Increased left ventricular mass index and nocturnal systolic blood pressure in patients with Type 2 diabetes mellitus and microalbuminuria

Nighttime blood pressure and glucose control impacts on left ventricular hypertrophy: The Japan Morning Surge Home Blood Pressure (J-HOP) Study

Several studies investigated the association between nighttime blood pressure (BP) and left ventricular hypertrophy (LVH) in diabetes, but since most of these studies were conducted in diabetes populations only, they did not compare differences in the impact of nighttime BP on LVH in subjects without diabetes. Moreover, data about the impact of glucose control in diabetes on the relationship between nighttime BP and LVH are sparse. We classified 1277 adults (age 64.7 ± 11.8 years) performing ambulatory BP monitoring while enrolled as part of the Japan Morning Surge Home Blood Pressure (J-HOP) study into groups according to the control status of daytime BP (systolic BP [SBP] < 135 mmHg or ≥135 mmHg), nighttime BP (SBP < 120 mmHg or ≥120 mmHg), and diabetes (HbA1c < 7.0% or ≥7.0%). LVH was assessed by echocardiography. LVH according to echocardiographic criteria was identified in 33.7% of the participants. The group with poorly controlled diabetes plus uncontrolled nighttime BP (n = 90) had a 2.1-fold higher risk of LVH compared to the group with controlled nighttime BP and non-diabetes (n = 505) (odds ratio [OR] 2.10, 95% confidence interval [CI]: 1.29-3.44). No association was observed between uncontrolled daytime BP and diabetes for LVH. In the participants with poorly controlled diabetes (n = 146), uncontrolled nighttime BP posed a 3.1-fold higher risk of LVH compared to controlled nighttime BP (OR 3.12, 95%CI: 1.47-6.62). This association was not found in controlled diabetes. Uncontrolled nighttime BP was associated with a risk of LVH, especially among individuals with poorly controlled diabetes.

A Review on Autonomic Functional Assessment in Diabetic Patients

In today's world, science has progressed significantly, yet most people are still unaware of diabetes. Lack of obesity, physical work, and lifestyle changes are the main factors. Diabetes is becoming more common all around the globe. Type 2 diabetes may go unnoticed for years, resulting in serious consequences and high healthcare expenses. The goal of this study is to look at a wide range of studies in which the autonomic function of diabetic people has been studied with the help of various autonomic function tests (AFTs). AFT is a non-invasive approach to assessing patients for testing sympathetic and parasympathetic responses to stimuli. AFT findings give us comprehensive knowledge of the autonomic physiology reactions in normal and in autonomic diseases like diabetes. This review will concentrate on AFTs that are scientifically valid, trustworthy, and clinically beneficial, according to experts.

Blood Pressure Variability and Autonomic Dysfunction

PURPOSE OF REVIEW

This review considers the relationship between abnormal blood pressure (BP) variability and autonomic dysfunction through an attempt to answer questions about its clinical relevance and pertinence to diabetes and cardiovascular autonomic neuropathy (CAN) and which therapeutic measures can lessen its cardiovascular impact.

RECENT FINDINGS

Office, ambulatory, and home BP monitoring identify posture-related, circadian, short-term, and long-term BP variabilities. Abnormal BP variability is a risk marker for organ damage, mortality, and cardiovascular events. Moreover, BP variability changes are common in diabetes and associated with CAN and possibly exacerbated by comorbidities like nephropathy, obstructive sleep apnoea syndrome, and chronic pain. The prognostic role of nondipping and reverse dipping is well documented in diabetes. Some findings suggest the possibility of restoring dipping with the dosage time of antihypertensive agents. Diabetes is a favorable scenario for altered BP variability, which might mediate the harmful effects of CAN. Preliminary data suggest the protective effect of targeting BP variability. However, further longitudinal outcome studies are needed. In the meantime, BP variability measures and practical expedients in antihypertensive treatment should be implemented in diabetes.

Ambulatory blood pressure monitoring in diabetes for the assessment and control of vascular risk

The diagnosis of hypertension and the clinical decisions regarding its treatment are usually based on daytime clinic blood pressure (BP) measurements. However, the correlation between BP levels and target organ damage, cardiovascular (CV) risk, and long-term prognosis, is higher for ambulatory (ABPM) than clinic measurements, both in the general population as well as in patients with diabetes. Moreover, there is consistent evidence in numerous studies that the asleep BP better predicts CV events than either the awake or 24h means. The prevalence of abnormal BP pattern and sleep-time hypertension is extensive in diabetes, often leading to inaccurate diagnoses of hypertension and its therapeutic control in the absence of complete and careful assessment of the entire 24h, i.e., daytime and night-time, BP pattern. Accordingly, ABPM should be the preferred method to comprehensively assess and decide the optimal clinical management of patients with diabetes directed to properly reduce elevated sleep-time BP, which might also lead to a significant reduction of CV events.

