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Ojective: To observe the effect of tianma gouteng decoction (TGD) on the endothelial function and the renal protein expression of spontaneously hypertensive rats, and to analyze its possible mechanism., Methods: Totally 18 6-week-old SHR were randomly divided into 3 groups according to randomized block design, the SHR control group, the TGD group, and the captopril group, 6 in each group. Meanwhile, Wistar Kyoto (WKY) rats of the same age were recruited as a WKY control group. Rats in the TGD group were administered with TGD at the daily dose of 10. 260 g/kg. Rats in the captopril group were administered with captopril at the daily dose of 3. 375 g/kg. 2 mL/100 g distilled water was administered to rats in the SHR control group and the WKY control group. All medication was performed by gastrogavage once per day till rats were 24 weeks old. Changes of blood pressure were measured once per two weeks. The relaxation of the thoracic aorta and the superior mesenteric artery was determined by vascular ring in vitro to reflect the endothelial function. The total renal protein was separated by two-dimensional electrophoresis (2-DE). The significantly deviated protein was verified by Western blot., Results: (1) Compared with the SHR control group, blood pressure was significantly lowered in rats (10 - 24 weeks old) of the captopril group (P <0.01, P <0.05). The hypotensive effect of TGD was obvious at the beginning of hypertension (10 -12 weeks) (P <0. 01). But along with the progression of hypertension, its hypotensive effect was not obvious (P>0. 05). (2) Compared with the SHR control group, the relaxation of the superior mesenteric artery was obviously improved in the TGD group (P <0. 05); the relaxation of the thoracic aorta and the superior mesenteric artery was obviously superior in the WKY control group (P <0. 01, P <0. 05). But there was no statistical difference in each relaxation index between the captopril group and the SHR control group (P >0. 05).(3) RESULTS: of 2-DE found 16 significantly differential renal protein, mainly involved nitric oxide (NO) system, oxidative stress, and cytoskeleton-related proteins. Results of Western blot showed that TGD could significantly improve expressions of Cu-Zn superoxide dismutase (SOD), N(G, N(G)-dimethylarginine dimethylaminohydrolase 2 (DDAH2), and pterin-4-alpha-carbinolamine dehydratase 1 (PCBD1) (P <0. 05)., Conclusion: GTD could protect the endothelial function of the superior mesenteric artery in SHR, and its intervention mechanism of hypertension induced early renal injury might be relevant to regulating the NO system and antioxidative stress.

Objective: To observe the differential protein expression profile of three different Chinese medicine compounds on spontaneous hypertensive rat, which were Banxiabaizhutianma Decoction, Dihuangyinzi Decoction and Tianmagouteng Decoction, and to elaborate their function characters and regulation pathway using the principal component analysis and analyze the basic theory of different treatment of hypertension., Methods: Give three compounds to 6-week-old SHR (Spontaneous hypertensive rat) as experimental group and captopril to 6-week-old WKY (Wistar-Kyoto rat) as control group by gavage. Monitor the blood pressure of rat tail to 24-week-old and then all rats were decapitated. Extracte the rental protein to finish two-dimensional electrophoresis experiments and get the differential protein spots using PDQuest software. Study the three different compounds' effect of trend on SHR blood pressure using PCAC principal component analysis., Results: The blood pressure of SHR remained rising from 6-week-old to 10-week-old, when Tianmagouteng Decoction had a significant anti-hypertension effect. But as the blood pressure of SHR remained high, Banxiabaizhutianma Decoction and Dihuangyinzi Decoction performed better in lowering blood pressure. At last, renal protein expression profile analysis showed that there were 84 significantly different proteins between SHR and WKY of 24-week-old and the PCA result showed that the principal component extraction was 95.951%, it was sure that Tianmagouteng Decoction and Banxiabaizhutianma Decoction had significantly changed rental protein spots on SHR while Dihuangyinzi Decoction had not., Conclusion: In the early stages of rising blood pressure, Tianmagouteng Decoction has significant anti-hypertensive effect. But when the blood pressure remain high, Banxiabaizhutianma Decoction and Dihuangyinzi Decoction are superior to Tanmagouteng Decoction in anti-hypertension. Banxiabaizhutianma Decoction and Tianmagouteng Decoction can significantly improve rental protein spots on SHR while Dihuangyinzi Decoction can not.

