A US government advisory committee is scrutinising an inhaled form of insulin.

The new drug is designed to help millions of people with diabetes who currently rely on injections to control their blood sugar levels.

The chief concern about the drug involves its long-term effects on the lungs.

The committee will also assess whether it is safe and effective for people who smoke or have lung disease, according to documents released by the US Food and Drug Administration.

The inhaled insulin, called Exubera, could help diabetics who are reluctant to take injections.