Controllable risk factors
Your health habits are key factors in determining your cardiovascular risk. In fact, you may be able to bring your blood pressure readings into a safe range simply by making changes in your lifestyle.
Doctors have long known that smoking promotes heart disease, but for a long time smoking didn’t appear to have a direct connection to hypertension. Observations have revealed a crucial link that earlier studies missed because blood pressure is generally measured in doctors’ offices and clinics, where smoking is prohibited.
When researchers tested blood pressure while people smoked, they discovered that within five minutes of lighting up, the subjects’ systolic pressures rose dramatically — more than 20 mm Hg, on average — before gradually declining to their original levels over the next 30 minutes. This means the typical smoker’s blood pressure soars many times throughout the day. Like people with labile hypertension (in which blood pressure may jump frequently in response to daily stresses), smokers may suffer “part-time” hypertension. For example, smokers with a prehypertensive reading of less than 140/90 mm Hg may actually have stage 1 hypertension every time they puff a cigarette.
This increase occurs because nicotine, whether smoked or chewed, constricts small blood vessels, forcing the heart to work harder to circulate blood. As a result, the heart speeds up and blood pressure rises. Nicotine also interferes with some antihypertensive drugs, most notably beta blockers. The chemicals in tobacco smoke raise heart disease risk in other ways, too. They can reduce the body’s oxygen supply, lower levels of HDL (“good”) cholesterol, and make blood platelets more likely to stick together and form clots that can trigger a heart attack.
Doctors first noticed a link between hypertension and sodium chloride — the most common form of dietary salt — in the early 1900s, when they found restricting salt in patients with kidney failure and severe hypertension brought their blood pressures down and improved kidney function. When a massive effort began in the 1960s to educate the public about reducing the risk of heart disease, one recommendation was that all Americans decrease salt consumption to prevent hypertension.
Nearly 50% of people who have hypertension are salt sensitive, meaning eating too much sodium clearly elevates their blood pressure and puts them at risk for complications. In addition, diabetics, the obese, and the elderly seem more sensitive to the effects of salt than the general population. Regardless of whether high salt intake increases blood pressure, it does interfere with the blood pressure–lowering effects of antihypertensive medications.
Excess weight and hypertension often go hand in hand because carrying even a few extra pounds forces your heart to work harder. People who are overweight are also more likely to develop diabetes, heart disease, arthritis, gallstones, sleep apnea, gout, and some cancers. It’s not weight alone that matters, but also where you carry your extra weight. People with excess fat in the abdominal area — a “potbelly” — are at greater risk for hypertension, high cholesterol, and diabetes (see Figure 1).
Figure 1. WHR
The waist-to-hip ratio (WHR) is one way to estimate how much weight a person is carrying around the abdomen versus around the hips. Men and women with a higher WHR (resembling an apple shape) have a higher risk for heart attack and stroke than men and women with a lower WHR (resembling a pear shape).
To determine your WHR:
With your abdomen relaxed, measure your waist at its narrowest (usually at the navel).
Measure your hips at the widest point (usually at the bony prominence).
Divide the waist measurement by the hip measurement.
Waist measurement/hip measurement = WHR
A healthy WHR for women is 0.8 or less (and a waist measurement of 35 inches or less), and a healthy WHR for men is 1.0 or less (and a waist measurement of 40 inches or less).
Compared with the physically active, couch potatoes are significantly more likely to develop hypertension and suffer heart attacks. Like any muscle, your heart gets stronger with exercise. A stronger heart pumps more blood more efficiently, with less force, through your body. Other cardiovascular benefits of exercise include losing excess weight, increasing levels of “good” HDL cholesterol, and making stroke-causing clots less likely.
Excessive drinking — having three or more drinks per day — is a factor in about 7% of hypertension cases. It can also interfere with antihypertensive medications, increase your risk of stroke, and lead to heart failure.
While moderate alcohol consumption (no more than one drink per day for women and two drinks a day for men) significantly lowers your risk of cardiovascular disease and has little effect on your blood pressure, heavier drinking has the opposite effect. How alcohol raises blood pressure is unknown, but it appears that once you go past two drinks per day, the more you drink, the higher your blood pressure. This effect becomes more pronounced as you age and occurs regardless of what type of alcohol you drink.