Background: Tianma Gouteng Yin Formula (TGYF) is widely used to treat hypertension-related symptoms in clinical practice in East Asia. It has been shown to have a blood pressure lowering effect, reducing total cholesterol, improving clinical symptoms and quality of life, and preventing the occurrence of stroke in hypertensive patients. Understanding the effect of Tianma Gouteng Yin Formula on blood pressure, quality of life and cardiovascular risk factors could be valuable for the management of high blood pressure., Objectives: To assess the efficacy and safety of Tianma Gouteng Yin Formula for treating primary hypertension compared to placebo or no treatment., Search Methods: English databases including Cochrane Central (CCTR), MEDLINE, EMBASE, AMED, CINAHL, IPA, and the Hypertension Group Specialised Register were searched up to July 2011. Chinese databases including Chinese Biomedical Database, TCMonline , Chinese Dissertation Database, CMAC and the Index to Chinese Periodical Literature were searched up to April 2010., Selection Criteria: Randomised and quasi-randomised controlled trials that compared TGYF with no treatment or placebo for primary hypertension., Data Collection and Analysis: No study was identified which met the inclusion criteria for this review., Main Results: No study was identified which met the inclusion criteria for this review., Authors' Conclusions: As no trials could be identified, no conclusions can be made about the role of TGYF in the treatment of primary hypertension. Well-designed randomized controlled studies need to be conducted and published.

Objective: To study the effect of Banxia Baizhu decoction on the spontaneously hypertensive rats and its possible mechanism., Methods: Male SHRs of 6 weeks old were randomly and equally divided into two groups, the control SHR group and the group treated with BXBZTMD, the treated group were treated with BXBZTMD orally for 18 weeks, the control SHR group and normotensive WKY group were fed with the same amount of distilled water. Rats' blood pressure was measured through carotid artery catheterization, and protein of kidney tissues was analyzed by two-dimensional electrophoresis after extraction and purification. Different protein spots expressed significantly which were anlyzed by PDQuest software were then identified by MALDI-TOF/TOF MS. The protein expressions of peroxidase 2 and Cu-Zn superoxide in kidney were determined by Western blot., Results: Compared SHR with WKY, 12 protein spots were changed. BXBZTMD could adjust kidney protein expression such as Cu-Zn superoxide dismutase, peroxidase 2 and may change kidney protein expression such as the alpha-beta-crystallin, which were closely related to oxidative stress. These discoveries of the target proteins suggested that BXBZTMD had curative effect by anti-oxidative stress., Conclusion: Oxidative stress plays an important role in the process of hypertensive renal injury. BXBZTMD can play a therapeutic role to oxidative stress. The discovery of the target protein provides a theoretical basis for the mechanism of the therapeutic effect of BXBZTMD.

What Is Known and Objective: Angiotensin-converting enzyme inhibitors (ACEI) are among the most commonly used antihypertensive agents worldwide. Factors associated with their discontinuation in clinical practice are not well defined as studies undertaken in different ethnic populations have yielded conflicting result. We aimed to identify predictors of ACEI discontinuation among Chinese patients., Methods: We used a validated clinical database for this cohort study. We included all adult patients aged ≥ 18 years who visited any primary care clinic in one Territory of Hong Kong and who were prescribed an ACEI from January 2004 to June 2007. The cumulative incidence of discontinuation 180 days after prescription of an ACEI was measured. Factors associated with discontinuation were evaluated by multiple regression analyses., Results: Among 9398 eligible patients, 14·0% discontinued their prescriptions. After controlling for patient's age, gender, socio-economic status, service type, district of residence, visit type and number of comorbidities, patients aged 70 or above [adjusted odds ratio (AOR) = 1·27, 95% CI 1·04-1·56, P = 0·022], male subjects (AOR = 1·21, 95% CI 1·05-1·40, P = 0·008), new visitors (AOR = 0·64, 95% CI 0·55-0·75, P < 0·001), patients who obtained their prescriptions in Family Medicine Specialist Clinic (FMSC) (AOR = 1·43, 95% CI 1·14-1·79, P = 0·002), patients who lived in the less urbanized district (AOR = 1·96, 95% CI 1·55-2·48, P < 0·001) and the most rural district (AOR = 1·24, 95% CI 1·03-1·49, P = 0·027), and patients with no comorbidity, were more likely to discontinue their medications., What Is New and Conclusion: Physicians should pay attention to adherence problems particularly when prescribing ACEI to male patients, those who are older than 70 years, have no comorbidity, live in less urbanized or more rural areas, qualify for fee-waiver, are new attendees of consultations or obtain their ACEI prescriptions in FMSC. Future research should evaluate the reasons for ACEI discontinuation among these higher-risk groups., (© 2011 Blackwell Publishing Ltd.)

