Weight control and antipsychotics: How to tip the scales away from diabetes and heart disease

As with weight gain, it is easier to prevent diabetes than to treat it. The psychiatrist can best help the patient with emerging carbohydrate dysregulation by collaborating with an internist, family physician, or endocrinologist.

Table 1

FACTORS RELATED TO HIGH RISK OF DEVELOPING TYPE 2 DIABETES

Weight gain with diabetes drugs Weight gain is associated not only with the use of antipsychotics but also with four classes of oral agents used to treat type 2 diabetes: sulfonylureas, meglitinides, phenylalanine derivatives, and thiazolidinediones. One class—biguanides—contributes to weight reduction, and one—alpha-glucosidase inhibitors—has a variable effect on body weight. These drugs also vary in their effects on serum lipids, including total cholesterol, LDL and HDL cholesterol, and triglycerides (Table 2).⁹

Many patients with type 2 diabetes require more than one agent to control plasma glucose. With time, insulin deficiency becomes more marked, and insulin therapy is frequently added to the regimen. Hypertension and hyperlipidemia are also very common in patients with type 2 diabetes and require medication to reduce the risk of cardiovascular events.¹⁰ As a result, the diabetic patient requiring antipsychotic drugs will likely need polypharmacy, and many of the drugs that might be used may lead to weight gain.

Assessing, managing weight gain

During each visit for the patient with schizophrenia, it is important to routinely weigh those receiving antipsychotics and ask about polydipsia and polyuria, which are early signs of incipient diabetes. A patient who is gaining significant weight (7% of baseline) while taking an antipsychotic and has risk factors for cardiovascular events (e.g., smoking, hypertension, hypertriglyceridemia) is a candidate for a change in antipsychotics.

Try to weigh patients at approximately the same time of day at each visit to compensate for possible diurnal weight changes related to polydipsia-hyponatremia syndrome.¹¹ Patients with this syndrome can gain 5 to 10 lbs (or more) per day and excrete the retained fluid at night. It occurs in 5 to 10% of chronically psychotic patients requiring institutional care and in 1 to 2% of outpatients. Patients with schizophrenia complicated by this syndrome may manifest polydipsia and polyuria secondary to psychosis rather than emerging diabetes. Thus, the clinician must be alert to both diabetes and the polydipsia-hyponatremia syndrome in this setting.

Weight-control approaches

Patients who are taking sedating antipsychotics (e.g., clozapine, olanzapine, or low-potency phenothiazines) may gain up to 30 lbs per year if they become physically inactive and do not reduce their food consumption. Thus, it is important to work with such patients to decrease their caloric intake.

A weight-loss program that produces a loss of 0.5 to 1% of body weight per week is considered safe and acceptable.¹² Mild to moderate obesity may be managed by reducing food intake by 500 calories and exercising 30 minutes each day.

CBT Cognitive-behavioral therapy (CBT) may help stem weight gain associated with antipsychotic use. Umbricht et al provided CBT to six patients with chronic psychosis who were receiving clozapine or olanzapine. Therapists in group and individual sessions focused on the causes of weight gain, lowcalorie nutrition, weight-loss guidelines, exercise programs, and relaxation strategies. Across 8 weeks, patients’ mean BMI decreased from 29.6 to 25.1 kg/m²

Table 2

METABOLIC EFFECTS OF ORAL ANTIHYPERGLYCEMIC DRUGS

Weight management program The Weight Watchers weight management program has shown mild success when offered to men and women with schizophrenia or schizoaffective disorder. Twenty-one patients who had gained an average of 32 lbs while taking olanzapine were enrolled in a Weight Watchers program at a psychiatric center.¹⁴ Mean starting BMI was 32 kg/m² among the 11 patients who completed the 10-week program. Those 11 lost an average of 5 lbs.

All seven men lost weight. Three of the four women gained weight, and one woman lost 13 lbs. Study subjects remained clinically stable during the 10-week study. Two of the three women who did not lose weight had disabling psychiatric symptoms. Participation rates were similar to those of typical Weight Watchers clientele, suggesting that patients requiring antipsychotics might benefit from treatments used for other obese patients.

Patient education Educating patients about nutrition and exercise may help them control their rate of weight gain during antipsychotic therapy.