Eli Lilly & Co.’s weight-loss drug Zepbound improved breathing problems in highly anticipated studies that may convince more insurers to cover the $1,000-a-month treatment. In two late-stage trials of patients with obstructive sleep apnea, a condition closely linked to obesity, Zepbound reduced the number of times breathing slowed or stopped during sleep by up to 63% from the baseline, Lilly said in a statement Wednesday.