NAFLD as a continuum: from obesity to metabolic syndrome and diabetes

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) has been increasing rapidly. It is nowadays recognized as the most frequent liver disease, affecting a quarter of global population and regularly coexisting with metabolic disorders such as type 2 diabetes, hypertension, obesity, and cardiovascular disease. In a more simplistic view, NAFLD could be defined as an increase in liver fat content, in the absence of secondary cause of steatosis. In fact, the clinical onset of the disease is a much more complex process, closely related to insulin resistance, limited expandability and dysfunctionality of adipose tissue. A fatty liver is a main driver for a new recognized liver-pancreatic α-cell axis and increased glucagon, contributing to diabetes pathophysiology.

MAIN TEXT

This review will focus on the clinical and pathophysiological connections between NAFLD, insulin resistance and type 2 diabetes. We reviewed non-invasive methods and several scoring systems for estimative of steatosis and fibrosis, proposing a multistep process for NAFLD evaluation. We will also discuss treatment options with a more comprehensive view, focusing on the current available therapies for obesity and/or type 2 diabetes that impact each stage of NAFLD.

CONCLUSION

The proper understanding of NAFLD spectrum-as a continuum from obesity to metabolic syndrome and diabetes-may contribute to the early identification and for establishment of targeted treatment.

Indexation of left ventricular mass to body surface area and height to allometric power of 2.7: is the difference limited to obese hypertensives?

Whether left ventricular mass (LVM) should be normalized to different indexes in relation to body size is still debated. We sought to evaluate the prevalence of left ventricular hypertrophy (LVH) defined by different indexation criteria in a cohort of hypertensive subjects categorized according to body mass index (BMI). A total of 2213 essential hypertensive subjects included in the Evaluation of Target Organ Damage in Hypertension (ETODH) were divided in three groups according to BMI thresholds (<25, 25-29.9 and >or=30 kg m(-2)). All patients underwent extensive investigations including quantitative echocardiography. LVH was defined as an LVM index equal to or higher than (1) 125 g m(-2) in men and 110 g m(-2) in women, (2) 51 g m(-2.7) in men and 47 g m(-2.7) in women. Overall, 687 out of 2213 patients (31.0%) were found to have LVH when LVM was indexed to body surface area (BSA) and 1030 (46.5%) when indexed to height(2.7). A total of 845 patients (38.2%) had normal BMI, 954 patients (43.1%) were overweight and 414 (18.7%) were obese. Prevalence rates of LVH in the three groups were 25.1, 31.6, 41.2% by indexation to BSA and 29.9, 50.5, 71.8% by indexation to height(2.7), respectively. LVM indexed to BSA markedly underestimates LVH prevalence in obese as well as overweight hypertensive patients. To avoid a systematic misclassification of cardiovascular risk, LVM should be routinely indexed to height(2.7) in overweight and obese patients representing a large percentage of the hypertensive population.

Reproducibility of nocturnal blood pressure fall in early phases of untreated essential hypertension: a prospective observational study

A number of studies have shown that a smaller than normal nocturnal blood pressure (BP) decrease is associated with cardiovascular disease. However, no large prospective studies have examined the reliability of nocturnal dipping within individuals. The aim of our study was to investigate the short-term variability of nocturnal BP fall in a large cohort of patients with recently diagnosed essential hypertension. In all, 414 uncomplicated never treated hypertensive patients referred to our outpatient hypertension hospital clinic (mean age 46+/-12 years; 257 M, 157 F) prospectively underwent: (1). repeated clinic BP measurements; (2). routine examinations recommended by WHO/ISH guidelines; and (3). ambulatory BP monitoring (ABPM) twice within a 4-week period. Dipping pattern was defined as a reduction in the average systolic and diastolic BP at night greater than 10% compared to average daytime values. Overall, 311 patients (75.1%) showed no change in their diurnal variations in BP. Of the 278 patients who had a dipping pattern on the first ABPM, 219 (78.7%) confirmed this type of profile on the second ABPM, while 59 (21.3%) showed a nondipping pattern. Among 37 dipper patients with >20% of nocturnal systolic BP decrease (extreme dippers), only 16 (43.2%) had this marked fall in BP on the second ABPM. Of the 136 patients who had a nondipping pattern on the first ABPM, 92 (67.6%) confirmed their initial profile on the second ABPM, while 44 (32.4%) did not. Patients with reproducible nondipping profile were older (48+/-12 years) than those with reproducible dipping profile (44+/-12 years, P<0.05). These findings indicate that: (1). short-term reproducibility of nocturnal fall in BP in untreated middle-aged hypertensives is rather limited: overall, one-fourth of patients changed their initial dipping patterns when they were studied again after a few weeks; (2). this was particularly true for extreme dipping and nondipping patterns; (3). abnormalities in nocturnal BP fall, assessed by a single ABPM, cannot be taken as independent predictors of increased cardiovascular risk.

