Urinary albumin excretion and nocturnal blood pressure in hypertensive patients with type II diabetes mellitus

E-Selectin Is Associated with Daytime and 24-Hour Diastolic Blood Pressure Variability in Type 2 Diabetes

E-selectin is an endothelial cell adhesion molecule involved in vascular inflammation. Elevated E-selectin has been reported in patients with high blood pressure and diabetes. Given the increasing clinical relevance of parameters derived from ambulatory blood pressure monitoring, further investigation of their relationships with E-selectin is of interest. In this study, we aimed to investigate the association between serum E-selectin, office blood pressure and 24 h ambulatory blood pressure parameters in patients with type 2 diabetes. Blood pressure variability was assessed by computing the standard deviation of mean systolic and diastolic blood pressure separately for daytime and nighttime during 24 h ambulatory blood pressure monitoring in a cohort of patients with type 2 diabetes (n = 132). Additionally, were assessed nighttime systolic dipping and pulse pressure separately for daytime, nighttime, and 24 h. Serum E-selectin was measured using the enzyme-linked immunosorbent assay technique. We found that E-selectin was consistently associated with 24 h diastolic blood pressure variability (r = 0.238; p = 0.019) and daytime diastolic blood pressure variability (r = 0.258; p = 0.012), after adjustment for confounding factors. No association of E-selectin with office blood pressure and other 24 h ambulatory blood pressure parameters was observed. In conclusion, endothelial activation indicated by elevated serum E-selectin is associated with increased ambulatory diastolic blood pressure variability in patients with type 2 diabetes.

Ambulatory Blood Pressure Monitoring in Type 2 Diabetes Mellitus: A Cross-sectional Study

Background: Ambulatory blood pressure (ABP) monitoring in type 2 diabetes (T2DM) is not yet routine in clini-cal practice.

Objectives: To quantify abnormal ABP patterns and their associations with diabetic complications, and to assess the reliabil-ity of office blood pressure (OBP) for assessing BP in T2DM.

Methods: In a cross-sectional study, eligible patients with T2DM underwent OBP and 24- hour ABP measurements under standardized conditions and screening for diabetic complications.

Results: 56 patients (mean age 67 + 10 years, males 50%) completed assessment. 43(73%) had a known history of hyper-tension. Non-dipping and nocturnal systolic hypertension (SHT) were prevalent in 31(55%) and 32(57%) patients, respec-tively. 16(29%) demonstrated masked phenomenon, but only three (7%) demonstrated white coat effect. Nocturnal SHT had a significant association with composite microvascular complications independent of daytime systolic BP control (adjusted odds ratio (OR) 1.72(CI 1.41-4.25). There was no association between other abnormal ABP patterns and diabetic complica-tions. The sensitivity and specificity of OBP for diagnosing HT or assessing BP control was 59% and 68% respectively. The positive and negative predictive values were 74% and 52% respectively.

Conclusion: Non-dipping, reverse dipping, nocturnal SHT and masked phenomenon are highly prevalent in patients with T2DM with or without a known history of hypertension. Compared with non-dipping, nocturnal SHT may be a stronger predictor of end organ damage. The reliability of OBP for assessing BP in T2DM is only modest. Patients with T2DM are likely to benefit from routine ABP monitoring.

Treatment-time regimen of hypertension medications significantly affects ambulatory blood pressure and clinical characteristics of patients with resistant hypertension

