ASHINGTON (AP) — A senior Republican lawmaker said Tuesday he plans to investigate spikes in the price of insulin for people with diabetes as Congress opened hearings on the high cost of prescription drugs.

"I have heard stories about people reducing their life-saving medicines, like insulin, to save money," said Senate Finance Committee Chairman Charles Grassley, R-Iowa. "This is unacceptable and I intend to specifically get to the bottom of the insulin price increase."

Across Capitol Hill, the House Oversight and Reform Committee held its own hearings. Chairman Elijah Cummings, D-Md., has al...