension. If you have been diagnosed with pre-hypertension or hypertension, the following are some lifestyle interventions that may help you to achieve a more optimal blood pressure. For those with mild hypertension, these measures can, in some cases, reduce or even eliminate the need for medications altogether. To put the effectiveness of www.thatsmags.com 27 these measures into perspective, keep in mind, studies show that treatment of hypertension by means of a single drug generally reduces systolic blood pressure in the range of 6.9-9.3 mm Hg.

Diet and Salt Intake

It is a well-accepted fact that diet and salt intake affect blood pressure. The Dietary Approaches to Stop Hypertension (DASH) trial demonstrated that a diet limiting the intake of red meat, sweets, and sugar containing beverages, while emphasizing fruits, vegetables, low-fat dairy products and including fish, nuts, poultry and whole grains can lower systolic and diastolic blood pressure by 11.4 and 5.5 mm Hg respectively. This rivals the effectiveness of using a single antihypertensive medication.

A subsequent trial called the DASH-Sodium trial showed that sodium restriction combined with the DASH diet can result in further reductions in systolic and diastolic blood pressures by an additional 3.0 and 1.6 mm Hg respectively.

Most guidelines recommend limiting salt consumption in the general population to no more than one teaspoon per day while those with hypertension should limit intake to one-half teaspoon per day. Keep in mind, foods can have a high salt content and not taste salty. In Western countries, approximately 75% of salt consumed is hidden in processed and restaurant foods. The remaining is added voluntarily during cooking or at the table.

Exercise

Studies have shown such a strong relationship between sedentary behavior and hypertension that multiple organizations around the world, including the World Health Organization, have recommended exercise as a primary treatment strategy for pre-hypertension and mild cases of hypertension. According to a review published in the journal Sports Medicine in 2000, regular low-moderate intensity physical activity can result in an average drop in systolic and diastolic blood pressures of 10.6 mm Hg and 8.2 mm Hg respectively. Reductions in blood pressure began as early as 1-10 weeks after initiating exercise training. According to the American College of Sports Medicine, current evidence supports the following exercise prescription (assuming it is approved by your physician) to lower blood pressure for individuals:

Frequency: Most (preferably all) days of the week

Duration: 30 minutes of continuous or accumulated (no less than 10 minutes each session)

Intensity: Moderate intensity (equivalent to brisk walking) with a noticeable increase in heart rate.

Type: Primarily aerobic/ endurance type activity supplemented by resistance training

Although exercise has a doseresponse relationship to health, the good news is you don’t have to train very aggressively to begin achieving blood pressure reductions associated with exercise.

Weight Loss

Excess body fat, especially abdominal fat, has been associated with increased incidence of hypertension. According to a 2003 article published in the journal Hypertension, on average, every one kg reduction in body weight can reduce systolic blood pressure by up to 2 mm Hg and diastolic blood pressure by 1mmHg. The most effective means to lose weight and prevent weight regain is through a disciplined and consistent combination of healthy food choices with moderate portion sizes and building physical activity into your daily life. Keep in mind, many fad diets such as high protein/low carbohydrate diets are not healthy, as they do not provide all of the nutrition you body needs. They are also difficult to sustain long-term, resulting in weight regain.

Alcohol Consumption

Heavy alcohol consumption increases the risk of hypertension. However, the effect of light to moderate consumption on the risk of hypertension remains controversial. Although guidelines vary, if you choose to drink, it is generally recommended that you should not exceed 30 mL of ethanol (e.g. 720 mL beer, 300 mL wine, or 60 mL 100-proof whiskey) per day in most men while women and lighter persons should not exceed 15 mL per day.

Relaxation Therapies

Meditation, yoga, and breathing exercises have shown some promising benefits for overall health and blood pressure control. However, these are currently considered adjunctive treatments, as more research is needed before they can be recommended as primary treatment strategies for hypertension.

Acupuncture

Reviews for acupuncture are mixed so it cannot be advocated currently as an effective treatment strategy for hypertension. However, it is safe to try as an adjunctive treatment regime.

In summary, based on the best available evidence, an average blood pressure above 120/80 in adults increases the risk for CVD. Lifestyle interventions are proven to be effective and safe primary strategies to both prevent and treat pre-hypertension and mild hypertension. In addition, they have the added benefits of being relatively cheap, risk free, and capable of favorably impacting other cardiovascular risk factors as well.

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