Patients with resistant hypertension (RH) are at greater risk for stroke, renal insufficiency, and cardiovascular disease (CVD) events than are those for whom blood pressure (BP) is responsive to and well controlled by therapeutic interventions. Although all chronotherapy trials have compared the effects on BP regulation of full daily doses of medications when ingested in the morning versus at bedtime, prescription of the same medications in divided doses twice daily (BID) is frequent. Here, we investigated the influence of hypertension treatment-time regimen on the circadian BP pattern, degree of BP control, and relevant clinical and laboratory medicine parameters of RH patients evaluated by 48-h ambulatory BP monitoring (ABPM). This cross-sectional study evaluated 2899 such patients (1701 men/1198 women), 64.2 ± 11.8 (mean ± SD) yrs of age, enrolled in the Hygia Project. Among the participants, 1084 were ingesting all hypertension medications upon awakening (upon-awakening regimen), 1436 patients were ingesting the full daily dose of ≥1 of them at bedtime (bedtime regimen), and 379 were ingesting split doses of ≥1 medications BID upon awakening and at bedtime (BID regimen). Patients of the bedtime regimen compared with the other two treatment-time regimens had lower likelihood of microalbuminuria and chronic kidney disease; significantly lower albumin/creatinine ratio, glucose, total cholesterol, and low-density lipoprotein (LDL) cholesterol; plus higher estimated glomerular filtration rate and high-density lipoprotein (HDL) cholesterol. The bedtime regimen was also significantly associated with lower asleep systolic (SBP) and diastolic (DBP) BP means than the upon-awakening and BID regimens. The sleep-time relative SBP and DBP decline was significantly attenuated by the upon-awakening and BID regimens (p < .001), resulting in significantly higher prevalence of non-dipping in these two treatment-time regimen groups (80.5% and 77.3%, respectively) than in the bedtime regimen (54.4%; p < .001 between groups). Additionally, the prevalence of the riser BP pattern, associated with highest CVD risk, was much greater, 31.0% and 29.8%, respectively, among patients of the upon-awakening and BID-treatment regimens, compared with the bedtime regimen (17.6%; p < .001 between groups). Patients of the bedtime regimen also showed significantly higher prevalence of properly controlled ambulatory BP (p < .001) as a result of a greater proportion of them showing complete control of asleep SBP and DBP means. Our findings demonstrate significantly lower asleep SBP and DBP means and attenuated prevalence of blunted nighttime BP decline, i.e., lower prevalence of CVD risk markers, in RH patients ingesting the full daily dose of ≥1 hypertension medications at bedtime than in those ingesting all of them upon awakening or ≥1 of them as split doses BID. In RH, ingesting the same medications BID neither improves ambulatory BP control nor reduces the prevalence of non-dipping, and cannot be considered chronotherapy. Collectively, findings of this study indicate that a bedtime hypertension medication regimen, in conjunction with proper patient evaluation by ABPM to corroborate the diagnosis of true RH and avoid treatment-induced nocturnal hypotension, should be the therapeutic scheme of choice for patients who, by conventional cuff methods (and in the absence of ABPM) and the morning-treatment regimen, have been mistakenly judged to be resistant to therapy.

24-hour and nighttime blood pressures in type 2 diabetic hypertensive patients following morning or evening administration of olmesartan

Ambulatory blood pressure monitoring (ABPM) allows determining of the nocturnal blood pressure fall (NBPF). An NBPF below 10% (nondipper pattern) has been related to increased cardiovascular risk, and it is a common finding in type 2 diabetic hypertensive patients. The authors evaluated the impact on 24-hour blood pressure, NBPF, and albuminuria of olmesartan 40 mg, administered in a morning- vs a nocturnal-based dosing scheme, in type 2 diabetic patients with newly diagnosed hypertension. Using a crossover design, 40 patients (42.1% men) received olmesartan 40 mg once daily at wake up or bedtime for 8 weeks. Patients underwent 24-hour ABPM at baseline and at weeks 8 and 16, and albumin to creatinine ratio was measured at baseline and 8 weeks. Night systolic blood pressure (BP) (P=.007) and mean BP (P=.012) were significantly reduced following the bedtime dose, compared with morning dosing. Night BP fall (%) was significantly reduced by bedtime dosing, compared with morning dosing (P=.0001). No differences were seen for urinary albumin excretion between both arms at week 8. Without affecting 24-hour BP control, night dosing of olmesartan increases nocturnal BP fall significantly more than conventional morning dosing, increasing the number of dipper diabetic hypertensive patients.

Blood pressure means rather than nocturnal dipping pattern are related to complications in Type 2 diabetic patients

AIM

To determine whether systolic and diastolic blood pressure (BP) means, during ambulatory BP monitoring (ABPM), are more strongly correlated with microvascular complications and echocardiographic structural alterations than night-time/daytime (N/D) BP ratio.

METHODS

A cross-sectional study was conducted in 270 Type 2 diabetes mellitus (DM) outpatients who underwent clinical and laboratory investigations, urinary albumin excretion rate (UAER) determination, echocardiography, office and 24-h ABPM (Spacelabs 90207).

