I too was slim, fit and obsessive about my healthy (Mediterranean style) diet when AF and later bg problems struck. So I don't think it was necessarily the Bisoprolol in your case. However, this does highlight the worrying fact that doctors are not alert to the bg-raising side effects that many drugs have, and when these are pointed out to them they don't seem to think it matters. I was prescribed Apixaban (anti-coagulant) but found out that it is known to have quite a high risk of raising bg. When I asked to change to Dabigatran, which is not known to raise bg, the doctor I spoke to was very reluctant. It was only when I went on strike and refused to take any more Apixaban that I got my way. AND I am obliged to take Furosemide (diuretic) at present, which is also known to raise bg. I have accepted that I do need to take the Furosemide regardless of risk, as there is no reallistic alternative, but I was shocked that no doctor to whom I spoke minded that I had been prescribed TWO bg raising drugs at once!