Metabolic syndrome: Difference between revisions

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The '''metabolic syndrome''', also known as the dysmetabolic [[syndrome]], metabolic syndrome X, or insulin resistance syndrome, is defined as "a cluster of metabolic risk factors for cardiovascular diseases and type 2 diabetes mellitus. The major components of metabolic syndrome X include excess abdominal fat; atherogenic dyslipidemia; hypertension; hyperglycemia; insulin resistance; a proinflammatory state; and a prothrombotic (thrombosis) state."<ref name="title">{{cite web |url=http://www.nlm.nih.gov/cgi/mesh/2008/MB_cgi?term=Metabolic+Syndrome+X |title=Metabolic Syndrome X |accessdate=2007-12-18 |author=National Library of Medicine |authorlink= |coauthors= |date= |format= |work= |publisher= |pages= |language= |archiveurl= |archivedate= |quote=}}</ref>
The '''metabolic syndrome''', also known as the dysmetabolic [[syndrome]], metabolic syndrome X, or insulin resistance syndrome, is defined as "a cluster of metabolic risk factors for cardiovascular diseases and type 2 diabetes mellitus. The major components of metabolic syndrome X include excess abdominal fat; atherogenic dyslipidemia; hypertension; hyperglycemia; insulin resistance; a proinflammatory state; and a prothrombotic (thrombosis) state."<ref name="title">{{cite web |url=http://www.nlm.nih.gov/cgi/mesh/2008/MB_cgi?term=Metabolic+Syndrome+X |title=Metabolic Syndrome X |accessdate=2007-12-18 |author=National Library of Medicine |authorlink= |coauthors= |date= |format= |work= |publisher= |pages= |language= |archiveurl= |archivedate= |quote=}}</ref>


It is a major public health concern worldwide with the growing [[obesity]] epidemic is its most noticeable effect,<ref>{{cite web |url=http://abcnews.go.com/Health/Diet/wireStory?id=3761598 |title=ABC News: The World Is Getting Rounder |accessdate=2007-11-17 |format= |work=}}</ref> 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.<ref>{{cite web |url=http://www.nhlbi.nih.gov/health/dci/Diseases/ms/ms_whatis.html |title=What Is Metabolic Syndrome? |accessdate=2007-11-17 |format= |work=}}</ref>
It is a major public health concern worldwide with the growing [[obesity]] epidemic is its most noticeable effect,<ref>{{cite web |url=http://abcnews.go.com/Health/Diet/wireStory?id=3761598 |title=ABC News: The World Is Getting Rounder |accessdate=2007-11-17 |format= |work=}}</ref> 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.<ref>{{cite web |url=http://www.nhlbi.nih.gov/health/dci/Diseases/ms/ms_whatis.html |title=What Is Metabolic Syndrome? |accessdate=2007-11-17 |format= |work=}}</ref>
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<font face="Gill Sans MT"> Metabolic syndrome (MS) is a constellation of metabolic derangements associated with vascular endothelial dysfunction and oxidative stress and is widely regarded as an inflammatory condition, accompanied by an increased risk for cardiovascular disease.</font><ref name=rentoukas2012>Rentoukas E, Tsarouhas K, Kaplanis I, Korou E, Nikolaou M, et al. (2012) [http://dx.doi.org/10.1371/journal.pone.0035739 Connection between Telomerase Activity in PBMC and Markers of Inflammationand Endothelial Dysfunction in Patients with Metabolic Syndrome]. ''PLoS ONE'' 7(4): e35739.</ref>
<font face="Gill Sans MT"> Metabolic syndrome (MS) is a constellation of metabolic derangements associated with vascular endothelial dysfunction and oxidative stress and is widely regarded as an inflammatory condition, accompanied by an increased risk for cardiovascular disease.</font><ref name=rentoukas2012>Rentoukas E, Tsarouhas K, Kaplanis I, Korou E, Nikolaou M, et al. (2012) [http://dx.doi.org/10.1371/journal.pone.0035739 Connection between Telomerase Activity in PBMC and Markers of Inflammationand Endothelial Dysfunction in Patients with Metabolic Syndrome]. ''PLoS ONE'' 7(4): e35739.</ref>