This study tested the hypothesis that younger, male patients or new clinic visitors, who were prescribed thiazide diuretics were more likely to have drug discontinuation and switching. All adult patients who visited any primary care clinic in one territory of Hong Kong, and who were prescribed a thiazide diuretic from January 2004 to June 2007 were included. The rates of discontinuation and switching, separately, 180 days after thiazide prescriptions were measured. Factors associated with discontinuation and switching were evaluated by multiple regression analyses. Among 9398 patients, 12.5% discontinued and 10.8% switched their prescriptions, whereas prescriptions of other patients remained the same. Younger patients (< 50 years (reference value); adjusted odds ratio (AOR) for 50-59 years=0.74, 95% confidence interval (CI) 0.61-0.90, P=0.002; AOR (60-69 years)=0.57, 95% CI 0.46-0.70, P < 0.001; AOR (≥ 70 years)=0.88, 95% CI 0.73-1.06, P=0.174), male subjects (AOR=1.23, 95% CI 1.07-1.40, P=0.003) and new visitors (AOR (repeat visitors)=0.55, 95% CI 0.47-0.65, P < 0.001) were more likely to be discontinuers. These associations between younger age (< 50 years (reference value); AOR (50-59) years=0.85, 95% CI 0.70-1.04, P=0.112; AOR (60-69 year)=0.79, 95% CI 0.65-0.98, P=0.028; AOR (≥ 70 years)=0.70, 95% CI 0.57-0.85, P < 0.001), male gender (AOR=1.29, 95% CI 1.12-1.48, P < 0.001) and new visitors (AOR (repeat visitors)=0.57, 95% CI 0.48-0.67, P < 0.001) were also significant for medication switching. Clinicians should monitor the medication-taking behavior more closely among patients aged 50-59 years, male subjects and new clinic visitors when thiazide was prescribed.

Objective: To study the vascular endothelial function recovery and its mechanism of Banxia Baizhu Tianma Decoction (BBTD)., Methods: 54 SH rats were randomly divided into three groups: the blank control group, BBTD group and Captopril treatment group. BBTD (at the daily dose of 4. 320 g crude drug/kg) and Captopril (at the daily dose of 3.375 g/kg) was administered from the 7th week to the 24th week. Another eighteen Wistar-Kyoto rats of the same ages were taken as the control. Medication was discontinued and effects were observed until the 32nd week. The blood pressure was determined by arterial carotis cannula. The concentration of serum NO2(-) and total anti-oxidation were determined by Griess and fluorescence recovery after photobleaching (FRAP). The acetylcholine (Ach)-dependent relaxation of superior mesenteric artery was detected using in vitro vascular ring. The mRNA expressions of IL-1, IL-6 and iNOS were detected by Real-time PCR at the 18th, 24th, and 32nd week., Results: BBTD could significantly lower blood pressure of SHR and the concentration of serum NO2(-) at the 18th and 24th week (P<0.05). The total anti-oxidation of SH rats increased at the 18th week (P<0.01), and ACh-dependent relaxation of superior mesenteric artery increased at the 24th week. The mRNA expressions of IL-1 was markedly suppressed by BBTD at the 18th, 24th, and 32nd week (P<0.05), while IL-6 and iNOS mRNA expression were significantly lowered only at the 32nd week (P< 0.01). Captopril could significantly lower blood pressure of SHR at the 18th and 24th week (P<0.05). It significantly increased the total anti-oxidation of SH rats at the 18th week (P<0.01). However, it could not increase ACh-dependent relaxation of superior mesenteric artery and regulate the concentration of NO2(-) at the 18th, 24th, and 32nd week. The mRNA expression of iNOS was markedly suppressed by Captopril at the 24th and 32nd week, while mRNA expressions of IL-1 and IL-6 were significantly lower only at the 32nd week (P<0.01)., Conclusions: BBTD showed similar effect in decreasing the blood pressure to captopril, but it showed better effect in improving the mesenteric endothelial dysfunction of SHR, which may be associated with its inhibition on NO and IL-1 expression, and improvement of the oxidative stress state.

What Is Known and Objective: Good compliance to anti-hypertensive medications has been recognized as a crucial factor to achieve optimal blood pressure control, but there were few studies addressing this issue among ethnic Chinese patients. This study aims to evaluate the factors associated with compliance to thiazide diuretics in a Chinese hypertensive population., Methods: From a clinical database, all adult Chinese patients aged ≥ 18 years who were prescribed a thiazide diuretic from the public health care sector in one large Territory of Hong Kong during January 2004 to June 2007 and attended at least twice for anti-hypertensive drug refill were included. Medication Possession Ratios were used to measure drug compliance for each patient, with a level ≥ 80% defined as compliant. We used binary logistic regression analysis to evaluate the factors associated with good compliance., Results and Discussion: From 8551 eligible patients, 84·5% were compliant (defined as MPR ≥ 80%). Fee payers (adjusted odds ratio [aOR] 1·28; 95% CI 1·12-1·46, P < 0·001) and follow-up visitors (aOR 2·47, 95% CI 2·13-2·87, P < 0·001) were significantly associated with better anti-hypertensive compliance. Patients who were newly prescribed thiazide diuretics and those with poorer socioeconomic status were more likely to be non-compliant to anti-hypertensive therapies. Patients' age, gender and number of co-morbidities were not significant associated factors., What Is New and Conclusion: Among Chinese patients, those who were newly prescribed thiazide diuretics and those with poorer socioeconomic status were more likely to be non-compliant to anti-hypertensive therapies. Closer monitoring and more intensive compliance-enhancing strategies had to be targeted towards these patients to enhance clinical outcomes., (© 2010 Blackwell Publishing Ltd.)

