The pressure generated by the beating heart forces the blood forward and stretches the elastic walls of the arteries. In between heartbeats, as the heart muscle relaxes, the arterial walls snap back to their original shape, moving the blood forward to the body’s tissues. With hypertension, the pressure in the arteries is high enough to eventually produce damage to the blood vessels.
Hypertension is defined as elevated blood pressure and is the leading cause globally of death and disability. It is the major risk factor for heart attack and stroke, and is also a significant risk factor for for chronic kidney disease and chronic heart failure. Because individuals with hypertension usually don’t have any symptoms, it is a disease that is often under-diagnosed. Diagnosis relies upon routine blood pressure screening to monitor and detect affected individuals.
At the end of the twelve-week study both groups lost weight, but the difference in the amount of muscle vs. fat loss was telling. The aerobic group lost 37 pounds over the course of the study. Ten of those pounds came from muscle. In contrast, the resistance-training group lost 32 pounds. None of the weight they lost came from muscle. When the resting metabolic rate of each group was calculated, the aerobic group was shown to be burning 210 fewer calories per day. The resistance-training group avoided this metabolic decline and instead was burning 63 more calories per day.
Diabetes mellitus occurs throughout the world but is more common (especially type 2) in more developed countries. The greatest increase in rates has however been seen in low- and middle-income countries,[101] where more than 80% of diabetic deaths occur.[105] The fastest prevalence increase is expected to occur in Asia and Africa, where most people with diabetes will probably live in 2030.[106] The increase in rates in developing countries follows the trend of urbanization and lifestyle changes, including increasingly sedentary lifestyles, less physically demanding work and the global nutrition transition, marked by increased intake of foods that are high energy-dense but nutrient-poor (often high in sugar and saturated fats, sometimes referred to as the "Western-style" diet).[101][106] The global prevalence of diabetes might increase by 55% between 2013 and 2035.[101]
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.