Home blood pressure measurement and its relationship with blood pressure control in a large selected hypertensive population

Despite the impressive increase of home blood pressure monitoring (BPM) among hypertensive patients over the last few years, a limited number of studies have analysed the rate of home BPM and its relationship with target blood pressure (BP) control, in representative samples of the hypertensive population. The objectives of the study were first to evaluate the prevalence of home BPM in a large selected group of treated hypertensive patients referred to our outpatient hypertension hospital clinic. Second, to assess the rate of satisfactory clinic BP control in patients with or without familiarity with home BPM. In all, 1350 consecutive hypertensive patients who attended our hypertension centre during a period of 12 months and were regularly followed up by the same medical team were included in the study. After informed consent all patients underwent the following procedures: (1) accurate medical history (implemented by a structured questionnaire on demographic and clinical characteristics, including questions concerning home BPM); (2) physical examination; (3) clinic BP measurement; (4) routine examinations; and (5) standard 12-lead electrocardiogram. A total of 897 patients (66%) out of 1350 (687 men, 663 women, age 58.6 +/- 12.3 years, mean clinic BP 141 +/- 16/87 +/- 9 mmHg ) were regularly practising home BPM. In this group of patients, home BPM was associated with a significantly greater rate of satisfactory BP control (49.2 vs 45.6%, P < 0.01). Patients performing home BPM were more frequently men (54 vs 46%, P < 0.02 ) younger (average age 57.8 +/- 12.0 vs 60.3 +/- 12.7 years, P < 0.001) and with a higher educational level (defined by more than 8 years of school, 71 vs 55%, P < 0.05) than their counterparts. There were no significant differences in duration of hypertension, hypercholesterolaemia, obesity, smoking, diabetes, associated cardiovascular diseases, left ventricular hypertrophy and compliance with drug treatment. This study demonstrates that: (1) home BPM is widely performed by hypertensive patients managed in a hypertension hospital clinic; (2) this practice is associated with a significantly higher rate of clinic BP control; and (3) age, male gender and educational level influence the adoption of home BPM.

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.

Spatial learning potentiates the stimulation of phosphoinositide hydrolysis by excitatory amino acids in rat hippocampal slices

Stimulation of phosphoinositide (PI) hydrolysis by excitatory amino acids (glutamate and ibotenate) or norepinephrine was potentiated in hippocampal slices from rats trained in an eight-arm radial maze, used as a test of spatial learning. No difference in basal or carbamylcholine-stimulated PI hydrolysis was found between control and trained animals. An increased PI response to excitatory amino acids and norepinephrine was not found in hippocampal slices prepared from animals trained in a shock conditioning avoidance test. These results suggest a possible involvement of specific glutamate receptors coupled with PI hydrolysis in the synaptic mechanisms underlying formation and/or storage of spatial memory.

A Novel Generalized Lipodystrophy-Associated Progeroid Syndrome Due to Recurrent Heterozygous LMNA p.T10I Mutation

BACKGROUND

Lamin A/C (LMNA) gene mutations cause a heterogeneous group of progeroid disorders, including Hutchinson-Gilford progeria syndrome, mandibuloacral dysplasia, and atypical progeroid syndrome (APS). Five of the 31 previously reported patients with APS harbored a recurrent de novo heterozygous LMNA p.T10I mutation. All five had generalized lipodystrophy, as well as similar metabolic and clinical features, suggesting a distinct progeroid syndrome.

