Systematic review and meta-analysis examining the relationship between postprandial hypotension, cardiovascular events, and all-cause mortality

Glucagon-like peptide-1 receptor agonists modestly reduced blood pressure among patients with and without diabetes mellitus: A meta-analysis and meta-regression

AIM

The cardiovascular benefits provided by glucagon-like peptide-1 receptor agonists (GLP-1RAs) extend beyond weight reduction and glycaemic control. One possible mechanism may relate to blood pressure (BP) reduction. We aim to quantify the BP-lowering effects of GLP1-RAs.

METHODS

A comprehensive database search for placebo-controlled randomized controlled trials on GLP-1RA treatment was conducted until December 2023. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with a mean difference (MD) in mmHg and 95% confidence intervals (CIs). The primary endpoint was the mean difference in systolic BP (SBP) and diastolic BP. Subgroup analyses and meta-regressions were done to account for covariates.

RESULTS

Compared with placebo, GLP-1RAs modestly reduced SBP [semaglutide: MD -3.40 (95% CI -4.22 to -2.59, p < .001); liraglutide: MD -2.61 (95% CI -3.48 to -1.74, p < .001); dulaglutide: MD -1.46 (95% CI -2.20 to -0.72, p < .001); and exenatide: MD -3.36 (95% CI -3.63 to -3.10, p < .001)]. This benefit consistently increased with longer treatment durations. Diastolic BP reduction was only significant in the exenatide group [MD -0.94 (95% CI -1.78 to -0.1), p = .03]. Among semaglutide cohorts, mean changes in glycated haemoglobin and mean changes in body mass index were directly associated with SBP reduction.

CONCLUSION

Patients on GLP-1RA experienced modest SBP lowering compared with placebo. This observed effect was associated with weight/body mass index reduction and better glycaemic control, which suggests that BP-lowering is an indirect effect of GLP-1RA and unlikely to be responsible for the benefits.

Circadian and Diurnal Regulation of Cerebral Blood Flow

Circadian and diurnal variation in cerebral blood flow directly contributes to the diurnal variation in the risk of stroke, either through factors that trigger stroke or due to impaired compensatory mechanisms. Cerebral blood flow results from the integration of systemic hemodynamics, including heart rate, cardiac output, and blood pressure, with cerebrovascular regulatory mechanisms, including cerebrovascular reactivity, autoregulation, and neurovascular coupling. We review the evidence for the circadian and diurnal variation in each of these mechanisms and their integration, from the detailed evidence for mechanisms underlying the nocturnal nadir and morning surge in blood pressure to identifying limited available evidence for circadian and diurnal variation in cerebrovascular compensatory mechanisms. We, thus, identify key systemic hemodynamic factors related to the diurnal variation in the risk of stroke but particularly identify the need for further research focused on cerebrovascular regulatory mechanisms.

Prevalence of postprandial hypotension in older adults: a systematic review and meta-analysis

BACKGROUND

Older adults with postprandial hypotension (PPH) increase susceptibility to falls, syncope, stroke, acute cardiovascular diseases and even death. However, the prevalence of this condition varies significantly across studies. We aimed to determine the prevalence of PPH in older adults.

METHODS

Web of Science, PubMed, Cochrane Library, Embase and CINAHL were searched from their inception until February 2023. Search terms included 'postprandial period', 'hypotension' and 'postprandial hypotension'. Eligible studies were assessed using the Joanna Briggs Institute tool. Meta-analyses were performed among similar selected studies.

RESULTS

Thirteen eligible studies were included, and data from 3,021 participants were pooled. The meta-analysis revealed a PPH prevalence of 40.5% [95% confidence interval (CI): 0.290-0.519] in older adults, and this was prevalent in the community (32.8%, 95% CI: 0.078-0.647, n = 1,594), long-term healthcare facility (39.4%, 95% CI: 0.254-0.610, n = 1,062) and geriatrics department of hospitals (49.3%, 95% CI: 0.357-0.630, n = 365). The pooled results showed significant heterogeneity (I2 > 90%), partially related to the different ages, sex, pre-prandial systolic blood pressure levels of participants, or the different criteria and methodology used to diagnose PPH.

