The latest news in U.S. health and medicine

African American men have a higher incidence of prostate cancer than white men, and also a higher rate of death due to prostate cancer. Although both biologic and socioeconomic factors may be to blame, better screening in this population may help to close the gap.

For your next blood pressure check, you may want to roll up both sleeves, according to the May 2012 issue of the Harvard Heart Letter.

An analysis of 20 different studies found that a substantial difference between the blood pressure readings from a person’s right and left arms may signal increased risk for cardiovascular problems. People with arm-to-arm pressure differences of 15 points or more were twice as likely to have peripheral artery disease (PAD) compared with those who had similar readings in both arms. Arm-to-arm pressure differences of 10 to 15 points or more also boosted the chances of having a stroke or dying from cardiovascular disease.

Having a stroke or dying from heart disease are obviously dire concerns. But don't underestimate the consequences of PAD, either. In this condition, arteries in the arms, legs, or other body parts beyond the heart and brain become clogged, usually from atherosclerosis, the buildup of fatty plaque that is also behind most heart attacks and strokes. An estimated 12 million Americans have PAD. Some of these people suffer from limited mobility and debilitating leg pain, but, says the Heart Letter, it can also lurk silently. PAD can be deadly as well, which might make differences in blood pressure from arm to arm an important early warning sign.

If you check your blood pressure at home, the May Harvard Heart Letter offers the following tips to ensure as accurate a reading as possible. Similar steps should also be undertaken in the doctor's office.

• Avoid caffeine, alcohol, and nicotine for 30 minutes before you take the reading.
• Sit quietly for a few minutes with your feet on the floor before inflating the cuff.
• Rest your arm so your elbow is level with your heart, and wrap the cuff over the bare skin of your upper arm.
• Take two readings. If they’re close, average them. If not, take a third reading and average the three.
• Repeat the procedure in the other arm.

Read the full-length article: "Arm-to-arm variations in blood pressure may warrant attention"

Humans once spent their nights in relative darkness. No longer. When the sun sets, TVs, computers, mobile devices, and artificial lighting burn on. The May issue of the Harvard Health Letter reports that this aspect of modern life may be great for efficiency, but not for health. At night, light throws the body's biological clock—the circadian rhythm—out of whack. Sleep suffers. The combination of poor sleep and exposure to artificial light exposure may contribute to a number of health problems.

Studies have linked working the night shift and getting exposed to light at night to several types of cancer (including breast and prostate cancer), diabetes, heart disease, and obesity. It's not exactly clear why nighttime light exposure seems to be problematic. It could be because exposure to light at night curbs the secretion of melatonin, a hormone that influences circadian rhythms.

But all light is not created equal, says the Health Letter. Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. While light of any kind can suppress the secretion of melatonin, blue light does so more powerfully. In an experiment, researchers exposed people to 6.5 hours of light—either blue or green. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much.

While fluorescent lightbulbs and LED lights are much more energy-efficient than incandescent lights, they also tend to produce more blue light. That means the proliferation of electronic devices with screens, as well as energy-efficient lighting, is increasing exposure to blue wavelengths, especially after sundown.

What can you do? The editors of the Harvard Health Letter make the following recommendations:

• Use dim red lights for nightlights. Red light has the least power to shift circadian rhythm and suppress melatonin.
• Avoid looking at brightly lit screens beginning two to three hours before bed.
• If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses.
• Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.

Read the full-length article: "Blue light has a dark side"

Is smoking just a little bit, or only now and then, really a health problem? Yes, says the May issue of Harvard Men’s Health Watch. Light and intermittent smoking are nearly as bad as heavy smoking.

The way doctors explain risk and smoking exposure may underplay the sizable risks of light smoking, giving some smokers false reassurance. Physicians traditionally quantify smoking in terms of “pack-years.” In this system, smoking one pack of cigarettes a day for one year equals one pack-year. When doctors point out that the risks of smoking rise with increasing pack-years of exposure, patients may mistakenly assume that light smoking is minimally hazardous or even safe. A recent study shatters that illusion.

To evaluate the effects of light smoking, researchers from the University of California, San Francisco, reviewed over 800 published studies of smoking in adults ages 18 and older. They homed in on 45 studies that met their standards for scientific excellence and competence. Although the individual investigations used different criteria for light and intermittent (“social”) smoking, each provided a careful evaluation of the health risks of low-dose cigarette exposure. All in all, light and intermittent smoking is nearly as dangerous as heavy smoking. The results are eye-opening, and, according to Harvard Men’s Health Watch, should cause health care professionals to reconsider the pack-years model of explaining smoking risk.

Despite new drugs that combat the urge to smoke and a wide variety of nicotine-replacement products, quitting smoking—whether light or heavy—remains a difficult undertaking. The May Harvard Men’s Health Watch offers the following tips:

• Make a list of reasons to quit and another list of people who have kicked the habit. These lists will help remind you why you want to quit and show you that other people who are no stronger or smarter than you have succeeded. Keep your lists handy and refer to them whenever you begin to waver.
• Pick a quitting date and stick to it. Plan to quit on a special day, such as a birthday. Steer clear of stressful periods, and avoid holidays if you are likely to be invited to smoke-filled parties.
• Encourage the smokers in your household or circle of friends to join you in quitting. An important study found that smoking behavior spreads through both close and distant social ties; your resolve and success can help your friends and, ultimately, your community.

Read the full article: "Light smoking: Dangerous in any dose"

Millions of women experience pain before, during, or after sexual intercourse—a medical condition called dyspareunia. This common problem can sap sexual desire and pleasure, strain relationships, and erode a woman’s quality of life. For postmenopausal women, in particular, it can bring up issues of aging and body image. Many women suffer in silence because they’re embarrassed or can’t find a doctor who specializes in problems of this nature. The May 2012 issue of the Harvard Women’s Health Watch describes how dyspareunia can be treated, and guides women to get the help they need.

Painful intercourse has many possible causes, including hormonal changes, medical and nerve conditions, skin diseases, and emotional problems such as anxiety and depression. Often, several are at work. The decline in estrogen production at menopause can thin vaginal tissue, resulting in dryness, burning, and pain. Another culprit is vestibulodynia, a chronic pain syndrome that causes discomfort with any kind of touch or pressure in the area around the vagina. Psychological factors may be involved, especially in women who associate the vaginal area with fear or injury.

Treatment often requires a multifaceted approach that includes medications and other therapies as well as self-care practices. These are some frequently prescribed strategies for managing dyspareunia:

Low-dose vaginal estrogen. This is the main treatment for painful vaginal changes related to menopause. It can also help in some cases of vestibulodynia and vulvar skin problems. Vaginal estrogen has less risk of side effects than oral estrogen.

Pelvic floor physical therapy. This relatively new technique hasn’t undergone rigorous study yet, but experts consider it safe and effective. A physical therapist uses hands-on techniques such as massage and gentle pressure to relax and stretch tightened tissues in the pelvic area. Women also learn exercises to help strengthen pelvic floor muscles, which may have been weakened by aging, childbirth, hormonal changes, and certain physical strains.

Counseling. Issues such as anxiety and poor communication in a relationship can contribute to painful sex, and painful sex can put stress on a relationship. Talking with a mental health professional or sex therapist may help.

Self-care. Treat vulvar skin gently. Wash with mild soap or plain water and pat dry. Avoid perfumed products such as bubble bath and douches. Choose cotton underwear, and avoid tight clothing.

Read the full-length article: "When sex gives more pain than pleasure"