American Equity Investment Life Holding Co. reported third-quarter net income of $56.2 million, or 75 cents per share, compared with a third-quarter 2012 net loss of $7.8 million, or 13 cents per share.  The West Des Moines-based insurer said in a release Monday that revisions to certain assumptions used in calculating its net income accounted for $20.2 million of the earnings increase for the third quarter. Similar revisions in assumptions increased the net loss in the year-ago quarter by $0.8 million. Annuity sales for the third quarter of 2013 were $1.054 billion, compared with $1.135 billion in annuity sales in the second quarter. Total invested assets were $29.8 billion as of Sept. 30. "Our assets under management are up 14 percent in the last 12 months and we are optimistic our sales momentum from the last two quarters will carry through the balance of the year and into 2014," said Executive Chairman David Noble.