Objective: We compared the short- and long-term cumulative incidences of add-on therapy across the major anti-hypertensive drug classes among Chinese patients who had newly received an antihypertensive agent., Materials and Methods: We analyzed 16,154 adult patients with uncomplicated hypertension who had newly received an antihypertensive monotherapy in one large territory of Hong Kong during January 2004 to June 2007. We compared the cumulative incidences of and factors associated with add-on therapy by drug classes at 180 days and 360 days using binary logistic regression analyses., Results: The crude cumulative incidences of add-on therapy at 180 days were not statistically significantly different among those receiving thiazide diuretics (6.26%), b-blockers (5.99%), calcium channel blockers (CCB) (5.95%) or drugs acting on the renin angiotensin system (RAS) (4.41%), and these figures were similar at 360 days (both p = 0.213). The odds ratios of add-on therapy for RAS (0.72, 95% CI 0.49 - 1.06), thiazide diuretics (1.08, 95% CI 0.85 - 1.37) and beta-blockers (1.02, 95% CI 0.86 - 1.22) were not statistically significant compared to CCB at 180 days and 360 days. Male patients and younger subjects were more likely to receive an add-on therapy in both time frames., Conclusions: This study suggested that the major antihypertensive drug classes had similar add-on rates in real-life clinical practice.

Background: Few studies address the profiles of antihypertensive compliance among ethnic Chinese. The levels of and factors associated with antihypertensive drug compliance among Chinese patients were evaluated in this study., Methods: All Chinese hypertensive patients who paid at least two consecutive visits in any government primary care clinics for antihypertensive drug refill in a large territory of Hong Kong from January 2004 to June 2007 were included. Medication possession ratio (MPR), defined as the ratio of total days of medication supplied (not including the last prescription) to total days in a period of time, was used a measure of drug compliance., Results: From 83,884 eligible patients, 71,685 (85.5%) had good compliance to antihypertensive drugs (MPR>or=80%). Binary logistic regression analysis was conducted, with good compliance as the outcome variable while controlling for potential confounders. Advanced age (adjusted ORs (aOR) 1.36-1.55, p<0.001), female gender (aOR for male patients 0.84, 95% CI 0.80 to 0.87, p<0.001), payment of fees (aOR 1.14, 95% CI 1.09 to 1.19, p<0.001), attendance in family medicine specialist clinic (aOR 1.52, 95% CI 1.40 to 1.66, p<0.001), follow-up visits (aOR 3.21, 95% CI 3.06 to 3.36, p<0.001) and use of drugs acting on the renin-angiotensin system (aOR 1.18, 95% CI 1.07 to 1.30, p=0.001) were positively associated with good compliance to drugs. Use of β-blockers was negatively associated with drug compliance (aOR 0.78, 95% CI 0.73 to 0.84, p<0.001)., Conclusions: Physicians should practice caution when prescribing antihypertensive drugs to patients with these factors where closer monitoring of their compliance patterns is warranted.

Antihypertensive drug switching induces substantial public health costs. This cohort study evaluated factors associated with switching of antihypertensive agents 180 days after the first date of prescription among ethnic Chinese patients. We included all adult patients aged > or =18 years, who had paid at least two consecutive visits to all public primary care clinics in one large territory of Hong Kong during the study period from January 2004 to June 2007. Binary logistic regression analyses were carried out with antihypertensive drug switching as an outcome variable, while controlling for age, gender, payment status, service types, district of residence, visit types and the number of comorbidities. Among 93,286 eligible patients, 5281 (5.7%) switched their antihypertensive prescriptions to another drug class within 180 days. Patients aged > or =70 years (adjusted odds ratio (aOR) 0.88, P=0.005), male subjects (aOR 0.87, P<0.001) and follow-up visitors (aOR 0.67, P<0.001) were less likely to have their drugs switched. When compared with thaizide diuretics, all other antihypertensive drug classes were associated with a lower likelihood of drug switching (aOR 0.27-0.69, all P<0.001). Closer observations of drug utilization profiles among these patient groups are recommended, and future studies should evaluate the reasons for drug switching.

