In most people with established essential hypertension, increased resistance to blood flow (total peripheral resistance) accounts for the high pressure while cardiac output remains normal. There is evidence that some younger people with prehypertension or 'borderline hypertension' have high cardiac output, an elevated heart rate and normal peripheral resistance, termed hyperkinetic borderline hypertension. These individuals develop the typical features of established essential hypertension in later life as their cardiac output falls and peripheral resistance rises with age. Whether this pattern is typical of all people who ultimately develop hypertension is disputed. The increased peripheral resistance in established hypertension is mainly attributable to structural narrowing of small arteries and arterioles, although a reduction in the number or density of capillaries may also contribute.
Both numbers in a blood pressure reading are important. But after age 50, the systolic reading is even more significant. Isolated systolic hypertension is a condition in which the diastolic pressure is normal (less than 80 mm Hg) but systolic pressure is high (greater than or equal to 130 mm Hg). This is a common type of high blood pressure among people older than 65.
It is common for there to be a development of visceral fat, after which the adipocytes (fat cells) of the visceral fat increase plasma levels of TNF-α and alter levels of a number of other substances (e.g., adiponectin, resistin, and PAI-1). TNF-α has been shown not only to cause the production of inflammatory cytokines, but also possibly to trigger cell signaling by interaction with a TNF-α receptor that may lead to insulin resistance. An experiment with rats fed a diet with 33% sucrose has been proposed as a model for the development of metabolic syndrome. The sucrose first elevated blood levels of triglycerides, which induced visceral fat and ultimately resulted in insulin resistance. The progression from visceral fat to increased TNF-α to insulin resistance has some parallels to human development of metabolic syndrome. The increase in adipose tissue also increases the number of immune cells present within, which play a role in inflammation. Chronic inflammation contributes to an increased risk of hypertension, atherosclerosis and diabetes.
Naturally, since the metabolic syndrome is a disorder of energy distribution and storage, fat accumulation explains for a significant proportion of cardiovascular risk. However, obesity without metabolic syndrome does not confer a significant cardiovascular risk, whereas metabolic syndrome without obesity is associated with a significant risk of diabetes and cardiovascular disease. This association of metabolic syndrome with diabetes can be illustrated by generalized lipodystrophy (near complete absence of adipose tissue). The animals and humans with generalized lipodystrophy develop signs of metabolic syndrome in the absence of adipose tissue; and the metabolic syndrome progresses to type 2 diabetes. Adipose tissue transplantation in transgenic mice with lipodystrophy can cure the type 2 diabetes.
First, the essence of MRT is to pack more exercise into less time. This is best achieved by employing high repetitions (15-20 reps per set, equating to about 60-65% 1RM) with minimal rest between sets4. The key to optimizing results is to train at maximal or near-maximal levels of effort. So take most sets to muscular failure or close to it (equating to a Rated Perceived Exertion [RPE] of 9 or 10 on a scale of 1-10). If you aren't sufficiently pushing yourself to complete each set, the metabolic effect and your results will suffer.
Studies in type 1 patients have shown that in intensively treated patients, diabetic eye disease decreased by 76%, kidney disease decreased by 54%, and nerve disease decreased by 60%. More recently the EDIC trial has shown that type 1 diabetes is also associated with increased heart disease, similar to type 2 diabetes. However, the price for aggressive blood sugar control is a two to three fold increase in the incidence of abnormally low blood sugar levels (caused by the diabetes medications). For this reason, tight control of diabetes to achieve glucose levels between 70 to120 mg/dl is not recommended for children under 13 years of age, patients with severe recurrent hypoglycemia, patients unaware of their hypoglycemia, and patients with far advanced diabetes complications. To achieve optimal glucose control without an undue risk of abnormally lowering blood sugar levels, patients with type 1 diabetes must monitor their blood glucose at least four times a day and administer insulin at least three times per day. In patients with type 2 diabetes, aggressive blood sugar control has similar beneficial effects on the eyes, kidneys, nerves and blood vessels.
It has not been contested that cardiovascular risk factors tend to cluster together; the matter of contention has been the assertion that the metabolic syndrome is anything more than the sum of its constituent parts. Phenotypic heterogeneity (for example, represented by variation in metabolic syndrome factor combinations among individuals with metabolic syndrome) has fueled that debate. However, more recent evidence suggests that common triggers (for example, excessive sugar-intake in the environment of overabundant food) can contribute to the development of multiple metabolic abnormalities at the same time, supporting the commonality of the energy utilization and storage pathways in metabolic syndrome.
Metabolic syndrome is quite common. Approximately 32% of the population in the U.S. has metabolic syndrome, and about 85% of those with type 2 diabetes have metabolic syndrome. Around 25% of adults in Europe and Latin America are estimated to have the condition, and rates are rising in developing East Asian countries. Within the US, Mexican Americans have the highest prevalence of metabolic syndrome. The prevalence of metabolic syndrome increases with age, and about 40% of people over 60 are affected.
[Guideline] Skyler JS, Bergenstal R, Bonow RO, et al. Intensive glycemic control and the prevention of cardiovascular events: implications of the ACCORD, ADVANCE, and VA Diabetes Trials: a position statement of the American Diabetes Association and a Scientific Statement of the American College of Cardiology Foundation and the American Heart Association. J Am Coll Cardiol. 2009 Jan 20. 53(3):298-304. [Medline].