Does diabetes lower sperm count?

Dee
My boyfriend and I were trying to have a baby for months nothing happened. He has diabetes and my sister (who has three kids and one more on the way) told me that him having diabetes lower his sperm count so it's harder to conceive. My daughter's dad and I only tried once and we got her. So I'm just wondering if it's thru, also my boyfriend has two other kids so I know he's capable of having kids.