Associations between nondipping of nocturnal blood pressure decrease and cardiovascular target organ damage in strictly selected community-dwelling normotensives

BACKGROUND: In hypertensives, nondippers are more likely than dippers to suffer silent, as well as overt, hypertensive target organ damage. In this study, we investigated whether a nondipper status was associated with target organ damage in normotensives. METHODS: We performed ambulatory blood pressure (BP) monitoring, echocardiography, and carotid ultrasonography and measured natriuretic peptides and urinary albumin (UAE) in 74 normotensive subjects with the following criteria: 1) clinical BP <140/90 mm Hg; 2) average 24-h ambulatory BP <125/80 mm Hg. RESULTS: The left ventricular mass index (LVMI) and the relative wall thickness (RWT) measured by echocardiography were greater in nondippers than dippers (LVMI: 103 +/- 26 v 118 +/- 34 g/m(2), P <.05; RWT: 0.38 +/- 0.07 v 0.43 +/- 0.09, P <.01). Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were higher in nondippers than dippers (ANP: 14 +/- 10 v 36 +/- 63 pg/mL, P <.01; BNP: 16 +/- 12 v 62 +/- 153 pg/mL, P <.05). There were no significant differences in UAE and intima-media thickness measured by carotid ultrasonography. CONCLUSIONS: Normotensive nondipping may not reflect renal damage, but may have a predominant effect on cardiac damage. Nondipping of nocturnal BP seems to be a determinant of cardiac hypertrophy and remodeling, and may result in a cardiovascular risk independent of ambulatory BP levels in normotensives.     

The influence of ambulatory blood pressure profile on global and regional functions of the left and the right ventricles in orderly treated hypertensive patients

BACKGROUND: The association between nondipping profile and adverse cardiovascular outcome is still controversial. Tissue Doppler imaging (TDI), a new and useful addition to standard echocardiographic imaging techniques, permits a quantitative assessment of both global and regional function and timing of myocardial velocities. In this study, we aimed to assess whether a reduced nocturnal fall in blood pressure (BP) in orderly treated hypertensive patients with satisfactory BP control is related to more prominent structural and functional alterations of the ventricles. METHOD AND RESULTS: Sixty-nine hypertensive patients with adequate BP control were divided into two groups with respect to ambulatory BP profiles as dippers and nondippers. In addition to conventional echocardiographic parameters, in septal and lateral segments of left ventricle and free wall of right ventricle, peak systolic velocity (Sm), early (Em), and late (Am) diastolic velocities, isovolumic contraction time (ICTm), isovolumic relaxation time (IRTm), and ejection times (ETm) were measured, and modified myocardial performance index (MPIm) was calculated. Left ventricular (LV) and atrial dimensions, ejection fraction, transmitral early to late diastolic flow ratio, LV mass index, and LV hypertrophy ratio did not differ between groups. Both regional and mean LV Sm, Em/Am, MPIm and right ventricular Sm and MPIm were similar in both groups. CONCLUSION: In treated hypertensive patients with satisfactory BP control, there was no significant difference in cardiac structural and functional abnormalities among dipper and nondipper subjects.     

The majority of nondipping men do not have increased cardiovascular risk: a population-based study

OBJECTIVE : To investigate whether nondipping and diabetes are independently related to metabolic risk profile and prevalence of target organ damage in a population setting. METHODS : A population-based cohort of 70-year-old men (n = 1057) was examined with 24-h ambulatory blood pressure monitoring, euglycemic hyperinsulinemic clamp and lipid and glucose determinations. We defined nondipping as a night-day systolic blood pressure ratio >or= 1 (n = 66). Urinary albumin excretion rate and echocardiographically determined left ventricular geometry were used as indices of target organ damage. RESULTS : Nondipping was not related to hypertension, but diabetes was more common in nondippers (26%) than in dippers (14%, P < 0.05). Nondiabetic nondippers did not differ from dippers regarding insulin sensitivity, plasma glucose or lipids. However, nondipping in diabetic subjects was associated with the most pronounced impairments in body mass index, serum triglycerides and fasting plasma glucose. Measures of target organ damage did not differ between nondippers and dippers in the whole population, but an interaction (P < 0.05) between nondipping and diabetes contributed to an increased left ventricular mass in diabetic nondippers. The urinary albumin excretion rate was independently related to diabetes. CONCLUSIONS : In this population study, an interaction between diabetes and nondipping was demonstrated regarding fasting plasma glucose, lipid levels and left ventricular mass, indicating that nondipping is a marker of risk in diabetic subjects. However, in the nondiabetic majority of the population, nondipping was not associated with either metabolic disturbances or target organ damage.     

