Blood pressure rises with aging and the risk of becoming hypertensive in later life is considerable.[37] Several environmental factors influence blood pressure. High salt intake raises the blood pressure in salt sensitive individuals; lack of exercise, obesity, and depression[38] can play a role in individual cases. The possible roles of other factors such as caffeine consumption,[39] and vitamin D deficiency[40] are less clear. Insulin resistance, which is common in obesity and is a component of syndrome X (or the metabolic syndrome), is also thought to contribute to hypertension.[41] One review suggests that sugar may play an important role in hypertension and salt is just an innocent bystander.[42]
Emerging data suggest an important correlation between metabolic syndrome and risk of stroke. [58] 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. [59] Metabolic syndrome may also be linked to neuropathy beyond hyperglycemic mechanisms through inflammatory mediators. [60]