Classification-based data mining for identification of risk patterns associated with hypertension in Middle Eastern population

sponsorship: The European Union (HEALTH-F7-2011-278249 EU-MASCARA, HEALTH-F7-305507 HOMAGE and the European Research Council Advanced Researcher Grant 294713 EPLORE) and the Fonds voor Wetenschappelijk Onderzoek Vlaanderen, Ministry of the Flemish Community, Brussels, Belgium (G.0881.13 and G.0880.13) currently support the Studies Coordinating Centre (Leuven, Belgium). (European Union|HEALTH-F7-2011-278249 EU-MASCARA, European Union|HEALTH-F7-305507 HOMAGE, European Union (European Research Council)|294713 EPLORE, Fonds voor Wetenschappelijk Onderzoek Vlaanderen, Ministry of the Flemish Community, Brussels, Belgium|G.0881.13, Fonds voor Wetenschappelijk Onderzoek Vlaanderen, Ministry of the Flemish Community, Brussels, Belgium|G.0880.13)

Background and Aims Genetic risk for elevated blood pressure (BP) has been associated with a higher risk of hypertension and cardiovascular disease. However, the generalizability of previous findings has been limited due to a lack of studies among Asian populations. This study aimed to investigate whether genetic risk for BP predicts the incidence of hypertension and chronic kidney disease (CKD) in Asian populations. Method We performed genome-wide association studies for systolic and diastolic BP (SBP and DBP, respectively) using data from the Korean Genome and Epidemiology Study (KoGES). We then meta-analyzed these results with summary statistics from Biobank Japan to construct polygenic risk scores (PRSs) and examined the association between BP PRSs and incident hypertension or CKD. This study included participants without hypertension, cardiovascular disease, or CKD at baseline (n=4349, median age 48.5 years, 48.8% men). Participants were categorized into four groups based on their PRS percentile (<5, 5–50, 50–95, >95). Results As the PRS percentile increases, the median SBP and DBP at baseline also increase. Compared to the lowest SBP PRS percentile, higher PRS percentile was associated with increased risk of hypertension (hazard ratio [HR] 1.49, 95% confidence interval [CI] 1.22–1.83 for PRS percentile 5–50, HR 1.94, 95% CI 1.58–2.38 for PRS percentile 50–95, and HR 2.35, 95% CI 1.80–3.07 for PRS percentile >95). Elevated DBP PRS was also associated with higher risk of hypertension (HR 1.27, 95% CI 1.04–1.54 for PRS percentile 5–50, HR 1.72, 95% CI 1.41–2.09 for PRS percentile 50-95, and HR 2.09, 95% CI 1.60–2.72 for PRS percentile >95). The highest PRS percentile for SBP and DBP was associated with earlier onsets of hypertension by median 11 and 9 years, respectively, compared to the lowest PRS percentile for SBP and DBP. However, both SBP and DBP RPSs were not associated with incident CKD. Conclusion Genetic risk for elevated BP was associated with a higher risk of incident hypertension and earlier onset of hypertension in the Asian population. However, there was no association between PRS for elevated BP and the incidence of CKD.

ABSTRACTThis study aimed to evaluate the association of abdominal obesity, apolipoprotein and insulin resistance (IR) with the risk of hypertension in postmenopausal women. We analyzed a total of 242 women aged between 35 and 70 years. Blood pressure (BP), anthropometric indices, lipid profile, fasting glucose, insulin, C-reactive protein (CRP) and apolipoprotein concentrations were measured. Homeostasis model assessment (HOMA) was used to assess IR. Hypertension was defined as a systolic BP (SBP) ≥140 mmHg and/or diastolic BP (DBP) ≥90 mmHg or current treatment with antihypertensive drugs. Women with hypertension showed significantly higher mean values of age, SBP and DBP, waist circumference (WC), fasting plasma glucose (FPG), insulin, HOMAIR and the apolipoprotein B (apoB). When analyses were done according to the menopausal status, higher prevalence of hypertension was observed in postmenopausal women (72.8% vs. 26.0%, p < 0.001) compared to their premenopausal counterparts. Postmenopausal women showed also significantly higher mean values of SBP and DBP, WC, HOMAIR and apoB. Multivariate linear regression analysis revealed that SBP was significantly affected by WC (p = 0.034), apoB (p = 0.038) and log HOMAIR (p = 0.007) in postmenopausal women. The interaction models revealed significant interaction between WC, apoB and log HOMAIR (WC×apoB×log HOMAIR) on SBP (p = 0.001) adjusted for age. In a multivariate logistic regression, adjusting for age and apoB, WC (p = 0.001), log HOMAIR (p = 0.007) and menopause (p = 0.008) were significantly associated with higher risk for hypertension. These results suggest that changes in WC, apoB and IR accompanying menopause lead to a greater prevalence of hypertension in postmenopausal women.

