Aetiology of essential hypertension

It is generally agreed that the aetiology of essential hypertension is multifactorial, encompassing both genetic and environmental factors.

Genetic factors

• hypertension is influenced by many gene and gene combinations (a complex polygenic disorder)
• several monogenic forms of hypertension have been identified e.g. – glucocorticoid remediable aldosteronism, Liddle’s syndrome, Gordon’s syndrome

Environmental factors

• overweight and obesity
  • several reports have identified a striking relationship between body weight and high BP and a direct relationship between overweight/obesity and hypertension
  • risk estimates from the Nurses’ Health Study suggest that obesity may be responsible for about 40% of hypertension, and in the Framingham Offspring Study, the corresponding estimates were even higher - 78% in men and 65% in women
  • relationship between obesity at a young age and change in obesity status over time is strongly related to future risk of hypertension
  • becoming normal weight reduced the risk of developing hypertension to a level similar to those who had never been obese
    
    
• sodium intake
  • migrant cross-sectional and prospective cohort studies have shown that sodium intake is positively associated with BP
    
    
• potassium
  • potassium intake is inversely related to BP
  • a higher level of potassium seems to blunt the effect of sodium on BP, with a lower sodium–potassium ratio being associated with a lower level of BP than that noted for corresponding levels of sodium or potassium on their own
    
    
• physical fitness
  • epidemiological studies have demonstrated an inverse relationship between physical activity and physical fitness and level of BP and hypertension
  • even modest levels of physical activity have been associated with a decrease in the risk of incident hypertension
    
    
• alcohol
  • direct relationship between alcohol consumption and BP was first reported in 1915 and has been repeatedly identified in contemporary crosssectional and prospective cohort studies (1)

Reference:

• (1) Whelton PK 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: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2018;138(17):e426-e483.