Predictors of diabetic nephropathy

Diabetic nephropathy (DN) is a leading cause of morbidity and mortality in diabetic patients representing a huge health and economic burden. Alarming recent data described diabetes as an unprecedented worldwide epidemic, with a prevalence of ∼6.4% of the world population in 2010, while the prevalence of CKD among diabetics was approximately 40%. With a clinical field hungry for novel markers predicting DN, several clinical and laboratory markers were identified lately with the promise of reliable DN prediction. Among those are age, gender, hypertension, smoking, sex hormones and anemia. In addition, eccentric left ventricular geometric patterns, detected by echocardiography, and renal hypertrophy, revealed by ultrasonography, are promising new markers predicting DN development. Serum and urinary markers are still invaluable elements, including serum uric acid, microalbuminuria, macroalbuminuria, urinary liver-type fatty acid-binding protein (u-LFABP), and urinary nephrin. Moreover, studies have illustrated a tight relationship between obstructive sleep apnea and the development of DN. The purpose of this review is to present the latest advances in identifying promising predictors to DN, which will help guide the future research questions in this field. Aiming at limiting this paramount threat, further efforts are necessary to identify and control independent modifiable risk factors, while developing an integrative algorithm for utilization in DN future screening programs.

Circadian pattern of ambulatory blood pressure in hypertensive patients with and without type 2 diabetes

There is strong association between diabetes and increased risk of end-organ damage, stroke, and cardiovascular disease (CVD) morbidity and mortality. Non-dipping (<10% decline in the asleep relative to awake blood pressure [BP] mean), as determined by ambulatory BP monitoring (ABPM), is frequent in diabetes and consistently associated with increased CVD risk. The reported prevalence of non-dipping in diabetes is highly variable, probably due to differences in the study groups (normotensive subjects, untreated hypertensives, treated hypertensives), relatively small sample sizes, reliance only on a single, low-reproducibility, 24-h ABPM evaluation per participant, and definition of daytime and nighttime periods by arbitrary selected fixed clock-hour spans. Accordingly, we evaluated the influence of diabetes on the circadian BP pattern by 48-h ABPM (rather than for 24 h to increase reproducibility of results) during which participants maintained a diary listing times of going to bed at night and awakening in the morning. This cross-sectional study involved 12 765 hypertensive patients (6797 men/5968 women), 58.1 ± 14.1 (mean ± SD) yrs of age, enrolled in the Hygia Project, designed to evaluate prospectively CVD risk by ABPM in primary care centers of northwest Spain. Among the participants, 2954 (1799 men/1155 women) had type 2 diabetes. At the time of study, 525/3314 patients with/without diabetes were untreated for hypertension, and the remaining 2429/6497 patients with/without diabetes were treated. Hypertension was defined as awake systolic (SBP)/diastolic (DBP) BP mean ≥135/85 mm Hg, or asleep SBP/DBP mean ≥120/70 mm Hg, or BP-lowering treatment. Hypertensive patients with than without diabetes were more likely to be men and of older age, have diagnoses of microalbuminuria, proteinuria, chronic kidney disease, obstructive sleep apnea, metabolic syndrome, and/or obesity, plus higher glucose, creatinine, uric acid, and triglycerides, but lower cholesterol and estimated glomerular filtration rate. In patients with diabetes, ambulatory SBP was significantly elevated (p < .001), mainly during the hours of nighttime sleep and initial hours after morning awakening, independent of presence/absence of BP-lowering treatment. Ambulatory DBP, however, was significantly higher (p < .001) in patients without diabetes, mainly during the daytime. Differing trends for SBP and DBP between groups resulted in large differences in ambulatory pulse pressure (PP), it being significantly greater (p < .001) throughout the entire 24 h in patients with diabetes, even after correcting for age. Prevalence of non-dipping was significantly higher in patients with than without diabetes (62.1% vs. 45.9%; p < .001). Largest difference between groups was in the prevalence of the riser BP pattern, i.e., asleep SBP mean greater than awake SBP mean (19.9% vs. 8.1% in patients with and without diabetes, respectively; p < .001). Elevated asleep SBP mean was the major basis for the diagnosis of hypertension and/or inadequate BP control among patients with diabetes; thus, among the uncontrolled hypertensive patients with diabetes, 89.2% had nocturnal hypertension. Our findings document significantly elevated prevalence of a blunted nocturnal BP decline in hypertensive patients with diabetes. Most important, prevalence of the riser BP pattern, associated with highest CVD risk among all possible BP patterns, was more than twice as prevalent in diabetes. Patients with diabetes also presented significantly elevated ambulatory PP, reflecting increased arterial stiffness and enhanced CVD risk. These collective findings indicate that diabetes should be included among the clinical conditions for which ABPM is recommended for proper CVD risk assessment.

