At what point do the five risk factors that predict type 2 diabetes and cardiovascular disease (CVD) signal metabolic syndrome? When and how often should psychiatrists check for metabolic abnormalities? How can you manage metabolic problems caused by a psychotropic that controls the patient’s psychiatric symptoms?
This article answers those questions by addressing:
- clinical guidelines for diagnosing metabolic syndrome
- suggested intervals for monitoring at-risk patients
- strategies for managing metabolic abnormalities with lifestyle changes or medication.
CASE REPORT: 'FAT' AND FRUSTRATED
Ms. S, age 37, has had bipolar disorder for 10 years. She has tried numerous medications including mood stabilizers, antidepressants, and atypical antipsychotics. The combination of quetiapine, 200 mg bid, and lithium, 300 mg bid, has controlled her symptoms for the past 6 months.
Her weight has increased 40 lbs over the past decade; much of her weight gain has occurred since the birth of her two children, ages 4 and 6. At 5 feet, 3 inches and 170 lbs, she is frustrated over her weight gain, especially on the eve of her 20-year high school reunion. She is convinced that her medications have prevented weight loss.
Her waist, measured at the umbilicus, is 37 inches. Her body mass index (BMI) is 30—indicating clinical obesity—and her blood pressure is in the high normal range (134/80 mm Hg). She has not had gestational diabetes and has not seen a medical doctor since her last pregnancy, but her father has type 2 diabetes and hypertension. She drinks wine occasionally at social events and does not smoke.
The psychiatrist orders a fasting lipid panel and fasting glucose test to further assess her risk of heart disease. Total cholesterol and low-density lipoprotein (LDL) cholesterol are normal. Triglycerides are 125 mg/dL (normal) and her high-density lipoprotein (HDL) is 45 mg/dL—5 mg/dL below normal for a woman her age. Fasting glucose is 86 mg/dL (normal).
The psychiatrist schedules a visit the following month to assess her cardiac and diabetic risk and to discuss weight-loss interventions.
Discussion. In a busy clinical setting, the psychiatrist must accurately gauge Ms. S’ metabolic risk and devise a management strategy. Do her weight and low HDL suggest metabolic syndrome? Is she overeating or making unhealthy dietary choices, or are her psychotropics causing weight gain? Would switching psychotropics lead to bipolar relapse?
IMPLICATIONS OF METABOLIC SYNDROME
Patients with metabolic syndrome are at increased risk for:
In a prospective study that followed 1,209 Finnish men over an average 11.4 years,4 men with metabolic syndrome were more likely than those with no metabolic problems to die from coronary heart disease, CVD, and any cause after adjustment for conventional cardiovascular risk factors. No one in either group had a baseline illness, suggesting that metabolic syndrome increases the risk of CVD or death regardless of whether underlying illness is present.
DEFINING METABOLIC SYNDROME
Metabolic syndrome is not a disease but a constellation of risk factors that provides a definable point of intervention before onset of type 2 diabetes or CVD.
According to the National Cholesterol Education Program—Adult Treatment Panel III (NCEP-ATP III), presence of three of these five criteria suggest metabolic syndrome:
- abdominal obesity
- insulin resistance
- high blood pressure
- elevated triglycerides
- below-normal HDL.
This definition offers a starting point for measuring risk factors in clinical practice and provides a definable target and parameters to avoid (Table 1).5 The guideline is also easy to follow: Waist circumference and blood pressure can be measured within seconds; blood glucose, HDL, and triglycerides can easily be measured before breakfast, after the patient has fasted for at least 6 hours.
Table 1
5 defined risk factors* for metabolic syndrome
| Risk factor | Clinically significant level |
|---|---|
| Abdominal obesity | |
| Men | Waist circumference >40 in (102 cm) |
| Women | Waist circumference >35 in (88 cm) |
| Blood pressure | |
| Systolic | >130 mm Hg |
| Diastolic | >85 mm Hg |
| HDL count | |
| Men | <40 mg/dL (<1.04 mmol/L) |
| Women | <50 mg/dL (<1.30 mmol/L) |
| Fasting glucose | |
| Men, women | >110 mg/dL (>6.11 mmol/L) |
| Triglycerides | |
| Men, women | >150 mg/dL (>1.70 mmol/L) |
| * If 3 risk factors are present, suspect metabolic syndrome | |
| HDL: high-density lipoprotein cholesterol | |
| Source: Adapted from reference 5. | |
MONITORING FREQUENCY
Although no empirical studies have addressed monitoring frequency for metabolic risk factors, several guidelines provide preliminary recommendations. Table 2 summarizes suggested intervals for monitoring weight, lipids, glucose, and waist circumference for patients taking atypical antipsychotics, based on recommendations from the 2004 American Diabetes Association (ADA) and American Psychiatric Association (APA) consensus development conference.6
Because atypicals are associated with serious metabolic risks, screen patients taking these agents for metabolic abnormalities at baseline and at regular intervals. Most guidelines recommend measuring blood pressure, BMI, waist circumference, fasting serum lipids (total, LDL, HDL, and triglycerides) and fasting glucose before starting or switching to an atypical and again 12 weeks later. Established risk for metabolic disturbances or dramatic metabolic changes (such as weight gain ≥7%, waist circumference ≥35 inches in women and ≥40 inches in men, or fasting blood sugars >110 mg/dL) demand more-frequent monitoring (ie, monitor high-risk patients quarterly).