The risk factors of mild decline in estimated glomerular filtration rate in a community-based population

We assessed predictors of changes in systolic (SBP) and diastolic (DBP) blood pressure during follow-up and of the development of hypertension in HIV-infected individuals. International cohort collaborative study (D:A:D) of established prospective cohorts of HIV-1-infected patients. Longitudinal analysis of changes in blood pressure (BP) was performed using mixed effects models in 17170 patients. Predictors of development of hypertension during follow-up (systolic BP > or =140 and/or diastolic BP > or =90 mmHg or initiation of antihypertensive treatment) were assessed using Cox models in 8 984 patients with a normal BP level at baseline. 73548 BP measurements with a median of 4 per patient (interquartile range [IQR]: 2-6) were recorded over a median follow-up of 2.3 years (IQR: 1.5-2.6). Risk factors significantly associated with a development of higher systolic BP and diastolic BP (differences > or =5 mmHg and P-values <0.001) during follow-up were: older age, male sex, higher body mass index (BMI) and use of BP-lowering drugs. In patients with normal BP at baseline, 1186 developed hypertension for an incidence of 72.1 per 1000 person-years (95% confidence interval: 68.2-76.0). Factors associated with development of hypertension were: male sex, higher BMI, older age, higher BP at baseline, high total cholesterol and clinical lipodystrophy. Cumulative duration of exposure to nucleoside reverse transcriptase inhibitors (P=0.75), protease inhibitors (P=0.92) as well as type of antiretroviral treatment at baseline (P=0.18) were not associated with a higher risk of hypertension. Cumulative duration of exposure to non-nucleoside reverse transcriptase inhibitors (NNRTIs) was significantly associated with lower risk of hypertension (hazard ratio=0.78 and 0.67 for those treated < or =10 months and >10 months compared with no exposure; P=0.005). Increased blood pressure in HIV-infected individuals is associated with established risk factors for hypertension. There was no evidence for an independent deleterious effect of any class of antiretroviral drugs on BP, although the use of NNRTIs was associated with a lower risk of development of hypertension.

We compared systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP) in predicting the risk of cardiovascular disease (CVD), stratifying results at age 60 years, when DBP decreases while SBP continues to increase. We prospectively followed 11 150 male physicians with no history of CVD or antihypertensive treatment through the 2-year questionnaire, after which follow-up began. Reported blood pressure was averaged from both the baseline and 2-year questionnaires. During a median follow-up of 10.8 years, there were 905 cases of incident CVD. For men aged <60 years (n=8743), those in the highest versus lowest quartiles of average SBP (>/=130 versus <116 mm Hg), DBP (>/=81 versus <73 mm Hg), and MAP (>/=97 versus <88 mm Hg) had relative risks (RRs) of CVD of 2.16, 2.23, and 2.52, respectively. Models with average MAP and PP did not add information compared with models with MAP alone (P>0.05). For men aged >/=60 years (n=2407), those in the highest versus lowest quartiles of average SBP (>/=135 versus <120 mm Hg), PP (>/=55 versus <44 mm Hg), and MAP (>/=99 versus <91 mm Hg) had RRs of CVD of 1.69, 1.83, and 1.43, respectively. The addition of other blood pressure measures did not add information compared with average SBP or PP alone (all P>0.05). These data suggest that average SBP, DBP, and MAP strongly predict CVD among younger men, whereas either average SBP or PP predicts CVD among older men. More research should distinguish whether MAP, highly correlated with SBP and DBP, better predicts CVD.