RESULTS

UAER, after multivariate adjustments, was associated with office BP (systolic: R(2)(a) 0.162, P < 0.001; diastolic: R(2)(a) 0.124, P < 0.001) and ABPM (24-h systolic: R(2)(a) 0.195, P < 0.001; 24-h diastolic: R(2)(a) 0.197, P < 0.001) but not with N/D BP ratios (systolic: R(2)(a) 0.062, P = 0.080; diastolic: R(2)(a) 0.063, P = 0.069). Similar results were observed for echocardiographic parameters. The presence of retinopathy was associated only with night-time BP values [systolic means: odds ratio (OR) 1.13, 95% confidence interval (CI) 1.03-1.24 and diastolic means: OR 1.21, CI 1.04-1.40 and N/D diastolic BP ratio > 0.90, OR 3.21, CI 1.65-6.25].

CONCLUSIONS

UAER and echocardiographic structural alterations had more consistent correlations of a greater magnitude with systolic BP means than with N/D BP ratios. The nocturnal BP values appear to be more relevant for diabetic retinopathy. BP measurement in patients with Type 2 DM should take into account the 24-h period rather than focusing on a specific time span of BP homeostasis.

Ambulatory blood pressure level rather than dipper/nondipper status predicts vascular events in type 2 diabetic subjects

To clarify which parameter, diurnal pattern of blood pressure (BP) or level of BP variability, has the stronger predictive value for fatal and nonfatal vascular events, vital status after a mean (+/-SD) follow-up period of 86+/-46 months was determined in 392 type 2 diabetic subjects without any history of vascular disease, in whom the 24-h BP profile had been monitored between 1988 and 1998. After the exclusion of 28 subjects who died during the follow-up period of causes unrelated to diabetes, 364 subjects were recruited for further analysis. A total of 147 first events, including 50 fatal vascular events and 97 nonfatal vascular events, were recorded during the follow-up period. The rates of various vascular events increased with both reduced nocturnal falls in systolic BP (SBP) and levels of all ambulatory BP parameters. The ambulatory BP parameter showing the largest area under the receiver operating characteristic curve (ROCAUC) for fatal events was the mean 24-h pulse pressure (PP), and that for nonfatal events was the mean nighttime SBP; both exceeded the respective values of nocturnal fall in SBP. Furthermore, when dipper and nondipper diabetic subjects were divided into subgroups based on the 24-h PP (54.3 mmHg) and the nighttime SBP (116.5 mmHg) cut-off points derived from the ROC analyses, Kaplan-Meier plots showed that the diabetic subgroups with high ambulatory BP levels had worse outcomes, independent of dipper/nondipper status. Finally, these parameters were applied to the Cox model with the values of nocturnal fall in SBP and other confounding factors, and results showed that mean 24-h PP and mean nighttime SBP predicted fatal and nonfatal vascular events, respectively, more strongly than nocturnal fall in SBP in type 2 diabetic subjects. These findings therefore suggest that ambulatory BP levels in type 2 diabetic subjects have a higher predictive value for organ damage and death compared with diurnal BP patterns or dipper/nondipper status.

Usefulness of home blood pressure measurement in the morning in type 2 diabetic patients

OBJECTIVE

Recently, repeated home blood pressure (HBP) measurements in the morning for a long period have been shown to have a stronger predictive power for mortality in patients with hypertension than occasional casual/clinic blood pressure (CBP) measurements. We studied whether HBP in the morning in type 2 diabetic patients is useful for prediction of diabetic complications.

RESEARCH DESIGN AND METHODS

The occurrence of diabetic complications (nephropathy, retinopathy, coronary heart disease [CHD], and cerebrovascular disease [CVD]) were examined in relation to morning HBP as well as to CBP in 170 type 2 diabetic patients treated with antidiabetic and antihypertensive drugs. Blood pressure was measured at the clinic during the day and at home after awakening in the morning. Clinic hypertension (CH) and morning hypertension (MH) were defined as systolic blood pressure (SBP) > or =130 mmHg and/or diastolic blood pressure (DBP) > or =85 mmHg. The relation of CH and MH to the prevalence of these events was examined.

RESULTS

There were no significant differences in the prevalence of nephropathy, retinopathy, CHD, and CVD between the two groups with (n = 131) and without CH (n = 39), whereas the prevalences of these events in the patients with MH (n = 97) were significantly higher (P < 0.05) than in those without MH (n = 73). The prevalence of nephropathy was highly associated with systolic MH.

CONCLUSIONS

Elevations of HBP in the morning in diabetic patients are strongly related to microvascular and macrovascular complications, especially nephropathy. It is concluded that the control of MH may prevent vascular complications in type 2 diabetic patients.