Administration-time differences in effects of hypertension medications on ambulatory blood pressure regulation

Specific features of the 24-h blood pressure (BP) pattern are linked to progressive injury of target tissues and risk of cardiovascular disease (CVD) events. Several studies have consistently shown an association between blunted asleep BP decline and risk of fatal and nonfatal CVD events. Thus, there is growing focus on ways to properly control BP during nighttime sleep as well as during daytime activity. One strategy, termed chronotherapy, entails the timing of hypertension medications to endogenous circadian rhythm determinants of the 24-h BP pattern. Significant and clinically meaningful treatment-time differences in the beneficial and/or adverse effects of at least six different classes of hypertension medications, and their combinations, are now known. Generally, calcium channel blockers (CCBs) are more effective with bedtime than morning dosing, and for dihydropyridine derivatives bedtime dosing significantly reduces risk of peripheral edema. The renin-angiotensin-aldosterone system is highly circadian rhythmic and activates during nighttime sleep. Accordingly, evening/bedtime ingestion of the angiotensin-converting enzyme inhibitors (ACEIs) benazepril, captopril, enalapril, lisinopril, perindopril, quinapril, ramipril, spirapril, trandolapril, and zofenopril exerts more marked effect on the asleep than awake systolic (SBP) and diastolic (DBP) BP means. Likewise, the bedtime, in comparison with morning, ingestion schedule of the angiotensin-II receptor blockers (ARBs irbesartan, olmesartan, telmisartan, and valsartan exerts greater therapeutic effect on asleep BP, plus significant increase in the sleep-time relative BP decline, with the additional benefit, independent of drug terminal half-life, of converting the 24-h BP profile into a more normal dipping pattern. This is the case also for the bedtime versus upon-awakening regimen of combination ARB-CCB, ACEI-CCB, and ARB-diuretic medications. The chronotherapy of conventional hypertension medications constitutes a new and cost-effective strategy for enhancing the control of daytime and nighttime SBP and DBP levels, normalizing the dipping status of their 24-h patterning, and potentially reducing the risk of CVD events and end-organ injury, for example, of the blood vessels and tissues of the heart, brain, kidney, and retina.

Effects of restricted fructose access on body weight and blood pressure circadian rhythms

High-fructose diet is known to produce cardiovascular and metabolic pathologies. The objective was to determine whether the timing of high fructose (10% liquid solution) intake affect the metabolic and cardiovascular outcomes. Male C57BL mice with radiotelemetric probes were divided into four groups: (1) 24 h water (control); (2) 24 h fructose (F24); (3) 12 h fructose during the light phase (F12L); (4) 12 h fructose during the dark phase (F12D). All fructose groups had higher fluid intake. Body weight was increased in mice on restricted access with no difference in total caloric intake. Fasting glycemia was higher in groups with restricted access. F24 mice showed a fructose-induced blood pressure increase during the dark period. Blood pressure circadian rhythms were absent in F12L mice. Results suggest that the timing of fructose intake is an important variable in the etiology of cardiovascular and metabolic pathologies produced by high fructose consumption.

Fibrinogen, Lp(a), Microalbuminuria and Left Ventricular Mass Index: Cardiovascular Disease Risk factors in Diabetes

The present work was undertaken to study interrelation of Fibrinogen, Lp(a) and LVMI in Type II diabetes patients with or without nephropathy. 100 Type II Diabetic patients attending OPD/IPD of DMC&H, Ludhiana were included. They were divided in two groups. Group I: 50 patients without microalbuminuria (MAU). Group II: 50 patients with MAU. Fibrinogen (Clauss method), Lp(a) and MAU were estimated on Multichannel Autoanalyzer Hitachi-911 (Roche). LVMI was estimated by echocardiography using formula of Devereux and Reicheck. Type II diabetes patients with MAU had significantly raised levels of Fibrinogen, Lp(a), and LVMI as compared to normoalbuminuric diabetics (P < 0.01). Group II patients had positive correlation between Lp(a) and LVMI but no relation between Fibrinogen and LVMI. MAU, marker of microangiopathy, is associated with higher Fibrinogen and Lp(a) levels. This becomes basis of increase cardiovascular risk as demonstrated by higher mean LVMI in Group II patients.

