The pick of the science week
Rest your heart
Getting too little sleep over prolonged periods may expose a person to a greater risk of heart problems. Sleeping fewer than 7.5 hours a day left a group of 1,255 older people prone to high blood pressure (average age 70.4) facing a one-third higher risk of cardiovascular problems including heart attack.
Researchers at Jichi Medical University in Japan monitored sleep patterns over about 50 months. Incidence of stroke and sudden cardiac death rose when the subjects regularly got less than 7½ hours sleep a night. The number of these events was lower for those who got more sleep and didn't experience a nocturnal rise in blood pressure.
The team, which published this week in the Archives of Internal Medicine, suggests that doctors should inquire about sleep duration when assessing patients with high blood pressure.
Hope for children with heart defects
A cardiac surgeon and colleagues at Munich University Hospital have grown replacement heart valves from stem-cells recovered from umbilical cord blood. The cells were seeded onto eight biodegradable scaffolds and then allowed to grow. The cells survived and spread, but also began releasing proteins associated with tissue function and structure.
While these were never suitable for actual transplants, the research team is hopeful that children born with heart defects might in time benefit from perfectly matched replacement heart valves grown from their own umbilical cord blood.
By numbers
45
The apparent "artery age" of a group of obese US children and teens assessed to gauge their level of artery blockage caused by cholesterol, the American Heart Association says.
56
The percentage of patients who were unaware that they had dangerously high blood pressure, in a cross-EU study published this week in the Journal of Hypertension.
149
The number of Martian days (162 Earth days) that the Phoenix lander spent working on Mars before sending its last message on November 2nd, Nasa says.
• Question of the Week:Should the Government introduce "healthy eating" legislation to control salt, fat and sugar content in processed foods and restrict the availability of snack foods?
Send your response, Yes or No, to science@irish-times.ie. Responses will be published on next week's Science Today page.