Objective To explore the effect of hospital health management mode in patients with prediabetes.Methods Eighty pre-diabetes patients who were randomly chosen from physical examination people in the physical examination center of our hospital from April 2011 to June 2011 were divided into the observation group and the control group.The observation group received the hospital health management mode of pre diabetes designed by ourselves,and the control group received the traditional management mode.The awareness rate of diabetes in patients with pre-diabetes,the fasting plasma glucose (FPG),2 h postprandial plasma glucose (2 h PG),systolic blood pressure (SBP),diastolic blood pressure (DBP),low-density lipoprotein (LDL),body mass index (BMI) were evaluated at the beginning of the study,six month after the study and one year after the study.The conversion rate of diabetes was compared one year after the study.Results The awareness rate of diabetes in patients with pre-diabetes,the levels of FPG,2 h PG,SBP and DBP were respectively(5.68 ± 0.43) mmol/L,(9.63 ± 0.67) mmol/L,(117.40 ± 7.40) mmHg,(72.90 ± 5.10) mmHg in the observation group,and were (6.84 ± 1.32) mmol/L,(10.75 ±0.91) mmol/L,(125.60 ± 10.20) mmHg,(77.30 ±6.91) mmHg in the control group,and the differences were statistically significant (x2 =19.156,t =5.030 6,2.285 2,3.955 4,2.615 2,respectively; P ＜ 0.05).The levels of LDL and BMI in the observation group showed a downward trend,but no differences were found in two groups (P ＞ 0.05).One year after the study,the levels of FPG,2 h PG,SBP,DBP,LDL and BMI in the observation group were respectively (5.57 ± 0.38) mmol/L,(9.51 ±0.47) mmol/L,(116.23±7.93) mmHg,(70.4±4.3) mmHg,(3.00±0.37) mmol/L and (23.4 ±2.48)kg/m2,and were lower than (6.91 ±1.15) mmol/L,(10.86±3.21) mmol/L,(128.3± 12.14) mmHg,(79.2 ±9.56) mmHg,(3.6 ±0.41) mmol/L and (27 ±5.41) kg/m2 in the control group,and the differences were statistically significant (P ＜0.05) ; the conversion rate of diabetes was 2.7％ (1/37)in the observation group,and was lower than the 15.8％ (6/38) in the control group,and the difference was statistically significant (x2 =2.405 1,P ＜ 0.05).Conclusions The hospital health management mode of pre diabetes designed by ourselves can improve the awareness rate of diabetes in patients with pre-diabetes,decrease the level of FPG,2hPG,SBP,DBP,LDL and BMI,and reduce the conversion rate of diabetes. Key words: Fasting plasma glucose; Glucose tolerance; Blood pressure; Pre-diabetes ; Hospital health management mode

Previous studies on the relationship between blood pressure (BP) and depression have produced inconsistent results (Paterniti et al., 2000; Lenoir et al., 2008; Stewart and Hirani, 2010; Siennicki-Lantz et al., 2012). There have been no studies examining changes in BP prior to depression over a relatively long period. Participants in this study were primary care patients aged 60 years or older who screened negative for depression using the Center for Epidemiologic Studies Depression Scale (CES-D < 16) and had no prior depression diagnosis. Participants were screened from 1991 to 1993 during regularly scheduled primary care appointments at an urban public health system (Callahan et al., 1994). Participants were then followed through December 31, 2010. The study end point was defined as the time to a physician diagnosis of clinical depression based on International Classification of Disease codes. For patients not diagnosed with depression, date of the last encounter with the health system was their study endpoints. Clinical information was extracted from the Regenstrief Medical Record System including all height, weight, systolic BP, diastolic BP from outpatient visits, and 15 diagnoses (hypertension, diabetes, atherosclerotic vascular disease, coronary artery disease, peripheral artery disease, congestive heart failure, cerebrovascular disease, cancer, anemia, chronic obstructive pulmonary disease, arthritis, liver disease, renal disease, thyroid disease, hyperlipidemia, and dementia). Age, gender, race, years of education, and history of smoking were collected at enrollment. Repeated systolic and diastolic BP from enrollment to study endpoints were used as dependent variables in mixed effect models with random intercepts and random slopes while adjusting for time dependent covariates of patients’ medical conditions. The BP measures were aligned to each patient’s study endpoint, indexing a BP measure by the number of years this measure was taken before the patient’s endpoint. A total of 2581 participants were included with a median of 21 BP measures per patient. The mean times from enrollment to endpoints for the depression and no-depression groups were 7.2 years (SD = 4.6) and 7.9 years (SD = 5.8), respectively. Participants in the incident depression group had lower systolic BP at enrollment than those without depression (p = 0.0057) and were younger, more likely to be a woman, had a higher mean body mass index, and a higher rate of arthritis at enrollment (p < 0.0001). No other differences in rates of medical conditions were evident and the total numbers of comorbid conditions did not differ between the two groups at enrollment (p = 0.1699). A significant interaction between depression group and time was found for systolic BP indicating that systolic BP of those with incident depression increased significantly more than in those without depression (p < 0.0001) while adjusting for age, gender, race, body mass index, smoking, and medical conditions. Figure 1 illustrates the model by plotting predicted mean systolic BP over time for participants with incident depression and those without depression. An increasing trend is seen in systolic BP over time for the incident depression group, whereas the no-depression group showed a slight decrease in systolic BP toward the study endpoint. No significant main effects or interactions were found when diastolic BP was used as the dependent variable. Figure 1 Predicted mean systolic blood pressure over time for participants with incident depression and those without depression based on the final mixed effect model. In this depression-free cohort of older primary care patients followed for 18 years, we found that increases in systolic BP preceded the diagnosis of depression. The increase in systolic BP in participants with incident depression cannot be attributed to differences in medical conditions including cardiovascular diseases as these conditions were adjusted for in the models. The mechanism underlying the increase in systolic BP in participants with incident depression is not clear. Although increasing BP may act as an independent risk factor for late-life depression, it is also likely that both BP and depression were affected by other underlying factors such as stress, inflammation, or incipient vascular diseases. To our knowledge, this is the first study examining longitudinal trends in BP in elderly participants with incident late-life depression. The inclusion of longitudinal BP measures over a long period made it possible to examine BP trends in participants prior to depression diagnosis. Our study also has the advantage of excluding participants with baseline depression so that BP changes prior to new depression diagnosis can be examined. Our results suggest that increases in BP may be an important indicator for incipient late-life depression as well as for cardiovascular diseases in the elderly population.

