If you have the causation backwards in your phrasing, that implies that perhaps some people simply can't get good sleep even though they might try. You could sa

If you have the causation backwards in your phrasing, that implies that perhaps some people simply can't get good sleep even though they might try. You could say: you're 30% more likely to have sleep problems in your 50s and 60s if you're in the very early stages of developing dementia. Perhaps the disease process makes the sleep problems unavoidable and trying sleep more won't help.