==Criteria==
==Diagnostic 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.<ref name="pmid17259468">{{cite journal |author=Meigs JB, Rutter MK, Sullivan LM, Fox CS, D'Agostino RB, Wilson PW |title=Impact of insulin resistance on risk of type 2 diabetes and cardiovascular disease in people with metabolic syndrome |journal=Diabetes Care |volume=30 |issue=5 |pages=1219–25 |year=2007 |pmid=17259468 |doi=10.2337/dc06-2484 |issn=}}</ref>  
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.<ref name="pmid17259468">{{cite journal |author=Meigs JB, Rutter MK, Sullivan LM, Fox CS, D'Agostino RB, Wilson PW |title=Impact of insulin resistance on risk of type 2 diabetes and cardiovascular disease in people with metabolic syndrome |journal=Diabetes Care |volume=30 |issue=5 |pages=1219–25 |year=2007 |pmid=17259468 |doi=10.2337/dc06-2484 |issn=}}</ref>  


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** Urinary albumin excretion rate ≥20μmg/g or albumin: creatinine ratio ≥30 mg/g.<ref name="pmid14766739">{{cite journal |author=Grundy SM, Brewer HB, Cleeman JI, Smith SC, Lenfant C |title=Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition |journal=Arterioscler. Thromb. Vasc. Biol. |volume=24 |issue=2 |pages=e13–8 |year=2004 |pmid=14766739 |doi=10.1161/01.ATV.0000111245.75752.C6}}</ref>
** Urinary albumin excretion rate ≥20μmg/g or albumin: creatinine ratio ≥30 mg/g.<ref name="pmid14766739">{{cite journal |author=Grundy SM, Brewer HB, Cleeman JI, Smith SC, Lenfant C |title=Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition |journal=Arterioscler. Thromb. Vasc. Biol. |volume=24 |issue=2 |pages=e13–8 |year=2004 |pmid=14766739 |doi=10.1161/01.ATV.0000111245.75752.C6}}</ref>


==Psychological components==
==Risk factors for developing metabolic syndrome==
 
===Suboptimal dietary potassium===
In a cros-sectional study of a representative sample of the U.S. population (>25,000 participants analyzed), Sharma and colleagues<ref name=sharmas2012>Sharma S, Chonchol M, Kendrick JB. (2012) Low Dietary Potassium Intake Is Associated with an Increased Risk of Metabolic Syndrome in US Adults. ''American Society of Nephrology Annual Meeting: Abstract Sessions, Session: Fluid, Electrolyte, and Acid-Base Disorders; Date/Time: Friday, November 2, 2012 10:00 AM - 12:00 PM''</ref> concluded: "''Low dietary potassium intake is associated with an increased risk of metabolic syndrome in US adults''."
 
The study merely identifies an association of low dietary potassium in adults meeting the diagnostic criteria of metabolic syndrome.  The association analysis suggested an increased risk of metabolic syndrome of 35% for those with metabolic syndrome consuming 44 mmol/day [1701 mg/day] or less, when compared to those consuming 84 mmol/day [3290 mg/day] or more.  The recommended intake of potassium for adult Americans: 120 mmol/day [4700 mg/day].  Accordingly, we do not know what the relative risk of metabolic syndrome when the lower potassium intakes compare with intakes greater than 120 mmol/day, nor from the associational study, whether some type of interventional study that raised potassium  intake to >120 mmol/day could prevent or mitigate the metabolic syndrome.   
 
 
===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.<ref name="pmid15204630">{{cite journal |author=Nelson TL, Palmer RF, Pedersen NL |title=The metabolic syndrome mediates the relationship between cynical hostility and cardiovascular disease |journal=Experimental aging research |volume=30 |issue=2 |pages=163–77 |year=2004 |pmid=15204630 |doi=10.1080/03610730490275148 |issn=}}</ref> Worthy of note, in a study, only high hostility and low HDL cholesterol predicted coronary heart disease.<ref name="pmid12433011">{{cite journal |author=Niaura R, Todaro JF, Stroud L, Spiro A, Ward KD, Weiss S |title=Hostility, the metabolic syndrome, and incident coronary heart disease |journal=Health psychology : official journal of the Division of Health Psychology, American Psychological Association |volume=21 |issue=6 |pages=588–93 |year=2002 |pmid=12433011 |doi= |issn=}}</ref> At present, there is no agreement on the nature of the relationship between hostility and the metabolic syndrome.
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.<ref name="pmid15204630">{{cite journal |author=Nelson TL, Palmer RF, Pedersen NL |title=The metabolic syndrome mediates the relationship between cynical hostility and cardiovascular disease |journal=Experimental aging research |volume=30 |issue=2 |pages=163–77 |year=2004 |pmid=15204630 |doi=10.1080/03610730490275148 |issn=}}</ref> Worthy of note, in a study, only high hostility and low HDL cholesterol predicted coronary heart disease.<ref name="pmid12433011">{{cite journal |author=Niaura R, Todaro JF, Stroud L, Spiro A, Ward KD, Weiss S |title=Hostility, the metabolic syndrome, and incident coronary heart disease |journal=Health psychology : official journal of the Division of Health Psychology, American Psychological Association |volume=21 |issue=6 |pages=588–93 |year=2002 |pmid=12433011 |doi= |issn=}}</ref> At present, there is no agreement on the nature of the relationship between hostility and the metabolic syndrome.



