MINNETONKA, Minn. (AP) — UnitedHealth Group Inc.'s second-quarter net income rose almost 8 percent, buoyed by steady enrollment growth.

The nation's largest health insurer's earnings topped Wall Street estimates. It also raised the low end of its full-year earnings forecast Thursday.

UnitedHealth is the first major health insurer to report earnings every quarter. As the industry leader based on revenue, many see it as a bellwether for other insurers. Its shares edged up in premarket trading.

The Minnetonka, Minn., company earned $1.44 billion, or $1.40 per share, in the three months ended June 30. That's up from $1.34 billion, or $1.27 per share, a year earlier.

Analysts, on average, expected earnings of $1.25 per share, according to a FactSet poll.

The company's enrollment increased by 3 million people, with a total enrollment of 45 million for the quarter.

Revenue rose 12 percent to $30.41 billion from $27.27 billion, but missed the $30.52 billion in revenue that Wall Street called for.

The Optum segment, which provides services such as technology outsourcing and pharmacy benefits management, reported $8.8 billion in revenue, a 21 percent increase. The company has touted that segment as an important source of future growth.

UnitedHealth now expects full-year earnings of $5.35 to $5.50 per share. Previously, the company predicted $5.25 to $5.50 per share. It still anticipates revenue of about $122 billion.

Wall Street foresees earnings of $5.43 per share on $122.48 billion in revenue.

Shares of UnitedHealth gained 37 cents to $66.60 in premarket trading.