Yuan-Yuan Kang

Prevalence, awareness, treatment and control of hypertension in elderly Chinese

We studied the prevalence, awareness, treatment and control of hypertension in an elderly Chinese population. The study subjects (age ⩾60 years) were recruited from a suburban town of Shanghai from 2006 to 2008. We administered a standardized questionnaire to collect information on medical history, the use of medications and lifestyle. We measured blood pressure three times consecutively using a validated Omron 7051 oscillometric device (Kyoto, Japan) after the subjects had rested for at least 5 min in the sitting position. We defined hypertension as a blood pressure of at least 140 mm Hg systolic or 90 mm Hg diastolic or as the use of antihypertensive drugs. The 3949 participants (mean age of 68.3 years) included 2185 (55.3%) women, 182 (4.6%) obese subjects (body mass index ⩾30 kg m−2) and 366 (9.3%) diabetic patients. The prevalence of hypertension was 59.4%. In the 2345 hypertensive patients, the awareness, treatment and control (<140/90 mm Hg) rates were 72.5%, 65.8% and 24.4%, respectively. In the 1542 treated hypertensive patients, 1196 (77.6%) used fixed-dose combinations of thiazide and reserpine or clonidine (n=1157, 75.0%) or of an angiotensin receptor blocker and hydrochlorothiazide (n=1) or free combinations (n=38, 2.5%), and 346 (22.4%) used a monotherapy of short-acting calcium channel blockers (n=217, 14.1%) or other classes of antihypertensive drugs (n=129, 8.3%). The corresponding control rates were 37.3% and 36.4%, respectively. In a stepwise logistic regression, the risk of uncontrolled hypertension was higher with older age (+10 years, odds ratio (OR) 1.19, P=0.03), female sex (OR 1.40, P=0.01), obesity (OR 2.35, P=0.0002) and heavy drinking (⩾300 g per week, OR 2.18, P=0.0007). In conclusion, in elderly Chinese, the prevalence of hypertension is high. In spite of reasonably high awareness and treatment rates, the control rate remains low, most likely due to an unhealthy lifestyle and the underuse and/or underdose of antihypertensive drugs.

Brachial-Ankle Pulse Wave Velocity as a Predictor of Mortality in Elderly Chinese

Pulse wave velocity (PWV) is a measure of arterial stiffness and predicts cardiovascular events and mortality in the general population and various patient populations. In the present study, we investigated the predictive value of brachial-ankle PWV for mortality in an elderly Chinese population. Our study subjects were older (≥60 years) persons living in a suburban town of Shanghai. We measured brachial-ankle PWV using an automated cuff device at baseline and collected vital information till June 30, 2013, during follow-up. The 3876 participants (1713 [44.2%] men; mean [±SD] age, 68.1±7.3 years) included 2292 (59.1%) hypertensive patients. PWV was on average 17.8 (±4.0) m/s and was significantly (P<0.0001) associated with age (r=0.48) and in unadjusted analysis with all-cause (n=316), cardiovascular (n=148), stroke (n=46), and noncardiovascular mortality (n=168) during a median follow-up of 5.9 years. In further adjusted analysis, we studied the risk of mortality according to the decile distributions of PWV. Only the subjects in the top decile (23.3–39.3 m/s) had a significantly (P⩽0.003) higher risk of all-cause mortality (hazard ratio relative to the whole study population, 1.56; 95% confidence interval, 1.16–2.08), especially in hypertensive patients (hazard ratio, 1.86; 95% confidence interval, 1.31–2.64; P=0.02 for the interaction between PWV and hypertension). Similar trends were observed for cardiovascular, stroke, and noncardiovascular mortality, although statistical significance was not reached (P≥0.08). In conclusion, brachial-ankle PWV predicts mortality in elderly Chinese on the conditions of markedly increased PWV and hypertension.

Accuracy of home versus ambulatory blood pressure monitoring in the diagnosis of white-coat and masked hypertension.

