Dr. Graham Jackson FRCP FACC FESC
Consultant Cardiologist, Cardiothoracic Centre
6th Floor, East Wing, St Thomas’ Hospital
Lambeth Palace Road, London SE1 7EH
February 2009
There remains considerable debate concerning the existence or not of the “metabolic syndrome” (1). The simplest approach is to regard it as an umbrella term for five key cardiovascular risk factors – abdominal obesity, increased fasting glucose (not diabetes), hypertension, increased triglycerides and decreased HDL cholesterol. Central obesity is the common denominator and when any two of the other risk factors are added the metabolic syndrome is defined (2). The metabolic syndrome increases coronary heart disease and stroke risk up to three-fold with an even greater risk for developing diabetes. Importantly for the sexologist is the recognition that erectile dysfunction and hypogonadism may precede the diagnosis or be a consequence of the metabolic syndrome(3). The sexologist and urologist may therefore have a pivotal role in reducing cardiovascular risk by being alert to the link and acting to identify subsequent cardiovascular and diabetic risk.
Physical Appearances
The definition of central obesity requires a tape measure placed 1cm above the umbilicus or mid-way between the lowest rib and iliac crest. With the patient breathing out and relaxed the tape measure is placed around the naked waist. In the Table are the measurements by ethnic group and gender:
Ethnic group
Waist circumference for central obesity in cm.
Europeans
≥ 94 men
≥ 80 women
Chinese
≥ 90 men
≥ 80 women
Japanese
≥ 90 men
≥ 85 women
South Asian
≥ 90 men
≥ 80 women
In the absence of specific data include South and Central Americans in the South Asian category and Sub-Saharan Africans and Arabs in the European category.
Other markers of risk
· A raised triglycerides – >1.7 mmol/L
· Reduced HDL cholesterol – <1.0 mmol/L in men and <1.3 mmol/L in women
· Hypertension – ≥130/85 mmHg or on treatment
· Fasting glucose > 6.1 mmol/L (probably 5.6 mmol/L)
Any two plus central obesity equals the metabolic syndrome definition.
Treatment
Lifestyle changes are essential. Regular exercise and a decreased calorie intake will lead to weight reduction. The Mediterranean diet consuming more fruits, vegetables, nuts, whole grains and olive oil reduces blood pressure, fasting glucose and triglycerides and may reduce the risk of the metabolic syndrome by 20% (4). Modest alcohol consumption (up to 14 units per week for women and 21 units per week for men) can raise HDL cholesterol but the calorie content of alcohol needs to be considered.
Global Risk Reduction
No cardiovascular risk factor should be judged in isolation. The “metabolic syndrome” is really a cluster of cardiovascular risk factors, all of which need to be addressed. In one study of pre-diabetic patients aggressive lifestyle changes resulted in a 60% reduction in developing future diabetes compared to a control group (5).
Who to Refer
The sexologist or urologist may see patients before a cardiac event. The opportunity exists to screen for cardiac risk and refer for specialised advice whilst at the same time treating the sexual issues and providing lifestyle advice. There is no need to collect risk factors – one is enough to justify action – and remember ED alone is a marker for cardiac risk (6).
References
1. Khan R, Buse J, Ferrannini E, Stern M. The metabolic syndrome : time for a critical appraisal. Diabetes Care 2005; 28: 2289-304
2. Opie LH. Metabolic Syndrome. Circulation 2007; 115: e32-e35 www.circulationaha.org
3. Makhsida N, Shah J, Yan G et al. Hypogonadism and metabolic syndrome : implications for testosterone therapy. J Urol 2005; 174: 827-34
4. Esposito K, Ciotola M, Giugliano F et al. Mediterranean diet improves erectile function in subjects with the metabolic syndrome. Int J Impot Res 2006; 18: 405-410
5. Tuomilehto J, Lindston J, Eriksson J et al. Prevention of type-2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med 2001; 344: 1343-1350
6. Jackson G. The metabolic syndrome and erectile dysfunction : multiple vascular risk factors and hypogonadism. Eur Urol 2006; 50: 426-7