A gravitational hypothesis of essential hypertension as a natural adaptation to increased gravitational stress caused by regular, prolonged sitting typical of modern life.

Background: Spaceflight studies have demonstrated that adaptation to increased gravitational stress after prolonged microgravity includes sympathetic activation, water retention, and arterial pressure increase, i.e. is very similar to essential hypertension, which looks like an advanced stage of adaptation to a further increase in gravitational stress.

Improved automatic analysis of ambulatory blood pressure data based on precise detection of individual night-time from diurnal profile of heart rate.

Background: Software programs sold with ambulatory blood pressure monitoring (ABPM) devices are designed to use some set 'typical' night-time (e.g. 2300-0700) to estimate daytime/night-time blood pressure (BP) with limited accuracy.