Objective: To investigate the changes in renin angiotensin system (RAS) in hypertrophied myocardium of spontaneous hypertensive rat (SHR), and the effect of Banxia Baizhu Tianma Decoction (BBTD) on the changes in haemodynamic parameters and mRNA of signaling molecules of RAS at different periods., Methods: Fifty-four male SHRs of 6 weeks old were randomly and equally divided into three groups: the untreated control group, the test group, and the positive control group, and they were treated respectively with distilled water, BBTD and captopril by dissolving in equal volume of water administrated via gavage for 18 weeks. Besides, 18 age matched Wistar-Kyoto (WKY) rats treated with distilled water were allocated in a normal control group. Rats were managed in batches at their age of 18, 24, and 32 weeks old. Rat's hemodynamic parameters were measured through carotid artery catheterization, myocardial pathology was observed, and their mRNA expressions of angiotensin (AGT), angiotensin-converting (ACE) and angiotension-converting 2 (ACE2) were determined by Real-time PCR., Results: Compared with WKY rats, the arterial pressure and left ventricular mass index (LVMI)in SHR were significantly higher at 18, 24 and 32 weeks respectively (P < 0.01); average cycle rate showed in electrocardiogram was higher (P < 0.05), though the blood stream was similar; mRNA expressions of AGT and ACE in heart tissue were markedly higher (P < 0.01), but that of ACE2 at 18 and 24 weeks were lower (P < 0.01). Compared with untreated SHR, arterial pressure at 18 and 24 weeks was lower (P < 0.05); cardiac muscle structure was improved; LVMI at 24 weeks was improved (P < 0.05); the mRNA expressions of AGT and ACE were suppressed but that of ACE2 increased at 18, 24,and 32 weeks significantly in the test group after BBTD treatment (P < 0.05)., Conclusions: Changes in RAS in the hypertrophied myocardium of SHR may be one of the molecular mechanisms for hypertension leading to left ventricular hypertrophy. BBTD can improve the hemodynamic parameters, regulate RAS, so as to lower the arterial pressure.

Discontinuation of antihypertensive combination therapy imposes a substantial public health burden, but few studies have addressed the factors associated with their discontinuation in Chinese patients. This study evaluated the association between patient age, gender, and number of comorbidities with discontinuation of combination therapies. From clinical databases, we included all adult patients prescribed an antihypertensive fixed-dose combination therapy during January 2004 to June 2007 in any government primary care clinics in one large Territory of Hong Kong. We studied the factors associated with drug discontinuation within 180 days after the first prescription date by multivariable regression analysis, controlling for age, gender, socioeconomic status, service setting, district of residence, visit types (new vs. follow-up), and the number of comorbidities. From 29 253 eligible patients, 7.1% discontinued their antihypertensive prescriptions. Younger (<50 years; adjusted odds ratios [aOR]: 0.78, 95% confidence interval [CI]: 0.66-0.92 for patients aged 50-59 years, P=0.003; aOR: 0.71, 95% CI: 0.60-0.84 for patients aged 60-69 years, P<0.001) and male patients (aOR: 1.19, 95% CI: 1.08-1.31, P<0.001) were more likely to have drug discontinuation. Patients with one (aOR: 0.64, 95% CI: 0.57-0.73, P<0.001) and at least two (aOR: 0.68, 95% CI: 0.54-0.87, P=0.002) comorbidities were less likely to have their medications discontinued. Combination therapies in Chinese patients had a low discontinuation rate when compared with Caucasian patients. Discontinuation was more likely among younger, male patients and those without concomitant comorbidities, in which more meticulous monitoring of their adherence patterns was needed.

Purpose: This cohort study evaluated the factors associated with discontinuation of antihypertensive pharmacotherapy among Chinese patients who were prescribed beta-blockers. We tested the hypothesis that patients' age, gender, socioeconomic status, clinical settings and the number of comorbidities were significantly associated with the discontinuation of beta-blockers., Methods: From a validated clinical database we included all adult patients 18 years or older who were prescribed a beta-blocker in any government primary care clinic in one large territory of Hong Kong during 01 January 2004-30 June 2007. We evaluated the cumulative incidence of drug discontinuation within 180 days of the prescriptions and the factors associated with discontinuation of beta-blockers by multivariable regression analysis., Results: From a total of 19,177 eligible patients (mean age = 59.1 years), 20.8% discontinued their medication. Younger patients [aged <50 years; adjusted odds ratios (aOR) 0.41-0.52 for patients aged >or=50 years; p < 0.001], female gender (aOR 0.87 for males, p = 0.001), fee-waivers (aOR 0.78 for fee-payers, p < 0.001), attendances in family medicine specialist clinics (FMSC) (aOR 1.49, p < 0.001) and staff clinics (aOR 2.32, p < 0.001), residence in more urbanized areas (aOR 0.80 for North District, p < 0.001), new visits (aOR 0.55 for follow-up visits, p < 0.001) and absence of concomitant comorbidities (aOR 0.60 for one comorbidity, p < 0.001; aOR 0.56 for two comorbidities, p = 0.002) were positively associated with drug discontinuation., Conclusions: Patients who were prescribed beta-blockers with these associated factors should be monitored more closely for antihypertensive drug adherence.