Different classifications of nocturnal blood pressure dipping affect the prevalence of dippers and nondippers and the relation with target-organ damage

OBJECTIVE: We assessed how different definitions of the awake and asleep periods and use of various blood pressure (BP) indices affect the extent of the nocturnal BP dip, the prevalence of dippers and nondippers, their respective reproducibilities and the relation of nondipping with target-organ damage. METHODS: We performed 24-h ambulatory BP monitoring twice and determined the left ventricular mass index and urinary albumin excretion as indices of target-organ damage in 150 hypertensive patients (off-medication). Awake and asleep periods were assessed using fixed and diary time methods, covering all readings available (wide) or excluding morning and evening transition hours (narrow). Nondipping (BP dip < 10%) was established for systolic BP and diastolic BP, their combinations (and/or), and mean arterial pressure. RESULTS: The different awake-asleep definitions caused significant variation in both the extent of the BP dip and the number of dippers and nondippers in comparison with the wide diary definition (i.e. use of actual awake and sleep periods). The prevalences of dippers and nondippers also varied significantly with the BP index. Reproducibility analyses of the BP dip and the dipping status yielded repeatability coefficients (expressed as percentages of nearly maximal variation) between 42.39 and 48.71%, and kappa values between 0.323 and 0.459, respectively. Some classifications, but not all, discriminated significantly between consistent dippers and nondippers in terms of left ventricular mass index or urinary albumin excretion. CONCLUSIONS: Use of different definitions of awake-asleep and BP indices affects significantly the classification of nocturnal BP dipping and its relation with hypertensive target-organ damage.     

Urinary albumin excretion among nondipper hypertensive patients is closely related with the pattern of nondipping

The relationship between 24-hour urinary albumin excretion (UAE) rate and the pattern of nondipping (isolated systolic nondipping, isolated diastolic nondipping, and both systolic and diastolic nondipping) is not known. Medical history, physical examination, laboratory analysis, and office and ambulatory blood pressure measurements were performed. Twenty-four hour urine specimens were collected to determine creatinine clearance and UAE. In total, 158 essential hypertensive patients (104 dippers, 54 nondippers) were included. Fourteen patients were isolated systolic nondippers, 7 patients were isolated diastolic nondippers, and 33 patients were both systolic and diastolic nondippers. Among nondipper patients, 17 had microalbuminuria and, among dipper patients, 9 had microalbuminuria (P < .0001). The median UAE of dippers was lower when compared with nondippers (5.25 mg/day vs.23 mg/day, P < .0001). The median UAE of isolated systolic nondippers, isolated diastolic nondippers, and both systolic and diastolic nondippers were 8.45 mg/day, 7.7 mg/day, and 25.5 mg/day, respectively (P = .001). Subgroup comparison of patients revealed that UAE was higher in patients with both systolic and diastolic nondippers when compared with dippers (P < .0001), isolated systolic nondippers (P = .001), and isolated diastolic nondippers (P =  .017). Not only nondipping itself, but nondipping profile may be related with UAE in essential hypertensive patients.     

Dipping is superior to cusums analysis in assessment of the risk of stroke in a case-control study

Background: Blunted nocturnal decline in blood pressure (BP) is associated with increased risk of stroke. Mean day-night BP difference (dipping) and cusums-derived circadian alteration magnitude (CDCAM) of BP are the common measures of diurnal BP variation. Although a significant number of clinical trials have demonstrated that dipping is associated with a lower risk of cardiovascular events, the clinical value of CDCAM of BP is unknown. We evaluated the association between dipping and CDCAM of BP and the risk of stroke.Methods: We analyzed 24-h ambulatory BP recordings of 110 control subjects and 91 stroke survivors enrolled in a case-control stroke study. Nondipping was defined as nocturnal drop of < 10 mm Hg in systolic BP. The associations between nondipping, CDCAM of BP, and risk of stroke were calculated in the same sample.Results: There were significantly fewer nondippers in the control group as compared with those among the stroke survivors. The odds ratio for stroke of nondippers was 2.3. By contrast, there was no significant difference in CDCAM of systolic BP between the control and stroke survivor groups. This finding could not be explained by the presence of reverse dippers in both groups.Conclusions: In this case-control study, classification of subjects into dippers and nondippers was found to be more clinically useful than cusums analysis of BP profile. Analysis of prospective data is needed to determine the clinical value of the cusums analysis of BP profile.     