METHODS

We report nine new patients and follow-up of two previously reported patients with the heterozygous LMNA p.T10I mutation and compare their clinical and metabolic features with other patients with APS.

RESULTS

Compared with other patients with APS, those with the heterozygous LMNA p.T10I mutation were younger in age but had increased prevalence of generalized lipodystrophy, diabetes mellitus, acanthosis nigricans, hypertriglyceridemia, and hepatomegaly, together with higher fasting serum insulin and triglyceride levels and lower serum leptin and high-density lipoprotein cholesterol levels. Prominent clinical features included mottled skin pigmentation, joint contractures, and cardiomyopathy resulting in cardiac transplants in three patients at ages 13, 33, and 47 years. Seven patients received metreleptin therapy for 0.5 to 16 years with all, except one noncompliant patient, showing marked improvement in metabolic complications.

CONCLUSIONS

Patients with the heterozygous LMNA p.T10I mutation have distinct clinical features and significantly worse metabolic complications compared with other patients with APS as well as patients with Hutchinson-Gilford progeria syndrome. We propose that they be recognized as having generalized lipodystrophy-associated progeroid syndrome. Patients with generalized lipodystrophy-associated progeroid syndrome should undergo careful multisystem assessment at onset and yearly metabolic and cardiac evaluation, as hyperglycemia, hypertriglyceridemia, hepatic steatosis, and cardiomyopathy are the major contributors to morbidity and mortality.

Ambulatory blood pressure, target organ damage and aortic root size in never-treated essential hypertensive patients

The relationship between ambulatory blood pressure (ABP), target organ damage (TOD) and aortic root (AR) size in human hypertension has not been fully explored to date. We investigated the relationship between ABP, different markers of TOD and AR size in never-treated essential hypertensive patients. A total of 519 grade 1 and 2 hypertensive patients (mean age 46+/-12 years) referred for the first time to our outpatient clinic underwent the following procedures: (1) routine examination, (2) 24 h urine collection for microalbuminuria (MA), (3) ambulatory blood pressure monitoring over two 24 h periods within 4 weeks, (4) echocardiography and (5) carotid ultrasonography. AR dilatation was defined by sex-specific criteria (> or =40 mm in men and > or =37 mm in women). AR diameter was increased in 3.7% of patients. Demographic variables (body mass index, age and male gender), average night-time diastolic blood pressure (BP) (but not clinic or average 48 h BP), left ventricular mass index and carotid intima-media (IM) thickness showed an independent association with AR size in both univariate and multivariate analyses. When TOD data were analysed in a categorical way, a stepwise increase in the prevalence of left ventricular hypertrophy (LVH) (I=17.5%, II=27.6%, III=35.8%) and carotid IM thickening (I=20.9%, II=28.8%, III=34.4%), but not in MA (I=6.8%, II=9.1%, III=8.7%) was found with the progression of AR size tertiles. Our results show that (1) AR enlargement in uncomplicated never-treated hypertensive patients has a markedly lower prevalence than traditional markers of cardiac and extracardiac TOD; (2) night-time BP, LVH and carotid IM thickening are independent predictors of AR dimension.

Prevalence and correlates of advanced retinopathy in a large selected hypertensive population. The Evaluation of Target Organ Damage in Hypertension (ETODH) study

OBJECTIVE

To describe the prevalence of advanced retinal microvascular lesions and their associations with cardiac and extracardiac signs of target organ damage (TOD) in a large selected hypertensive population.

METHODS

A total of 2172 non-diabetic untreated and treated uncomplicated essential hypertensives consecutively attending for the first time our hospital outpatient hypertension clinic and included in the Evaluation of Target Organ Damage in Hypertension (ETODH), an observational ongoing registry of hypertension-related TOD, were considered for this analysis. Advanced hypertensive retinopathy was defined by the presence of any of the following lesions: flame-shaped haemorrhages, soft exudates or cotton wool spots and papilloedema. Left ventricular hypertrophy (LVH), carotid structural abnormalities, such as plaques and intima media (IM) thickening, and microalbuminuria were diagnosed according to the 2003 ESH/ESC guidelines criteria.

