Hearts and kidneys: If one's diseased, better keep a close eye on the other.

Research work from two studies involving over 50,000 patients indicates that kidney disease somehow speeds up heart disease well before it has ravaged the kidneys. Doctors have finally proven that heart disease can trigger kidney destruction too.

In chronic kidney disease the kidneys lose their ability to filter waste out of the bloodstream so slowly that symptoms are not obvious until the organs are damaged. Most of them however will die of heart disease before their kidneys are really badly damaged.

Heart disease narrows arteries all over the body, kidneys included. Also, some heart imaging tests use compounds that may harm kidneys.

Hence cardiologists and primary care physicians should carefully monitor heart disease patients for declining kidney function. Systolic blood pressure -- the top number -- should never be above 130, and the so-called "bad" or LDL cholesterol should be below 70.