Stress, menopausal status and nocturnal blood pressure dipping patterns among hypertensive women

BACKGROUND:

A less than 10% decline in blood pressure during the night is known as a nondipping blood pressure (BP) pattern. Nondipping BP has been shown to be associated with target organ damage and poorer cardiovascular outcomes. Additionally, some evidence suggests that hypertensive nondipping women are at greater risk for target organ damage than hypertensive nondipping men.

OBJECTIVE:

To determine whether stress, demographics, menopausal status or sleep quality are associated with nondipping BP among hypertensive women.

METHODS:

A cross-sectional study design was used to describe the relationship between stress and dipping status among a sample of hypertensive women and to describe the sample by age, ethnicity, marital status, menopausal status, current medications and sleep quality.

RESULTS:

The study sample consisted of 47 women (mean [± SD] age 57±13.9 years) with essential or office hypertension who underwent 24 h ambulatory BP monitoring, and completed stress and sleep quality measurements. Thirty-one women (66%) were classified as dippers and 16 (34%) were classified as nondippers. Nondippers were older (P=0.04), postmenopausal (P=0.003) and had lower stress scores (P=0.02) than their dipper counterparts. Postmenopausal status significantly predicted nondipping (OR 16; 95% CI 1.9 to 136.4).

CONCLUSION:

These findings were of interest given that some women had a nondipping BP pattern and significantly lower stress scores. It is possible that there are fundamentally different physiological mechanisms that explain this nondipping phenomenon. In the future, the identification of specific hemodynamic mechanisms associated with nondipping could potentially influence the choice of antihypertensive treatment regimens for nondipper hypertensive patients.     

Is HOMA index a predictor of nocturnal nondipping in hypertensives with newly diagnosed type 2 diabetes mellitus?

OBJECTIVE: Insulin resistance is involved in glucose intolerance, type 2 diabetes mellitus and hypertension. We aimed to analyze relationship between insulin resistance and nocturnal nondipping. METHODS: Patients underwent physical and biochemical evaluation, clinic and ambulatory blood pressure measurements. The homeostasis model assessment (HOMA) index was calculated. RESULTS: Ninety-six essential hypertensive patients, of whom 42 were dippers, with newly diagnosed type 2 diabetes mellitus were included. Nighttime average heart rate and mean arterial pressure of nondippers were higher than dippers (P<0.0001 and 0.001). Nondippers had higher fasting plasma glucose, serum insulin levels and HOMA indices than dipper patients (P=0.006, <0.0001 and <0.0001). Ten dippers and 36 nondippers were insulin resistant (P<0.0001). Clinic (r=+0.22, P=0.031), daytime average (r=+0.27, P=0.007), nighttime average (r=+0.33, P=0.001), 24-h average systolic (r=+0.25, P=0.015) and nighttime average diastolic blood pressures (r=+0.31, P=0.002) were positively correlated with homeostasis model assessment index. Nighttime mean arterial pressure and heart rates (daytime, nighttime, 24-h average) showed positive correlation with homeostasis model assessment index. In multivariate analysis, high homeostasis model assessment index was associated with increased nondipping risk (odds ratio: 1.85, confidence interval: 1.24-2.76, P=0.003). After adjustment of several factors, average nighttime systolic (P<0.0001), diastolic (P<0.0001) and 24-h diastolic blood pressure (P=0.029) and heart rate (P=0.001) measurements of insulin resistant patients were higher than nonresistant patients. CONCLUSIONS: Insulin resistance is related with diurnal blood pressure variation. The HOMA index may be a predictor of nocturnal nondipping in patients with essential hypertension and newly diagnosed type 2 diabetes mellitus.     