Non-dipping in diabetic patients: insights from the siesta

Non-dipping, ie failure to lower blood pressure during sleep, has been found to be more prevalent in diabetic than in non-diabetic subjects. However, the reasons remain to be clarified. Diabetic patients may wake up more frequently during the night (for instance, due to nocturia). This may result in inclusion of awake blood pressure measurements in the night-time average and thus erroneously raise this average, causing misclassification of patients as non-dippers. However, non-dipping in diabetes may be due to blunted effect of sleep itself on blood pressure secondary to autonomic neuropathy. We undertook this study in order to further clarify this question. We studied 23 diabetic patients, and 23 matched controls who underwent 24-h ambulatory blood pressure monitoring, and reported taking an afternoon nap. Afternoon nap, by virtue of its short duration, is devoid of interruptions, and thus can be used as a model for tiled, non-interrupted sleep. We found that, both in diabetic patients and controls, blood pressure declined during the afternoon nap in a similar magnitude to the night-time decline. However, this decline was significantly blunted in the diabetic patients (13.9 +/- 2.2% decline in diastolic blood pressure during naptime in the diabetic patients, as compared with 24 +/- 2.3% decline in diastolic blood pressure during the siesta in the control group, P < 0.02). The blunted decline of blood pressure during the nap in diabetic patients demonstrates that non-dipping is due to the blunted effect of sleep itself. This can be another facet of autonomic dysfunction seen in diabetes mellitus.

Microalbuminuria in essential hypertension: significance, pathophysiology, and therapeutic implications

Some patients with essential hypertension manifest greater than normal urinary albumin excretion (UAE). The significance of this association, which is the object of this review, is not well established. Hypertensive patients with microalbuminuria manifest greater levels of blood pressure, particularly at night, and higher serum levels of cholesterol, triglycerides, and uric acid than patients with normal UAE. Levels of high-density lipoprotein cholesterol, on the other hand, were lower in patients with microalbuminuria than in those with normal UAE. Patients with microalbuminuria manifested greater incidence of insulin resistance and thicker carotid arteries than patients with normal UAE. After a follow-up of 7 years, we observed that 12 cardiovascular events occurred among 54 (21.3%) patients with microalbuminuria and only two such events among 87 patients with normal UAE (P < 0.0002). Stepwise logistic regression analysis showed that UAE, cholesterol level, and diastolic blood pressure were independent predictors of the cardiovascular outcome. Rate of creatinine clearance from patients with microalbuminuria decreased more than that from those with normal UAE. In conclusion, these studies suggest that hypertensive individuals with microalbuminuria manifest a variety of biochemical and hormonal derangements with pathogenic potential, which results in hypertensive patients having a greater incidence of cardiovascular events and a greater decline in renal function than patients with normal UAE.

Blood pressure control, microalbuminuria and cardiovascular risk in Type 2 diabetes mellitus

Type 2 (noninsulin-dependent) diabetes mellitus (DM) affects about 3% of the UK population. Diabetes often coexists with a cluster of other potent cardiovascular risk factors, including hypertension, dyslipidaemia and increased tendency for thrombosis, and increases the risk of early death from cardiovascular causes by about threefold. Microalbuminuria or proteinuria also may be present, further increasing the risk of cardiovascular mortality. Cardiovascular risk factors must be treated aggressively in patients with Type 2 diabetes and control of blood pressure at 140/85 mm Hg or lower is a priority. The management of hypertension in patients from some ethnic groups demands special consideration because they have a high incidence of diabetes and hypertensive complications. Patients must be urged to adopt appropriate lifestyle changes in the first instance but additional drug treatment for hypertension is usually required. All the major classes of antihypertensive agents lower blood pressure in Type 2 diabetic patients but have different effects on metabolic risk factors in different ways. Low-dose thiazide diuretics, beta-blockers, calcium channel blockers and angiotensin converting enzyme (ACE) inhibitors have been shown to reduce cardiovascular risk. Individually, the effects of low-dose thiazide diuretics and beta-blockers on glucose and lipid metabolism is clinically insignificant, though in combination much larger metabolic effects are seen. ACE inhibitors and calcium channel blockers have no, or small, beneficial effects on glucose and lipid metabolism, while the greater beneficial effects of alpha1-blockers on lipid profiles may render them especially useful in the Type 2 diabetic patient. Long-acting calcium-channel blockers and ACE inhibitors protect renal function and are suitable as first line therapy in patients with microalbuminuria or proteinuria. Until results from the current batch of randomized, placebo-controlled trials comparing different classes of antihypertensive agents are available, the choice of antihypertensive agent is difficult. Addressing overall cardiovascular risk factors, rather than hypertension alone, is essential in the management of the hypertensive Type 2 diabetic patient.

