(Bloomberg) — Aetna Inc. shares rose to a record after the company added 1 million people to its health-insurance rolls, lifting first-quarter earnings and prompting it to boost its annual forecast.

Operating earnings this year will be $7.20 to $7.40 a share, the Hartford, Connecticut-based insurer said Tuesday in a statement. In February, Aetna had predicted operating earnings of at least $7 a share. Analysts had estimated $7.19 on average, according to data compiled by Bloomberg.

Aetna has benefited as more people sign up for insurance, spurred by President Barack Obama's Patient Protection and Affordable Care Act. The company said it provided medical coverage for 23.7 million people as of March 31, up from 22.7 million a year earlier.