Renal involvement and left ventricular hypertrophy are novel risk factors for morbidity and mortality in diabetes mellitus

Diabetes mellitus and its complications are major causes of morbidity and mortality. Traditionally hypertension and poor diabetic control have been considered to be major risk factors for the development of cardiac involvement. This review will examine two novel risk factors, namely renal involvement and left ventricular hypertrophy. Renal involvement is manifested by increased excretion of protein in the urine and/or decreasing renal function. Several large studies have shown that both these factors are significant risk factors for cardiac involvement and increased mortality both in diabetic and non-diabetic subjects. There is strong evidence to suggest an association between renal and cardiac involvement. Cardiac hypertrophy is an important risk factor for the development of cardiac involvement. It is generally assumed that ventricular hypertrophy is a result of hypertension. However, it has been shown to be associated with metabolic disorders such as central obesity, diabetes mellitus and hypercholesterolemia, even in the absence of hypertension. The prevalence of ventricular hypertrophy is increased in patients with diabetes mellitus, especially in the presence of renal involvement. Diabetic patients with renal involvement and cardiac hypertrophy have also been shown to have an increased risk for developing cardiac complications and having an increased mortality rate. Thus these two risk factors are important in the prognosis of the diabetic patient. Follow-up of the diabetic patient should include careful examination for the presence of proteinuria, reduced renal function and left ventricular hypertrophy in the hope that treatment of these factors may reduce morbidity and mortality.

Circadian rhythms in blood pressure regulation and optimization of hypertension treatment with ACE inhibitor and ARB medications

Specific features of the 24 h-blood pressure (BP) pattern are linked to the progressive injury of target tissues and risk of cardiac and cerebrovascular events. Studies have consistently shown an association between blunted asleep BP decline and increased incidence of fatal and nonfatal cardiovascular events. Thus, there is growing interest in how to achieve better BP control during nighttime sleep in addition to during daytime activity, according to the particular requirements of each hypertension patient. One approach takes into consideration the endogenous circadian rhythm-determinants of the 24-h BP pattern, especially, the prominent day-night variation of the renin-angiotensin-aldosterone system, which activates during nighttime sleep. A series of clinical studies have demonstrated a different effect of the angiotensin-converting enzyme (ACE) inhibitors benazepril, captopril, enalapril, lisinopril, perindopril, quinapril, ramipril, spirapril, and trandolapril when routinely ingested in the morning vs. the evening. In most cases, the evening schedule exerts a more marked effect on the asleep than awake BP means. Similarly, a once-daily evening, in comparison to morning, ingestion schedule of the angiotensin receptor blockers (ARBs) irbesartan, olmesartan, telmisartan, and valsartan exerts greater therapeutic effect on asleep BP, plus significant increase in the sleep-time relative BP decline, with normalization of the circadian BP profile toward a more dipping pattern, independent of drug terminal half-life. Chronotherapy, the timing of treatment to body rhythms, is a cost-effective means of both individualizing and optimizing the treatment of hypertension through normalization of the 24-h BP level and profile, and it may constitute an effective option to reduce cardiovascular risk.

Circadian pattern of ambulatory blood pressure in untreated hypertensive patients with and without metabolic syndrome

There is a strong association between metabolic syndrome (MS) and increased risk of end-organ damage, cardiovascular disease, stroke, and cardiovascular mortality. Moreover, non-dipping (<10% decline in the asleep relative to the awake blood pressure [BP] mean) and elevated ambulatory pulse pressure (PP), among other factors related to the circadian BP pattern, have also been associated with increased cardiovascular morbidity and mortality. This cross-sectional study investigated the circadian BP pattern in 2,045 non-diabetic untreated patients with uncomplicated essential hypertension (941 men/1,099 women), 48.7+/-11.9 yrs of age, classified by the presence or absence of MS. BP was measured by ambulatory monitoring for 48 consecutive hours to substantiate reproducibility of the dipping pattern. Physical activity was simultaneously monitored every min by wrist actigraphy to accurately calculate mean BP when awake and asleep for each subject. MS was present in 40.7% of the patients. Patients with MS were characterized by a significantly higher 24 h mean of systolic BP and a lower diastolic BP compared to patients without MS. Accordingly, ambulatory PP was significantly elevated the entire 24 h in MS patients. The prevalence of an altered non-dipper BP profile was significantly higher in MS patients (48.4 vs. 36.1% in patients without MS, p < 0.001). MS patients were characterized, among other risk factors, by significantly higher uric acid, fibrinogen, leukocyte count, hemoglobin and globular sedimentation velocity, plus lower estimated glomerular filtration rate. Apart from corroborating the significant increased prevalence of a blunted nocturnal BP decline in MS, this study documents ambulatory PP is higher in MS, without differences between groups in mean arterial pressure. This elevated PP might reflect increased arterial stiffness in MS. MS patients were also characterized by elevated values of relevant markers of cardiovascular risk, including fibrinogen and globular sedimentation velocity. These collective findings indicate that MS should be included among the clinical situations in which ambulatory BP monitoring is recommended.