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Metabolic syndrome
OMIM 605552
MedlinePlus 0072903
MeSH D024821

The metabolic syndrome, also known as the dysmetabolic syndrome, metabolic syndrome X, or insulin resistance syndrome, is defined as "a cluster of metabolic risk factors for cardiovascular diseases and type 2 diabetes mellitus. The major components of metabolic syndrome X include excess abdominal fat; atherogenic dyslipidemia; hypertension; hyperglycemia; insulin resistance; a proinflammatory state; and a prothrombotic (thrombosis) state."[1]

It is a major public health concern worldwide with the growing obesity epidemic is its most noticeable effect,[2] 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.[3]


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 tissue injury.

Metabolic syndrome (MS) is a constellation of metabolic derangements associated with vascular endothelial dysfunction and oxidative stress and is widely regarded as an inflammatory condition, accompanied by an increased risk for cardiovascular disease.[4]

Diagnostic 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.[5]

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.[6]

Risk factors for developing metabolic syndrome

Suboptimal dietary potassium

In a cros-sectional study of a representative sample of the U.S. population (>25,000 participants analyzed), Sharma and colleagues[7] concluded: "Low dietary potassium intake is associated with an increased risk of metabolic syndrome in US adults."

The study merely identifies an association of low dietary potassium in adults meeting the diagnostic criteria of metabolic syndrome. The association analysis suggested an increased risk of metabolic syndrome of 35% for those with metabolic syndrome consuming 44 mmol/day [1701 mg/day] or less, when compared to those consuming 84 mmol/day [3290 mg/day] or more. The recommended intake of potassium for adult Americans: 120 mmol/day [4700 mg/day]. Accordingly, we do not know what the relative risk of metabolic syndrome when the lower potassium intakes compare with intakes greater than 120 mmol/day, nor from the associational study, whether some type of interventional study that raised potassium intake to >120 mmol/day could prevent or mitigate the metabolic syndrome.


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.[8] Worthy of note, in a study, only high hostility and low HDL cholesterol predicted coronary heart disease.[9] 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.[6]

Other consequences

The metabolic syndrome could also promote the development of cancer, polycystic ovary syndrome (PCOS), and nonalcoholic fatty liver disease".[10]

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.[11]

References

  1. National Library of Medicine. Metabolic Syndrome X. Retrieved on 2007-12-18.
  2. ABC News: The World Is Getting Rounder. Retrieved on 2007-11-17.
  3. What Is Metabolic Syndrome?. Retrieved on 2007-11-17.
  4. Rentoukas E, Tsarouhas K, Kaplanis I, Korou E, Nikolaou M, et al. (2012) Connection between Telomerase Activity in PBMC and Markers of Inflammationand Endothelial Dysfunction in Patients with Metabolic Syndrome. PLoS ONE 7(4): e35739.
  5. 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.
  6. 6.0 6.1 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.
  7. Sharma S, Chonchol M, Kendrick JB. (2012) Low Dietary Potassium Intake Is Associated with an Increased Risk of Metabolic Syndrome in US Adults. American Society of Nephrology Annual Meeting: Abstract Sessions, Session: Fluid, Electrolyte, and Acid-Base Disorders; Date/Time: Friday, November 2, 2012 10:00 AM - 12:00 PM
  8. 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.
  9. 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]
  10. 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.
  11. Cowey S, Hardy RW (2006). "The metabolic syndrome: A high-risk state for cancer?". Am. J. Pathol. 169 (5): 1505–22. PMID 17071576[e]