The relationship between nighttime dipping in blood pressure and cerebral hemodynamics in nonstroke patients

Inadequate dipping in nighttime blood pressure (BP) is associated with cerebrovascular disease. The authors aimed to determine whether inadequate nocturnal dipping was associated with abnormalities in cerebrovascular hemodynamics in individuals without stroke. Participants in this study underwent 24-hour ambulatory BP monitoring followed by morning transcranial Doppler measurements of blood flow velocities (BFVs) in the middle cerebral artery during supine rest, head-up tilt, hypocapnia, and hypercapnia. Nighttime BP decline by <10% was considered nondipping. Of the 102 nonstroke participants (mean age, 53.6 years), 35 (34%) were dippers. Although nondippers had similar BFV and cerebrovascular resistance (CVR) while supine, they had a lower BFV (P=.04) and greater CVR (P=.02) during head-up tilt compared with dippers. Moreover, greater nighttime dipping in both systolic BP (P=.006) and diastolic BP (P=.03) were associated with higher daytime BFV and lower CVR (P=.01 for systolic BP; P=.02 for diastolic BP). Inadequate nocturnal BP dipping is associated with lower daytime cerebral blood flow, especially during head-up tilt.     

Reduced nocturnal fall in blood pressure,assessed by two ambulatory blood pressure monitorings and cardiac alterations in early phases of untreated essential hypertension

To investigate whether in recently diagnosed essential hypertensives a reduced nocturnal fall in blood pressure (BP), established on the basis of two 24-h ambulatory blood pressure monitorings (ABPM) is related to a greater cardiovascular damage. In all, 355 consecutive, recently diagnosed, never-treated essential hypertensives referred for the first time to our outpatient clinic were included in the study. Each patient underwent the following procedures: (1) two 24-h ABPMs performed within 3 weeks, (2) 24-h urinary collection for microalbuminuria, (3) nonmydriatic photography of ocular fundi, (4) echocardiography, (5) carotid ultrasonography. We defined nondipping profile as a night-day systolic and diastolic fall < or =10 % (mean of two ABPMs). A dipper BP profile was found in 238 patients, whereas in 117 patients a nondipper profile was present. The two groups were similar for age, gender, body mass index, smoking habit, clinic BP, 48-h BP and heart rate, while, by definition, night-time systolic and diastolic BP were significantly higher in nondippers than in dippers (130/81 vs 121/74 mmHg, P < 0.0001).The prevalence of left ventricular hypertrophy (LVH) defined by four different criteria: (a) LV mass index (LVMI) > or = 125 g/m(2) in both genders; (b) LVMI > or = 134 gm(2) in men and > or = 110 in women; (c) LVMI> or = 125 g/m(2) in men and > or = 110 g/m(2) in women; (d) LVMI > or = 51 g/m(2.7) in men and > or = 47 g/m(2.7) in women was significantly higher in nondippers than in dippers (a: 12 vs 7%, P < 0.05; b: 16 vs 7%, P < 0.01; c: 20 vs 11%, P < 0.01; d: 35 vs 23% P < 0.02) and this finding was associated with a significant increase in aortic root and left atrium dimensions. There were no differences between the two groups in the prevalence of carotid and retinal changes and microalbuminuria. In conclusion our findings suggest that never-treated hypertensives with a reduced BP fall in the night time, defined on the basis of two ABPMs, have a higher prevalence of TOD than dippers, in terms of echocardiographic LVH. In this population setting, cardiac structural alterations are a more sensitive marker of the impact of the nocturnal BP load on cardiovascular system than other extracardiac signs of TOD.     

Sleep quality and blood pressure dipping in obstructive sleep apnea

Background:Obstructive sleep apnea (OSA) is associated with poor sleep quality and a high incidence of nondipping. The aim of this study was to determine the association of sleep quality and nocturnal blood pressure (BP) dipping in an OSA population.Methods:A total of 44 untreated subjects with mild to severe OSA underwent overnight-attended polysomnography and 24-h ambulatory BP monitoring. Subjects were off antihypertensive medication. The percentage of slow wave sleep, percentage of time awake after sleep onset during the sleep period, sleep efficiency, and arousal index were chosen as measurements of sleep quality. Dipping was evaluated using the change in systolic BP, diastolic BP, and mean arterial pressure. Patients were classified as dippers and nondippers based on a nocturnal drop in mean arterial pressure > 10%. Differences between groups were evaluated by independent sample t tests. Pearson correlation and linear regression were used to evaluate the association of sleep quality and dipping.Results:There were no differences between dippers and nondippers with regard to body mass index, age, or respiratory disturbance index. A total of 84% were nondippers. No difference was found between dippers and nondippers in sleep quality. None of the sleep quality measures correlated with the measurements of dipping. In multiple regression analyses, the percentage of slow wave sleep and arousal index each independently predicted only a small percentage of the variance (approximately 10%) of nocturnal DBP dipping.Conclusions:The prevalence of nondipping was very high in a population of untreated patients with mild to severe OSA. Nonetheless, sleep quality did not appear to be related to BP dipping.     