Background: We investigated accuracy of home blood pressure (BP) monitoring in the diagnosis of white-coat and masked hypertension in comparison with ambulatory BP monitoring. Methods: Our study participants were enrolled in the China Ambulatory and Home BP Registry, and underwent clinic, home, and 24-h ambulatory BP measurements. We defined white-coat hypertension as an elevated clinic SBP/DBP (≥140/90 mmHg) and a normal 24-h ambulatory (<130/80 mmHg) or home SBP/DBP (<135/85 mmHg), and masked hypertension as a normal clinic SBP/DBP (<140/90 mmHg) and an elevated 24-h ambulatory (≥130/80 mmHg) or home SBP/DBP (≥135/85 mmHg). Results: In untreated patients (n = 573), the prevalence of white-coat hypertension (13.1 vs. 19.9%), masked hypertension (17.8 vs. 13.1%), and sustained hypertension (46.4 vs. 39.6%) significantly (P ⩽ 0.02) differed between 24-h ambulatory and home BP monitoring. In treated patients (n = 1201), only the prevalence of masked hypertension differed significantly (18.7 vs. 14.5%; P = 0.005). Regardless of the treatment status, home compared with 24-h ambulatory BP had low sensitivity (range 47–74%), but high specificity (86–94%), and accordingly low positive (41–87%), but high negative predictive values (80–94%), and had moderate diagnostic agreement (82–85%) and Kappa statistic (0.41–0.66). In untreated and treated patients, age advancing was associated with a higher prevalence of white-coat hypertension and a lower prevalence of masked hypertension defined by 24-h ambulatory (P ⩽ 0.03) but not home BP (P ≥ 0.10). Conclusion: Home BP monitoring has high specificity, but low sensitivity in the diagnosis of white-coat and masked hypertension, and may therefore behave as a complementary to, but not a replacement of, ambulatory BP monitoring.

Strategies for Classifying Patients Based on Office, Home, and Ambulatory Blood Pressure Measurement

Hypertension guidelines propose home or ambulatory blood pressure monitoring as indispensable after office measurement. However, whether preference should be given to home or ambulatory monitoring remains undetermined. In 831 untreated outpatients (mean age, 50.6 years; 49.8% women), we measured office (3 visits), home (7 days), and 24-h ambulatory blood pressures. We applied hypertension guidelines for cross-classification of patients into normotension or white-coat, masked, or sustained hypertension. Based on office and home blood pressures, the prevalence of white-coat, masked, and sustained hypertension was 61 (10.3%), 166 (20.0%), and 162 (19.5%), respectively. Using daytime (from 8 AM to 6 PM) instead of home blood pressure confirmed the cross-classification in 575 patients (69.2%), downgraded risk from masked hypertension to normotension (n=24) or from sustained to white-coat hypertension (n=9) in 33 (4.0%), but upgraded risk from normotension to masked hypertension (n=179) or from white-coat to sustained hypertension (n=44) in 223 (26.8%). Analyses based on 24-h ambulatory blood pressure were confirmatory. In adjusted analyses, both the urinary albumin-to-creatinine ratio (+20.6%; confidence interval, 4.4–39.3) and aortic pulse wave velocity (+0.30 m/s; confidence interval, 0.09–0.51) were higher in patients who moved up to a higher risk category. Both indexes of target organ damage and central augmentation index were positively associated (P⩽0.048) with the odds of being reclassified. In conclusion, for reliably diagnosing hypertension and starting treatment, office measurement should be followed by ambulatory blood pressure monitoring. Using home instead of ambulatory monitoring misses the high-risk diagnoses of masked or sustained hypertension in over 25% of patients.

The prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population: a prospective study

BackgroundThere is limited information on prevalent and incident atrial fibrillation in Chinese. We aimed to investigate the prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population.MethodsIn a population—based prospective study in elderly (≥60 years) Chinese, we performed cardiovascular health examinations including a 12-lead electrocardiogram at baseline in 3,922 participants and biennially during follow-up in 2,017 participants. We collected information on vital status during the whole follow-up period.ResultsThe baseline prevalence of atrial fibrillation was 2.0 % (n = 34) in 1718 men and 1.6 % (n = 36) in 2204 women. During a median 3.8 years of follow-up, the incidence rate of atrial fibrillation (n = 34) was 4.9 per 1000 person-years (95 % confidence interval [CI], 3.4–6.9). In univariate analysis, both the prevalence and incidence of atrial fibrillation were higher with age advancing (P < 0.0001) and in the presence of coronary heart disease (P ≤ 0.02). Of the 104 prevalent and incident cases of atrial fibrillation, only 1 (1.0 %) received anticoagulant therapy (warfarin). These patients with atrial fibrillation, compared with those with sinus rhythm, had significantly higher risks of all-cause (n = 261, hazard ratio [HR] 1.87, 95 % CI, 1.09–3.20, P = 0.02), cardiovascular (n = 136, HR 3.78, 95 % CI 2.17–6.58, P < 0.0001) and stroke mortality (n = 44, HR 6.31, 95 % CI 2.81–14.19, P = 0.0003).ConclusionsAtrial fibrillation was relatively frequent in elderly Chinese, poorly managed and associated with higher risks of mortality.

