GDF15 linked to maternal risk of nausea and vomiting during pregnancy

GDF15, a hormone acting on the brainstem, has been implicated in the nausea and vomiting of pregnancy, including its most severe form, hyperemesis gravidarum (HG), but a full mechanistic understanding is lacking1-4. Here we report that fetal production of GDF15 and maternal sensitivity to it both contribute substantially to the risk of HG. We confirmed that higher GDF15 levels in maternal blood are associated with vomiting in pregnancy and HG. Using mass spectrometry to detect a naturally labelled GDF15 variant, we demonstrate that the vast majority of GDF15 in the maternal plasma is derived from the feto-placental unit. By studying carriers of rare and common genetic variants, we found that low levels of GDF15 in the non-pregnant state increase the risk of developing HG. Conversely, women with β-thalassaemia, a condition in which GDF15 levels are chronically high5, report very low levels of nausea and vomiting of pregnancy. In mice, the acute food intake response to a bolus of GDF15 is influenced bi-directionally by prior levels of circulating GDF15 in a manner suggesting that this system is susceptible to desensitization. Our findings support a putative causal role for fetally derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by prepregnancy exposure to the hormone, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

Fetally-encoded GDF15 and maternal GDF15 sensitivity are major determinants of nausea and vomiting in human pregnancy

Human pregnancy is frequently accompanied by nausea and vomiting that may become severe and life-threatening, as in hyperemesis gravidarum (HG), the cause of which is unknown. Growth Differentiation Factor-15 (GDF15), a hormone known to act on the hindbrain to cause emesis, is highly expressed in the placenta and its levels in maternal blood rise rapidly in pregnancy. Variants in the maternal GDF15 gene are associated with HG. Here we report that fetal production of GDF15, and maternal sensitivity to it, both contribute substantially to the risk of HG. We found that the great majority of GDF15 in maternal circulation is derived from the feto-placental unit and that higher GDF15 levels in maternal blood are associated with vomiting and are further elevated in patients with HG. Conversely, we found that lower levels of GDF15 in the non-pregnant state predispose women to HG. A rare C211G variant in GDF15 which strongly predisposes mothers to HG, particularly when the fetus is wild-type, was found to markedly impair cellular secretion of GDF15 and associate with low circulating levels of GDF15 in the non-pregnant state. Consistent with this, two common GDF15 haplotypes which predispose to HG were associated with lower circulating levels outside pregnancy. The administration of a long-acting form of GDF15 to wild-type mice markedly reduced subsequent responses to an acute dose, establishing that desensitisation is a feature of this system. GDF15 levels are known to be highly and chronically elevated in patients with beta thalassemia. In women with this disorder, reports of symptoms of nausea or vomiting in pregnancy were strikingly diminished. Our findings support a causal role for fetal derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by pre-pregnancy exposure to GDF15, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

Socioeconomic deprivation: an important largely unrecognized risk factor in primary prevention of cardiovascular disease

Background

Socioeconomic deprivation is associated with higher cardiovascular morbidity and mortality. Whether deprivation status should be incorporated in more cardiovascular risk estimation scores remains unclear.

Purpose

This study evaluates how socioeconomic deprivation status affects the performance of three primary prevention cardiovascular risk scores.

Methods

The Generation Scotland Scottish Family Health Study was used to evaluate the performance of three cardiovascular risk scores with (ASSIGN) and without (SCORE2, PCE) socioeconomic deprivation as a covariate in the risk prediction model. Deprivation was defined by Scottish Index of Multiple Deprivation score. The predicted 10-year risk was evaluated against the observed event rate for the cardiovascular outcome of each risk score. The comparison was made across three groups defined by the deprivation index score consisting of group 1 defined as most deprived, group 3 defined as least deprived and group 2 which consisted of individuals in the middle deprivation categories.

Results

The study population consisted of 15,506 individuals (60.0% female, median age of 51). Across the population 1,808 (12%) individuals were assigned to group 1 (most deprived), 8,119 (55%) to group 2, and 4,708 (32%) to group 3 (least deprived). Risk scores based on models that did not include deprivation status significantly under predicted risk in the most deprived (6.4% observed versus 4.6% predicted for SCORE2 and 6.7% observed versus 4.7% predicted for PCE, p<0.001 for both). Both risk scores also significantly overpredicted the risk in the least deprived group (4.0% observed versus 4.7% predicted for SCORE2, p=0.007 and 4.2% observed versus 4.9% predicted for PCE, p=0.028). In contrast, no significant difference was demonstrated in the observed versus predicted risk when using the ASSIGN risk score, which included socioeconomic deprivation status in the risk model.

Conclusions

Socioeconomic status is a largely unrecognized risk factor in primary prevention of cardiovascular disease. Risk scores that exclude socioeconomic deprivation as a covariate under- and overestimate the risk in the most and least deprived individuals, respectively. This study highlights the importance of incorporating socioeconomic deprivation status in risk estimation systems to ultimately reduce inequalities in health care provision for cardiovascular disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation.Health Data Research UK which receives its funding from HDR UK Ltd (HDR-5012) funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust.

Resting and exercise haemodynamic characteristics of patients with advanced heart failure and preserved ejection fraction

Aims

This study aimed to describe haemodynamic features of patients with advanced heart failure with preserved ejection fraction (HFpEF) as defined by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC).

Methods and results

We used pooled data from two dedicated HFpEF studies with invasive exercise haemodynamic protocols, the REDUCE LAP‐HF (Reduce Elevated Left Atrial Pressure in Patients with Heart Failure) trial and the REDUCE LAP‐HF I trial, and categorized patients according to advanced heart failure (AdHF) criteria. The well‐characterized HFpEF patients were considered advanced if they had persistent New York Heart Association classification of III–IV and heart failure (HF) hospitalization < 12 months and a 6 min walk test distance < 300 m. Twenty‐four (22%) out of 108 patients met the AdHF criteria. On evaluation, clinical characteristics and resting haemodynamics were not different in the two groups. Patients with AdHF had lower work capacity compared with non‐advanced patients (35 ± 16 vs. 45 ± 18 W, P = 0.021). Workload‐corrected pulmonary capillary wedge pressure normalized to body weight (PCWL) was higher in AdHF patients compared with non‐advanced (112 ± 55 vs. 86 ± 49 mmHg/W/kg, P = 0.04). Further, AdHF patients had a smaller increase in cardiac index during exercise (1.1 ± 0.7 vs. 1.6 ± 0.9 L/min/m², P = 0.028).

Conclusions

A significantly higher PCWL and lower cardiac index reserve during exercise were observed in AdHF patients compared with non‐advanced. These differences were not apparent at rest. Therapies targeting the haemodynamic compromise associated with advanced HFpEF are needed.