Mendelian randomization (hypothesis generating) of epidemiology (a systematic review of epidemiology is still only as strong as the epidemiology itself, so not at all) in patients with heart failure on sglt2's. Lower ketone bodies had better HF outcomes, but also along ethnic lines (so other variables could account for it as well)
Not that these populations were not doing ketogenic eating patterns, or low carb, just their background ketone levels in their typical diet while on sglt2s, so high carb
The MR finding that genetically elevated ketones causally increase HF risk challenges the “ketones-as-superfuel” hypothesis and suggests potential harm from chronic ketone elevation. This aligns with emerging data from genetic mouse models showing that constitutive ketone overproduction or impaired use leads to cardiac dysfunction.
But that doesn't follow also from the paper
Ketone metabolism dysfunction was defined as β-HB levels in the highest tertile (>2.41 mmol/L) combined with acetoacetate:β-HB ratio <0.15, indicative of impaired ketone use.
SGLT2 inhibitors promote endogenous ketogenesis through multiple mechanisms including hepatic substrate availability modification and direct metabolic effects, potentially contributing to their cardioprotective properties.
So its possible the sglt2 is interfering with ketone use (hence the ketone build up in a high carb diet), resulting in their negative outcomes, but their opinion is against ketones in general.
Even if you take this epidemiology as truth - are you a east asian taking a sglt2 alongside a high carb diet while maintaining ketone levels > 2.25mmol/l?