The serum PTH levels in 81 healthy aged people (60-71) 248 aged patients with non-thyroid diseases were determined by radioimmunoassay. Values in founty Nonmal younger people (28-45) served as controls. The results showed that the serum PTH contents of healthy aged subjects as a whole were higher than those in the controls (p<0.01), even more significantly in females (p<0.01). The differences betwean the serum PTH contents of patients with hyertension, tumor, diabetes, brain infarction, CRF, pneumonitis and...