Cardiovascular Risks of Dipping Status and Chronic Kidney Disease in Elderly Japanese Hypertensive Patients

Chronic kidney disease (CKD) increases the risk of cardiovascular events and is often associated with the nondipping pattern of blood pressure (BP). We evaluated ambulatory BP, CKD, and the incidence of cardiovascular events in 811 older hypertensive patients. CKD and the dipping pattern increased the risk of cardiovascular events independent of the 24‐hour systolic BP level (CKD: hazard ratio [HR], 2.37; 95% confidence interval [CI], 1.24–4.54; nondippers: HR, 2.16; 95% CI, 1.19–3.91; extreme dippers: HR, 2.38; 95% CI, 1.17–4.83). However, after adjustment for covariates that included CKD, the risk in nondippers was insignificant (HR, 1.83; 95% CI, 0.998–3.34; P=.051), while the risk in extreme dippers remained (HR, 2.59; 95% CI, 1.26–5.32; P=.009) (CKD: HR, 1.81; 95% CI, 0.93–3.54; P=.081). Patients with CKD have an increased risk of cardiovascular events. CKD and other cardiovascular risk factors may account for some of the increased risk in nondippers, but it does not explain the higher risk in extreme dippers.     

Disruption of ultradian and circadian rhythms of blood pressure in nondipper hypertensive patients

Ultradian rhythms in blood pressure (BP) are known to exist, but their modification in hypertension is largely unknown. The present study was undertaken to assess the integrity of ultradian and 24-hour BP rhythms in dipper (n=100) and nondipper (n=20) hypertensive patients compared with 44 dipper normotensive individuals. Fourier analysis was used to fit ultradian (12, 8, and 6 hour) and 24-hour rhythms in BP and heart rate (HR). Mesor, amplitude, and acrophase were calculated for individual and overall rhythm curves. All subjects showed significant ultradian or 24-hour BP and HR rhythms. Systolic and diastolic BP mesor was higher in hypertensive patients compared with normotensive patients. The percentage of variability in ambulatory BP that could be explained by fitting ultradian and 24-hour rhythms was reduced in nondippers compared with normotensives or dippers. Amplitude of ultradian and 24-hour rhythms in BP increased in dippers and decreased in nondippers. Ultradian and 24-hour rhythms in HR did not differ among the 3 groups examined. Results indicate that in nondippers, blunted ultradian and 24-hour rhythm amplitude in BP was accompanied by a loss of rhythm integrity.     

Association Between Nondipper Behavior and Serum Calcium in Hypertensive Patients with Mild-to-Moderate Chronic Renal Dysfunction

A nondipping BP pattern has been shown to be predictive of end-organ damage, cardiovascular events, and mortality. The mechanisms of blunted nocturnal BP fall are multifactorial. We assessed whether total corrected serum calcium and ionic calcium (iCa) are associated with a blunted nocturnal BP fall in both treated and untreated hypertensive patients with stages 1–3 of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI). Clinical data and 24-hour ambulatory blood pressure monitoring were obtained in a cohort of 231 essential hypertensive patients. Among the entire cohort, 107 were nondippers and 124 were dippers. Only in nondippers, we found significant correlations between iCa and 24-hour systolic blood pressure (SBP; r = 0.21, P < .03), diurnal SBP (r = 0.21, P < .03), and 24-hour pulse pressure (PP; r = 0.23, P < .02). The ambulatory arterial stiffness index (AASI) was significantly related with 24-hour PP in both dippers and nondippers after adjusting for age. Both AASI and 24-hour PP were higher in nondippers than in dippers. In addition, in nondippers, the prevalence of estimated glomerular filtration rate (eGFR) <60 mL/minute/1.73 m² was higher than in dippers (50% vs. 33.7%, P < .02). Logistic regression showed that patients with eGFR ≥60 mL/minute/1.73 m² had lower risk of nondipper status than patients with eGFR <60 mL/minute/1.73 m² (odds ratio = 2.445; 95% confidence interval = 1.398–4.277, P < .002). In conclusion, serum iCa could participate in the pathogenesis of nondipping pattern. Increased large artery stiffness may be a mechanism of the deleterious influence of nondipping on cardiovascular outcome. Hypertensive subjects with stage 3 of NKF KDOQI had a greater loss of circadian BP rhythm than those in stages 1 and 2.     

