Hypertension refers to a clinically significant increase in blood pressure and constitutes an important risk factor for cardiovascular disease (http://www.who.int/whr/2002/en/; ref. 72). Lifestyle exposures that elevate blood pressure, including sodium intake, alcohol and excess weight73 are well-described risk factors. Genetic factors are also important74,75. Estimates of λs are approximately 2.5-3.5.
