Dr. Yohanan: Unfortunately, the most recent studies have shown that the cardiovascular benefit of exercise is rather modest. You begin to see some benefit in patients who can sustain moderate to vigorous exercise on the order of four to five hours a week. So it is not 30 minutes on the treadmill three of four times a week, as some people have heard. There are other reasons to exercise, such as weight loss, but exercise is not going to really affect lipid levels or yield much in terms of cardiovascular health. The bottom line is that diets low in fats and high in complex carbohydrates (such as the South Beach diet and the Dean Ornish diet) tend to help people lower their LDL modestly, but only if they really follow the diets religiously. In terms of weight loss, there was a study in JAMA this past year that compared several diets, and found that it didn’t much matter if the diet was low carb, low fat, Weight Watchers, whatever—as long as the dieter stuck to it. One important factor in the metabolic syndrome is high fructose corn syrup, which is found in many processed foods. It is difficult for the body to digest, and probably has some correlation with the increased prevalence of hyperlipidemia. So if someone comes into the office and has a high cholesterol level I think it's helpful to have a sense of how much processed food they're eating. As to what instruction to give, rather than prescribing a specific diet plan, I like what Michael Pollan says in The Omnivore's Dilemma: eat food, mostly plants, not too much. The corollary to that, also from Pollan is: don't eat food that doesn't rot. In any case, I tend to give a person three to six months to try lifestyle changes, and if they don’t reach their LDL goal, I start a statin.

TCPR: Can you give us a little primer on which statins are typically used?

Dr. Yohanan: Statins work by reducing the body’s production of cholesterol, and the ones that have been around the longest are Lipitor (atorvastatin) and Zocor (simvastatin). In terms of which to choose, it is a coin flip. Generic Zocor is now available, and so it is a bit cheaper than Lipitor, but Lipitor will soon go off patent as well. There are some newer statins, such as Crestor (rosuvas- tatin), but in general I am more in favor of medicines that have been around for a while, because you become familiar with the dos- ing and the side effects. Of course, many psychiatrists will be more comfortable referring patients to their primary care doctors to manage hyperlipidemia. In that case, be sure to ask your patients if they’re taking the medicine as prescribed.

TCPR: Are statins safe?

Dr. Yohanan: Yes, they are pretty safe. The big side effects you worry about with a statin are liver dysfunction [primarily elevations in alanine aminotransferate (ALT)] and rhabdomyolysis (a breakdown of muscle tissue, in which there is an elevation in the enzyme creatine phosphokinase, or CPK). If you are starting statin therapy you should get baseline liver function tests and a CPK.

TCPR: Is there anything that psychiatrists should be particularly watchful of in patients taking statins?

Dr. Yohanan: Since hypothyroidism can predispose patients to the myopathy caused by statins, you want to be particularly vigilant about monitoring thyroid stimulating hormone (TSH) if you have a patient on both lithium and statins.

TCPR: So let’s say you start a patient on statins. How frequently do you monitor their lipid levels?

Dr. Yohanan: You would check an LDL level about six weeks after you started the statin, then 12 weeks after that. Once you are at the goal LDL level you can check it every four to six months.

TCPR: Let’s move on to obesity. In psychiatry, we confront this issue especially when we prescribe some of the atypical antipsychotics. How should we monitor and treat this problem?

Dr. Yohanan: At a minimum, every psychiatrist who prescribes atypicals should have a scale in their office. You may want to have a tape measure to monitor waist circumference as well.

TCPR: What extra information does waist circumference give you beyond what you would learn from a patient’s weight? 

Dr. Yohanan: Waist circumference has traditionally been one of the criteria for metabolic syndrome. The reason is that when peo- ple gain weight, some tend to gain that weight in their extremities, whereas others gain in the waist, which we term abdominal obesity. Abdominal obesity is a specific risk factor for diabetes. But it’s far more important to simply measure weight, and then to calculate the BMI (Body Mass Index), which is weight (in kg) divided by the square of the height (in meters). There is also a formu- la for calculating BMI using pounds and inches, and the easiest way to do this is to go to one of many BMI calculator websites, such as the NIH site at http://www.nhlbisupport.com/bmi/. Patients with a BMI above 25 are considered overweight, and those above 30 are considered obese.

TCPR: So how do we help patients manage weight gain?

Dr. Yohanan: The first thing is to minimize the impact of the patient’s medication. For example, in one study, Zyprexa (olanzap- ine) led to an average weight gain of 37 pounds in a year (Strassnig M et al., Schizophr Res 2007 Jul;93:90-8). It is generally more