RESULTS

Among the whole study population, 33 patients (1.5%) were found to have advanced hypertensive retinopathy. Patients with these retinal lesions were similar to those without for age, body mas index, known duration of hypertension, smoking habit, total serum cholesterol, fasting blood pressure and prevalence of antihypertensive treatment; whereas mean systolic and diastolic blood pressures were higher in the former group. The prevalence rates of LVH, carotid plaques, carotid IM thickening and microalbuminuria in patients with and without retinopathy were 57%, 67%, 69%, 19% and 25%, 47%, 44%, 12%, respectively. In a multivariate logistic regression analysis, advanced retinopathy was significantly associated with LVH (OR = 4.0), carotid IM thickening (OR = 2.9), carotid plaques (OR = 2.8), but not with microalbuminuria.

CONCLUSIONS

Our study indicated that: (i) advanced retinopathy is a rare finding in non-diabetic hypertensive patients seen in a specialist setting; (ii) a strong relation exists between retinal microvascular lesions and cardiac and macrovascular markers of TOD.

Awareness of hypertension guidelines in primary care: results of a regionwide survey in Italy

Unsatisfactory blood pressure (BP) control so often described in treated hypertensive populations is also explained by insufficient physicians' awareness of experts' guidelines. We assessed awareness of current recommendations about hypertension management in a general practice setting, using the World Health Organization/International Society of Hypertension (WHO/ISH) 1999 guidelines as reference. In a regionwide survey, a total of 5133 physicians (three-quarters of all active general practitioners in Lombardy, a region of north-western Italy) were contacted by letter and received a multiple choice 10-item questionnaire. Data on physicians' demographic characteristics, information on hypertension prevalence and their perception of BP control among their patients were also requested in an additional form. The number of answers in agreement with WHO/ISH guidelines was used as an awareness measure. This was considered adequate if correct answers to six out of 10 questions, including an appropriate definition of hypertension, were provided. Of the 1256 returned questionnaires (a 24.5% response rate), 1162 were suitable for analysis. The mean score of correct answers was 5.3 points and only 20.1% of the study population correctly answered at least six of the questions (including that on the definition of hypertension in the elderly). Guidelines awareness was negatively related to increase in physicians' age and duration of clinical practice and by the male gender. Finally, the physicians reported a high rate of achieved BP control, and those who were considered to have achieved highest rates (>75%) of control in their patients had a lower rate of adequate knowledge than those who reported less-successful therapeutic results (18 vs 25%, P<0.01), suggesting that they ignored or disregarded the goal BP recommended by the guidelines. This large regional survey shows that a sufficient degree of guidelines awareness is present in a minority of primary-care physicians in the Italian region of Lombardy. Therefore, further efforts are required to intensify information strategies for improving professional education, training and practice organization aimed at achieving therapeutic goals. Physicians with longer duration of clinical practice represent a particularly relevant target group for these interventions.

Behavioral effects of amylin injected intracerebroventricularly in the rat

Amylin is a peptide of pancreatic origin that has been reported to possess high-affinity binding sites in the brain and to affect central dopaminergic and serotonergic neurotransmission. Administered ICV the peptide induced a dose-dependent decrease of locomotor activity without affecting grooming and sniffing. At a dose of 5 micrograms/ rat, it antagonized the hypermotility and stereotypies induced by s.c. injection of amphetamine (2 mg/kg) or of the dopamine receptor agonist, apomorphine (250 mg/kg). Amylin did not change significantly the effect of haloperidol (0.5 mg/kg, s.c.) on locomotor activity, grooming, and sniffing. Moreover, the peptide did not modify the locomotor behavior of animals injected with the 5-HT2 antagonist, ritanserin (2 mg/kg, s.c.). These results suggest that amylin may exert motor effects, probably by interfering with central dopaminergic neurotransmission.

