The primary problem in metabolic syndrome is insulin resistance. In the body's attempt to compensate for insulin resistance, extra insulin is produced, leading to elevated insulin levels. The elevated insulin levels can lead, directly or indirectly, to the characteristic metabolic abnormalities seen in these patients. Frequently, the insulin resistance will progress to overt type 2 diabetes, which further increases the risk of cardiovascular complications.
^ Jump up to: a b c d e f Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo Jr. JL, Jones DW, Materson BJ, Oparil S, Wright Jr. JT, Roccella EJ, et al. (December 2003). "Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure". Hypertension. Joint National Committee On Prevention. 42 (6): 1206–52. doi:10.1161/01.HYP.0000107251.49515.c2. PMID 14656957. Archived from the original on 20 May 2012. Retrieved 1 January 2012.
POPs primarily impact the thyroid gland by decreasing its ability to make thyroid hormone, disrupting thyroid hormones once they are made, and causing thyroid hormones to be removed from the body faster. If your metabolism is a large jumbo jetliner, the thyroid gland is one of the engines. POPs appear to work in part by blowing out the thyroid engine.
The clinical value of using "metabolic syndrome" as a diagnosis has previously been debated due to different sets of conflicting and incomplete diagnostic criteria. These concerns have led the American Diabetes Association and the European Association for the Study of Diabetes to issue a joint statement identifying eight major concerns on the clinical utility of the metabolic syndrome diagnosis.[69] The principal argument has been that when confounding factors such as obesity are accounted for, diagnosis of the metabolic syndrome has a negligible association with the risk of heart disease.[70]
Eating healthfully. The Dietary Approaches to Stop Hypertension (DASH) diet and the Mediterranean diet, like many healthy-eating plans, limit unhealthy fats and emphasize fruits, vegetables, fish and whole grains. Both dietary approaches have been found to offer important health benefits — in addition to weight loss — for people who have components of metabolic syndrome.
^ Alberti KG, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato KA, Fruchart JC, James WP, Loria CM, Smith SC (October 2009). "Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity" (PDF). Circulation. 120 (16): 1640–45. doi:10.1161/CIRCULATIONAHA.109.192644. PMID 19805654.
Many expert groups recommend a slightly higher target of 150/90 mmHg for those over somewhere between 60 and 80 years of age.[99][100][101][105] The JNC-8 and American College of Physicians recommend the target of 150/90 mmHg for those over 60 years of age,[13][106] but some experts within these groups disagree with this recommendation.[107] Some expert groups have also recommended slightly lower targets in those with diabetes[99] or chronic kidney disease with protein loss in the urine,[108] but others recommend the same target as for the general population.[13][103] The issue of what is the best target and whether targets should differ for high risk individuals is unresolved,[109] although some experts propose more intensive blood pressure lowering than advocated in some guidelines.[110]
Type 1 and type 2 diabetes were identified as separate conditions for the first time by the Indian physicians Sushruta and Charaka in 400–500 CE with type 1 associated with youth and type 2 with being overweight.[108] The term "mellitus" or "from honey" was added by the Briton John Rolle in the late 1700s to separate the condition from diabetes insipidus, which is also associated with frequent urination.[108] Effective treatment was not developed until the early part of the 20th century, when Canadians Frederick Banting and Charles Herbert Best isolated and purified insulin in 1921 and 1922.[108] This was followed by the development of the long-acting insulin NPH in the 1940s.[108]

Cataracts and glaucoma are also more common among diabetics. It is also important to note that since the lens of the eye lets water through, if blood sugar concentrations vary a lot, the lens of the eye will shrink and swell with fluid accordingly. As a result, blurry vision is very common in poorly controlled diabetes. Patients are usually discouraged from getting a new eyeglass prescription until their blood sugar is controlled. This allows for a more accurate assessment of what kind of glasses prescription is required.