Consider Salt Sensitivity in Women’s Midlife Hypertension

Americans eat too much salt, but the influence of dietary sodium is especially noticeable in women, whose blood pressure may become more salt sensitive in their 4srcs or 5srcs. Primary care providers should take note and not underestimate salt’s ability to affect blood pressure later in life, warn women’s health experts.

Most adults have a strong response to dietary sodium. Blood pressure rises significantly when individuals switch from a low-salt to a high-salt diet. Interestingly, some data suggest women get more sensitive to salt in their late 4srcs, around the menopausal transition. “Women tend to be more sensitive to salt and its effects on blood pressure, especially during perimenopause and postmenopause,” according to Ashley L. Mutchler, PhD, assistant professor at Meharry Medical College in Nashville, Tennessee.

“Increased salt sensitivity also contributes to a higher risk of heart disease in this population,” said Mutchler in an interview.

Estrogen and Blood Pressure

While all the mechanisms related to blood pressure changes around menopause are not understood, research is focusing on the role of estrogen, which helps regulate blood pressure by influencing how the kidneys process sodium, Mutchler said.

It is likely that estrogen helps regulate the blood pressure of younger women in multiple ways: By acting as a vasodilator, by increasing nitric oxide, and by acting on the kidneys, which are estrogen-receptive organs.

In menopause, without estrogen, the body has a harder time dealing with salt, which contributes to the slow increase in blood pressure, said cardiologist Kayle Shapero, MD, PhD, assistant professor of medicine at The Warren Alpert Medical School of Brown University, Providence, Rhode Island.

This connection between hormones, salt sensitivity, and heart health highlights why monitoring blood pressure as well as sodium intake is especially important for women as they age.

Primary care doctors should be aware that some women will start to experience a rise in blood pressure during the menopause transition or during perimenopause, said Chrisandra Shufelt, MD, professor and chair of the Division of General Internal Medicine, associate director of the Women’s Health Research Center, Mayo Clinic, Jacksonville, Florida, and former president of the Menopause Society.

Getting Good Blood Pressure Readings Outside of the Exam Room

Increased blood pressure doesn’t cause obvious symptoms, and accurate blood pressure readings can be elusive. White coat hypertension is real, which is why so many groups encourage educating patients about self-measured blood pressure monitoring or home blood pressure monitoring to confirm a diagnosis of elevated or high blood pressure outside of a doctor’s office.

According to Umesh A. Patel, MD, a cardiologist at the Louisiana Heart Center, Covington, Louisiana, at-home devices are especially helpful for patients who:

• Need closer monitoring because they have risk factors for high blood pressure or conditions related to it (such as kidney disease);
• Have a family history of high blood pressure; or
• Have a personal history of gestational diabetes or pregnancy-related hypertension.

Patients can keep a journal of readings to show their doctor or buy a monitor that connects to a smartphone and averages measurements, Patel said. Look for an automatic monitor that uses a bicep cuff and meets the American Medical Association criteria. (Wrist and finger monitors give less reliable readings and are not recommended.) The American Heart Association’s website can give patients tips to avoid common pitfalls.

Testing frequency depends on a patient’s age, heart disease risk factors, and other variables. Risk factors such as a history of gestational diabetes or preeclampsia warrant more frequent monitoring, as often as once a month, according to Patel.

In an article published in Clinical Hypertension in 2src24, the author calls out-of-office blood pressure measurement essential to prevent high blood pressure misdiagnosis before explaining the advantages and limitations of ambulatory blood pressure monitoring compared with home blood pressure monitoring for managing hypertension.

Rule Out Other Common Causes of Elevated Blood Pressure

While many midlife health changes are related to hormonal changes in women, it is important to recognize that elevated blood pressure might indicate sleep apnea, stressed Shapero.

Shufelt concurs — obstructive sleep apnea is another common cause of elevated blood pressure in midlife women. “Before menopause, 3% of women have sleep apnea. After menopause, 11% of women have it,” she said.

Sometimes women attribute sleep apnea symptoms such as morning headaches to perimenopausal symptoms such as insomnia or hot flashes. Another common issue, midlife weight gain, may contribute to sleep apnea and increased blood pressure.

There are so many different reasons for increases in a midlife woman’s blood pressure; it is important that primary care physicians ask about them, said Shufelt.

How to Help Patients Reduce Their Sodium Intake

Counseling patients on how to cut back on salt may take more time and effort than a typical primary care physician can provide, but don’t discount the impact of simple cheerleading. And focus on the basics: Advise choosing fresh meat, fruits, and vegetables, and reading labels. Refer them to the Dietary Approaches to Stop Hypertension diet — a free, effective resource. Tell patients that their salt preference can fade in as quickly as a couple of weeks.

Encouragement from a health professional has been shown to help individuals monitor their salt intake and read nutrition labels, according to data published in Patient Education and Counseling in 2src23. However, behavioral interventions alone may not be sufficient to prevent hypertension and may need to be combined with other salt reduction or blood pressure–lowering measures.

Patients who are interested and need the help can be referred to a registered dietitian. Since the passage of the Affordable Care Act, patients have had easier access to consultations with registered dietitians for preventative care.

Guidance From a Registered Dietician (RD) Can Make a Difference

Working with a dietitian is a good way to help people cut back on salt, said Theresa Gentile, MS, RD, spokesperson for the Academy of Nutrition and Dietetics. “It can be easier to approach changes step by step with the help of a dietitian,” she said.

Gentile likes to advise people trying to reduce salt intake to eat one additional serving of fruit or vegetable a day. This adds potassium to the diet, which can help counteract sodium.

At the same time, they share low-sodium lifestyle tips, and dietitians can help with other midlife health challenges, such as increases in cholesterol levels and weight gain. Patients can find a local registered dietitian using the database on the Academy’s website, eatright.org.

Mutchler, Shapero, and Gentile disclosed no relevant financial conflicts of interest. Shufelt is the principal investigator of a National Institutes of Health–funded study on young women with functional hypothalamic amenorrhea.