Obstructive sleep apnea (OSA) is a common but frequently undiagnosed sleep-related breathing disorder defined as an average of at least 10 apneic and hypopenic episodes per sleep hour, which leads to excessive daytime sleepiness. Multiple studies have shown OSA to be an independent risk factor for the development of essential hypertension, even after adjusting for age, gender, and degree of obesity.
In the United States, metabolic syndrome has a high prevalence in African Americans, particularly African American women, and this has been attributed to the higher prevalence of obesity, hypertension, and diabetes in this population.  However, the highest age-adjusted prevalence of metabolic syndrome in the United States is found in Mexican Americans, approximately 31.9% of whom had the condition (compared with 27% of the general population) in a 1988-1994 survey. 
This is true for two reasons. Not only are many fad diets low fat, but they are also low calorie. Your body is not stupid! It can see that you are not taking in enough energy to support your basal metabolic rate. Your basal metabolic rate is the number of calories that your body requires to run your heart, brain, liver, digestive system, lungs etc. This critical number is very responsive to the environment because back in the good old days food wasn’t widely available. If you weren’t able to find food for a few days then your whole system slowed down to require less calories and protect you from dying.
"Brittle" diabetes, also known as unstable diabetes or labile diabetes, is a term that was traditionally used to describe the dramatic and recurrent swings in glucose levels, often occurring for no apparent reason in insulin-dependent diabetes. This term, however, has no biologic basis and should not be used. Still, type 1 diabetes can be accompanied by irregular and unpredictable high blood sugar levels, frequently with ketosis, and sometimes with serious low blood sugar levels. Other complications include an impaired counterregulatory response to low blood sugar, infection, gastroparesis (which leads to erratic absorption of dietary carbohydrates), and endocrinopathies (e.g., Addison's disease). These phenomena are believed to occur no more frequently than in 1% to 2% of persons with type 1 diabetes.
As you lose weight your leptin levels drop, signalling to your body that it should probably start to slow things down. In this case you can feel hungry all of the time, but also sluggish and weight loss stops. Some people even see weight gain which can either send you into frustration nation… or alternatively lead you to cut more calories and drive your metabolic rate and gut hormone signalling down even further! Yikes!
In type 2 diabetes, there also is a steady decline of beta cells that adds to the process of elevated blood sugars. Essentially, if someone is resistant to insulin, the body can, to some degree, increase production of insulin and overcome the level of resistance. After time, if production decreases and insulin cannot be released as vigorously, hyperglycemia develops.
High blood pressure is a common and dangerous condition. Having high blood pressure means the pressure of the blood in your blood vessels is higher than it should be. But you can take steps to control your blood pressure and lower your risk of heart disease and stroke. About 1 of 3 U.S. adults—or about 75 million people—have high blood pressure.1 Only about half (54%) of these people have their high blood pressure under control.1 Many youth are also being diagnosed with high blood pressure.2 This common condition increases the risk for heart disease and stroke, two of the leading causes of death for Americans.3 Get more quick facts about high blood pressure, or learn more about high blood pressure in the United States.
Emerging data suggest an important correlation between metabolic syndrome and risk of stroke.  Each of the components of metabolic syndrome has been associated with elevated stroke risk, and evidence demonstrates a relationship between the collective metabolic syndrome and risk of ischemic stroke.  Metabolic syndrome may also be linked to neuropathy beyond hyperglycemic mechanisms through inflammatory mediators.