Dyslipidemia and Metabolic Syndrome in Women – Nov 2009
The metabolic syndrome is a common problem in the population, with one recent community-base study demonstrating a prevalence of 16% of mid-life women1. Hypertriglyceridemia is associated with diabetes mellitus and obesity; together with low high density lipoprotein (HDL) cholesterol, these two factors alone are strongly linked to increased risk for cardiovascular disease in women2. It is therefore important to recognize the constellation of presenting signs and symptoms that constitute the metabolic syndrome and to counsel patients appropriately.
Definition
The metabolic syndrome consists of several components:
- Abdominal obesity
- Atherogenic dyslipidemia
- Elevated blood pressure
- Insulin resistance and/or glucose intolerance
- Proinflammatory state
- Prothrombotic state
The syndrome is believed to be important because the clustering of these risk factors accounts for more morbidity than their combination would otherwise suggest, an example of particularly unhealthy synergy.
Although precise clinical definitions vary, the National Cholesterol Education Program's Adult Treatment Panel III report presents the following criteria for definition for women3:
| Clinical Measurement | Cutoff level |
| Abdominal circumference | 88cm (35 inches) |
| Triglycerides | 150 mg/dL |
| HDL Cholesterol | 50 mg/dL |
| Elevated BP | 130/85 mm Hg |
| Fasting glucose | 110 mg/dL |
A woman who meets any 3 of the 5 criteria above is considered to have metabolic syndrome.
The above definition has been adjusted by the World Health Organization to include a smaller waist circumference for women of Asian descent. In Asian women, who tend to be petite and are less likely to be very obese, a waist circumference of 80cm is recommended as the cutoff level.
Further Assessment
A patient with the risk clustering of the metabolic syndrome is at high risk for cardiovascular disease. Individuals with this disorder should undergo a targeted family history to discover whether or not type2 diabetes or coronary artery disease is prevalent among other family members. A history of prothrombotic events (venous thromboembolism) among family members should be sought. In the absence of a family history, there is no indication for routine screening for thrombophilias. Although many individuals with metabolic syndrome will also have evidence of inflammation, such as high C-reactive protein (CRP), routine CRP screening has not yet been widely advocated.
It is important to rule out type 2 diabetes in patients with metabolic syndrome. A glucose tolerance test is usually not necessary. Periodic glucose monitoring should be performed, however.
Treatment
Patients with metabolic syndrome should be counseled to modify their lifestyles. Moderate reduction in caloric intake, sufficient to result in a 5-10% loss of body weight, should be undertaken, along with moderate exercise. These lifestyle changes may result in a reversal of the dyslipidemia, as measured by increasing HDL and decreasing triglycerides. Patients with metabolic syndrome may benefit from a consultation with a nutritionist to review their dietary intake. An eating pattern that is high in fresh fruits and vegetables and low in processed carbohydrates is generally beneficial, and a low glycemic eating pattern will help to minimize progression to glucose intolerance and frank diabetes.
When lifestyle measures are inadequate, women should be treated with pharmacologic agents to improve their lipid profiles. 'Statin' drugs can and should be used to assure that low density lipoprotein (LDL) cholesterol remains below 100 mg/dL. When HDL alone is the problem, niacin can be given to increase it. Flushing, sometimes mistaken for menopausal hot flashes, can accompany niacin therapy. Niacin can be taken in 500mg tablets or capsules twice a day. Long-acting forms of the vitamin may reduce the side effect of flushing. Triglycerides can usually be treated by dietary control, with some benefit from statin type drugs. Bile acid sequestrants can also be used to regulate very high triglycerides, but have significant side effects.
Hypertension should be controlled medically when needed. Women who have elevated blood pressure above 140/90 should receive pharmacotherapy and should not attribute their blood pressure elevations to 'white coat hypertension' or 'stress'. African-American women are at particularly high risk for hypertension and its complications, and should be most aggressively treated. Caucasian women under age 55 with mild hypertension may not require treatment. It is important to re-evaluate antihypertensive therapy in women who are planning to become pregnant.
- Torrens JI, Sutton-Tyrrell K, Zhao X, Matthews K, Brockwell S, Sowers M, Santoro N. Relative androgen excess during the menopausal transition predicts incident metabolic syndrome in midlife women: Study of Women's Health Across the Nation. Menopause 2008 )ct 27 [Epub ahead of print]
- Gotto AM. High-density lipoprotein cholesterol and triglycerides as therapeutic targets for preventing and treating coronary artery disease. Am Heart J 2002; 144:S33-42.
- Grundy SM, Brewer HB, Jr, Cleeman JI, Smith SC, Lenfant C. NHLBI/AHA Conference Proceedings: Definition of the Metabolic SyndromeReport of the National Heart, Lung and Blood Institute/American Heart Association Conference on Scientific Issues Related to Definition. Circulation 2004; 109:433-438.