Characteristics and Determinants of the Sublingual Microcirculation in Populations of Different Ethnicity

No previous population study assessed sublingual capillary density (CD) or perfused boundary region (PBR). Lower PBR indicates greater glycocalyx width. In 252 Han and 220 She Chinese and 254 Flemish people (mean age, 51.1 years; 54.7% women), representing random population samples, we measured total and perfused CD and PBR in the sublingual capillary bed, using oblique profiled epi-illumination, and cardiovascular risk factors. In multivariable analyses, we modeled ethnicity as random effect. Significance level was &agr;⩽0.05. Compared with Chinese, Flemish had lower total (577 versus 546 n°/mm2) and perfused (338 versus 320 n°/mm2) CD, but similar perfused-to-total CD ratio (mean, 0.59). Perfused-to-total CD ratio increased with age (effect size per 1–SD increase, +0.015 per year), body mass index (+0.008 per kg/m2), total cholesterol (+0.012 per mmol/L), and Framingham risk score (+0.018 per point) with no ethnic differences in these associations. For age and Framingham risk score, associations with perfused-to-total CD ratio were driven by positive relationships with perfused CD, whereas associations with total CD were nonsignificant. Chinese when compared with Flemish had higher hematocrit (43.0 versus 41.1%), PBR (2010 versus 1876 nm), and pulse rate (72.6 versus 63.3 bpm). PBR standardized for hematocrit, perfused CD, and pulse rate decreased with body mass index (–26.7 nm/kg/m2), mean arterial pressure (–30.6 nm/mm Hg), and diastolic pressure (–28.5 nm/mm Hg) with no ethnic differences in these associations. In conclusion, a higher cardiovascular risk profile is associated with functional recruitment of capillaries with preserved glycocalyx that protects the endothelial lining.

Association of Anthropometric and Bioelectrical Impedance Analysis Measures of Adiposity with High Molecular Weight Adiponectin Concentration.

Objective To investigate the relationship between adiposity measures and plasma concentration of high molecular weight (HMW) adiponectin. Methods In a Chinese sample (n = 1081), we performed measurements of anthropometry and bioelectrical impedance analysis (BIA). We defined overweight and obesity as a body mass index between 24 and 27.4 kg/m² and ≥ 27.5 kg/m², respectively, and central obesity as a waist circumference ≥ 90 cm in men and ≥ 80 cm in women. Plasma HMW adiponectin concentration was measured by the ELISA method. Results Plasma HMW adiponectin concentration was significantly (P < 0.0001) higher in women (n = 677, 2.47 μg/mL) than men (n = 404, 1.58 μg/mL) and correlated with advancing age in men (r = 0.28) and women (r = 0.29). In adjusted analyses, it was lower in the presence of overweight (n = 159, 1.26 μg/mL in men and n = 227, 2.15μg/mL in women) and obesity (n = 60, 1.31 μg/mL and n = 82, 2.10 μg/mL, respectively) than normal weight subjects (n = 185, 2.07μg/mL and n = 368, 2.94 μg/mL, respectively) and in the presence of central obesity (n = 106, 1.28 μg/mL and n = 331, 2.12 μg/mL, respectively) than subjects with a normal waist circumference (n = 298, 1.74 μg/mL and n = 346, 2.74 μg/mL, respectively). In multiple regression analyses stratified for gender, adjusted for confounders and considered separately each of the adiposity measures, all adiposity measures were significantly (r -0.18 to -0.31, P < 0.001) associated with plasma HMW adiponectin concentration. However, in further stratified and adjusted regression analyses considered stepwise all adiposity measures, only waist-to-hip ratio was significantly (P < 0.05) associated with plasma HMW adiponectin concentration in men (r = -0.10) and women (r = -0.15). Conclusions Anthropometric measures of obesity, such as waist-to-hip ratio, but not BIA measures, are independently associated with plasma adiponectin concentration.

