The fact that the diagnostic criteria for metabolic syndrome vary between ethnic populations is testimony to significant nuances in the manifestation of metabolic syndrome in these groups. The original metabolic syndrome criteria were derived in mostly Caucasian populations, and some have argued for modification of individual criteria for specific ethnic subgroups, as has been done with waist circumference for patients of Asian origin. 
Approximately half of individuals with hypertension have OSA, and approximately half with OSA have hypertension. Ambulatory BP monitoring normally reveals a "dip" in BP of at least 10% during sleep. However, if a patient is a "nondipper," the chances that the patient has OSA is increased. Nondipping is thought to be caused by frequent apneic/hypopneic episodes that end with arousals associated with marked spikes in BP that last for several seconds. Apneic episodes are associated with striking increases in sympathetic nerve activity and enormous elevations of BP. Individuals with sleep apnea have increased cardiovascular mortality, in part likely related to the high incidence of hypertension. http://www.sandysidhumedia.com/wp-content/uploads/2013/12/SSM_Logo_White.png
According to the Mayo Clinic, doctors may use other tests to diagnose diabetes. For example, they may conduct a fasting blood glucose test, which is a blood glucose test done after a night of fasting. While a fasting blood sugar level of less than 100 milligrams per deciliter (mg/dL) is normal, one that is between 100 to 125 mg/dL signals prediabetes, and a reading that reaches 126 mg/dL on two separate occasions means you have diabetes.