Nocturnal blood pressure and relation to vasoactive hormones and renal function in hypertension and chronic renal failure

The purpose of this study was to assess the blood pressure profile and to measure vasoactive hormones in patients with essential hypertension (n=61), secondary hypertension (n=32) and chronic renal failure (n=32) matched with healthy control subjects (n=35), and to study the relationship between circadian changes in blood pressure and baseline levels of vasoactive hormones and renal function. Non-invasive, automatic blood pressure measurement was performed for 24 or 48 h. Venous plasma concentrations of renin, angiotensin II, aldosterone, arginine vasopressin, atrial natriuretic peptide and endothelin were measured. The mean 24-h blood pressure was higher in all groups of hypertensive patients than in control subjects. The nocturnal blood pressure fall was preserved in essential hypertension, in contrast to secondary hypertension in which it was attenuated. In the patients with chronic renal failure the 24-h mean blood pressure was the same as in the controls. Night-time blood pressure was higher among the chronic renal failure patients than in the control group, and the nightly blood pressure fall in both diastolic and systolic blood pressure was reduced. Plasma concentrations of renin activity, arginine vasopressin, atrial natriuretic peptide, aldosterone and endothelin were significantly increased in secondary hypertension and chronic renal failure, compared to essential hypertension and control subjects. Plasma angiotensin II was increased in chronic renal failure compared to essential hypertension and controls. Estimated creatinine clearance and nightly blood pressure dips were inversely correlated in essential and secondary hypertension, i.e. with a decreasing renal function both systolic and diastolic nightly blood pressure dips were gradually attenuated. In the whole group of patients the nightly systolic and diastolic blood pressure dips were negatively correlated to basal plasma renin activity, plasma aldosterone and atrial natriuretic peptide levels, i.e. the higher the basal plasma hormone level the lower the blood pressure dip. In conclusion, patients with essential hypertension have elevated but normally configured 24-h blood pressure profiles, and patients with different kinds of secondary hypertension have elevated 24-h blood pressure profiles and attenuated nightly systolic and diastolic blood pressure falls. The more the renal function is reduced and the more the plasma levels of renin and aldosterone are increased, the more the nocturnal fall in blood pressure is reduced. It is suggested that the attenuated or absent decrease in nocturnal blood pressure in secondary renal hypertension is caused by an abnormally increased secretion of vasoactive hormones and/or by so far unknown factors released from the diseased kidney.

Circadian blood pressure variation versus renal function

Several published reports describe an abnormal circadian blood pressure profile in chronic renal failure subjects. Factors other than renal failure, including age, diagnosis of diabetes mellitus, autonomic dysfunction, and race, also may affect circadian blood pressure profiles. To further elucidate the relationship between renal function and circadian blood pressure variation, we compared day/night circadian blood pressure changes in three groups of male veteran hypertensive patients: group A, creatinine clearance (CC) > 80 mL/min, n = 20; group B, CC 20 to 80 mL/min, n = 19; and group C, CC < 20 mL/min, n = 14. We use postural changes in catecholamines, renin, and aldosterone as a measure of autonomic function. No significant difference in day/night percent change in systolic, diastolic, mean arterial pressure (MAP), or heart rate was seen by renal function group. Regression analysis using age, diagnosis of diabetes mellitus, postural hormonal changes, and creatinine clearance found race to be the only significant predictor of the day/night percent change in MAP (P < 0.05). Compared with whites, black subjects had higher nocturnal heart rates (P = 0.01); smaller day/night heart rate changes (P = 0.03); significantly higher diastolic blood pressure (P = 0.01); and a trend toward smaller day/night change in diastolic blood pressure (P = 0.06). In conclusion, renal function level does not influence day/night blood pressure changes. The blunting or reversal of the normal circadian blood pressure pattern seen in some chronic renal failure hypertensive subjects may be attributable to the association between chronic renal failure and cofactors associated with abnormal circadian blood pressure, including black race and possibly severity of atherosclerosis.