Most hypoalbuminemia is caused by acute and chronic inflammation... It depends on the cause of your low thyroid as to whether that can be the cause or not...
Are you taking replacement thyroid hormones to correct your hypothyroidism? If so, what medication are you taking, what dosage and how long have you been on it? What are your actual thyroid hormone levels, with reference ranges?
Do you know if you have Hashimoto's? That's where the inflammation would come from with hypothyroidism.