Dear Doctor: I've suffered from atrial fibrillation for several years now. I recently read that overall heart health could reduce the risk of the condition. Is it too late for me, considering I've already been diagnosed?

Dear Reader: You're not alone in asking this question, especially in light of this new report. Atrial fibrillation, or AFib, affects more than 2 million people in the United States, making it the most common heart-rhythm abnormality in the country.

For those not familiar with the condition: The atria are the chambers of the heart that pump blood into the ventricles, which are the more muscular chambers that then push blood out to the rest of the body. Injuries to the atria can happen for a variety of reasons, leading to abnormal electrical conduction and what is known as atrial fibrillation. In these circumstances, the atria quiver instead of contracting rhythmically, creating the possibility that the blood in the chambers will form a clot, travel to the brain and cause a stroke. In fact, 15 percent of all strokes are caused by AFib.

The new study you reference assessed ways to prevent AFib. Researchers analyzed data from 13,182 men and women, ages 45 to 64, who had filled out questionnaires from 1987 through 1989 about their health habits. The participants were reassessed four more times: from 1990 through 1992; from 1993 through 1995; from 1996 through 1998; and from 2011 through 2013. Data included height and weight, smoking status, blood pressure, cholesterol levels and blood sugar levels. Questionnaires also assessed participants' diet and level of physical activity.

From all of this information, the authors divided people into three different health categories: inadequate, average or optimal. Over the years of the study, up until Dec. 31, 2014, the authors also identified those in each category who developed atrial fibrillation.

After adjusting for confounding factors, the authors found that people in the average health category had a 37 percent decreased risk of AFib compared to those in the inadequate health category. And those in the optimal health category had a 57 percent decrease in risk compared to those with inadequate health.

Note that diet and cholesterol level did not appear to have any effect upon atrial fibrillation.

One problem with the study, however is that the authors didn't explain how they adjusted for binge drinking, which is a major risk factor for this condition. In fact, AFib occurs in 60 percent of binge drinkers. But even moderate amounts can cause the abnormal rhythm. A 2014 study found that, compared to people who had less than one drink per week, those who had seven to 14 drinks per week had a 14 percent greater risk of atrial fibrillation; those with 15 to 21 drinks per week had a 39 percent greater risk of AFib. Another factor on which the researchers were unclear is how they controlled for the impact of exercise; moderate exercise decreases the risk of AFib, while extreme exercise increases the risk.

If you have had atrial fibrillation for many years, it may be difficult for your heart to resume a normal rhythm.

However, removing risk factors such as hypertension, diabetes, smoking, sleep apnea and excessive alcohol consumption can reduce the frequency of AFib. Further, among people who underwent a heart ablation procedure to stop AFib, 62 percent of those who made lifestyle changes were able to eliminate the condition, compared to 26 percent of those who didn't make such changes. And, as we said, moderate exercise may slightly decrease the risk of AFib.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Is it true that HIV can now be considered a chronic disease? Does that mean people are no longer looking for a true cure?

Dear Reader: To answer this, we first have to agree on the meaning of "chronic disease," which, believe it or not, has more than a few definitions. Rather than take a deep dive into those important but perhaps snooze-inducing distinctions, let's go with the most common understanding of the term. That is, a chronic disease is one that cannot be cured, but with ongoing medication and treatment can be managed. And thanks to the stunning success of antiretroviral therapies, infection with HIV now fits that definition of chronic disease.

As most of our readers probably know, HIV is shorthand for the human immunodeficiency virus. The virus undermines the immune system by attacking certain white blood cells that are vital to the ability to fight infection. The loss of these white blood cells leaves HIV-positive individuals vulnerable to disease, infection and complications of illness. AIDS is the stage of HIV infection at which damage to the immune system is profound, and patients are unable to fight off a host of opportunistic infections. For people with AIDS, infections that a healthy immune system would brush off become potentially deadly.

