scott@vtx-cpd.com

Replying to Anna M. 13/05/2025 - 09:31

Hi Anna,

The connection between hypothyroidism and fructosamine lies in how thyroid hormone levels influence protein metabolism, particularly albumin turnover. Fructosamine reflects the average blood glucose over the preceding two to three weeks by measuring the degree of glycation of circulating proteins, especially albumin. In hypothyroid dogs, there is a reduction in protein turnover, including albumin, which can result in artificially elevated fructosamine levels that do not accurately reflect glycaemic control. This can make it appear as though a diabetic dog is poorly regulated when, in fact, glucose levels may be acceptable.

So in dogs with concurrent hypothyroidism and diabetes, fructosamine may overestimate average blood glucose, particularly if the hypothyroidism is not well controlled. For monitoring these patients, I generally recommend placing greater emphasis on home blood glucose curves or using continuous glucose monitoring if available, as these provide real-time data that are not influenced by protein metabolism. It’s also important to ensure that the hypothyroidism is well managed and that T4 levels are within the therapeutic range before placing much weight on fructosamine values. If fructosamine is used, it should be interpreted cautiously and in the context of clinical signs, body weight trends, and serial blood glucose data, rather than in isolation.

I hope this helps clarify the connection, and I’d be happy to discuss further if helpful. Let me know how you are getting on with the course.

Best regards,

Scott 🙂

Replying to Jane Sedgewick 06/05/2025 - 16:46

Hi Jane,

Great question! t’s something many of us are wrestling with as SDMA becomes a routine part of senior wellness panels. I completely agree, identifying early kidney changes is only worthwhile if we know what to do with that information, and the evidence on early intervention, particularly before azotaemia, is still catching up. IRIS Stage 1 CKD is now formally recognized and includes patients with persistent renal changes like proteinuria or elevated SDMA in the absence of azotaemia. While we don’t yet have large prospective studies showing that intervention in these cases extends lifespan, there is growing support for the idea that earlier detection allows us to modify risk factors and potentially slow progression. Interventions might include addressing proteinuria with ACE inhibitors or ARBs even before creatinine rises, ensuring optimal hydration (especially in older or low body condition dogs), and, in selected cases, adjusting diet to moderate phosphorus and protein intake, though timing of dietary change is still a debated topic.

That said, in real-world clinical practice, I rarely find myself asking for SDMA unless it’s already included in a panel. Most of the dogs I see already have obvious disease, and if they’re azotemic, then SDMA really adds little, its value as an early biomarker becomes moot.

But for earlier-stage cases, especially the older dog who “seems well” but turns up with a borderline USG and mildly elevated SDMA, it does prompt more thoughtful discussion. Ideally, I think SDMA is most useful when paired with urine findings and muscle condition score as part of a broader screening protocol. A persistently elevated SDMA across timepoints, particularly in the presence of proteinuria or low USG, is much more convincing than a single raised value. That layered context helps distinguish signal from noise and guides whether to start more frequent monitoring, recommend dietary changes, or even consider ACE inhibition pre-emptively.

Are you seeing more cases now where SDMA is elevated in isolation? How are you deciding when to act and when to wait?

I hope you are having a lovely weekend.

Scott 🙂

Replying to Yvonne McGrotty 10/05/2025 - 16:40

I consider Britney to be a legend too… she is still in her 40’s!

Scott 🙂