- Diverse Causes of Hypertension: Pathophysiology and Background
- The Relationship Between Essential Hypertension and Salt Intake: Major Factors in Essential Hypertension
- Systolic and Diastolic Blood Pressure in Hypertensive Patients: The Relationship Between Age and Blood Pressure Patterns
- The Relationship Between Salt Reduction and Blood Pressure Reduction: A Meta-Analysis of the Effects of Salt Reduction on Blood Pressure
- Interpretation and Limitations of Cited Studies: Caution in Interpreting the INTERSALT Study
Diverse Causes of Hypertension: Pathophysiology and Background
There are several factors involved in the regulation of hypertension. Some cases of hypertension are caused by clear factors, such as elevated hormone levels due to benign tumors that increase blood pressure, or severe narrowing of the renal arteries. Additionally, conditions like smoking, which hardens the arteries and leads to vascular insufficiency, can precede and contribute to hypertension. Hypertension without such clear causes is referred to as essential hypertension.
The Relationship Between Essential Hypertension and Salt Intake: Major Factors in Essential Hypertension
In patients with essential hypertension, the primary factors controlling resting blood pressure are thought to be sodium and the kidneys. The INTERSALT study (BMJ. 1988 Jul 30; 297(6644): 319–328) reported a significant difference in the prevalence of hypertension related to salt intake. It was found that in populations with a daily salt intake of less than 2 grams, there were no cases of hypertension (Mancilha-Carvalho JJ, et al. J Hum Hypertens. 1989; 3: 309-14.).
Systolic and Diastolic Blood Pressure in Hypertensive Patients: The Relationship Between Age and Blood Pressure Patterns
In hypertensive patients, elderly individuals tend to have higher systolic blood pressure, while younger individuals tend to have higher diastolic blood pressure. The INTERSALT study found a significant correlation between salt intake and systolic blood pressure, even when adjusted for age, gender, BMI, and alcohol consumption. This correlation, despite being influenced by antihypertensive medications, still indicates a relationship between salt intake and blood pressure.
The Relationship Between Salt Reduction and Blood Pressure Reduction: A Meta-Analysis of the Effects of Salt Reduction on Blood Pressure
A recent meta-analysis examining the effects of salt restriction on blood pressure has confirmed that salt reduction is associated with blood pressure reduction (He HJ et al. BMJ. 2013 Apr 3;346). These results suggest a relationship between salt reduction and blood pressure reduction.
Interpretation and Limitations of Cited Studies: Caution in Interpreting the INTERSALT Study
The INTERSALT study is often cited as evidence of the relationship between salt intake and blood pressure, but it is also interpreted as showing no relationship when extreme cases are excluded. When citing studies, it is important to thoroughly read the entire paper and consider its limitations before referencing it.