Impact of abnormal nocturnal blood pressure fall on vascular function

BACKGROUND: It is well known that nondipping pattern of arterial hypertension has a harmful effect on target organs such as the brain, heart, and kidneys. However, it remains uncertain whether abnormal dipping patterns of nocturnal blood pressure (BP), such as extreme and reverse dipping, influence vascular function. METHODS: This study comprised consecutive 2800 individuals (1554 men and 1246 women). All were nondiabetic and had uncomplicated, untreated essential sustained hypertension based on office measurements. After a 2-week wash-out period, 24-h ambulatory BP recordings were obtained and patients were classified by their nocturnal systolic BP fall (132 extreme dippers with >20% nocturnal systolic BP fall; 1235 dippers with >10% but <20% fall; 1146 nondippers with >0% but <10% fall; and 287 reverse dippers with <0% fall). Microalbumin, ACR (albumin/creatinine ratio), and microglobulin values were measured in all groups. RESULTS: Extreme dippers did not differ from dippers with regard to microalbumin, microglobulin excretion, or ACR. On the contrary, reverse dippers had significantly (P <.0001) higher values, compared with nondippers, for microalbumin (49.5 v 37.2 mg/dL), microglobulin (10.33 v 8.71 mg/dL), ACR (104.9 v 65.2), and percentages of abnormal values for these parameters. CONCLUSIONS: Microalbuminuria, an index of vascular function, differentiates reverse dippers from nondippers, but not extreme dippers from dippers among hypertensive patients.     

Behavioural and psychosocial correlates of nondipping blood pressure pattern among middle-aged men and women at work

The underlying pathogenetic mechanisms of nondipping blood pressure (BP) pattern are not completely understood. Especially the role of psychosocial correlates remains unclear. The aim was to assess the association between nondipping BP pattern, behavioural and psychosocial factors in a sample of working men and women. The study sample included 167 working men and women aged 40-64 years from the BELSTRESS cohort. Socio-demographic, behavioural and psychosocial factors were assessed by self-administered questionnaires. Participants were medically examined and underwent an ambulatory BP monitoring during 24 h. Nondipping was defined when the average nocturnal decline in BP was <10%. The prevalence of nondipping for both systolic and diastolic BP was 7.8%. Nondipping was not significantly related to smoking, alcohol consumption and leisure time physical activity. A crude significant association was observed between nondipping and sleep problems. After adjusting for gender, education and body mass index, the risk for nondipping was associated with job strain, living alone, being unsatisfied about the contact with one's children, depressive symptoms and vital exhaustion. Nondipping BP pattern was consistently related to psychosocial factors in this study: positive associations were observed with measures of job strain, poor private life support (living alone and being unsatisfied about the contact with one's children) and mental health problems (depressive symptoms and vital exhaustion).     

Insulin resistance is associated with reduced nocturnal falls of blood pressure in normotensive, nonobese type 2 diabetic subjects

To assess the relationship between insulin resistance and ambulatory blood pressure (BP) pattern, we determined glucose infusion rate (GIR) as a marker of insulin resistance using a glucose clamp method, and measured 24-h BPs in 25 normotensive, nonobese type 2 diabetic subjects. They were divided into two groups: 11 dippers and 14 nondippers. Clinical characteristics were similar in the two groups except for orthostatic fall in systolic BP. The median GIR level was significantly lower in nondippers than in dippers (P < 0.05). Spearman's rank correlation revealed that the GIRs were negatively correlated with the systolic, diastolic and mean BPs during nighttime (P < 0.05 or less), but not with daytime or whole day BPs. Moreover, based on a logistic regression analysis, the GIR as well as orthostatic fall in systolic BP discriminated independently between dippers and nondippers. Thus, our results suggest that insulin resistance is associated with decreased nocturnal BP fall in type 2 diabetic subjects.     

