Lipolysis and ketosis both end in ‑sis.
Does that suffix have the same meaning in both the words?
No. The suffix in lipolysis is -lysis, while the suffix in ketosis is -osis.
The word ketosis comes from 'keto- combining form of ketone, + -osis', where -osis is a 'suffix expressing state or condition, in medical terminology denoting "a state of disease," from L. -osis, from Gk. -osis'. Ketosis is a disease 'characterised by elevated levels of ketone bodies in the blood'.
The connection between the two is that the process of lipolysis produces ketones, an excess of which is called ketosis, but this is not an etymological connection.