Do other cardiovascular risk factors influence the impact of age on the association between blood pressure and mortality? The MORGAM Project

The impact of sex on blood pressure and anthropometry trajectories from early adulthood in a Nigerian population: insights into women's cardiovascular disease risk across the lifespan

BACKGROUND

Sex disparities in blood pressure and anthropometry may account for differences in cardiovascular (CV) risk burden with advancing age; modulated by ethnic variability. We explored trajectories of blood pressures (BPs) and anthropometric indices with age on the basis of sex in an urban Nigerian population.

METHODS

We conducted a secondary analysis on data from 5135 participants (aged 16-92 years; 2671(52%) females) from our population-based cross-sectional study of BP profiles. We utilized the WHO STEPS and standardized methods for documenting BPs, body mass index (BMI) and waist circumference (WC). Data was analyzed using Analysis of variance (ANOVA), Spearman correlation analysis and mean difference in variables (with 95% confidence interval). We explored the influence of age and sex on BP profiles and specific anthropometric indices using generalized regression analysis.

RESULTS

In those aged 15-44 years, males had significantly higher systolic BP (SBP) and pulse pressure (PP). However, mean SBP and PP rose more steeply in females from 25 to 34 years, intersected with that of males from 45 to 54 years and remained consistently higher. Difference in mean BPs (95% Confidence Interval) (comparing < and > 45 years) was higher in females compared to males for SBP (17.4 (15.8 to 19.0) v. 9.2 (7.7 to 10.7), DBP (9.0 (7.9 to 10.1) v. 7.8 (6.7 to 8.9)), and PP (8.4 (7.3 to 9.5) v. 1.4 (0.3 to 2.5)). Females had significantly higher BMI and WC across all age groups (p < 0.001). Age more significantly correlated with BPs, BMI and WC in females. Interaction models revealed that SBP was significantly predicted by age category in females from (15-54 years), while DBP was only significantly predicted by age in the 15-34-year category (p < 0.01). BMI and WC were significantly predicted by age only in the 25-34-year category in females, (p < 0.01).

CONCLUSIONS

Our population demonstrates sex disparity in trajectories of SBP, PP, BMI and WC with age; with steeper rise in females. There is a need to focus on CV risk reduction in females, starting before, or during early adulthood.

Association between high blood pressure and long term cardiovascular events in young adults: systematic review and meta-analysis

OBJECTIVE

To evaluate and quantify the future risk of cardiovascular events in young adults with high blood pressure.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and Web of Science were searched from inception to 6 March 2020. Relative risks were pooled using a random effects model and expressed with 95% confidence intervals. Absolute risk difference was calculated. Dose-response relations between blood pressure and individual outcomes were assessed by a restricted cubic spline model.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were selected that investigated the adverse outcomes of adults aged 18-45 with raised blood pressure. The primary study outcome was a composite of total cardiovascular events. Coronary heart disease, stroke, and all cause mortality were examined as secondary outcomes.

RESULTS

Seventeen observational cohorts consisting of approximately 4.5 million young adults were included in the analysis. The average follow-up was 14.7 years. Young adults with normal blood pressure had increased risk of cardiovascular events compared with those with optimal blood pressure (relative risk 1.19, 95% confidence interval 1.08 to 1.31; risk difference 0.37, 95% confidence interval 0.16 to 0.61 per 1000 person years). A graded, progressive association was found between blood pressure categories and increased risk of cardiovascular events (high normal blood pressure: relative risk 1.35, 95% confidence interval 1.22 to 1.49; risk difference 0.69, 95% confidence interval 0.43 to 0.97 per 1000 person years; grade 1 hypertension: 1.92, 1.68 to 2.19; 1.81, 1.34 to 2.34; grade 2 hypertension: 3.15, 2.31 to 4.29; 4.24, 2.58 to 6.48). Similar results were observed for coronary heart disease and stroke. Generally, the population attributable fraction for cardiovascular events associated with raised blood pressure was 23.8% (95% confidence interval 17.9% to 28.8%). The number needed to treat for one year to prevent one cardiovascular event was estimated at 2672 (95% confidence interval 1639 to 6250) for participants with normal blood pressure, 1450 (1031 to 2326) for those with high normal blood pressure, 552 (427 to 746) for those with grade 1 hypertension, and 236 (154 to 388) for those with grade 2 hypertension.

