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Biomedical subjects

M A Dichiara

Publications and source records attributed to M A Dichiara.

12 recordsLinked to original sources
PubMed1995

Heredity and obesity-associated hypertension: impact of hormonal characteristics and left ventricular mass.

OBJECTIVES: To investigate the influence of heredity on obesity-associated hypertension, we evaluated casual and 24-h blood pressure, left ventricular mass and some metabolic and hormonal measurements in normotensive obese subjects. DESIGN: Healthy, normotensive obese subjects (n = 81) with positive or negative family history of hypertension were studied. Both groups were also subdivided according to a positive or a negative family history of obesity. Accordingly, 45 obese subjects had a positive family history of hypertension, 25 of these having a positive (subgroup A) and 20 having a negative family history of obesity (subgroup B). The other 36 obese subjects had a negative family history of hypertension, 19 of these having a positive (subgroup C) and 17 having a negative family history of obesity (subgroup D). METHODS: Casual and 24-h systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) were evaluated. Serum fasting blood sugar, total cholesterol and triglycerides levels, urinary excretion of sodium, immunoreactive fasting insulin, plasma ANF levels, plasma renin activity (PRA), plasma aldosterone level, plasma adrenaline and noradrenaline levels and echocardiographic total left ventricular mass (LVM) and LVM:height ratio were also calculated. RESULTS: Twenty-four-hour DBP, 24-h MBP, LVM, LVM:height ratio, total cholesterol and PRA values were significantly higher in normotensive obese offspring of hypertensive parents than in obese offspring of normotensive parents. Twenty-four-hour DBP and MBP, LVM, LVM:height ratio, insulin level, insulin:glucose ratio and PRA were significantly higher in subgroup A than in subgroup B. Fasting blood sugar level, 24-h DBP and MBP, insulin level, insulin:glucose ratio, PRA, noradrenaline, adrenaline and plasma aldosterone levels were significantly higher in subgroup C than in subgroup D. Multivariate analysis also indicated that 24-h MBP and PRA levels were significantly influenced by the association between a positive family history of hypertension and obesity. CONCLUSIONS: The present results suggest that a family history of obesity might increase the risk of developing hypertension in obese subjects. An elevated PRA may precede the development of hypertension in obese subjects who are at risk for developing hypertension.

Adult↗
PubMed1995

Central obesity and hypertension: pathophysiologic role of renal haemodynamics and function.

OBJECTIVE: To investigate the role of alterations in renal haemodynamics and function and in plasma renin activity on obesity-induced hypertension. DESIGN: Renal haemodynamics and function, salt-regulating hormones and structural cardiac parameters were evaluated in 20 lean normotensives and in 64 obese subjects with central or peripheral fat distribution, 43 of them were normotensives and 21 of them were hypertensives. Obesity and central fat distribution were defined according to sex-specific 85th percentile respectively of Body Mass Index (BMI) and Waist to Hip Ratio (WHR). MEASUREMENTS: Serum immunoreactive insulin (IRI), plasma renin activity (PRA), plasma aldosterone (PA), microalbuminuria (UAE) and 24h urinary excretion of sodium (NaU) were evaluated by current methods. Renal haemodynamics was evaluated by radionuclide study according to Schlegel's and Gate's methods. By radionuclide study, effective renal plasma flow (ERPF), effective renal blood flow (ERBF), glomerular filtration rate (GFR), filtration fraction (FF) and renal vascular resistances (RVR) were measured. Left ventricular mass (LVM) and indexed for body height (LVM/H), cardiac output (CO) and total peripheral resistances (TPR) by ecocardiography were also calculated. RESULTS: CO, LVM and LVM/H were significantly (P < 0.05) higher in all the obese groups than lean controls. In addition, LVM and LVM/H were significantly (P < 0.05) higher in obese hypertensives than obese normotensives either with central fat distribution. TPR values were significantly (P < 0.05) higher in central obese hypertensives than peripheral obese hypertensives and than central obese normotensives. Moreover, IRI levels were significantly (P < 0.05) higher in central normotensive and hypertensive obese subjects than lean subjects. ERBF and ERPF were significantly (P < 0.05) lower and PRA levels were significantly higher only in central obese than lean subjects. On the contrary RVR were significantly (P < 0.05) higher in both obese hypertensive groups and in central obese normotensives than lean subjects. Comparisons between peripheral and central obese groups indicated that PRA, RVR and UAE were significantly (P < 0.05) higher and ERBF and ERPF values were significantly (P < 0.05) lower in both central obese groups than comparable subjects with peripheral obesity. Multiple regression analysis indicated that RVR increased significantly (P < 0.05) with WHR and PRA but not with CO and IRI. CONCLUSIONS: Our results indicate that obesity with body fat distribution of central type, more than obesity of peripheral type, is associated to abnormalities in renal haemodynamics and function. These data are consistent with the indication that change in renal haemodynamics take place at an early stage in the obesity-induced hypertension.

Adult↗
PubMed1994

Central obesity and hypertension. Relationship between fasting serum insulin, plasma renin activity, and diastolic blood pressure in young obese subjects.