CONCLUSIONS

PPH is a prevalent condition in older adults. Further research is needed to confirm this result, and priority should be given to establishing international consensus on PPH diagnostic criteria and designing its diagnostic procedure.

Non-pharmacological interventions for older adults with postprandial hypotension: A scoping review

BACKGROUND

Older adults frequently suffer from postprandial hypotension, associated with an increased risk of falls, syncope, acute cardiovascular and cerebrovascular diseases, and even death. Researchers use non-pharmacological interventions, but related literature is dispersed and lacks a latest summary.

OBJECTIVE

The aim of this study was to map and examine non-pharmacological interventions currently employed to assist older adults with postprandial hypotension and lay a solid foundation for future studies.

METHODS

This study adhered to the JBI methodology for scoping reviews and preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews. PubMed, Web of Science, Embase, Cochrane Library, CINAHL, SCOPUS, Chinese Biomedical Journal, China National Knowledge Infrastructure, VIP and WAN FANG Data were retrieved from their inception to 1 August 2022.

RESULTS

Two randomized controlled trials and seven quasi-experimental studies were included. Small meals, exercise interventions, fibre with meals, green tea and water therapy have been reported to prevent postprandial hypotension effectively; however, position changes have been reported to have no impact on postprandial blood pressure decrease. Additionally, the blood pressure determination methods and test meals may affect observed trial effects.

CONCLUSION

Large samples and long-term follow-up studies are needed to prove the efficacy and safety of existing non-pharmacological interventions. Future studies should develop a BP determination method based on the postprandial BP decline trajectory induced by a given test meal to improve the reliability of study results.

RELEVANCE TO CLINICAL PRACTICE

This review broadly summarizes existing studies on developing and validating non-pharmacological interventions for older adults with postprandial hypotension. It also analyses special factors that may influence the trial effects. This may provide a useful reference for future research.

Postprandial Hypotension and Impaired Postprandial Sustained and Selective Attention in Older Inpatients: Is There a Link?

OBJECTIVES

The study aimed to investigate the prevalence of postprandial hypotension (PPH) in older inpatients, to verify the overall postprandial behavior of blood pressure and attentional performances, and to explore the overall associations between blood pressure (including PPH) and attentional performances. Eventually, we aimed to investigate differences on PPH, blood pressure values and attentional performances based on the subjects' frailty status.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A sample of older inpatients at the Geriatric Unit of the University Hospital of Messina (Italy).

METHODS

Basal, preprandial, and postprandial blood pressures (75 minutes after the meal) were measured for each patient; PPH was detected according to its empirical definition. Global cognitive functioning, and sustained and selective attention were assessed; a 46-item Frailty Index was calculated.

RESULTS

The sample consisted of 112 inpatients (54 females), with a mean age of 80.9 years. The prevalence of PPH was 30.4%; in the postprandial window, a reduction in blood pressure between 10 and 20 mm Hg and a reduction of >20 mm Hg were reported by 27.1% and 29.9% of inpatients, respectively. In the postprandial evaluation, sustained and selective attention markedly decreased. No significant associations were found between PPH occurrence and the postprandial dip of attentional performances, and no significant cognitive differences were found between inpatients with and without PPH. On the other hand, reduced postprandial attentional performances were associated especially with preprandial lower systolic and diastolic blood pressure values. Ultimately, no significant differences in PPH occurrence were found between frail and nonfrail inpatients; frail inpatients significantly exhibited also an overall lower cognitive functioning.

CONCLUSIONS AND IMPLICATIONS

In our sample, PPH and impaired postprandial attentional performances were not associated, even though this association deserves further investigation. In hospitalized older adults, the accurate management of blood pressure levels appears relevant, because we evidenced that low blood pressure (especially preprandial) was associated with poor attentional functioning. Although the plausible occurrence of several interfering and confounder factors was observed in an acute care setting, we consider that the screening of attentional functioning among hospitalized older patients could be helpful.