CONCLUSIONS

Young adults with raised blood pressure might have a slightly increased risk of cardiovascular events in later life. Because the evidence for blood pressure lowering is limited, active interventions should be cautious and warrant further investigation.

Does Estimated Pulse Wave Velocity Add Prognostic Information?

The Reference Values for Arterial Stiffness Collaboration has derived an equation using age and mean blood pressure to estimated pulse wave velocity (ePWV), which predicted cardiovascular events independently of Systematic COoronary Risk Evaluation (SCORE) and Framingham Risk Score. The study aim was to investigate the independent association between ePWV and clinical outcomes in 107 599 apparently healthy subjects (53% men) aged 19 to 97 years from the MORGAM Project who were included between 1982 and 2002 in 38 cohorts from 11 countries. Using multiple Cox-regression analyses, the predictive value of ePWV was calculated adjusting for country of inclusion and either SCORE, Framingham Risk Score, or traditional cardiovascular risk factors (age, sex, smoking, systolic blood pressure, body mass index [BMI], total and high-density lipoprotein cholesterol). Cardiovascular mortality consisted of fatal stroke, fatal myocardial infarction, or coronary death, and the composite cardiovascular end point consisted of stroke, myocardial infarction, or coronary death. Model discrimination was assessed using Harrell’s C -statistic. Adjusting for country and logSCORE or Framingham Risk Score, ePWV was associated with all-cause mortality (hazard ratio, 1.23 [95% CI 1.20–1.25] per m/s or 1.32 [1.29–1.34]), cardiovascular mortality (1.26 [1.21–1.32] or 1.35 [1.31–1.40]), and composite cardiovascular end point (1.19 [1.16–1.22] or 1.23 [1.20–1.25]; all P <0.001). However, after adjusting for traditional cardiovascular risk factors, ePWV was only associated with all-cause mortality (1.15 [1.08–1.22], P <0.001) and not with cardiovascular mortality (0.97 [0.91–1.03]) nor composite cardiovascular end point (1.10 [0.97–1.26]). The areas under the last 3 receiver operator characteristic curves remained unchanged when adding ePWV. Elevated ePWV was associated with subsequent mortality and cardiovascular morbidity independently of systematic coronary risk evaluation and Framingham Risk Score but not independently of traditional cardiovascular risk factors.

Impact of Age and Target-Organ Damage on Prognostic Value of 24-Hour Ambulatory Blood Pressure

Markers of target-organ damage and 24-hour ambulatory blood pressure (BP) measurement improve cardiovascular risk stratification. The prevalence of target-organ damage and raised BP increases with aging. The study aim was to evaluate the impact of age and target-organ damage on the prognostic value of ambulatory BP. Markers of target-organ damage and ambulatory BP were measured in 1408 healthy people aged 41 or 51 (middle-aged group), and 61 or 71 (older group) years. The primary outcome was cardiovascular events after 16 years of follow-up, with data obtained from national registries. The prognostic value of BP was evaluated with Cox regression models, adjusted for traditional risk factors and target-organ damage, including left ventricular mass, pulse wave velocity, carotid plaques, and urine albumin/creatinine ratio. A total of 323 events were observed. In comparison with traditional risk factors, adding systolic BP and presence of target-organ damage improved risk stratification by increasing concordance index from 0.711 to 0.728 ( P =0.01). In middle-aged subjects with target-organ damage, increment in pulse pressure (hazard ratio, 1.70; 95% confidence interval, 1.31–2.21; P <0.01) and increment in average real variability (hazard ratio, 1.29; 95% confidence interval, 1.05–1.59; P =0.02) were associated with a greater risk of cardiovascular disease compared with subjects without target-organ damage: hazard ratio, 1.04 (95% confidence interval, 0.74–1.46; P =0.81); P for interaction, 0.02; and hazard ratio, 0.89 (95% confidence interval, 0.69–1.14; P =0.36); P for interaction, 0.01. Target-organ damage may be a marker of individual susceptibility to the harmful effects of pulse pressure and BP variability on the cardiovascular system in middle-aged individuals.