Sleep plays a vital role in the overall health of our bodies. In a recent study published last month, researchers found strong correlations with too little sleep and (surprising to me) too much sleep with impaired glucose tolerance. They observed, "... that over this timespan, approximately 20% of those with long and short sleep duration developed type 2 diabetes or impaired glucose tolerance versus only 7% among subjects who were average duration sleepers." (h/t SD) They continue that the risk of developing type II diabetes doubles for people who sleep too little or too long.
Interestingly enough improper sleep habits also impacts your risks for cardiovascular disease, obesity and mortality. A general rule of thumb to follow is for adults to shoot for adults 7-8 hours of sleep. If you have problems getting to sleep, a potential remedy would be to use Melatonin.