Up to 80% of autistic people have sleep problems. Are many of them at risk of health problems related to poor sleep? https://www.autismspeaks.org/family-services/health-and-wellness/sleep
Interestingly, there's not that many, if any credible sources of information about the issue other than daytime functioning.
Compared to those typically developing, they tend to have trouble staying asleep, sleep less, spend more time awake in bed, take longer to fall asleep, and get less REM sleep. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111973/
I'm autistic too and seem to average less than 6 hours a night even with white noise, black out curtains, magnesium supplementation, avoiding caffeine sources (even morning intake may affect my sleep), regular exercise (from cycling to work, active job), sunrise simulator. My family members seem to sleep better even without the sleep hacks.
The health risks of poor sleep include: Diabetes, obesity, heart problems from insulin resistance. https://www.ncbi.nlm.nih.gov/pubmed/20371664
HGH deficiency possibly affecting height (while growing), body composition, and muscle and bone health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC297368/
Low testosterone possibly affecting exercise recovery, body composition, muscle strength and mass, etc. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445839/
Skin health (premature skin aging, breakouts, dark circles under eyes etc). http://home.bt.com/lifestyle/fashion-beauty/what-missing-out-on-your-beauty-sleep-really-does-to-your-skin-11363981593584
Increased beta amyloid. https://www.sciencedaily.com/releases/2018/04/180413155301.htm
Accumulation of sleep debt. Sleep restriction of six hours a night for two weeks is similar to pulling two all nighters in a row! https://www.ncbi.nlm.nih.gov/pubmed/12683469
Accidents from a lack of alertness.
Increased injury risk from slower recovery from exercise.