Metabolic syndrome
The metabolic syndrome, also known as the dysmetabolic syndrome, metabolic syndrome X, or insulin resistance syndrome, is a major public health concern worlwide. The growing obesity epidemic is its most noticeable effect,[1] but the metabolic syndrome can be present in the absence of frank obesity. Almost one fourth of Americans have metabolic syndrome, and the proportion keeps raising.[2] The metabolic syndrome is a serious disturbance of body metabolism and physiology, consisting of resistance of certain cell types of the body to the ability of the hormone insulin to promote cellular entry of the energy-rich molecule, glucose, and two or more of the following abnormalities: high blood pressure (or use of drugs to control hypertension); high levels of serum triglycerides; low levels of high-density lipoprotein (HDL) cholesterol; overweight; detectable levels of the protein, albumin, in the urine (microalbuminuria). The abnormalities of triglyceride levels typically associate with other blood fat disturbances (dyslipidemia) that foster atherosclerosis (buildup of plaques in artery walls the predispose to reduced blood flow to vital organs (e.g., the heart) and to formation of blood clots that can break off and clog vital vessels to the brain, causing stroke. The biochemical factors that promote clot formation are also stimulated in the metabolic syndrome, and the syndrome appears to be one of a chronic state of inflammation, the typical body response to tisue injury.
Criteria
There exists different clinical definitions of the metabolic syndrome. There is disagreement about the relative importance of insulin resistance in the cluster of risk factors, and two definitions do not require this risk factor.[3]
It is defined by the World Health Organisation using the following criteria:
- Insulin resistance, identified by one of the following:
- Type 2 diabetes
- Impaired fasting glucose
- Impaired glucose tolerance
- or, for those with normal fasting glucose levels (<110mg/dL), glucose uptake below the lowest quartile for background population under investigation under hyperinsulinemic, euglycemic conditions
- in conjunction with any two of the following:
- Antihypertensive medication and/or high blood pressure (≥140mmHg systolic or ≥90mmHg diastolic)
- Plasma triglycerides ≥150mg/dL (≥1.7mmol/L)
- HDL cholesterol <35mg/dL (0.9mmol/L) in men or <39mg/dL (1.0mmol/L) in women
- BMI (Body Mass Index) >30kg/m² and/or waist:hip ratio >0.9 in men, >0.85 in women
- Urinary albumin excretion rate ≥20μmg/g or albumin: creatinine ratio ≥30 mg/g.[4]
Psychological components
An interesting but yet underdevelopped aspect of research on the metabolic syndrome relates to the syndrome's psychological components. Cynical hostility appears to predict the metabolic syndrome, which in turn predicts cardiovascular disease.[5] Worthy of note, in a study, only high hostility and low HDL cholesterol predicted coronary heart disease.[6] At present, there is no agreement on the nature of the relationship between hostility and the metabolic syndrome.
Consequences of the metabolic syndrome
Diabetic complications and cardiovascular diseases
The metabolic syndrome is thus a cluster of risk factors for diabetes complications and cardiovascular diseases. The syndrome includes proinflammatory and prothrombotic features.[4]
Other consequences
The metabolic syndrome could also promote the development of cancer, polycystic ovary syndrome (PCOS), and nonalcoholic fatty liver disease".[7]
Cancer
A number of components of the metabolic syndrome (MS) are likely to contribute, especially in combination, to cause cancer. While the MS-colon cancer is the most convincing link, other epidemiologic studies investigating the link of MS with other cancers are awaited.[8]
References
- ↑ ABC News: The World Is Getting Rounder. Retrieved on 2007-11-17.
- ↑ What Is Metabolic Syndrome?. Retrieved on 2007-11-17.
- ↑ Meigs JB, Rutter MK, Sullivan LM, Fox CS, D'Agostino RB, Wilson PW (2007). "Impact of insulin resistance on risk of type 2 diabetes and cardiovascular disease in people with metabolic syndrome". Diabetes Care 30 (5): 1219–25. DOI:10.2337/dc06-2484. PMID 17259468. Research Blogging.
- ↑ 4.0 4.1 Grundy SM, Brewer HB, Cleeman JI, Smith SC, Lenfant C (2004). "Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition". Arterioscler. Thromb. Vasc. Biol. 24 (2): e13–8. DOI:10.1161/01.ATV.0000111245.75752.C6. PMID 14766739. Research Blogging.
- ↑ Nelson TL, Palmer RF, Pedersen NL (2004). "The metabolic syndrome mediates the relationship between cynical hostility and cardiovascular disease". Experimental aging research 30 (2): 163–77. DOI:10.1080/03610730490275148. PMID 15204630. Research Blogging.
- ↑ Niaura R, Todaro JF, Stroud L, Spiro A, Ward KD, Weiss S (2002). "Hostility, the metabolic syndrome, and incident coronary heart disease". Health psychology : official journal of the Division of Health Psychology, American Psychological Association 21 (6): 588–93. PMID 12433011. [e]
- ↑ Biddinger SB, Kahn CR (2006). "From mice to men: insights into the insulin resistance syndromes". Annu. Rev. Physiol. 68: 123–58. DOI:10.1146/annurev.physiol.68.040104.124723. PMID 16460269. Research Blogging.
- ↑ Cowey S, Hardy RW (2006). "The metabolic syndrome: A high-risk state for cancer?". Am. J. Pathol. 169 (5): 1505–22. PMID 17071576. [e]