Variations in blood pressure after a 75g oral glucose load and their implications for detecting hypertension and postprandial hypotension in Chinese adults: a cross-sectional study

Aims

Current hypertension guidelines fail to discriminate between fasting and postprandial blood pressure (BP) measurements. Meal ingestion often triggers a marked increase in splanchnic blood flow, potentially inducing a sustained fall in systolic BP of ≥20 mmHg, termed postprandial hypotension (PPH). This study aimed to evaluate BP responses to a 75 g glucose drink and its implications for detecting hypertension and PPH in community-dwelling adults.

Methods and results

A stratified multi-stage random sampling method was used to obtain a nationally representative sample of n = 4429 adult residents between April 2020 and January 2021 in China. BP and heart rate (HR) were measured before, and 1 and 2 h after, a 75 g glucose drink. When fasting, 38.4% of the study population had high BP (BP ≥140/90 mmHg). Following the glucose drink, SBP and DBP decreased (SBP by 6.2 [95% CI: 5.8, 6.6] mmHg and 8.1 [7.7, 8.5] mmHg, DBP by 4.7 [4.4, 4.9] mmHg and 6.1 [5.8, 6.4] mmHg), and HR increased (by 4.3 [4.0, 4.5] bpm and 2.6 [2.4, 2.9] bpm) at 1 and 2 h (P < 0.001 for all), with only 30.9% and 27.0% of the study population having high BP at 1 and 2 h, respectively. After adjustment for age and sex distribution, 19.9% of the general population was estimated to have PPH. Postprandial hypotension was associated with an increased risk of combined cardiovascular disease and stroke.

Conclusion

Ingestion of a 75 g glucose drink often lowers BP, frequently leading to PPH and influencing the detection of hypertension. Accordingly, guidelines for measurements of BP and interpretation of outcomes should consider the potential impact of meal ingestion on BP.