According to one school of thought, the antiretroviral drugs that are now the main treatment regimen for people living with HIV amount to a functional cure. But just because infection with HIV is no longer a near-certain path to developing AIDS, that doesn't mean living with the virus is problem-free. The drugs, which must be taken daily and for the rest of an infected person's life, are extremely powerful. Cumulative toxicity becomes a real concern. And while the antiretrovirals do prevent an HIV infection from progressing to full-blown AIDS, the individual's immune system remains affected by the presence of the virus and, consequently, is less robust. Add in the ability of HIV, like all viruses, to rapidly mutate and become resistant to existing drugs, and infection remains a serious condition.

Compared to the early days of the HIV crisis, when each new development in decoding and understanding the virus was heralded, things may now seem quiet on the news front. But as researchers focus on both prevention and a cure, the science continues to move forward.

For many, the idea of a vaccine is the gold standard. In that regard, there has been encouraging news from researchers at the University of Massachusetts, who recently reported that they are about to enter into a phase 1 trial to assess the safety of a potential HIV vaccine. Other scientists are looking into topical medications that can stop the virus at the site of infection.

And thanks to ongoing advances in the field of immunotherapy, there is renewed hope of finding a cure. Earlier this year, researchers at the University of Maryland reported success in engineering immunotherapeutics that target and neutralize the virus on multiple fronts and across multiple strains. (And yes, that's a greatly simplified explanation.)

An estimated 36 million people worldwide now live with HIV, and while scientific advances don't always make headlines, they do make a difference.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I am an 88-year-old man who, until recently, played a decent game of golf twice a week. Then, about 18 months ago, I began to experience weakness throughout my body, especially in my legs. Casual research indicated that Crestor, a statin I have taken for several years, was likely to blame. My doctor took me off Crestor two months ago in hopes that the condition would reverse, but any improvement is insignificant. Why do doctors prescribe debilitating drugs with no regard to side effect warnings?

Dear Reader: Pharmaceuticals are a large part of a doctor's armamentarium in treating and preventing disease. The medication you mentioned, Crestor (rosuvastatin), is one of many statins used to lower cholesterol. These medications are beneficial in decreasing the possibility of heart attacks and strokes in people who are at risk, as data have repeatedly born out.

But statins also can lead to mild or debilitating muscle aches in 1.5 to 5 percent of people taking them. In rare cases, they can cause a severe breakdown of muscle, a condition known as rhabdomyolysis. Theoretically, water-soluble statins such as rosuvastatin, pravastatin and fluvastatin are less likely to cause muscle aches; in fact, I've seen rhabdomyolysis twice with Crestor.

As your doctor knows, when a patient experiences muscle aches while taking a statin, the best course of action is to stop taking the drug. Sometimes the reduction in muscle aches is immediate, sometimes not. The average time that it takes for people to develop muscle aches with a statin is 6.3 months; the average time it takes for the muscle aches to improve after stopping a statin is 2.3 months.

Patients should be warned about statins' potential side effects and be monitored for them. But to come back to your question concerning what a doctor should do about medications with both potential benefits and potential side effects, my answer is don't overprescribe them.

As for statins, many in the medical community advocate their use for a large swath of the general population, often using cardiovascular risk calculators to estimate a person's chances of a heart attack and thus their need for a cholesterol-lowering medication. However, preliminary findings from a 2016 Kaiser study question the efficacy of the calculator, which means many doctors who make statin recommendations may be overestimating the risk of a cardiovascular event.

That said, statins are far from the only commonly prescribed drugs with a substantial risk of side effects.

Anti-hypertensive medications, which effectively lower the risk of heart attacks and strokes, can pose additional problems. Thiazide diuretics can lower sodium levels, sometimes to dangerous levels, leading to hospitalization and even death, while ACE inhibitors and angiotensin-receptor blockers can elevate potassium levels and cause abnormal heart rhythms.

Opiates control pain in the short term but can be abused in the long term. And, of course, chemotherapy, while curative for many cancers, often has severe side effects.

While doctors can't go through every potential side effect of a medication, they do need to take the time to describe the most common risks. And they need to be careful in not overprescribing medication.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)