Higher fasting fibroblast growth factor 21 was associated with a greater decline in postprandial blood pressure

BACKGROUND

A fall in blood pressure (BP) following a meal is well known and is usually a transient phenomenon, due to appropriate cardiovascular adjustments. Older individuals and those with high BP experience a greater postprandial fall that can manifest as postprandial hypotension (PPH). Fibroblast growth factor 21 (FGF21) is positively associated with BP, and is known to increase after meal ingestion. We explored whether fasting FGF21 or its postprandial change would be associated with meal induced BP change, after accounting for several covariates.

METHODS

Eighty-three Western Australian adults were studied. Supine resting BP was recorded and an oral glucose test was administered. Serial measurements of systolic BP (SBP) and diastolic BP (DBP) were then made in duplicate every 30 min up to 120 min. Fasting and 120 min blood samples were analysed for FGF21 and clinical chemistry. Multiple linear regression analyses of the incremental area under curve of postprandial SBP and DBP was conducted on 12 known determinants.

RESULTS

The final parsimonious model based on backward regression of postprandial SBP included fasting SBP, gender, fasting insulin and fasting FGF21 (β = -0.009 (95% confidence interval (CI): 0.017, -0.002, P = 0.015)). For postprandial DBP these included fasting DBP, gender, fasting glucose, fasting insulin and fasting FGF21 (β = -0.005; 95% CI: 0.010, -0.001, P = 0.021).

CONCLUSIONS

A higher fasting FGF21, independent of glucose and insulin, was associated with a greater postprandial decline in SBP and in DBP.

Postprandial Hypotension: An Underreported Silent Killer in the Aged

Orthostatic hypotension (OH) is one of the most common autonomic dysfunctions, with high prevalence in populations of elderly, hypertensive, diabetic, or Parkinson's patients. Evidence is emerging that OH co-occurs with postprandial hypotension (PPH); a greater prevalence of PPH than of OH is reported for Parkinson's disease patients. OH is diagnosed by measuring the blood pressure changes associated with postural changes and often produces alterations in consciousness or other such bothersome symptoms as fainting. PPH is diagnosed by measuring the blood pressure changes associated with ingesting high carbohydrate test meals. Because of the time lag between food ingestion and absorption, PPH is often not reported as symptomatic and, therefore, not diagnosed as PPH. OH and PPH are independent predictors for all causes of mortality. Relative underdiagnosis may qualify PPH as a "silent killer" disease. This review is aimed at providing updates on the epidemiology, pathophysiology, and clinical aspects associated with the diagnosis and treatment of PPH. Highlighting the current gaps in knowledge and research about PPH is expected to make medical practitioners more cognizant of the dangers of underdiagnosis and motivate future research to identify individuals and populations at high risk for PPH and its sequelae.

Glycemic Index Versus Wheat Fiber on Arterial Wall Damage in Diabetes: A Randomized Controlled Trial

OBJECTIVE

High cereal fiber and low-glycemic index (GI) diets are associated with reduced cardiovascular disease (CVD) risk in cohort studies. Clinical trial evidence on event incidence is lacking. Therefore, to make trial outcomes more directly relevant to CVD, we compared the effect on carotid plaque development in diabetes of a low-GI diet versus a whole-grain wheat-fiber diet.

RESEARCH DESIGN AND METHODS

The study randomized 169 men and women with well-controlled type 2 diabetes to counseling on a low GI-diet or whole-grain wheat-fiber diet for 3 years. Change in carotid vessel wall volume (VWV) (prespecified primary end point) was assessed by MRI as an indication of arterial damage.

RESULTS

Of 169 randomized participants, 134 completed the study. No treatment differences were seen in VWV. However, on the whole-grain wheat-fiber diet, VWV increased significantly from baseline, 23 mm3 (95% CI 4, 41; P = 0.016), but not on the low-GI diet, 8 mm3 (95% CI -10, 26; P = 0.381). The low-GI diet resulted in preservation of renal function, as estimated glomerular filtration rate, compared with the reduction following the wheat-fiber diet. HbA1c was modestly reduced over the first 9 months in the intention-to-treat analysis and extended with greater compliance to 15 months in the per-protocol analysis.

CONCLUSIONS

Since the low-GI diet was similar to the whole-grain wheat-fiber diet recommended for cardiovascular risk reduction, the low-GI diet may also be effective for CVD risk reduction.