Introduction/Background: Renal denervation (RDN) is an emerging therapy shown to significantly reduce BP. Research Questions/Hypothesis: Impact of RDN on obese hypertensive Patients are unknown. Goals/Aims: Aim of our study to analyze the Impact of RDN on obese hypertensive patients. Methods/Approach: Patients were stratified into 2 groups Obese and non obese. Pre- and post-procedural. BP measurements were analyzed using repeated measures ANOVA to assess the changes in systolic (SYS) and diastolic (DIA) BP over time. Results/Data (descriptive and inferential statistics): This retrospective study included 50 hypertensive patients who underwent RDN with Symplicity Spyral from March 2023 to August 2024. The cohort had a mean age of 61.7 years. Pre-RDN mean SYS and DIA BP were 163.7 mmHg and 86.7 mmHg, respectively. The impact of renal denervation on blood pressure (BP) was examined in obese and non-obese groups. Initially, the non-obese group had a higher SYS BP (180 mmHg) compared to the obese group (160 mmHg). Post-RDN, SYS BP decreased to 145 mmHg in the non-obese group and to 140 mmHg in the obese group. Six months post-RDN, SYS BP stabilized at around 140 mmHg in both groups. RDN effectively reduced and maintained lower SYS BP in both groups over six months.The forest plot analysis showed that Dyslipidemia (DLP) significantly reduced the odds of achieving the SYS BP target (OR = 0.17, p = 0.036). Both regression lines showed strong fits (SYS BP: R 2 = 0.8277; DIA BP: R 2 = 0.997). Repeated Measures ANOVA indicated significant changes in SYS BP over time (p &lt; .001, η 2 p = 0.590), with significant interaction between time and BMI category (p = 0.038). Logistic regression analysis highlighted DLP as a significant predictor, reducing the likelihood of achieving the systolic BP Target (OR = 0.17, p = 0.036). Other factors like BMI, age, CKD, and EF% were not significant predictors. Conclusion(s): Renal denervation (RDN) with Symplicity Spyral effectively reduces blood pressure in both obese and non-obese individuals, with sustained improvements over six months. Dyslipidemia significantly decreases the likelihood of achieving target BP, while other factors such as BMI, age, chronic kidney disease (CKD), and ejection fraction percentage (EF%) are not significant predictors. These findings support the use of RDN as a viable intervention for managing hypertension, highlighting the importance of addressing dyslipidemia in hypertensive patients.