Early signs of left ventricular dysfunction in adolescents with type 1 diabetes mellitus: the importance of impaired circadian modulation of blood pressure and heart rate

Diabetic cardiomyopathy is a well-defined complication of diabetes that occurs in the absence of ischemic heart disease or hypertension. Moreover impaired circadian blood pressure (BP) variation has been associated with autonomic dysfunction. The aim of our study was to evaluate diurnal BP fluctuations and autonomic function and their association with left ventricular function in adolescents with Type 1 diabetes mellitus (T1DM). In 48 normotensive, normoalbuminuric diabetic adolescents, with a mean (+/-SD) age of 17.3 (+/-4.1) yr and a mean (+/-SD) diabetes duration of 8.5 (+/-3.3) yr, 24-h ambulatory BP was recorded. Moreover 24-h heart rate (HR) monitoring was performed. Myocardial structural parameters were studied by echocardiogram. Left ventricular end-diastolic (EDDLV) and end-systolic diameters (ESDLV) were estimated and left ventricular mass index (LVMI) was calculated using the Devereux formula. The patients were divided into 2 groups according to the absence of decrease (non-dippers) or the decrease (dippers) of nocturnal diastolic BP (DBP). The non-dippers showed, in comparison with the dippers, reduced mean 24-h HR (79.6 vs 84.0 beats/min, p=0.05) and reduced mean day-time HR (81.3 vs 86.0 beats/min, p=0.05). The nondippers also presented greater ESDLV (28.7 vs 25.9 mm, p=0.001) and EDDLV (47.8 vs 45.1 mm, p=0.040), and LVMI (90.2 vs 78.3 g/m2, p=0.044), in comparison with the dippers. During stepwise multiple regression, the most important variables affecting LVMI were mean HR (day): (b=-0.40, p=0.001), high frequency domain variable of HR variability (b=0.38, p=0.016) and glycosylated hemoglobin (b=0.67, p=0.001). In conclusion, we found that a group of normotensive diabetic adolescents with impaired nocturnal BP reduction, also had autonomic dysfunction, together with impaired left ventricular function. These findings suggest that there is a close relationship between autonomic function and left ventricular remodeling in patients with T1DM, which may be attributed to altered diurnal BP profile, autonomic neuropathy and poor glycemic control.

Circadian variation of blood pressure: the basis for the chronotherapy of hypertension

Ambulatory blood pressure (BP) measurements present a close correlation with target organ damage and cardiovascular events, including myocardial infarction, stroke and cardiovascular mortality. With the use of this measurement technique, a significant circadian variation has been shown to characterize BP. This circadian BP variation, although affected by a variety of external factors, represents the influence of internal factors such as ethnicity, gender, autonomic nervous system tone, vasoactive hormones, and hematologic and renal variables. In most individuals, BP presents a morning increase, a small post-prandial valley, and a deeper descent during nocturnal rest. However, under certain pathophysiological conditions, the nocturnal BP decline may be reduced or even reversed. This cannot be determined by traditional clinical or home BP assessments. Subjects with a diminished nocturnal BP decline (non-dipper pattern) have a significantly worse prognosis than the ones with a normal dipper pattern. In particular, the non-dipper circadian BP pattern represents a risk factor for left ventricular hypertrophy, microalbuminuria, cerebrovascular disease, congestive heart failure, vascular dementia and myocardial infarction. The normalization of the circadian BP pattern to a dipper profile is a novel therapeutic goal, and accumulating medical evidence suggests this can delay the progression towards the renal and cardiovascular pathology known to be a consequence of the non-dipper BP pattern. The features of the circadian BP profile have direct implications for improving the drug-delivery of antihypertensive therapies as well as the qualification of patients for medication trials and assessment.

Relationship between urinary albumin excretion and left ventricular mass with mortality in patients with type 2 diabetes

Increased urinary albumin excretion (UAE) has been shown to be associated with increased cardiovascular mortality in patients with type 2 diabetes. This study evaluated whether the association between UAE and cardiovascular mortality in 880 patients with type 2 diabetes was related to an increase in left ventricular mass (LVM). LVM was estimated by electrocardiographic index, namely adjusted Cornell voltage. LVM was significantly different between the stages of albuminuria (8.17 +/- 0.12 in normoalbuminuric, 9.05 +/- 0.21 in microalbuminuric, and 10.30 +/- 0.30 in overt albuminuric patients; P < 0.001). There also was a positive correlation between log UAE and LVM independent of BP. During 5 yr of follow-up, survivors had significantly lower LVM (8.62 +/- 0.11 versus 9.88 +/- 0.45; P = 0.0140) and lower UAE (154.60 +/- 16.53 versus 446.62 +/- 114.11; P = 0.0003) than nonsurvivors. The results indicate that patients with type 2 diabetes and increased UAE should be evaluated for increased LVM as an important and potentially reversible cardiovascular risk factor.

