There is some evidence (not much) for an increased risk of malaria infection in people with diabetes (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3294394/) and there seems to be a dose effect with increasing blood glucose. Malaria has also been linked with dysglycemia which could be serious for people with diabetes (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0065193).