Shared Genes in Blood Pressure and Comorbid Traits (page 819)
Hypertension is highly heritable, yet few genetic risk factors have been identified to date, leading some to suggest that genome wide association studies (GWAS) cannot be used to uncover its genetic architecture. However, in this issue of Hypertension, Andreassen et al identified 42 novel gene variants in a systolic blood pressure GWAS, applying a novel statistical method that leverages genetic pleiotropy, the association of 1 gene with >1 disease or trait. Many of the newly identified genes are related to lipid metabolism and regulation, suggesting pathogenetic mechanisms involving lipid biology. Results of pleiotropy analyses suggested that some of the overlap between blood pressure and cardiovascular risk factors found in epidemiological studies may arise from shared genetic factors. There was a high degree of genetic overlap between blood pressure and low-density lipoprotein–cholesterol, body mass index, and bone mineral density, but little overlap with other cardiovascular risk factors related to the metabolic syndrome known to be associated with hypertension (type 2 diabetes mellitus, triglycerides, and high-density lipoproteins). Genetic overlap was also observed between blood pressure and schizophrenia, as well as celiac disease and type I diabetes mellitus, the latter suggesting a pathogenetic link between immunologic factors and blood pressure. These findings, suggesting that hypertension shares genetic mechanisms with lipid disturbances and immune abnormalities, may have implications for early diagnosis, prevention strategies, and therapeutic regimes in hypertension.
White Coat and Masked Hypertension Prognosis (page 675)
White coat and masked hypertension are common among untreated and treated patients and can be identified by ambulatory or home blood pressure monitoring. The International Database of HOme blood pressure in relation to Cardiovascular Outcomes (IDHOCO) has been constructed to investigate the clinical usefulness of home blood pressure monitoring on the basis of outcome data. The database included 6458 participants from 5 populations with a median follow-up of 8.3 years and is based on individual participants’ data analyses. In this issue of Hypertension, Stergiou et al reported new findings from the IDHOCO database on the prognostic significance of white coat and masked hypertension detected by home measurements separately in untreated and treated subjects. The analysis showed that masked hypertension is associated with increased risk of cardiovascular events in both untreated and treated subjects (upper and lower parts of figure, respectively), which is close to that of sustained hypertension. However, white coat hypertension was associated with increased cardiovascular risk in untreated but not in treated subjects. These findings have important implications for clinical practice because the prognostic relevance of white coat hypertension detected by home measurements seems to differ in untreated and treated subjects. Whether our current findings based on the self-measured home blood pressure can be extrapolated to ambulatory blood pressure monitoring needs further investigation.
Maternal Obesity and Childhood Cardiometabolic Outcomes (page 683)
The prevalence of childhood obesity is increasing. Although many postnatal sociodemographic and lifestyle-related characteristics are well-known risk factors for childhood obesity, intrauterine exposures may also play a role. Maternal prepregnancy obesity is strongly associated with obesity and an adverse cardiometabolic profile in offspring, but it remains unclear whether these associations are explained by direct intrauterine mechanisms, or shared environmental, lifestyle-related, or genetic factors. In this issue of Hypertension, associations of maternal and paternal prepregnancy body mass index (BMI) with childhood cardiometabolic outcomes were compared to obtain further insight in the underlying mechanisms. Results from the population-based prospective cohort study from early pregnancy onward among 4871 mothers, fathers, and children showed that higher maternal and paternal prepregnancy BMI were associated with higher childhood BMI, total body and abdominal fat mass measures, systolic blood pressure and insulin levels, and lower high-density lipoprotein–cholesterol levels, with stronger associations present for maternal prepregnancy BMI. Maternal prepregnancy obesity was also strongly associated with the risk of childhood overweight and clustering of cardiometabolic risk factors. These findings suggest that maternal prepregnancy BMI may influence cardiometabolic health of offspring through direct intrauterine mechanisms. Our study provides further insight into the long-term cardiometabolic consequences of maternal obesity during pregnancy and is important from a cardiovascular developmental perspective. Further studies are needed to explore whether interventions focused on reduction of maternal weight during pregnancy will lead to better cardiometabolic health in offspring.
- © 2014 American Heart Association, Inc.