Few studies have addressed the profile of adherence among ethnic Chinese patients. This study evaluated the factors associated with adherence with angiotensin-converting enzyme inhibitors (ACEIs), an increasingly common antihypertensive drug of choice. The authors included all adult patients who were prescribed an ACEI and paid at least 2 consecutive visits to any primary care clinics of one large territory of Hong Kong from January 2004 to June 2007. The determinants of good adherence to ACEI, as defined by a medication possession ratio > or = 80%, were evaluated by multivariate regression analysis. From 6408 eligible patients, 88.0% were adherent. Patients attending family medicine specialist clinics (adjusted odds ratio [AOR] = 1.46, 95% confidence interval [CI]: 1.12-1.91, P = .005) and follow-up visitors (AOR = 2.98, 95% CI: 2.49-3.55, P < .001) were significantly more likely and attendees of staff clinics (AOR = 0.48, 95% CI: 0.25-0.94, P = .033) were less likely to be adherent to ACEIs. Patients' age, gender, socioeconomic status, district of residence, and the number of comorbidities were not found to be associated with good adherence. Adherence-enhancing strategies should therefore be particularly focused on the new visitors (likely to be drug naive), and future research directions should delineate the best health service setting that could facilitate adherence to ACEIs.

We studied the profiles of all-cause and cardiovascular (CVS) mortality among users of different antihypertensive classes in a Chinese population. From electronic patient records, a cohort study was conducted among 18,338 patients who ever newly prescribed an alpha-blocker, thiazide diuretic, beta-blocker, calcium channel blocker (CCB) or agents acting on the renin-angiotensin system (RAS) without drug discontinuation or switching in the public primary-care sector in a large Territory of Hong Kong during January 2004-June 2007. The odds ratios of mortality (all-cause and CVS) were evaluated according to the prescribed antihypertensive drug classes by Cox proportional hazards regression analyses. A total of 823 deaths (4.5%) were reported during the study period. The crude proportions of all-cause mortality were highest in alpha-blockers (6.2%) and CCB (5.7%), but lowest in beta-blockers (2.8%). Compared with CCB, patients on thiazide diuretics were shown to have statistically significantly lower all-cause (adjusted hazard ratios (aHRs) 0.75, 95% CI 0.60, 0.93, P=0.010) and CVS mortality (aHR 0.40, 95% CI 0.21, 0.78, P=0.007), but the 95% CI of the odds ratios of the major drug classes overlapped. When each drug class was used as a reference group, or when patients with only uncomplicated hypertension were included, their respective 95% CI similarly overlapped. Antihypertensive drug classes were associated with statistically comparable odds of all-cause and CVS mortality. This finding from real-life clinical practice further supports the position statements from international guidelines, which recommend that the major antihypertensive drug classes are suitable for initiating pharmacotherapy for the management of hypertension.

Background: Although poor control of hypertension is a problem worldwide, most published studies of adherence to antihypertensive medications have involved only white subjects., Objective: This study examined levels of and factors associated with short-term adherence to beta-blocker therapy among a representative sample of ethnic Chinese patients with hypertension from a large territory in Hong Kong., Methods: Data for all hypertensive patients aged > or = 18 years who received a prescription for a beta-blocker at a visit to any public primary care clinic in the New Territory East cluster of Hong Kong and made at least 1 subsequent visit for a refill of this prescription between January 2004 and June 2007 were obtained from a validated clinical database generalizable to the Chinese population. The proportion of patients who were adherent to beta-blocker therapy was measured based on the medication possession ratio (MPR), calculated over 2 consecutive visits. Good adherence was defined as an MPR > or = 80%. Factors potentially associated with adherence to beta-blockers were investigated using multivariable logistic regression analysis, with adjustment for age, sex, payment status, service type, district of residence, visit type, and number of comorbidities., Results: Data were obtained for 15,918 eligible patients (62.2% female; mean age, 59.1 years). Of these patients, 81.3% were adherent to beta-blocker therapy. Factors associated with a greater likelihood of good adherence to beta-blocker therapy were age > or = 50 years (adjusted odds ratio [AOR], age 50-59 years = 1.53 [95% CI, 1.38-1.70]; AOR, age 60-69 years = 1.85 [95% CI, 1.64-2.10]; AOR, age > or = 70 years = 1.88 [95% CI, 1.66-2.12]; all, P < 0.001); fee paid versus fee waived (AOR = 1.16 [95% CI, 1.06-1.28]; P = 0.001); attendance at a family medicine specialist clinic (AOR = 1.30 [95% CI, 1.09-1.54]; P = 0.003); and follow-up visit versus new-patient visit (AOR = 2.67 [95% CI, 2.42-2.95]; P < 0.001)., Conclusion: Among these Chinese patients with hypertension, younger patients, those whose fees were waived, and those who were newly prescribed a beta-blocker had a greater likelihood of being nonadherent.

