High fructose intakes can increase postprandial lipaemia and are associated with an increased incidence of metabolic disorders such as type 2 diabetes and cardiovascular disease (Chong, Fielding, & Frayn, 2007; Geidl-Flueck & Gerber, 2023). It has been demonstrated that females display a higher hepatic de novo lipogenesis in response to a high-fructose meal compared with males, yet this did not translate into increased postprandial lipaemia (Low et al., 2018). Furthermore, other data suggest females display a lower postprandial lipaemia in response to a mixed meal (Pramfalk et al., 2015), and therefore potential sex differences in the lipaemic response to different sugars are currently unclear. Accordingly, the aim of the present study was to assess sex differences in the postprandial lipaemic response to ingestion of a drink containing either sucrose (high-fructose) or maltodextrin (glucose-only polymer).
In a randomised, double-blind, cross-over design, expired breath and plasma samples were collected from 24 healthy participants (12 female and 12 male) for 360 minutes after ingestion of a drink containing 50 g fat (spiked with 200 mg [U-13C]palmitate) with 100 g of either maltodextrin (MD) or sucrose (SU). Normality of data were checked by visual inspection of residuals. Total and incremental area under the curve were calculated for each outcome and used to analyse differences between sexes within each condition using both an independent t-test and ANCOVA with fat free mass (FFM) as a covariate.
Males had a higher TAG iAUC (mean±95%CI) concentration compared to females after SU ingestion (128.0±73.2 mmol/L*360min vs 47.79±27.61 mmol/L*360min, p=0.02) but there was no sex difference after MD ingestion (72.39±55.41 mmol/L*360min vs 28.95±16.17 mmol/L*360min, p=0.13). After MD and SU ingestion females had higher plasma glucose iAUC concentrations (MD 306.5±78.0 mmol/L*360min vs 117.0±123.5 mmol/L*360min, p=0.005; SU 200.5±84.6 vs 108.0±47.4, p=0.02 SU) and higher plasma insulin iAUC concentrations (MD 59.87±17.0 umol/L*360min vs 33.5±11.8 umol/L*360min, p=0.005; SU 34.97±10.1 umol/L* 360min vs 16.01±5.2 umol/L*360min, p<0.001) compared to males but this did not remain when FFM was added as a covariate (glucose MD 236.63±98.7 mmol/L*360min vs 241.03±92.18 mmol/L*360min, p=0.9; glucose SU 199.01±101.89 mmol/L*360min vs 109.34±95.16 mmol/L*360min p=0.3; insulin MD 48.86±21.04 umol/L*360min vs 44.51±21.04 umol/L* 360min, p=0.8; insulin SU 34.95±12.04 pmol/L*360min vs 16.03±12.04 pmol/L*360min, p=0.8). After SU ingestion females had higher plasma lactate iAUC concentrations compared to males (308.9±50.1 mmol/L*360min vs 218.8±52.8 mmol/L*360min, p=0.007) but this did not remain when FFM was added as a covariate (289.71±78.55 mmol/L*360min vs 236.35±73.36 mmol/L*360min, p=0.42). There were no meaningful sex differences in plasma VLDL-rich TAG [Sf 20-400] tAUC, plasma NEFA tAUC, plasma BHB tAUC concentrations, total fat and carbohydrate oxidation, or total exogenous fat oxidation with or without FFM as a covariate (p>0.05 for all).
These data demonstrate that despite a larger relative dose of fat and sugar, females display a lower lipaemic response than males following high-sugar oral fat tolerance tests. These responses cannot be explained by differences in whole-body or exogenous fat oxidation rates, and therefore further research on the mechanisms of sex differences in response to sugar intake is warranted.