Annie Saint-Remy

INTRODUCTION AND AIMS: High blood pressure (HBP) is a worldwide public health issue. The pathophysiology of primary HBP - the most common form of HBP - remains largely unknown. Recent observations in rodents and patients suggest that gut microbiota (GM) may influence BP homeostasis, namely via carbohydrate fermentation end-products.

In kidney transplant (Kt) recipients , hypertension is a major risk for cardiovascular complications but also for graft failure. Blood pressure (BP) control is therefore mandatory. Office BP (OBP) remains frequently used for clinical decisions, however home BP (HBP) have brought a significant improvement in the BP control. Sodium is a modifiable risk factor, many studies accounted for a decrease of BP with a sodium restricted diet. Increased potassium intake has been also recommended in hypertension management. Using an agreement between office and home BP, the present study investigated the relations between the BP control in Kt recipients and their urinary excretion and dietary consumption of sodium and potassium.

The guidelines for treating high blood pressure, published in 2007, have been discussed in 2009. Currently, when hypertension is confirmed, it is proposed to treat the patients with a blood pressure goal of 130-139/80-85 mmHg whatever the diseases associated with hypertension. The authors recommended that if the patient tolerates lower blood pressures, the treatment could be continued. Many questions remained without any clear answer for the lowest protective target of blood pressure. The choice of antihypertensive agents appears to become more important in people with high cardiovascular risk. However, never forget to improve the cardiovascular risk by modifying the lifestyle and diet of the whole hypertensive population and by optimally acting on the associated risk factors identified.

Hypertension occurs frequently among hemodialysis (HD) patients and can be due to many factors, such as salt intake, elevated sympathetic tone, and uremic toxins. It is responsible for the high cardiovascular risk associated with renal disease. Generally, in HD patients, while there is an elevation of systolic blood pressure (BP), diastolic BP seems to decrease, and the resultant effect is high pulse pressure, which can have a deleterious effect on the cardiovascular system. Although controversial, in the HD population the relationship between BP and risk of death seems to be U shaped, probably because of pre-existing cardiac disease in patients with the lowest BP. In chronic kidney disease, BP lower than 130/80 mmHg is recommended, but an appropriate target for BP in the HD population remains to be established. Moreover, there is no consensus regarding which routine peridialysis BP (pre- or post-dialysis BP, or both) can ensure the diagnosis of hypertension in this population. Ambulatory BP monitoring remains the gold standard to quantify the integrated BP load applied to the cardiovascular system. As well, home BP assessment could contribute to improve the definition of an optimal BP in the HD population. An ideal goal for post-dialysis systolic BP seems to be a value higher than 110 mmHg and lower than 150 mmHg. However, HD patients are generally old and often have cardiac complications, so a reasonable pre-dialysis target systolic BP could be 150 mmHg. It is prudent to suggest that an improvement in BP control is necessary in the HD population, first by slow and smooth removal of extracellular volume (dry weight) and thereafter by the use of appropriate antihypertensive medication.