PROFESSOR RAINFORD WILKS discussed some of the risk factors:
Genetics There is no doubt that there is a genetic contribution to hypertension and a lot of work has gone on in terms of the genetics, molecular biology, the genome and a few genes have been identified which are associated with hypertension.
Obesity There is no doubt that obesity increases the risk of hypertension. When you look at a population with hypertension, a greater proportion of them would be obese and even when you look at it prospectively (you follow a set of obese people who are not hypertensive and a set of non-obese people who are not hypertensive, if they remain in their respective categories), you will see a greater proportion of the obese people turning into hypertensives.
Salt There is no doubt about the role of salt in hypertension although it has been mired in a lot of controversy and the exact metabolic pathway has not been fully worked out. There are also discussions about whether obesity is working through salt, because the person who is obese is likely to have eaten more and eating more calories carries the risk of eating more salt, unless you are very careful to avoid it. Biologists are also looking at hormones such as renin and angiotensin which impact blood vessels and sodium retention to better understand hypertension.
Alcohol chronic alcohol intake has now been shown to increase the risk of hypertension. Binge drinking causes hypertension surges.
Psychosocial stress This is always hard to measure and just as hard to define but accepted as a risk factor. People living in more urbanised setting show a higher prevalence but it is difficult to say if it is a marker for something else or a specific factor on its own because you find that the person in the urban setting is the one who is going to eat the most salt, is less physically active, and exposed to more stressors. Multivariate analysis will separate the impact of the various factors.
Early life origin It's controversial but evidence is mounting that intrauterine and perinatal lives have an impact on development of chronic diseases and not just environmental factors. The biology is being worked out, involving hypothalomo-pituitary-adrenal axis interplay. Babies who are smaller and undernourished at birth have a greater risk for the chronic diseases - hypertension and diabetes.
Sedentarism just being inactive has been shown to have some independent effect, that is, independent of just being obese. But again one wonders if the impact of sedentarism isn't working through obesity. The
corollary of that is that if people exercise, even in the absence of weight loss, they can bring down their blood pressure.
