Can Metformin Intake Cause Pulmonary Hypertension?

Hi, my name is Sandra. I am asking you if diabetes type 2 drug Metformin can cause Pulmonary Hypertension. I have been taking Metformin for about 4 years & have T2 diabetes. In the last 6-8 months mysterious swelling like lumps have developed each side just above my collar bone. I have had a dye scan, xrays and blood tests. the Dr says the lumps he thinks, are lung related. 2 weeks ago I have a breathing test and then the Dr said I have a chronic lung condition. I read online that Metformin can cause Pulmonary Hypertension. I stopped taking the drug yesterday. Thanks, Regards Sandra