Background To date, few studies have assessed the association between remnant cholesterol (RC) and hypertension. However, these studies have been constrained by employing a snapshot approach, which limits our understanding of its longitudinal effects. Purpose To investigate the association between cumulative exposure to RC and its variability with incident hypertension. Methods A total of 2,926 participants aged ≥ 20 years who underwent three sequential visits between 2002 and 2011 (exposure period), were enrolled and followed up until 2018. Hypertension was defined as: systolic blood pressure (SBP) ≥ 140 mmHg, diastolic blood pressure (DBP) ≥ 90 mmHg, or anti-hypertensive medication consumption. Low-density lipoprotein cholesterol (LDL-C) was calculated using Martin-Hopkins method. RC was calculated as the difference between total cholesterol and the sum of high-density lipoprotein cholesterol and LDL-C. Cumulative RC (CumRC) exposure was calculated as: ((RC 2002 + RC 2005) ÷ 2) × time 2002-2005 + ((RC 2005 + RC 2009) ÷ 2) × time 2005-2009. The CumRC burden was calculated as the weighted sum of the differences between the average RC levels at each pair of consecutive examinations and the clinical RC cutoff (determined as the corresponding values for the population attributed percentiles of LDL-C = 130 mg/dL). The variability of the RC was assessed using the standard deviation (SD) and coefficient of variance (CV). Multivariable Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Results During a median follow-up duration of 6.12 years, 600 events of hypertension occurred. Accordingly, our fully adjusted model (including SBP and DBP as covariates) showed that the association between CumRC and CumRC burden and incident hypertension was not significant in neither continuous [1.04 (0.96-1.11), 1.06 (0.98-1.14)] nor categorical analysis [Q4 vs. Q1: 1.04 (0.80-1.36); &amp;gt;0 vs. 0: 1.11 (0.94-1.32)]. However, in terms of variability, RC’s SD and CV were associated with higher risk of hypertension by both continuous [1.11 (1.04-1.18) and 1.13 (1.04-1.23)] and categorical analysis [Q4 vs. Q1: 1.36 (1.07-1.74) and 1.33 (1.05-1.68); respectively]. As a sensitivity analysis, adjusting for insulin resistance did not alter our results. Importantly, we observed that the association between cumulative RC exposure and its variability with incident hypertension was more pronounced among participants with normal blood pressure (P for interaction = 0.004 and 0.003, respectively). Conclusion Lowering the RC’s variability may help to prevent the incidence of hypertension, particularly among individuals with normal blood pressure.

Hypertension represents a complex condition that substantially increases the global cardiovascular disease burden and related deaths. This study compares three tree-based machine learning approaches-Decision Tree (DT), Random Forest (RF), and eXtreme Gradient Boosting (XGBoost)-using 96 multi-domain features to predict reductions in both systolic and diastolic blood pressure following antihypertensive treatment in patients with varying comorbidity profiles. Our approach utilizes paired t-test analyses to examine blood pressure changes before and after medication across different patient categories, while employing comprehensive decision tree visualisation to create interpretable decision pathways that identifying predictive associations between medications and blood pressure outcomes. Analysis of 160 patients indicated significant blood pressure improvements in all studied patient groups, with systolic blood pressure reductions showing statistical significance (p = 0.001) and diastolic blood pressure changes demonstrating similar significance levels (p = 0.02). The Decision Tree method showed optimal performance for systolic blood pressure prediction, recording 93% F1-score and 83% AUC values, whilst Random Forest demonstrated excellence performance in diastolic blood pressure prediction with 98% F1-score and 92% AUC. XGBoost performed less effectively than the other two algorithms across metrics. Through decision tree analysis, we identified strong predictive associations between diuretics and ACE inhibitors with systolic blood pressure reduction, whilst nitrate compounds and combined medication regimens showed significant predictive relationships with diastolic blood pressure decrease. The machine learning models successfully integrated diverse patient characteristics across multiple domains, including demographics, clinical parameters, lifestyle factors, and socioeconomic determinants. Our findings from this 160-patient cohort demonstrate the clinical utility of interpretable machine learning models for medication response prediction, providing valuable insights that can guide personalized antihypertensive therapy selection and inform clinical decision-making through data-driven treatment approaches.