Nocturnal blood pressure elevation predicts progression of albuminuria in elderly people with type 2 diabetes

Ambulatory 24-hour pulse pressure predicts progression of albuminuria in persons with diabetes mellitus. The authors assessed whether nocturnal blood pressure (BP) patterns added predictive information and examined the multivariate-adjusted association of nocturnal BP patterns with progression of urine albumin excretion during follow-up in a multiethnic cohort of older people (n=957) with type 2 diabetes mellitus who were free of macroalbuminuria. Albuminuria was assessed by spot urine measurement of albumin-to-creatinine ratio at baseline and annually for 3 years. Participants were categorized according to their sleep/wake systolic BP ratio as dippers (ratio 0.9 to 1; n=475), and nocturnal BP risers (ratio >1; n=187). The proportion exhibiting progression of albuminuria in dippers, nondippers, and risers was 17.6%, 22.9%, and 27.3%, respectively (P for linear trend = .01). A nocturnal BP rise was independently associated with progression of albuminuria (hazard ratio, 1.68; 95% confidence interval [CI], 1.09-2.60; P=.02), whereas office pulse pressure was not. When ambulatory 24-hour pulse pressure was added to the model, the nocturnal BP rise remained an independent predictor of progression of albuminuria (hazard ratio, 1.58; 95% CI, 1.02-2.45; P=.04). Nocturnal nondipping (without BP increase) was not an independent predictor. In conclusion, nocturnal BP rise on ambulatory monitoring is superior to office BP to predict worsening of albuminuria in elderly individuals with type 2 diabetes and adds to the information provided by 24-hour pulse pressure.     

Relation of extent of nocturnal blood pressure decrease to cardiovascular remodeling in never-treated patients with essential hypertension

The clinical significance of the extent of a decrease in nocturnal blood pressure (BP) and the resulting classification of hypertensives as "dipper" (decrease in BP >10% day BP) or "nondipper" (decrease in BP <10% day BP) has been questioned recently. The aim of our study was to evaluate if the extent of a nocturnal BP decrease, established on the basis of a single 24-hour BP monitoring, is related to cardiovascular remodeling in essential hypertension. We enrolled 253 never-treated essential hypertensives (24-hour BP > or = 140 and/or 90 mm Hg); for each patient we recorded 24-hour BP, left ventricular (LV) echocardiogram, Doppler transmitral flow velocities, and carotid-femoral pulse-wave velocities. A dipper BP profile was found in 161 patients, whereas 92 patients were nondippers. The 2 groups did not differ with regard to age, gender, body mass index, 24-hour and daytime BP, and 24-hour, daytime, and nighttime heart rate. All LV morphologic characteristics LV systolic and diastolic functional parameters, mitral Doppler-derived diastolic indexes, as well as carotid-femoral pulse-wave velocity, and aortic index distensibility were not significantly different between dippers and nondippers. The prevalence of LV hypertrophy and diastolic dysfunction was also similar between the 2 groups. The extent of a decrease in nocturnal BP did not correlate with any cardiovascular parameter. In conclusion, in never-treated hypertensives, the extent of a nocturnal BP decrease is not related to LV morpho-functional characteristics and aortic distensibility; therefore, the nondipping status established on the basis of a single 24-hour BP monitoring does not identify hypertensive patients with greater cardiovascular damage.     

Left ventricular diastolic function is related to glucose in a middle-aged population

OBJECTIVES: To examine the relation between left ventricular (LV) diastolic function and glucose metabolism in individuals without previously diagnosed diabetes mellitus. DESIGN: A cross-sectional population-based study. SETTING: A university hospital. SUBJECTS: Thirty-five men and women 56-58 years of age without previously diagnosed diabetes or heart disease. MAIN OUTCOME MEASURES: Left ventricular diastolic function assessed by pulsed Doppler tissue imaging and its relation to fasting plasma glucose, glucose postload and glycated haemoglobin. LV diastolic function was determined by measuring early diastolic filling peak velocity (Em wave cm s-1), late diastolic filling peak velocity (Am wave cm s-1) and their ratio Em/Am. RESULTS: Peak Em velocity, peak Am velocity and their ratio Em/Am correlated with fasting plasma glucose (r=-0.42, P=0.01; r=0.47, P=0.04 and r=-0.53, P=0.001, respectively). There was a correlation between peak Em velocity, the ratio of Em/Am and glycated haemoglobin. LV diastolic function was also related to glucose postload. CONCLUSIONS: Left ventricular diastolic function is related to concentrations of fasting plasma glucose, glucose postload and glycated haemoglobin even below the threshold of diabetes. This indicates that glucose concentrations already in the upper end of the normal range has negative impact on cardiac function.