Numbers to Live By

By Stacey Colino

Understanding key numbers-BMI, blood-sugar level-can lead to better health.


Blood Pressure


Healthy number: Less than 120/80 mmHg.

Blood pressure refers to the force of blood against the walls of your arteries when your heart beats (systolic pressure, the top number) and during rests between beats (diastolic pressure, the bottom) and is measured in millimeters of mercury (mmHg). "The lower yours is, the better," says Holly Thacker, M.D., director of the Center for Specialized Women's Health at the Cleveland Clinic. High blood pressure, or hypertension, is 140/90 mmHg or higher. Hypertension is called "the silent killer" because it often has no symptoms and, left untreated, can lead to stroke, heart disease, kidney damage, and vision and memory problems. (If your top number is between 120 and 139 and the lower is between 80 and 89, you have prehypertension, which also carries risks.)
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Have yours checked:
Every time you see a doctor, including an ob-gyn. To lower your numbers, consume a low-fat, low-sodium diet; exercise often; maintain a healthy weight; limit alcohol intake; don't smoke; and manage stress. Your doctor may prescribe a diuretic to flush out excess sodium. If that and lifestyle changes don't work, other medicines, like an angiotensin converting enzyme (ACE) inhibitor, may be prescribed.


Blood Sugar

Healthy number:
A fasting blood-sugar level of 99 mg/dL or less.

A fasting blood-sugar test measures glucose (sugar) in milligrams per deciliter (mg/dL) of blood after you haven't eaten for at least eight hours. A level of 126 mg/dL or higher indicates diabetes, a condition in which your body doesn't produce enough insulin (which converts blood sugar into energy) or use insulin properly. Diabetes more than doubles your risk of heart disease and increases your chances of kidney disease, vision loss, and other health issues.
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Have yours checked: At age 45, then every three years after that. (Your doctor may test you earlier if you are overweight or have a family history of diabetes.) Some doctors also do a hemoglobin A1C test, which measures glycated hemoglobin (HbA1C), a substance in red blood cells that forms when glucose attaches to hemoglobin. This "gives a better picture of average blood sugar over the previous three months," says Wendy S. Klein, an internist in Richmond, Virginia. An optimal A1C reading is less than 5.7 percent. To improve your blood-sugar numbers, shed any excess pounds.


Cholesterol

Healthy number: Total cholesterol under 200 mg/dL; LDL cholesterol under 100 mg/dL. "The higher your cholesterol levels, the greater your risk of heart disease," says Nieca Goldberg, M.D., director of the Langone Women's Heart Center at New York University, in New York City. To minimize health risks, your total cholesterol should stay under 200 mg/dL (cholesterol is measured by milligrams of cholesterol per deciliter of blood). But it's actually low-density lipoprotein (LDL) cholesterol-the "bad," artery-clogging kind-that causes the damage. "Elevated LDL levels cause the formation of plaque in the artery walls," explains Goldberg, which leads to atherosclerosis and an increased risk of heart attack and stroke. For most people, the optimal level of LDL is under 100 mg/dL (and under 70 mg/dL if you have diabetes or heart disease).
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Have yours checked:
Starting at age 20 and older. "You should have a fasting blood test to measure total cholesterol and LDL, plus the other lipids, triglycerides, and HDL [high-density lipoprotein]," says Goldberg. "If the numbers are normal, you don't have to recheck them for five years." If the numbers are not where they should be, the best way to improve your cholesterol levels is to lose excess weight; exercise more often; stick with a diet that is low in cholesterol, saturated fat, and trans fats; and get your levels rechecked yearly. Even if you do all this, you may still need to take a cholesterol-lowering medication.


HDL Cholesterol

Healthy number: 50 mg/dL or higher. High-density lipoprotein, or HDL, is the "good" cholesterol, so the higher your number, the better your health. "HDL cholesterol helps remove harmful LDL cholesterol from arteries," says Goldberg. An HDL level lower than 50 mg/dL is a heart-disease risk factor for women, while a level of 60 mg/dL or higher helps protect you from heart disease. The best ways to raise your HDL are to quit smoking; exercise; eat monounsaturated fats (olive oil is one source) instead of saturated and trans fats; and avoid having more than one alcoholic drink a day. When HDL is low and LDL is seriously high, cholesterol-lowering drugs, like statins, as well as niacin supplements can help.

Have yours checked:
See "Cholesterol."




Triglycerides


Healthy number:
Less than 150 mg/dL. Triglycerides are a type of fat in the blood, and elevated levels increase your risk of type 2 diabetes and heart disease. Your triglyceride level (measured by milligrams of triglycerides per deciliter of blood, or mg /dL) is borderline high if it is between 150 and 199 mg /dL and high if it's 200 mg /dL or higher.
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Have yours checked: Annually. It's usually part of the same test used to gauge your cholesterol. People with a high level are often low in HDL cholesterol and vice versa. Research suggests elevated triglycerides may be a greater risk factor for heart disease in women than in men, though no one knows exactly why this is. Just consider it another good reason to get your level into the target zone. To do that, lose weight, quit smoking, consume no more than one alcoholic drink a day, and exercise regularly.


Thyroid

Healthy number: A thyroid-stimulating hormone level under 4.0 mIU/L. Produced by the pituitary gland, the thyroid-stimulating hormone (TSH) directs the thyroid gland in your neck to secrete the hormones thyroxine (T4) and triiodothyronine (T3). Besides helping regulate your metabolism, body temperature, and heart rate, these hormones affect skin, hair, muscle strength, mood, and mental functioning. If your TSH level is high, above 4.5 mIU/L (or milli-international units of TSH per liter of blood), your thyroid isn't producing enough hormones to help your body function efficiently.

Have yours checked: Starting at age 35. Hypothyroidism is a condition that is fairly common among women and can raise cholesterol and triglyceride levels and lead to heart problems and depression. If your TSH level is high, your doctor may prescribe a thyroid replacement medication. If it is normal, recheck it every five years.


Body Mass Index...keep reading Numbers to Live By


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