Ambulatory Blood Pressure Monitoring in the Prediction and Prevention of Coronary Heart Disease

We reviewed studies of ambulatory blood pressure monitoring (ABPM) in patients with symptomatic coronary heart disease (CHD) or asymptomatic coronary lesions and in patients at high coronary risk, such as in the presence of hypertension. We identified ten cross-sectional and seven prospective studies in patients with CHD or coronary lesions. These studies showed that patients with CHD or coronary lesions often had nocturnal non-dipping or increased blood pressure variability, and might have increased risk of coronary events, due to either uncontrolled hypertension or treatment-induced hypotension identified by ABPM. We identified ten observational studies in hypertensive patients and normotensive subjects and five therapeutic trials in hypertension. These observational studies demonstrated that one or more ambulatory blood pressure components might provide predictive value for coronary events above and beyond clinic blood pressure. The therapeutic trials were less conclusive, but suggestive of additional value for the prevention of coronary events.

Pulse Waves in the Lower Extremities as a Diagnostic Tool of Peripheral Arterial Disease and Predictor of Mortality in Elderly Chinese

Patients with peripheral arterial disease may have elongated upstroke time in pulse waves in the lower extremities. We investigated upstroke time as a diagnostic tool of peripheral arterial disease and predictor of mortality in an elderly (≥60 years) Chinese population. We recorded pulse waves at the left and right ankles by pneumoplethysmography and calculated the percentage of upstroke time per cardiac cycle. Diagnostic accuracy was compared with the conventional ankle-brachial index method (n=4055) and computed tomographic angiography (34 lower extremities in 17 subjects). Upstroke time per cardiac cycle at baseline (mean±SD, 16.4%±3.1%) was significantly (P<0.0001) associated with ankle-brachial index in men (n=1803; r=−0.44) and women (n=2252; r=−0.32) and had an overall sensitivity and specificity of 86% and 80%, respectively, for the diagnosis of peripheral arterial disease (upstroke time per cardiac cycle, ≥21.7%) in comparison with computed tomographic angiography. During 5.9 years (median) of follow-up, all-cause and cardiovascular deaths occurred in 366 and 183 subjects, respectively. In adjusted Cox regression analyses, an upstroke time per cardiac cycle ≥21.7% (n=219; 5.4%) significantly (P<0.0001) predicted total and cardiovascular mortality. The corresponding hazard ratios were 1.98 (95% confidence interval, 1.48–2.65) and 2.29 (1.58–3.32), respectively, when compared with that of 2.10 (1.48–3.00) and 2.44 (1.57–3.79), respectively, associated with an ankle-brachial index of ⩽0.90 (n=115; 2.8%). In conclusion, pulse waves in the lower extremities may behave as an accurate and ease of use diagnostic tool of peripheral arterial disease and predictor of mortality in the elderly.

Efficacy and tolerability of initial high vs low doses of S-(-)-amlodipine in hypertension

In an 8‐week randomized trial of patients with mild or moderate hypertension, the authors investigated the efficacy and tolerability of initial high (5.0 mg/d) vs low (2.5 mg/d) doses of S‐(‐)‐amlodipine (equivalent to 5 and 10 mg of racemic amlodipine, respectively). In the S‐(‐)‐amlodipine 2.5‐mg group (n=263), 24‐hour ambulatory systolic/diastolic blood pressure (±standard deviation) decreased from 131.5±15.0/82.1±10.7 mm Hg at baseline to 126.0±13.5/78.5±9.5 mm Hg at 8 weeks of follow‐up by a least square mean (±standard error) change of 6.0±0.6/3.8±0.4 mm Hg. In the S‐(‐)‐amlodipine 5‐mg group (n=260), the corresponding changes were from 133.6±13.7/83.1±9.9 mm Hg to 125.0±12.0/78.2±8.9 mm Hg by 8.1±0.6/4.7±0.4 mm Hg, respectively. The between‐group differences in changes in 24‐hour systolic/diastolic blood pressure were 2.1/0.9 (P=.02/.17) mm Hg. Similar trends were observed for daytime and nighttime ambulatory and clinic blood pressure. The incidence rate was similar for all adverse events. An initial high dose of S‐(‐)‐amlodipine improved ambulatory blood pressure control with similar tolerability as an initial low dose in hypertension.