Isolated ambulatory hypertension and changes in target organ damage in treated hypertensive patients

Isolated ambulatory hypertension is a condition characterized by elevated ambulatory but normal clinic blood pressure (BP), and has been reported to be associated with increased cardiovascular risk in untreated subjects. However, little is known about the relationship between this condition and intermediate end points such as target organ damage (TOD) in treated hypertensives. We investigated the impact of isolated ambulatory hypertension on left ventricular hypertrophy (LVH) and microalbuminuria (MA) in a selected sample of treated nondiabetic hypertensives with effective and prolonged clinic BP control (BP<140/90 mmHg). Clinic BP measurements, routine diagnostic procedures, echocardiography and 24-h urine collection for MA, were undertaken in 80 patients (mean age 53+/-8 years) with essential hypertension attending our hospital outpatient centre at baseline and after an average follow-up of 30 months. At follow-up evaluation BP status was assessed by self-measurement of BP and ambulatory BP monitoring (ABPM). At the follow-up visit, 51 out of 80 patients (63.7%) reached a BP control according to ABP (average daytime BP<132/85 mmHg) criteria (group I) whereas the remaining 29 did not (group II); home BP was controlled (BP<135/85 mmHg) in all members of group I and in 86% of group II. In the overall study population, mean Sokolow voltage, LV mass index (LVMI) and urinary albumin excretion (UAE) decreased compared to baseline from 24.1+/-5.0 to 18.9+/-5.1 mm (P<0.05), 115.6+/-24.1 to 97.7+/-21.6 g/m(2) (P<0.01), 11.8+/-23.7 to 5.8+/-14.9 mg/24 h (P<0.05), respectively. The prevalence of ECG LVH, altered LV patterns and MA fell from 7.5 to 2.5% (P=NS), from 45 to 25 (P<0.01) and from 13.7 to 5.1% (P<0.05), respectively. However, when data were analysed separately for the two groups a significant decrease of echo LVH and MA was found only in patients with controlled ABP. LVMI and MA decreased from 117.1+/-23.1 to 95.9+/-22.1 g/m(2) (P<0.01) and 12.8+/-24.7 to 4.1+/-5.7 mg/24 h (P<0.05) in group I, and from 114.1+/-24.8 to 102.3+/-20.3 (P=NS) and 11.9+/-22.1 to 6.3+/-18.1 mg/24 h (P=NS) in group II. In conclusion, in the present study isolated ambulatory hypertension in treated patients is associated with a lack of regression in cardiac and extracardiac TOD, suggesting that a tight BP control throughout the 24 h plays a key role in lowering hypertension-induced structural and functional alterations at cardiac and renal level.

A new method for body fat evaluation, body adiposity index, is useful in women with familial partial lipodystrophy

BMI is a widely used method to evaluate adiposity. However, it has several limitations, particularly an inability to differentiate lean from fat mass. A new method, body adiposity index (BAI), has been recently proposed as a new measurement capable to determine fat excess better than BMI. The aim of this study was to investigate BAI as a mean to evaluate adiposity in a group of women with familial partial lipodystrophy (FPLD) and compare it with BMI. Thirteen women with FLPD Dunnigan type (FPLD2) and 13 healthy volunteers matched by age and BMI were studied. Body fat content and distribution were analyzed by dual X-ray absorptiometry (DXA). Plasma leptin was also measured. BAI was significantly lower in FPLD2 in comparison to control group (24.6 ± 1.5 vs. 30.4 ± 4.3; P < 0.001) and presented a more significant correlation with total fat (%) (r = 0.71; P < 0.001) and fat Mass (g) (r = 0.80; P < 0.001) than BMI (r = 0.27; P = 0.17 for total fat and r = 0.52; P = 0.006 for fat mass). There was a correlation between leptin and BAI (r = 0.57; P = 0.01), [corrected] but not between leptin and BMI. In conclusion, BAI was able to catch differences in adiposity in a sample of FPLD2 patients. It also correlated better with leptin levels than BMI. Therefore, we provide further evidence that BAI may become a more reliable indicator of fat mass content than the currently available measurements.