Background: Noncompliance and nonpersistence to antihypertensive drugs is a recognized worldwide problem. Calcium channel blockers (CCBs) are commonly prescribed among Chinese patients yet few studies have been conducted to study the factors associated with their compliance, discontinuation, and switching profiles., Methods: From clinical databases we studied 20,156 patients prescribed a CCB as their antihypertensive monotherapy from January 2004 to June 2007 in a large Territory of Hong Kong. We evaluated their compliance by medication possession ratios (MPRs), cumulative incidences of discontinuation and switching within 180 days after the prescription; and evaluated their associated factors using multivariable logistic regression analyses., Results: The crude compliance level, discontinuation and switching rates at 180 days were 85.0, 3.1, and 5.0%, respectively. Older patients (aged > or =50 years; adjusted odds ratio (aOR) 1.21-1.34, P < 0.001), female gender (aOR 0.89, 95% confidence interval (CI) 0.82-0.96 for males, P = 0.004), fee payers (aOR 1.09, 95% CI 1.00-1.20, P = 0.050), service settings in family medicine specialist clinic (FMSC) (aOR 1.64, 95% CI 1.33-2.01, P < 0.001), and follow-up visits (aOR 3.24, 95% CI 2.93-3.58, P < 0.001) were positively associated with good compliance. Younger age and new visits were significantly associated with drug discontinuation or switching., Conclusions: Younger patients, male subjects, and new visitors were more likely to be noncompliant to CCB among ethnic Chinese. They represent the target subjects where primary care physicians should spend more effort on patient education to improve drug compliance.

Background: Antihypertensive drug discontinuation imposes a substantial health services burden but few studies have addressed the factors associated with their discontinuation in Chinese patients. This study evaluated the association between age, gender, and drug classes with antihypertensive discontinuation., Methods: From clinical databases, we included all adult patients prescribed an antihypertensive medication during January 2004 to June 2007 in one large territory of Hong Kong. We studied the factors associated with drug discontinuation within 180 days after the first prescription date by multivariable regression analysis., Results: From 93,286 eligible patients, 13.2% discontinued their antihypertensive prescriptions. Younger (<50 years; adjusted odds ratio (aOR) = 0.63 for patients aged 50-59 years; 0.52 for patients aged 60-69 years; 0.70 for those aged >or=70 years; all P < 0.001) and male patients (aOR = 1.05, P = 0.027) were more likely to have drug discontinuation. When compared with thiazide diuretics, patients prescribed beta-blockers were more likely (aOR = 1.67, P < 0.001) and patients prescribed calcium channel blocker (CCB) (aOR = 0.76, P < 0.001) and combination therapy (aOR = 0.73, P < 0.001) were less likely to have drug discontinuation. Stratified analyses in different age and gender groups reported similar results; except that only elderly male patients (aOR = 1.12, P = 0.002) and younger patients (aOR = 2.43 for patients aged <50 years, P < 0.001) prescribed beta-blocker were more likely to have drug discontinuation., Conclusions: Discontinuation of antihypertensive drug treatment in ethnic Chinese is more likely to occur in younger, male patients, or those prescribed beta-blockers. These data suggest that more meticulous monitoring of patient adherence is required in patients with these characteristics.

