U.S. workers whose wages stagnated over the last decade also saw their health insurance degrade, even as medical costs gobbled up a growing share of their income, two new studies show. An estimated 29 million adults who had health insurance lacked adequate coverage in 2010, leaving them exposed to medical expenses such as high deductibles that they couldn't afford, according to a survey by the nonprofit Commonwealth Fund. That is up from 16 million underinsured people in 2003, the survey found, underscoring the rising burden that insurance plans are placing on consumers as the industry raises required co-pays and deductibles. "Underinsured families are at nearly as high risk as the uninsured because, while they have health insurance, holes or limits in their plans expose them to often unaffordable medical costs," said Commonwealth Fund Senior Vice President Cathy Schoen, lead author of the new report, which was published in the journal Health Affairs. More workers also simply lost coverage over the last decade, the survey found. Fifty-two million adults ages 19 to 64 did not have insurance at some point in 2010, up from 46 million in 2003.