Prolactin as a protective factor in stress-induced biological changes

The adenohypophyseal hormone prolactin (PRL) is released during stress of physical and psychological nature. In animals, this hormone facilitates adaptive behavior, induces analgesia, and enhances grooming behavior. It also reduces corticosterone secretion and the incidence of gastric ulcers induced by physical stress. It is possible that PRL plays a protective role against stress-induced biological modifications in animals.

Effects of calcitonin gene-related peptide on extrapyramidal motor system

The effects of central administration of calcitonin gene-related peptide (CGRP, 1 or 100 ng/rat) on behavioral and biochemical parameters related to the extrapyramidal motor system were investigated in male rats. The peptide-induced catalepsy occurred only at the dose of 100 ng/rat and hypomotility at both doses used. Calcitonin gene-related peptide increased haloperidol-induced catalepsy and decreased apomorphine-induced hypermotility at the doses of 1 and 100 ng/rat. Although these behaviors are related to dopamine, no significant change of striatal DA or DOPAC concentration were observed after central administration of the peptide. Other neurotransmitters may be directly or indirectly involved in these behavioral effects of CGRP.

Body composition study by dual-energy x-ray absorptiometry in familial partial lipodystrophy: finding new tools for an objective evaluation

BACKGROUND

Familial partial lipodystrophies (FPLD) are clinically heterogeneous disorders characterized by selective loss of adipose tissue, insulin resistance and metabolic complications. Until genetic studies become available for clinical practice, clinical suspicion and pattern of fat loss are the only parameters leading clinicians to consider the diagnosis. The objective of this study was to compare body composition by dual energy X-ray absorptiometry (DXA) in patients with FPLD and control subjects, aiming to find objective variables for evaluation of FPLD.

METHODS

Eighteen female patients with partial lipodystrophy phenotype and 16 healthy controls, matched for body mass index, sex and age were studied. All participants had body fat distribution evaluated by DXA measures. Fasting blood samples were obtained for evaluation of plasma leptin, lipid profile and inflammatory markers. Genetic studies were carried out on the 18 patients selected that were included for statistical analysis. Thirteen women confirmed diagnosis of Dunnigan-type FPLD (FPLD2).

RESULTS

DXA revealed a marked decrease in truncal fat and 3 folds decrease in limbs fat percentage in FPLD2 patients (p <0.001). Comparative analysis showed that ratio between trunk and lower limbs fat mass, characterized as Fat Mass Ratio (FMR), had a greater value in FLPD2 group (1.86 ± 0.43 vs controls 0.93 ± 0.10; p <0.001) and a improved accuracy for evaluating FPLD2 with a cut-off point of 1.2. Furthermore, affected women showed hypoleptinemia (FLPD2 4.9 ± 2.0 vs controls 18.2 ± 6.8; p <0.001), insulin resistance and a more aggressive lipid profile.

CONCLUSION

In this study, assessment of body fat distribution by DXA permitted an objective characterization of FLPD2. A consistent pattern with marked fat reduction of lower body was observed in affected patients. To our knowledge this is the first time that cut-off values of objective variables were proposed for evaluation of FPLD2.

Short-term reproducibility of nocturnal non-dipping pattern in recently diagnosed essential hypertensives

OBJECTIVE

To investigate in a selected population of patients with a recently diagnosed essential hypertension the short-term intrasubject variability of diurnal changes in blood pressure (BP).

METHODS

Two hundred and eight consecutive, recently diagnosed, never treated essential hypertensives (119 men, 89 women, 46 +/- 12 years) underwent 24-h ambulatory BP monitoring (ABPM) twice within 3 weeks. Dipping pattern was defined as a reduction in average systolic and diastolic BP at night greater than 10% compared to average daytime values.

RESULTS

177 subjects (85%) showed no change in their diurnal variations in BP. Of the 159 subjects who had a dipping pattern on first ABPM, 134 (90.6%) confirmed this type of profile on the second ABPM, while 15 (9.4%) showed a non-dipping pattern. Of the 59 subjects who had a non-dipping pattern on the first ABPM, 43 (72.2%) confirmed their initial profile on the second ABPM, while 16 (28.8%) did not.

