Emergency department visits for hypertension with complications and secondary hypertension also rose, from 71.2 per 100,000 population in 2006 to 84.7 per 100,000 population in 2011, while again, admission rates fell, dropping from 77.79% in 2006 to 68.75% in 2011. The in-hospital mortality rate for admitted patients dropped as well, from 1.95% in 2006 to 1.25% in 2011. 
Another method is to have the individual wear a device that monitors and records the blood pressure at regular intervals during the day to evaluate blood pressure over time. This is especially helpful during the diagnostic process and can help rule out "white coat" hypertension, the high measurements that are sometimes present only when the person is in the doctor's office and not at other times. (See High Blood Pressure: Using an Ambulatory Blood Pressure Monitor on FamilyDoctor.org.)
Again, the answer to why has already been discovered! We have a 24hr clock in our body, known as the circadian rhythm. This rhythm controls what hormones are released and when, it controls our wake sleep rhythm and when working properly signals what physiological processes happen during the day and at night. When you think about it, it is a pretty simple concept that we should be eating during the day and not eating during our biological night. People who are ‘night owls’ often eat during their biological night and it has been shown that the insulin and glucose response to a meal eaten at night is that of a DIABETIC! I was shocked when I first discovered this! This means that even a ‘healthy’ thin person is predisposed to weight gain and gets stuck in fat storage mode if they eat all night long. This is aggravated in people who are predisposed to insulin resistance and metabolic hormone chaos!
The earliest surviving work with a detailed reference to diabetes is that of Aretaeus of Cappadocia (2nd or early 3rd century CE). He described the symptoms and the course of the disease, which he attributed to the moisture and coldness, reflecting the beliefs of the "Pneumatic School". He hypothesized a correlation of diabetes with other diseases, and he discussed differential diagnosis from the snakebite which also provokes excessive thirst. His work remained unknown in the West until 1552, when the first Latin edition was published in Venice.
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. 
[Guideline] Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018 Jun. 71(6):e13-e115. [Medline]. [Full Text].