For a theory that has so many people convinced that it is a factor in human as well as in feline diabetes, there is an amazingly small amount of research on the topic. The earliest paper by Michael Somogyi, is from the 1930s and was not published in a widely recognized medical journal (i.e., it was in the Weekly Bulletin of the St. Louis Medical Society). Note that this was a report based on 5 human subjects and urine glucose, not blood glucose was measured. More recent reports note that Somogyi's observations have not been reliably reproduced under controlled conditions.
Gale, EA., et al., Lancet, 1980, pp 279-282, In search of the Somogyi effect wrote:
Although some patients had a very rapid fluctuation from hypoglycaemia to hyperglycaemia, we found no evidence that changes in counterregulatory hormone levels were responsible.The preceding interval of hypoglycemia was often prolonged, which implied defective homeostasis, and the difference between the patients with apparent rebound and those without could not be explained in terms of circulating levels of cortisol, growth hormone, or glucagon. Other workers have noted very variable changes in growth-hormone and cortisol levels after acute hypoglycsemia in unstable diabetics. We did not measure catecholamines and cannot rule out the possibility that they were partly responsible for the difference between our groups. However, the evidence presented here suggests that free insulin is the major factor involved.
In addition to the dearth of empirical research, there is even less that pertains to cats and none that addresses Somogyi phenomenon in the use of Lantus. Given that the presence of Somogyi is believed to be associated with doses that are raised in too large of an increment, it is surprising that this IM vet would not be an enthusiastic supporter of the Queensland/Rand tight regulation protocol. (FYI - there is another TR protocol and the vet may have assumed this was the one you were referring to.)
This is a link to info on Chronic Somogyi Rebound on Wiki. I would draw your attention to the section on Controversy:
Although this theory is well known among clinicians and individuals with diabetes, there is little scientific evidence to support it. Clinical studies indicate that a high fasting glucose in the morning is more likely because the insulin given on the previous evening fails to last long enough.[5] Recent studies using continuous glucose monitoring show that a high glucose in the morning is not preceded by a low glucose during the night.[6] Furthermore, many individuals with hypoglycemic episodes during the night fail to wake due to a failure of release of epinephrine during nocturnal hypoglycemia.[7] Thus, Somogyi's theory is not assured and may be refuted.
This information pertains to humans, not cats. However, the phenomenon was based on humans and extrapolated to felines so I'm going to presume the issues with the paucity as well as quality of the research are the same.
