Kidney Disease & Health Archive

A substance called trimethylamine N-oxide, which is produced when your body digests red meat, may raise the risk of cardiovascular problems.

Experts used to think that red meat raised your risk of heart disease simply because it was high in saturated fat. But today that picture has gotten more complicated thanks to the discovery of a metabolite — a substance produced during digestion and metabolism — called trimethylamine N-oxide, or TMAO.

According to a news article published June 11 in JAMA, three recent analyses have linked high blood levels of TMAO with a higher risk for both cardiovascular disease and early death from any cause. In one of those studies, researchers found that people with higher levels of TMAO in their blood may have more than twice the risk of heart attack, stroke, or other serious cardiovascular problems, compared with people who have lower levels. Other studies have found links between high TMAO levels and heart failure and chronic kidney disease.

Kidney stones strike twice as many men as women, but there are simple ways to stop their formation.

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If you've ever passed a kidney stone, you will never forget it, and you'll do anything to avoid it again. If you haven't, here is what you could expect: unbearable pain centered in your mid- to lower back that often comes in waves for 20 minutes to an hour at a time, until the tiny stones finally pass out of the body through your urine.

Unfortunately, as you age, the odds of getting kidney stones tends to rise. "Kidney stones are more common in men than in women, and in about half of people who have had one, kidney stones strike again within 10 to 15 years without preventive measures," says Dr. Brian Eisner, co-director of the Kidney Stone Program at Harvard-affiliated Massachusetts General Hospital.

Research we're watching

 Image: © wildpixel/Thinkstock

Can a high-tech water bottle help prevent painful kidney stones? The National Institutes of Health is hoping to find out. As many as one in every 11 people in the United States today has experienced a painful kidney stone. Kidney stones, a condition also referred to as nephrolithiasis or urolithiasis, are hard deposits that form inside the kidneys. They can be as small as a grain of sand or the size of a marble or larger. Symptoms of a stone include excruciating pain, interrupted urine flow, or bleeding inside the urinary tract. In short, kidney stones are definitely something you want to avoid. One way to keep stones from developing is to drink lots of water. The problem is, people who have had a stone often don't drink enough water to prevent new ones from forming, even when they're told how important it is to stay hydrated.

This trial, which will enroll 1,642 people, is trying to change that by using a "smart" water bottle that not only encourages people to drink a target amount of water each day, but also tracks their consumption using an app. People in the test group who reach their daily fluid intake targets will get financial incentives. Health coaches will provide added support to help participants achieve their goals. The findings could shed new light on how to get people to change their behavior to prevent this common and painful condition. For more information on the trial or to see if you qualify, visit www.health.harvard.edu/push.

Ask the doctors

Q. My bad cholesterol has been rising, and my doctor suggested that I start taking a statin. I've read that red yeast rice has many of the cholesterol-lowering benefits of a statin, and I would rather go the natural route. However, I recently heard on a newscast that red yeast rice can have adverse effects on the kidneys. Is it still safe for me to take this supplement?

A. It's true that red yeast rice, which contains monacolin K, a chemical that's identical to the active ingredient in the cholesterol-lowering drug lovastatin (Mevacor), may reduce your LDL (bad) cholesterol and lower your total cholesterol. However, an independent analysis of a dozen 600-milligram (mg) capsules of red yeast rice products conducted a few years ago found that the actual monacolin K content varied widely — from 0.1 mg to 10.9 mg. (The lowest dose of lovastatin is 20 mg.) In addition, one-third of the products were contaminated with a potentially toxic compound called citrinin, which can damage the kidneys. The Food and Drug Administration (FDA) has blocked the sale of red yeast rice supplements that contain enough of the active ingredient to make them as effective as lovastatin because they haven't undergone the drug approval process. Unlike FDA-approved drugs, supplements can be sold without proof of effectiveness and purity.

Fatty plaque in the arteries that feed the kidneys poses a danger to the heart and brain.

Controlling blood pressure and blood sugar will help both your heart and your kidneys.

On the surface, it's difficult to see how coronary artery disease and kidney damage might be related. But on the cellular level, the two conditions often go hand in hand. A closer look reveals the key. Underlying both conditions are two powerful risk factors: high blood pressure and diabetes, each of which damages the heart and kidneys independently.

If your weather forecaster warns about a heat wave this summer, take it seriously. A study by Harvard researchers found that people with certain conditions were at an increased risk of winding up in the hospital during periods of high heat. Their work was published Dec. 23, 2014, in The Journal of the American Medical Association.

Researchers analyzed hospitalization rates for specific diseases among 23 million Medicare beneficiaries between 1999 and 2010. What sent older adults to the hospital most often during a heat wave? Heatstroke, fluid and electrolyte disorders, kidney failure, urinary tract infections, and sepsis (a dangerous blood infection). For some diseases, the risk of hospitalization was elevated for up to five days after a heat wave day, suggesting that preventing and treating heat-related illnesses is crucial both during and after a heat wave.