Isolated systolic hypertension and central blood pressure: Implications from the national nutrition and health survey in Taiwan

Importance of central BP assessment in ISH of the young. Which devices are best suited for practical use?

Isolated systolic hypertension (ISH), defined as brachial systolic blood pressure (bSBP) ≥140 mmHg and diastolic blood pressure (DBP) <90 mmHg, is highly prevalent among young subjects and in the elderly. The prognostic significance of ISH in young individuals remains the object of large debate which might be solved, at least in part, if considering the prognostic role of central BP. For any given value of pBP, the cardiovascular (CV) risk is better defined by central BP (cBP). Young individuals with ISH have long been considered at low CV risk, given the assumption that a "spurious hypertension" phenotype characterized by elevated peripheral (brachial) BP (pBP), normal cBP, and elevated BP amplification was often found in this population. However, this remains to be proven, because many other studies found no differences in BP amplification between ISH and sisto-diastolic hypertension. Despite numerous attempts, methodologies for cBP assessment by non-invasive devices are currently not standardized. As a result, different devices could provide different cBP values despite using the same biological signals. Devices providing accurate estimates of BP amplification as a dimensionless ratio between amplitudes of central and peripheral arterial waveforms might be well suited for clinical purposes in young individuals with ISH. There is urgent need of well-designed prospective studies aiming at longitudinally evaluating the amount of CV risk associated with elevated cBP in young subjects with ISH and their related incremental prognostic value.

Relationship between heart rate and central aortic blood pressure: implications for assessment and treatment of isolated systolic hypertension in the young

Isolated systolic hypertension in the young (ISHY) remains a challenging problem, partly due to the differences in central aortic pressure observed in studies investigating ISHY. The fundamental relationship between heart rate and central aortic pressure, and more precisely, the relationship between heart rate and amplification of central aortic pressure in the periphery, underpins the assessment and, as a consequence, the treatment of ISHY. Physiology warrants that an increase in heart rate would lead to increased amplification of the pressure pulse between the aorta and the brachial artery. Heart rate generally decreases with age, in particular over the first two decades of life. Thus, a higher heart rate in the young would result in higher pulse pressure amplification, and therefore an elevated brachial systolic pressure would not necessarily translate to elevated aortic systolic pressure. However, elevated heart rate is not a consistent feature in ISHY, and studies have shown that ISHY can present with either high or low central aortic systolic pressure. In this brief review, we summarize the physiological aspects underlying the relationship between heart rate and central aortic blood pressure and its amplification in the brachial artery, how this relationship changes with age, and examine the implications of these effects on the assessment and treatment of ISHY.

Isolated systolic hypertension and its associated risk factors in Iranian middle age and older population: a population-based study

Background

Isolated systolic hypertension (ISH), is the most common form of hypertension in older adults. However, the ISH prevalence is not well known in many developing countries such as Iran. This study was conducted to determine the ISH prevalence and its related risk factors in an Iranian population.

Methods

Data were obtained from the second phase of the Shahroud eye cohort study (ShECS) in 2014. ShECS is a longitudinal population-based study which the first phase had been conducted in 2009 using the stratified multistage cluster sampling design on 5190 people aged 40 to 70 years. The ISH prevalence was determined based on the eighth Joint National Commission guidelines for different demographic variables. The associated risk factors were estimated by multiple logistic regression and a two-tailed p-value less than 0.05 was considered significant.

Results

The ISH prevalence was 15.89% (95% CI: 14.88–16.96). It was 15.68% (14.12–17.39) and 15.87% (14.54–17.29) for men and women, respectively. The prevalence of ISH increased significantly with increasing age. The 65–70 compared to 45–69 year age group (OR = 4.21), body mass index (OR = 1.03), diabetes (OR = 1.64), retirement, compared to practitioner job (OR = 1.53), and waist to hip ratio (WHR) (OR = 9.81) were significantly associated with ISH prevalence.

Conclusions

ISH is highly prevalent among the older adult population in Iran. Given the risk of cardiovascular disease associated with ISH, it is recommended to conduct education and public health interventions to improve the detection, prevention, and treatment of ISH.

Prevalence and determinants of isolated systolic and isolated diastolic hypertension in India: Insights from the national family health survey (NFHS)- 4

Background

Isolated Systolic Hypertension (ISH) and Isolated Diastolic Hypertension (IDH) are often the ignored forms of hypertension and are determinants of future cardiac and neurological events and contribute to mortality. However, the nationally representative estimates of both these forms of hypertension remain unknown from India.

Aim

To estimate the ISH and IDH from a nationally representative survey of India.

Material and Methods

The present study used data from 7,23,181 people (15-54 years), recorded during the fourth round (2015-2016) of the National Family Health Survey (NFHS), India. The prevalence of ISH and IDH was calculated for state comparison, while multilevel logistic regression analysis was done to assess the correlates of both types of hypertension.

Results

The prevalence of ISH and IDH was found to be 1.2% (95% CI 1.0-1.4) and 5.7% (95% CI 5.2-6.2), respectively. The prevalence of both ISH and IDH increased with age, with a more significant increase in systolic pressure towards the higher age. Northeastern states of India (Assam, Meghalaya, and Arunachal Pradesh) had the highest prevalence of both forms of hypertension. On multilevel logistic regression, male gender, increasing age groups (highest odds ratio (OR) being in 45-49 year age group), alcohol, and diabetes positively predicted both ISH and IDH. Urban residence, literacy, and tobacco were positive predictors of IDH, whereas urban residence, smoking, and literacy negatively predicted ISH.

Conclusion

ISH and IDH have a significant presence among the population of India. This data provides insights to formulate strategies at the primary and primordial prevention levels.