Type 1 is no reason to give up alcohol. Unless you want to.
As others have said, some drinks contain carbs which need to be considered when carb counting.
But the biggest risk is a low BG a few hours later.
The way I understand it is our basal insulin (e.g. Lantus) is used to mop up the glucose which is constantly dripped from our liver.
However, livers don't like alcohol - they see it as poison. So, when our liver comes across some alcohol, it will not release anything until it has dealt with the poison. As a result, it doesn't drip glucose so the basal insulin doesn't have much to work with and our BG goes low.
There are a few ways to handle this - top up on carbs, such as toast, (without insulin) after drinking or reduce your basal dose.
