My friend has 0% for chronic sinitus and 0% for chronic rhinitis. He was unable to get a sleep study in the army, but just had one earlier this year (he got out in 2018). He has pretty bad sleep apnea and is required to wear a CPAP. He wants to file for sleep apnea secondary to the two afforementioned disabilities. Does the VA acknowledge that the sleep apnea is secondary to those or is a nexus note needed to make the link?