Hyperglycemia and nocturnal systolic blood pressure are associated with left ventricular hypertrophy and diastolic dysfunction in hypertensive diabetic patients

Background

The aim of this study was to determine if hypertensive type 2 diabetic patients, when compared to patients with essential hypertension have an increased left ventricular mass index (LVMI) and a worse diastolic function, and if this fact would be related to 24-h pressoric levels changes.

Methods

Ninety-one hypertensive patients with type 2 diabetes mellitus (DM) (group-1 [G1]), 59 essential hypertensive patients (group-2 [G2]) and 26 healthy controls (group-3 [G3]) were submitted to 24-h Ambulatory Blood Pressure Monitoring (ABPM) and echocardiography (ECHO) with Doppler. We calculated an average of fasting blood glucose (AFBG) values of G1 from the previous 4.2 years and a glycemic control index (GCI) (percentual of FBG above 200 mg/dl).

Results

G1 and G2 did not differ on average of diurnal systolic and diastolic BP. However, G1 presented worse diastolic function and a higher average of nocturnal systolic BP (NSBP) and LVMI (NSBP = 132 ± 18 vs 124 ± 14 mmHg; P < 0.05 and LVMI = 103 ± 27 vs 89 ± 17 g/m²; P < 0.05, respectively). In G1, LVMI correlated with NSBP (r = 0.37; P < 0.001) and GCI (r = 0.29; P < 0.05) while NSBP correlated with GCI (r = 0.27; P < 0.05) and AFBG (r = 0.30; P < 0.01). When G1 was divided in tertiles according to NSBP, the subgroup with NSBP≥140 mmHg showed a higher risk of LVH. Diabetics with NSBP≥140 mmHg and AFBG>165 mg/dl showed an additional risk of LVH (P < 0.05; odds ratio = 11). In multivariate regression, both GCI and NSBP were independent predictors of LVMI in G1.

Conclusion

This study suggests that hyperglycemia and higher NSBP levels should be responsible for an increased prevalence of LVH in hypertensive patients with Type 2 DM.

Association of low-grade urinary albumin excretion with left ventricular hypertrophy in the general population: the MONICA/KORA Augsburg Echocardiographic Substudy

BACKGROUND

Even mild renal dysfunction is a predictor of cardiovascular morbidity. We investigated whether sub-threshold microalbuminuria or mildly decreased estimated glomerular filtration rate (eGFR) are related to left ventricular hypertrophy (LVH) in the general population.

METHODS

Urinary albumin-to-creatinine ratio (UACR) served to determine albuminuria, eGFR was estimated using modification of diet in renal disease (MDRD) formula, and LV geometry was assessed echocardiographically in the third MONItoring of trends and determinants in CArdiovascular disease/Cooperative Health Research in the Augsburg Area (MONICA/KORA) Augsburg survey (n = 1187).

RESULTS

The prevalence of LVH increased in parallel with UACR. Compared with the first tertile of this normal population, the age, systolic blood pressure (SBP), body mass index, gender and diabetes adjusted odds ratio (OR) for LVH was elevated already in the second (4.32-8.75 mg/g in men; 4.60-9.48 mg/g in women; OR: 2.10, P = 0.001) as well as in the third UACR-tertile (> or =8.76 mg/g in men; > or =9.49 mg/g in women; OR: 1.63, P = 0.035). Likewise, adjusted SBP increased with UACR-tertiles [129 vs 132 (P = 0.036) and 137 mmHg (P < 0.001) in the first, second and third tertile, respectively], whereas diastolic blood pressure was significantly elevated only in the third UACR-tertile [79 vs 80 and 81 mmHg (P = 0.002) in the tertiles, respectively]. In contrast, tertiles of eGFR or mildly impaired eGFR (<90 ml/min/1.73 m(2)) were not associated with the prevalence of LVH in multivariate models.

CONCLUSIONS

At the general population level, even low-grade albuminuria is associated with LVH. Thus, the conventional UACR-threshold of microalbuminuria (30 mg/g) may be too conservative given that end organ damage such as LVH is observed with increased frequency at much lower levels.

Left ventricular hypertrophy in normoalbuminuric type 2 diabetic patients not taking antihypertensive treatment

BACKGROUND

Left ventricular hypertrophy (LVH) is an independent risk factor for myocardial ischaemia, cardiac arrhythmia, sudden death, and heart failure, all common findings in patients with type 2 diabetes.

AIM

To determine the prevalence of, and risk factors for, LVH in normoalbuminuric type 2 diabetic patients not taking antihypertensive treatment.