Background: International guidelines on management of hypertension recommend any major classes of antihypertensive drugs. However, the low prescribing rate of thiazides has been attributed to concerns about electrolyte disturbances and studies between antihypertensive drug classes and hyponatremia/hypokalemia among Chinese patients were scarce., Methods: From clinical databases we included 2,759 patients who received their first-ever antihypertensive monotherapy from January 2004 to June 2007 in a large territory of Hong Kong. We studied the plasma sodium and potassium levels 8 weeks after prescriptions and factors associated with hyponatremia and hypokalemia by multivariable regression analyses., Results: Among major antihypertensive drug classes, thiazide users had the lowest sodium level (139.6 mEq/l, 95% confidence interval (CI) 139.3, 140.0, P < 0.001) and patients-prescribed calcium channel blockers (CCBs; 3.92 mEq/l, 95% CI 3.89, 3.95) or thiazide diuretics (3.99 mEq/l, 95% CI 3.93, 4.04) had the lowest potassium levels (P < 0.001). Multivariate analysis reported that advanced age (> or =70 years, odds ratio (OR) 7.49, 95% CI 2.84, 19.8, P < 0.001), male gender (OR 2.38, 95% CI 1.45, 3.91, P < 0.001), and thiazide users (OR 2.42, 95% CI 1.29, 4.56, P = 0.006) were significantly associated with hyponatremia, while renin-angiotensin system (RAS) (OR 0.31, 95% CI 0.13, 0.73, P = 0.008) and beta-blockers (BBs) (OR 0.35, 95% CI 0.23, 0.54, P < 0.001) users were less likely to present with hypokalemia. However, the proportions having normonatremic (95.1%) and normokalemic (89.4%) levels were high., Conclusions: In view of the low prevalence of hyponatremia and hypokalemia associated with thiazides, physicians should not be deterred from prescribing thiazide diuretics as first-line antihypertensive agents as recommended by most international guidelines.

Background: There is a scarcity of studies addressing the factors associated with impaired fasting glucose in Chinese patients with uncomplicated hypertension. We included 1,218 patients newly prescribed a single antihypertensive drug in the public primary healthcare setting in Hong Kong, where their fasting glucose levels were measured 6-7 weeks after the first-ever antihypertensive prescription., Methods: The odds ratios of having above borderline (> or = 6.1 mmol/l) and adverse (> or = 7.0 mmol/l) glucose levels, respectively, were studied according to patient age, gender, socioeconomic status, clinic types and antihypertensive drug classes by multivariable regression analyses., Results: The fasting glucose levels were statistically similar (p = 0.786) among patients prescribed thiazide diuretics (5.48 mmol/l, 95%, 5.38, 5.59), calcium channel blockers (5.46 mmol/l, 95% C.I. 5.37, 5.54), beta-blockers (5.42 mmol/l, 95% C.I. 5.34, 5.51) and drugs acting on the renin angiotensin system (RAS) [5.41 mmol/l, 95% C.I. 5.20, 5.61]. Multivariate analyses reported no significant associations between antihypertensive drug class and impaired fasting glucose. Elderly patients and male gender were significantly more likely to present with above borderline and adverse readings respectively., Conclusion: Clinicians should be aware of the increased risk of impaired fasting glucose in these groups, and use of thiazides should not in itself deter its use as a first-line antihypertensive agent among ethnic Chinese patients.

Background: Increasing use is being made of routinely collected electronic patient data in health services research. The aim of the present study was to evaluate the potential usefulness of a comprehensive database used routinely in the public healthcare system in Hong Kong, using antihypertensive drug prescriptions in primary care as an example., Methods: Data on antihypertensive drug prescriptions were retrieved from the electronic Clinical Management System (e-CMS) of all primary care clinics run by the Health Authority (HA) in the New Territory East (NTE) cluster of Hong Kong between January 2004 and June 2007. Information was also retrieved on patients' demographic and socioeconomic characteristics, visit type (new or follow-up), and relevant diseases (International Classification of Primary Care, ICPC codes)., Results: 1,096,282 visit episodes were accessed, representing 93,450 patients. Patients' demographic and socio-economic details were recorded in all cases. Prescription details for anti-hypertensive drugs were missing in only 18 patients (0.02%). However, ICPC-code was missing for 36,409 patients (39%). Significant independent predictors of whether disease codes were applied included patient age > or = 70 years (OR 2.18), female gender (OR 1.20), district of residence (range of ORs in more rural districts; 0.32-0.41), type of clinic (OR in Family Medicine Specialist Clinics; 1.45) and type of visit (OR follow-up visit; 2.39). In the 57,041 patients with an ICPC-code, uncomplicated hypertension (ICPC K86) was recorded in 45,859 patients (82.1%). The characteristics of these patients were very similar to those of the non-coded group, suggesting that most non-coded patients on antihypertensive drugs are likely to have uncomplicated hypertension., Conclusion: The e-CMS database of the HA in Hong Kong varies in quality in terms of recorded information. Potential future health services research using demographic and prescription information is highly feasible but for disease-specific research dependant on ICPC codes some caution is warranted. In the case of uncomplicated hypertension, future research on pharmaco-epidemiology (such as prescription patterns) and clinical issues (such as side-effects of medications on metabolic parameters) seems feasible given the large size of the data set and the comparability of coded and non-coded patients.