CONCLUSION

These findings indicate that short-term reproducibility of diurnal changes in BP in early phases of untreated essential hypertension, characterized by a large prevalence of dipping pattern, is overall satisfactory. However, our study underlines that also in this particularly selected population of hypertensives the definition of non-dipping status on the basis of a single ABPM remains unreliable in about one-third of patients.

Effects of cytidine-diphosphocholine on acetylcholine-mediated behaviors in the rat

The phosphatidylcholine precursor, cytidine-diphosphocholine (CDP-choline), was injected intraperitoneally (IP) at the dose of 10 or 20 mg/kg/day for 20 days to 24-month-old male rats of the Sprague-Dawley strain that showed cognitive and motor deficits. The drug was also injected in animals with behavioral alterations induced pharmacologically with a single injection of the cholinergic receptor antagonist, scopolamine, with prenatal exposure to methylazoxymethanol (MAM rats), or with bilateral injections of kainic acid into the nucleus basalis magnocellularis (NBM). Learning and memory capacity of the animals, studied with tests of active and passive avoidance behavior, was improved after treatment with CDP-choline in all experimental groups. An improvement in motor performance and coordination in the rotorod and open field tests was also observed in aged rats. These results indicate that this drug affects central mechanisms involved in cognitive behaviors, probably through a cholinergic action.

Acetylcarnitine reduces the immobility of rats in a despair test (constrained swim)

Male rats forced to swim in a cylinder adopted an immobile posture. Immobility was reduced by acetylcarnitine (5, 10, and 20 mg/kg) and by antidepressant drugs, such as desipramine and iproniazid, injected 24, 5, and, again, 1 h prior to behavioral testing. Acetylcarnitine also potentiated the anti-immobility effect of antidepressant drugs in the despair test. Chronic (10 days) treatment with acetylcarnitine mimicked the effect found after acute administration. It is possible that the action of the acetylcarnitine on the despair test is indicative of an antidepressant activity of this drug that is dependent on a change in the sensitivity of monoamine receptors in the brain.

Effects of acute or chronic administration of risperidone on motor and sexual behavior of male rats

A number of experiments were carried out to explore the behavioral profile of a novel antipsychotic, risperidone, after acute or chronic administration, in a dose range of 0.1-10 mg kg-1. This drug did not affect the acquisition and retention of avoidance behaviors in a dose of 0.1 mg kg-1, either after acute or chronic administration. Higher doses induced a inhibited acquisition and a facilitated extinction (only after chronic treatment) of active avoidance behavior, but no significant effect on the retention of passive avoidance responses. In contrast, haloperidol inhibited the acquisition and facilitated the extinction of active avoidance behavior, and reduced the retention of passive avoidance reaction at the dose of 0.1 mg kg-1 injected either acutely or chronically. Ambulation and rearing of rats rated in an open field was increased by risperidone injected acutely at the dose of 1 mg kg-1. Under the same experimental conditions, grooming appeared to be reduced. In the same test, acute or chronic haloperidol 1 or 10 mg kg-1 inhibited all behavioral items. Furthermore, in contrast to haloperidol, the acute or chronic administration of risperidone in a dose range of 0.1-10 mg kg-1 did not substantially induce catalepsy and did not affect apomorphine-induced stereotypies. Also, the dose of 0.1 mg kg-1 induced a facilitation of male sexual behavior by increasing the frequency and reducing the latency of mountings, intromissions and ejaculations, while haloperidol 1 or 10 mg kg-1 inhibited this behavior. These findings suggest that the pharmacological profile of risperidone differs from that of classical neuroleptics, like haloperidol, probably due to different mechanism or site of action.