To examine the effect of rosiglitazone on insulin resistance and blood pressure in patients with essential hypertension, classified based on abnormalities of their renin-angiotensin system. A total of 24 hypertensive nondiabetic patients (age 58 +/- 6 years, BMI 30 +/- 5 kg/m2) were studied before and after rosiglitazone treatment. After 2 weeks off antihypertensive medication, subjects received a euglycemic-hyperinsulinemic clamp (40 mU. m(-2). min(-1)) with 6,6-[2H2]glucose infusion, ambulatory blood pressure monitoring, and blood tests for cardiovascular risk factors. Subjects were then placed on rosiglitazone (4 mg orally b.i.d.) and their usual antihypertensive medications (but not ACE inhibitors) for 16 weeks, and baseline tests were repeated. There was no change in fasting plasma glucose (83 +/- 2 vs. 82 +/- 2 mg/dl, P = 0.60), but fasting insulin decreased (16.1 +/- 1.4 vs. 12.5 +/- 0.9 micro U/ml, P < 0.01). Total glucose disposal during the clamp increased (5.0 +/- 0.4 vs. 5.9 +/- 0.5 mg. kg(-1). min(-1), P < 0.001), with no change in suppression of hepatic glucose output. There were significant decreases in mean 24-h systolic (138 +/- 2 vs. 134 +/- 2 mmHg, P < 0.02) and diastolic (85 +/- 2 vs. 80 +/- 2 mmHg, P < 0.0001) blood pressure, and the decline in systolic blood pressure was correlated with the improvement in insulin sensitivity (r = 0.59, P < 0.005). Triglycerides (135 +/- 16 vs. 89 +/- 8 mg/dl, P < 0.01), LDL cholesterol (129 +/- 6 vs. 122 +/- 8 mg/dl, P = 0.18), and HDL cholesterol (51 +/- 3 vs. 46 +/- 3 mg/dl, P < 0.02) all decreased, with no change in the LDL-to-HDL ratio. Plasminogen activator inhibitor-1 and C-reactive protein also declined significantly. Rosiglitazone treatment of nondiabetic hypertensive patients improves insulin sensitivity, reduces systolic and diastolic blood pressure, and induces favorable changes in markers of cardiovascular risk. Insulin sensitizers may provide cardiovascular benefits when used in the treatment of patients with hypertension.

Blood Pressure Goals: How Low Is Safe in CKD?

The aim of the study was to analyze changes of systolic and diastolic blood pressure values over five and ten years separately boys and girls and to estimate correlation between them. Three age groups from 8 centers in Serbia were evaluated: Group 1: 10 year old patients, Group 2: 15 year old and Group 3: 20 year old. Group with normal blood pressure values, prehypertensive and hypertensive group were analyzed. Regarding the period of follow-up we analyzed: 10/15 years period-children between 10 and 15 years, 15/20 years period-children between 15 and 20 years, and 10/20 years period-children between 10 and 20 years. Significant increase of diastolic blood pressure was noticed for both genders in 10/15 years period of prehypertensive population, while in hypertensive children, boys showed decline in frequency for systolic and diastolic blood pressure and girls only for diastolic. In 15/20 years period there was significant decrease of prehypertensive and significant increase of hypertensive diastolic blood pressure frequency. In 10/20 years period significant reduction in frequency of prehypertensive systolic blood pressure was noticed, while only hypertensive group of boys showed significant reduction regarding systolic blood pressure frequency. Prehypertensive diastolic and hypertensive systolic blood pressure fluctuations are more related to age.

To compare the effects of an alpha, beta blocker, arotinolol, in the treatment of essential hypertension between patients with a dipper and those with a non-dipper profile by means of 24-h ambulatory blood pressure monitoring (ABPM), a multicenter single blind parallel trial was carried out in five clinical centers. After a one-week single blind placebo run-in period, the patients underwent ABPM if their clinic diastolic blood pressure (DBP) ranged from 90-109 mmHg and their clinic systolic blood pressure (SBP) was <180 mmHg. They were divided into two groups according to the absence (non-dipper group, 24 cases) or presence (dipper group, 23 cases) of nocturnal BP reduction > or =10% of daytime BP. ABPM was measured again at the end of the active treatment phase. All patients were given Arotinolol 10-20 mg twice daily for 4 weeks. Twenty four-hour systolic and diastolic average BPs (MSBP, MDBP), 24-h systolic and diastolic blood pressure load (LS BP, LDBP), daytime systolic and diastolic average BPs (dMSBP, dMDBP), daytime systolic and diastolic blood pressure load (dLSBP, dLDBP), nighttime systolic and diastolic average BPs (nMSBP, nMDBP) and nighttime systolic and diastolic blood pressure load (nLSBP, nLDBP) were calculated. Arotinolol was effective in 78.2% of dippers and 54.2% of non-dippers, but the difference in effectiveness between these groups was not statistically significant. After treatment, SBP and DBP-including 24-h, daytime and nighttime systolic and diastolic BPs- were significantly reduced in both groups. During the daytime period, the systolic and diastolic blood pressures were significantly reduced in both dippers and non-dippers, while nighttime systolic and diastolic blood pressures were significantly reduced only in the non-dipper group. No significant changes were found in the dipper group over this period. In conclusion, Arotinolol, which can be dosed twice daily, is an effective antihypertensive agent which effectively lowers blood pressure during the day while reducing nighttime blood pressure more in non-dippers than in dippers, without excessive lowering blood pressure in the latter.