DESIGN

Cross-sectional study.

METHODS

From 1994 to 1998, M-mode echocardiography was performed by one experienced examiner in 262 consecutive, normoalbuminuric Caucasian type 2 diabetic patients, all with blood pressure <160/95 mmHg and not taking antihypertensive medication. Mean +/- SD age was 54 +/- 10 years, 109 were women, and median known duration of diabetes was 4 (range 1-28) years. Body mass index (BMI) was 28 +/- 5 kg/m(2), and blood pressure 134 +/- 13/79 +/- 8 mmHg, all means +/- SD. Median urinary albumin excretion rate was 9 (range 2-30) mg/24 h.

RESULTS

The prevalence of LVH indexed to height(2.7) was 43% (95%CI 38-50%), and was similar in men and women. BMI, HbA(1c) and log urinary albumin excretion were significantly associated with left ventricular hypertrophy in a logistic regression model, whereas sex, age, known duration of diabetes and blood pressure were not. Similar results were obtained for left ventricular mass index.

DISCUSSION

LVH was frequent in our normoalbuminuric type 2 diabetic patients not taking antihypertensive treatment. Several potentially modifiable risk factors, such as raised BMI, poor glycaemic control and elevated urinary albumin excretion rate, were associated with LVH.

Adverse effects of left ventricular hypertrophy in the reduction of endpoints in NIDDM with the angiotensin II antagonist losartan (RENAAL) study

AIMS/HYPOTHESIS

We explored the impact of baseline left ventricular hypertrophy (LVH) and losartan treatment on renal and cardiovascular (CV) events in 1,513 patients from the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) trial, which studied the effects of losartan on the progression of renal disease and/or death in patients with type 2 diabetes and nephropathy.

MATERIALS AND METHODS

LVH was assessed using ECG criteria (Cornell product and/or Sokolow-Lyon voltage). The risk of renal or CV events was determined by a proportional hazards model fit with treatment allocation and presence of LVH. Covariates at baseline included age, sex, systolic BP, mean arterial pressure, pulse, proteinuria, serum creatinine, albumin and haemoglobin.

RESULTS

A total of 187 subjects (12%) had LVH at baseline. Treatment with losartan resulted in a significant decrease in the Cornell product (-6.2%) and Sokolow-Lyon voltage (-6.3%). LVH was shown to be significantly associated with the primary endpoint, which was a composite of doubling of serum creatinine (DSCR), endstage renal disease (ESRD) or death (hazard ratio [HR]=1.44, p=0.011), as well as with the composite renal endpoint of DSCR/ESRD (HR=1.42, p=0.031) and CV events (HR=1.68, p=0.001). Losartan treatment of patients with LVH decreased the CV as well as renal risk to a level similar to that of patients without LVH.

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes and nephropathy, LVH is associated with significantly increased risk of CV events and the progression of kidney disease. Importantly, in patients with LVH, losartan reduced the CV as well as the renal risk to a level similar to that seen in subjects without LVH.

Left ventricular dysfunction in hypertensive patients with Type 2 diabetes mellitus

AIMS

To characterize left ventricular function in hypertensive patients with Type 2 diabetes and normal ejection fraction, and to relate these findings to pathogenic factors and clinical risk markers.

METHODS

We examined 70 hypertensive patients with Type 2 diabetes mellitus with ejection fraction > 0.55 and fractional shortening > 0.25, all without any cardiac symptoms. Thirty-five non-diabetic subjects served as control subjects. Left ventricular longitudinal function was examined by tissue Doppler derived myocardial strain rate and peak systolic velocities.

RESULTS

Hypertensive patients with diabetes had a significantly higher systolic strain rate (-1.1 +/- 0.3 s(-1) vs. -1.6 +/- 0.3 s(-1), P < 0.001) and lower systolic peak velocities (3.3 +/- 1.0 vs. 5.6 +/- 1.0 cm/s, P < 0.001) compared with control subjects. Myocardial systolic strain rate correlated significantly to left ventricular mass (r = 0.40, P < 0.01) and to both HbA1c (r = 0.43, P < 0.01), and fructosamine (r = 0.40, P < 0.01), but was not related to serum levels of carboxymethyllysine, albuminuria, blood pressure (dipping/non-dipping), or oral hypoglycaemic therapy. Patients with diastolic dysfunction had significantly higher levels of urine albumin [21.0 (5-2500) mg/l, vs. 9.5 (1-360), P < 0.01], heart rate (78 +/- 13 vs. 67 +/- 10 b.p.m., P < 0.005), and seated diastolic blood pressure (85 +/- 6 vs. 81 +/- 7 mmHg, P < 0.05) and non-dipping diastolic blood pressure was more frequent.