Effects of RGH 2202 on cognitive and motor behavior of the rat

The behavioral activity of the thyrotropin-releasing hormone (TRH) analogue, L-6-ketopiperidine-2-carbonyl-leucyl-L-prolinamide (RGH 2202), has been studied in animal models of central neurotransmission disruption. In 24-month-old rats, repeated administration of the peptide (5 or 10 mg/kg/day, injected IP for 20 days) was followed by a facilitated acquisition of active avoidance behavior in the shuttle-box test and retention of passive avoidance reaction in a step-through passive avoidance task. Also, ambulation in an open field was increased and motor performance and co-ordination in the rotorod test was facilitated by the treatment. Scopolamine-induced amnesia was reverted by RGH 2202 in adult rats tested both in active and passive avoidance tasks. Cognitive deficits induced in rats by prenatal manipulation with methylazoxymethanol (MAM) were reduced in adulthood by repeated administration with RGH 2202. These results indicate that the TRH-analogue, RGH 2202 may improve cognitive and motor disturbances in aging or induced by central neurotransmission disruption. It is possible that the peptide is functioning, at least in part, by intervening with the central cholinergic neurotransmission.

Left ventricular concentric remodelling and extracardiac target organ damage in essential hypertension

Left ventricular (LV) concentric remodelling is an adaptive change in cardiac geometry frequently observed in arterial hypertension. This study was addressed to investigate the extent of extracardiac target organ damage (TOD) in patients with LV concentric remodelling. Two groups of never-treated essential hypertensives, 31 with normal LV geometry (group I, relative wall thickness: 0.39) and 31 with LV concentric remodelling (group II, relative wall thickness: 0.47) matched for age, sex, body mass index and mean 24-h systolic blood pressure (BP), were included in the study. They underwent clinical and laboratory examination, 24-h ambulatory BP monitoring (ABPM), 24-h urinary collection for microalbuminuria, non-mydriatic photography of ocular fundi, echocardiography and carotid ultrasonography. In both groups age (I: 51 +/- 11 years; II: 51 +/- 11 years), body mass index (I: 25 +/- 3 kg/m(2); II: 26 +/- 3 kg/m(2)), clinic and 24-h ABPM values (I: 149 +/- 11/95 +/- 8, 142 +/- 11/91 +/- 7 mm Hg; II: 150 +/- 11/98 +/- 9, 142 +/- 12/92 +/- 9 mm Hg) were similar by design. There were no differences between patients with normal LV geometry and with LV concentric remodelling in LVM index (97 +/- 16 vs 99 +/- 16), carotid intima-media thickness (0.7 +/- 0.02 vs 0.7 +/- 0.02) and carotid plaques prevalence (35% vs 35%). Furthermore, no significant differences among the two groups were found in the prevalence of retinal changes and microalbuminuria. These results suggest that in hypertensive patients with similar BP and LVMI levels, LV concentric remodelling is not associated with more prominent TOD.

Effects of vinburnine on experimental models of learning and memory impairments

Retrograde amnesia can be induced experimentally in mice by injecting them with scopolamine (3 mg/kg, IP) or by inducing seizures with pentylenetetrazol (50 mg/kg, IP), and in rats by subjecting them to hypobaric hypoxia (at a barometric pressure of 300 mmHg for 3 min). We have studied the effects of vinburnine (VNB) in these amnesic states compared to vincamine (VNC) and nicergoline (NCG), in order to assess its activity on drug-induced learning and memory impairments. Vinburnine reduced the disrupting effect of both scopolamine and pentylenetetrazol-induced seizures on the retention of a step-through passive avoidance behavior in mice and on the acquisition of shuttle-box active avoidance behavior in rats. This effect was dose-related up to 20 mg/kg, the peak effect dose after IP administration, and more pronounced than that of VNC and NCG in some tests. These results indicate that VNB influences learning and memory processes disrupted by a pharmacological manipulation. In particular, as scopolamine acts as anticholinergic drug, it is possible that VNB mechanism of action includes also a stimulation of acetylcholine neurotransmission.

Effects of calcitonin on morphine tolerance and withdrawal syndrome in morphine physically dependent rats

We investigated the effect of acute or chronic peripheral administration of [Asu1.7]eel-calcitonin on the development of tolerance to the analgesic effect of morphine and on the naloxone-precipitated withdrawal syndrome in morphine-dependent rats. Neither the analgesic effect of acute morphine nor the development of tolerance to the antinociceptive effect of this drug was modified by calcitonin. However, the chronic but not the acute administration of calcitonin attenuated some signs and symptoms of morphine withdrawal.