Genetic and familial factors in essential hypertension and related traits

Relationship between parental hypertension and cardiometabolic risk factors in adolescents

This study aimed to investigate the relationship between parental hypertension and cardiometabolic risk factors in adolescents. The authors analyzed data of 554 adolescents aged 13 to 19 years from the Korean National Health and Nutrition Examination Survey 2013. The associations between parental hypertension and cardiometabolic abnormalities in adolescents were evaluated through multivariate logistic regression. Parental hypertension was noted in 16.2% of participants. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for overweight (OR, 2.08; 95% CI, 1.01-4.28) and obesity (OR, 2.11; 95% CI, 1.09-4.07) were significantly higher in participants with parental hypertension. The adjusted ORs for abdominal obesity (OR, 2.36; 95% CI, 1.01-5.56), high blood pressure (OR, 3.05; 95% CI, 1.19-7.78), and elevated alanine transaminase defined as >35 IU/L (OR, 2.86; 95% CI, 1.03-7.95) were significantly higher in participants with parental hypertension. Prevention of cardiometabolic risk factors should be reinforced in the offspring of hypertensive parents.

The influence of family history of hypertension on disease prevalence and associated metabolic risk factors among Sri Lankan adults

BACKGROUND

Hypertension is a major contributor to the global non-communicable disease burden. Family history is an important non-modifiable risk factor for hypertension. The present study aims to describe the influence of family history (FH) on hypertension prevalence and associated metabolic risk factors in a large cohort of South Asian adults, from a nationally representative sample from Sri Lanka.

METHODS

A cross-sectional survey among 5,000 Sri Lankan adults, evaluating FH at the levels of parents, grandparents, siblings and children. A binary logistic regression analysis was performed in all patients with 'presence of hypertension' as dichotomous dependent variable and using family history in parents, grandparents, siblings and children as binary independent variables. The adjusted odds ratio controlling for confounders (age, gender, body mass index, diabetes, hyperlipidemia and physical activity) are presented below.

RESULTS

In all adults the prevalence of hypertension was significantly higher in patients with a FH (29.3%, n = 572/1951) than those without (24.4%, n = 616/2530) (p < 0.001). Presence of a FH significantly increased the risk of hypertension (OR:1.29; 95% CI:1.13-1.47), obesity (OR:1.36; 95% CI: 1.27-1.45), central obesity (OR:1.30; 95% CI 1.22-1.40) and metabolic syndrome (OR:1.19; 95% CI: 1.08-1.30). In all adults presence of family history in parents (OR:1.28; 95% CI: 1.12-1.48), grandparents (OR:1.34; 95% CI: 1.20-1.50) and siblings (OR:1.27; 95% CI: 1.21-1.33) all were associated with significantly increased risk of developing hypertension.

CONCLUSIONS

Our results show that the prevalence of hypertension was significantly higher in those with a FH of hypertension. FH of hypertension was also associated with the prevalence of obesity, central obesity and metabolic syndrome. Individuals with a FH of hypertension form an easily identifiable group who may benefit from targeted interventions.

Endogamy and variation in blood pressure levels in Croatian island isolates

Blood pressure variation was investigated among populations inhabiting islands and peninsula of Middle Dalmatia, Croatia. The number of previous anthropological studies pointed to isolation and different genetic population structure in this environmentally fairly homogeneous area. Variation in blood pressure (systolic and diastolic) among the populations of the islands of Brac, Hvar, Korcula, and the Peljesac peninsula was assessed at three levels involving village populations, regional (western and eastern) populations and the entire island populations. The blood pressure data were collected from 3834 adult individuals inhabiting 37 rural communities and were adjusted for age and body mass index. Variation in blood pressure levels existed among regions and villages. Due to the history of differential settlement, small village sizes and high levels of reproductive isolation, the observed blood pressure variation could be attributed to founder effect, genetic drift and inbreeding. The involvement of genetic factors was tested by relating blood pressure variation among villages to degree of isolation among them. Blood pressure means and proportions of hypertensives increased with endogamy levels in males. In females, this effect could not be observed. However, in both sexes the highest proportions of hypertensives (more than 40%) were found in villages that are most reproductively closed (endogamy greater than 80%). These populations are considered particularly promising for further genetic epidemiological research.

Geographic variation in vascular mortality in Eurasia: spatial autocorrelation analysis of mortality variables and risk factors

The geographic variation patterns of vascular mortality and their major risk factors from 68 samples in Eurasia are described in this work. The goodness-of-fit tests and analysis of variance indicate significant differences in incidence of mortality from the studied diseases, as well as in risk factors among the various geographic regions in four age groups. Correlation analysis points out the two general tendencies for the majority of studied traits: (a) significant positive association with latitude and (b) significant negative correlation with longitude. In turn, one-dimensional correlograms showed no specific geographic pattern at least up to 3000 km for all studied variables. However, at the large geographic scale a long-distance differentiation pattern was indicated for total serum cholesterol and body mass index; regional patches--for total death rate, mortality rate from cardiovascular and ischaemic heart diseases, systolic and diastolic blood pressure; and a local patches pattern was detected for mortality rate from stroke. Two-dimensional correlograms uncovered three distinct and significant patterns of variation: (a) a north-south trend for total mortality rate, for death rate from cardiovascular and ischaemic heart diseases, for diastolic and systolic blood pressure and for body mass index; (b) a northwest-southeast pattern for mortality rate from cerebrovascular disease; and (c) local patches for total serum cholesterol.

Genetic epidemiological study of blood pressure in a sedentary rural agricultural population of West Bengal, India

To study the genetic epidemiology of blood pressure (BP), data on 78 families were collected from a sedentary agricultural population of eastern India. The general levels of both systolic (SBP) and diastolic (DBP) blood pressures are found to be low (mean SBP = 106.41 mm Hg; mean DBP = 63.94 mm Hg). Trends of blood pressures with age are similar to those reported earlier (e.g., in the Framingham study). Environmental variables--e.g., occupation and tobacco use--do not have any direct significant effect on blood pressure variability in this population. Path analysis of family data shows a highly significant familial aggregation and yields a genetic heritability (maximum) estimate of 0.3 for both SBP and DBP. Sib-sib and mother-child correlation estimates are, respectively, 0.3 and 0.25. Father-child correlation estimates are 0.13 for SBP and near zero for DBP. A pseudopolygenic model yields the best fit to the data on SBP, while for DBP a proper resolution of various models considered could not be obtained.