CONCLUSIONS

Long axis left ventricular systolic function was significantly decreased in hypertensive patients with Type 2 diabetes mellitus, and is associated with hyperglycaemia and left ventricular hypertrophy. Diastolic dysfunction was closely related to increased diastolic blood pressure, non-dipping and increased urinary albumin excretion.

Thiazolidinediones and congestive heart failure--exacerbation or new onset of left ventricular dysfunction?

BACKGROUND

Patients with diabetes mellitus have a high incidence of coronary heart disease and congestive heart failure (CHF). Thiazolidinediones (TZD) are a new class of pharmacological agents for the treatment of Type 2 diabetes mellitus, which have many beneficial cardiovascular effects. Peripheral oedema and weight gain have been reported in 4.8% of subjects on TZDs alone, with a higher incidence noted in those receiving combination insulin therapy (up to 15%), but there is limited data on the occurrence of CHF.

METHODS AND RESULTS

In this paper, we report on six cases of TZD-induced fluid retention with symptoms and signs of peripheral oedema and/or CHF that occurred in subjects attending our diabetic clinic. The predominant finding in all cases was of diastolic dysfunction. All subjects were obese and hypertensive, with 5/6 having the additional risk factor of LVH, 5/6 subjects had microvascular complications, whilst 3/6 were also on insulin therapy.

CONCLUSION

We suggest that obese, hypertensive diabetics may benefit from echocardiographic screening prior to commencement of TZDs, as these agents may exacerbate underlying undiagnosed left ventricular diastolic dysfunction.

Modeling the circadian variability of ambulatorily monitored blood pressure by multiple-component analysis

The use of a set of new end points derived from ambulatory blood pressure monitoring (ABPM), in addition to the blood pressure (BP) values themselves, has been advocated to improve the sensitivity and specificity in diagnosing hypertension and to evaluate a person's response to treatment. An adequate estimation of rhythmic parameters depends, however, on the ability to describe properly the circadian pattern of BP variability. The purpose of this study was to identify a simple model that could characterize sufficiently well the circadian pattern of BP in normotensive healthy volunteers sampled by ambulatory monitoring. We studied 278 clinically healthy Spanish adults (184 men), 22.7 +/- 3.3 yr of age, without medical history of hypertension and mean BP from ambulatory profiles always below 135/85 mmHg for systolic/diastolic BP, who underwent sequential ABPM providing a total of 1115 series of BPs and heart rates (HRs), sampled on each occasion at 0.5h intervals for 48 h. Subjects were assessed while adhering to their usual diurnal activity and nocturnal sleep routine, without restrictions but avoiding the use of medication. The circadian rhythm in BP and HR for each subject was established by multiple-component analysis. A statistically significant 24h component is documented for 97% of the BP profiles, with a significant second (12h) harmonic documented in 65% of the profiles. Other ultradian harmonic components were significant in less than 20% of the profiles. A statistically significant increase in the coefficient of determination (percent of overall variability explained by the function fitted to the data) was only obtained after including the periods of 24 and 12 h for BP, and periods of 24, 12, and 6 h for HR in the model components. Although other ultradian components can be demonstrated as statistically significant in a small percent of subjects, a rather simple model including only the two first harmonics of the 24h period describes sufficiently well, at the specified sampling rate, the circadian pattern of BP in normotensive subjects. Departure from this model could characterize overt pathology, as recently demonstrated in the diagnosis of preeclampsia.

Left ventricular mass index increases in proportion to the progression of diabetic nephropathy in Type 2 diabetic patients

The aim of our cross-sectional case-control study was to evaluate the mechanism of increased cardiac morbidity and mortality in Type 2 diabetic patients with normo-, micro-, and macroalbuminuria. Twenty-nine Type 2 diabetic patients with normoalbuminuria (group N), 19 patients with microalbuminuria (group M1), and seven patients with macroalbuminuria (group M2) were investigated. Groups were not significantly different concerning age, sex and diabetes duration. All patients took their normal medication throughout the study and had no clinical evidence of heart disease. Left ventricular mass index (LVMI) and systolic function were determined by echocardiography. As to the elevation of urinary albumin excretion levels, LVMI was significantly elevated, 101.4+/-20 gm(-2) of group N, 119.5+/-29 gm(-2) of group M1, and 141.9+/-27 gm(-2) of group M2. The prevalence of left ventricular hypertrophy (LVH) was significantly higher in group M2 (100%), and M1 (58%), as compared with group N (24%), but was not significantly different between groups M1 and M2. The body mass index and systolic blood pressure were significant independent predictors of LVMI by multiple regression analysis. In conclusion, the mechanism of the link between albuminuria and cardiovascular mortality was suggested to be LVH.