The earlier in life that hypertension begins, the higher the risk for later cardiovascular disease (CVD) and death, a large Chinese study suggests.
Researchers found that individuals age 45 years or younger at the time of hypertension onset had more than twice the adjusted risks for CVD and all-cause mortality after an average follow-up of 6.5 years.
Of special note, the risks gradually declined with each decade increase in the age of hypertension onset among both untreated and treated patients, the authors reported today today in the Journal of the American College of Cardiology.
“Our study suggested that the consideration of hypertension onset age would provide novel and preventive information beyond traditional cardiovascular risk assessment systems,” senior author Hao Xue, MD, Chinese PLA General Hospital, Beijing, told theheart.org | Medscape Cardiology by email.
“It also highlights the need to include age at hypertension diagnosis in cardioprotective guidelines and policies,” he said.
The age of hypertension onset is under increasing scrutiny, including recent reports linking early onset with cardiovascular death in midlife in the Framingham Heart Study and with hypertensive end-organ damage in the CARDIA study.
These studies, however, did not examine all-cause mortality and were conducted in predominantly white populations. So the new findings in a large Asian population help fill a research gap, the authors observe.
“For many, this is an affirmation that blood pressure in the young is important to identify and intervene,” said Daniel W. Jones, MD, professor of medicine and physiology, University of Mississippi Medical Center, Jackson, told theheart.org | Medscape Cardiology. “Patients and providers need to pay attention to this.”
The prevalence of hypertension is increasing globally, and because of infrequent contact with the health system, many young adults, particularly men, often go undiagnosed and untreated, he noted.
Further, the excess CVD risks observed in the study would likely have been greater if hypertension had been defined by the more stringent US blood pressure (BP) threshold of 130/80 mm Hg.
“The risk from blood pressure begins long before the definition of hypertension,” Jones said. “It begins at about 115 (mm Hg) systolic blood pressure.”
In late 2017, the American Heart Association, American College of Cardiology, and nine other health organizations redefined hypertension, lowering the target from 140/90 mm Hg to 130/80 mm Hg for all adults.
The 2018 European guidelines recommend drug therapy to a systolic BP target less than 140 mm Hg for most patients and to less than 130 mm Hg for patients younger than 65 years who can tolerate it.
The current study covers an earlier period and involves 71,245 participants in the prospective Kailuan study who were free of hypertension and CVD in the first survey (2006 to 2007) and were followed biennially until their death or December 2017.
New-onset hypertension, defined by either blood pressure of at least 140/90 mm Hg or the use of an antihypertensive medication on two or more consecutive visits, was identified in 20,221 participants during follow-up.
Cases were divided into four groups based on age at onset (<45 years, 45-54 years, 55-64 years, ≥65 years) and had an average age of 38.7 years, 50.5 years, 59.4 years, and 71.6 years, respectively. In all, 38% reported antihypertensive medication use.
Ultimately, 19,887 pairs of case and age- and sex-matched normotensive participants were included in the analysis. Cases were more likely to be ever-smokers and ever-drinkers, and to have a higher body mass index, heart rate, fasting blood glucose, triglycerides, total cholesterol, and estimated glomerular filtration rate.
During follow-up, there were 1672 incident CVD cases and 2008 deaths.
After multivariate adjustment, the risks of CVD and all-cause mortality were highest for individuals with hypertension onset before age 45 years.
Table. CVD, All-Cause Mortality by Hypertension Onset Age
| Average Hazard Ratio |
95% Confidence Interval |
|
|---|---|---|
| Cardiovascular Disease (P for interaction = .38) |
||
| <45 yrs | 2.26 | 1.19 – 4.30 |
| 45-54 yrs | 1.62 | 1.24 – 2.12 |
| 55-64 yrs | 1.42 | 1.12 – 1.79 |
| ≥65 yrs | 1.33 | 1.04 – 1.69 |
| All-cause Mortality (P for interaction <.01) | ||
| <45 yrs | 2.59 | 1.32 – 5.07 |
| 45-54 yrs | 2.12 | 1.55 – 2.90 |
| 55-64 yrs | 1.30 | 1.03 – 1.62 |
| ≥65 yrs | 1.29 | 1.11 – 1.51 |
Similar patterns were observed for stroke in CVD subtype analyses, and in several sensitivity analyses.
In further analysis, the median systolic BP of the treated group was significantly higher than the untreated group (147 mm Hg vs 141 mm Hg; P <.01).
“The treated population did not show a better blood pressure control in our study,” Xue said. “This may reflect an indication bias that patients with more severe symptoms (in this case, higher blood pressure) would be more likely to be treated. Therefore, the higher blood pressure in treated groups may result in the same risk pattern as the untreated group.”
He also noted that a national survey found that just 9% of young people in China had hypertension but that rates of hypertension awareness, treatment, and control were significantly lower in younger patients than older generations.
“Large-scale randomized controlled trials are still warranted to determine ideal target BP levels among young hypertensive patients,” Xue said. “In addition, more aggressive efforts are needed to develop management strategies that sustain long-term blood pressure control.”
In China, several hospitals have already taken some measures to improve hypertension awareness by installing electronic sphygmomanometers in public places, including airports and markets, he said. “It would cover more high-risk populations of hypertension and attract people to pay more attention on their blood pressure conditions.”
Jones said their team is using social media to obtain informed consent from patients identified with elevated BP in one of their clinics and then mailing them a pad and BP monitor to measure BP at regular intervals. Patients then interact on social media with nurse practitioners, who can prescribe and adjust medications.
In an accompanying editorial, Teemu J. Niiranen, MD, University of Turku, Finland, and colleagues said that the present study provides additional “compelling evidence” on the adverse effects of early-onset hypertension.
“The implications of this work are potentially far-reaching,” they write. “The authors correctly speculate that assessment of hypertension-onset age could improve overall CVD risk stratification, and that individuals with early-onset hypertension might benefit from more intensive hypertension treatment, including lifestyle interventions and antihypertensive therapy.”
The editorialists note that parental age of hypertension also may be useful for estimating risk in offspring, and that their own research suggests self-report could improve the feasibility of incorporating hypertension-age onset assessment into clinical practice.
Although younger patients tend to overlook the health hazards of hypertension, current guidelines do not recommend using age of hypertension onset as part of a CVD risk assessment. Contemporary recommendations also do not yet emphasize the importance of adequate therapy in young patients, Niiranen and colleagues point out.
“Future guideline iterations could include revisions that specify treatment approaches for patients with early-onset hypertension, given their considerable greater lifetime CVD risk when compared with patients with late-onset hypertension,” they conclude.
Jones and the editorialists have disclosed no relevant financial relationships.
J Am Coll Cardiol. Published online June 8, 2020. Abstract, Editorial
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