This study was designed to evaluate the role of fasting serum insulin and plasma renin activity in obesity-induced hypertension. In view of this, plasma catecholamines, fasting serum insulin (IRI), urinary sodium excretion (NaU), plasma renin activity (PRA), and plasma aldosterone (PA) levels were assessed in young (age less than 40 years) normotensive (n = 27) and hypertensive (n = 14) subjects with central obesity and in lean normotensives (n = 20). Central obesity was evaluated by waist-to-hip ratio (WHR) according to the indication of the Italian Consensus Conference of Obesity. PRA, PA, IRI, and plasma norepinephrine levels were significantly (P < .05) higher in both obese groups than in lean normotensives. PRA was significantly (P < .05) higher and NaU was significantly (P < .05) lower in obese hypertensives than in obese normotensives. Diastolic blood pressure correlated directly with WHR and PRA in normotensive and hypertensive obese subjects and with IRI but only in normotensive obese subjects. Multiple regression analysis indicated that diastolic blood pressure values increased with WHR (P < .05), IRI (P < .005), and PRA (P < .002), but not with body mass index, NaU, and norepinephrine levels. Our results indicated that increased PRA could play an important role in the development of hypertension in subjects with central obesity.

Adult↗
PubMed1992

Left ventricular function response to exercise in normotensive obese subjects: influence of degree and duration of obesity.

This study has been designed to evaluate whether duration and severity of obesity can influence left ventricular function response to exercise in obese subjects without other known cardiovascular risk factors such as hypertension, diabetes or hyperlipoproteinemia. A total of 29 obese subjects were included and they were divided, according to their body mass index and to Garrow's criteria as follows: Overweight or mildly obese subjects: body mass index from 25 to 30 kg/m2; moderately obese subjects: body mass index > 30 and < 40 kg/m2. Both obese groups were further subdivided according to their duration of obesity evaluated by accurate anamnesis in subgroup A (duration of obesity less than 120 months) and subgroup B (duration of obesity more than 120 months). Left ventricular ejection fraction was detected by blood pool gated radionuclide angiocardiography both at rest and after symptom-limited bicycle ergometer procedure. At peak exercise left ventricular ejection fraction increased significantly (p < 0.05) only in overweight subjects. Exercise produced an increase of left ventricular ejection fraction in 14 overweight and in 5 moderately obese subjects and a decrease in 2 moderately obese subjects. At peak exercise mean heart rate and mean blood pressure increased significantly (p < 0.001) in both groups. When obese subjects were subgrouped according to duration of obesity, left ventricular ejection fraction increased significantly (p < 0.05) only in overweight subjects with duration of obesity less than 120 months. Duration of obesity correlated inversely with percent change in left ventricular ejection fraction (EF) at peak exercise (delta EF) (r = -0.59; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Left ventricular diastolic and systolic function in normotensive obese subjects: influence of degree and duration of obesity.

The present study was carried out to evaluate systolic and diastolic parameters in overweight and moderately obese, but otherwise healthy subjects, and in a lean control group, to determine whether degree and duration of obesity can influence left ventricular function. A total of 27 subjects, 17 overweight or with moderate obesity and 10 lean, healthy subjects were included. Patients were divided into three groups according to their body mass index (BMI) and to Garrow's criteria as follows: lean control group (BMI less than 25 kg.m-2); overweight subjects (BMI from 25 to 30 kg.m-2); moderately obese subjects (BMI greater than 30 less than 40 kg.m-2). Systolic and diastolic parameters were measured using blood pool gated radionuclide angiography. Left ventricular (LV) ejection fraction (EF), peak ejection rate (PER), time to PER (tPER), peak filling rate (PFR) and time to PFR (tPFR) were evaluated. PER and PFR values were normalized for end-diastolic volume (EDV). EF and PFR were significantly lower (P less than 0.05) both in moderately obese and in overweight subjects and tPFR was significantly (P less than 0.05) prolonged in both groups in comparison to lean controls. Only in moderately obese subjects was PER significantly (P less than 0.05) decreased and tPER significantly (P less than 0.05) prolonged in comparison to lean controls. As compared to overweight individuals, moderately obese subjects were characterized by a significant decrease (P less than 0.05) in LVEF and PER and by a significant increase (P less than 0.05) in tPER, without relevant change in PFR and in tPFR.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1989

Platelet function in hypo- and hyperthyroidism.

Alterations in cardiovascular hemodynamics are found in patients with hypofunction of the thyroid. Frank hypothyroidism favours the development of coronary heart disease. Platelets are thought to be important in atherosclerotic lesions initiation and progression. We studied platelet sensitivity to several agonists and to a physiological antagonist, prostacyclin, and thromboxane production in patients with hyperthyroidism and hypothyroidism. No statistically significant differences were found between platelets activities in patients and control subjects. We conclude that increased platelet function is not a direct indicator of susceptibility to cardiovascular diseases in patients with hypothyroidism whereas the hyperdynamic state, cardinal manifestation of thyrotoxicosis, is not associated with platelet activation.

Adult↗
PubMed1984

[Behavior of thyroid hormones and TSH in chronic active hepatitis].

The authors studied total and free circulating thyroid hormones, rT3, TBG and TSH behaviour on chronic liver disease in 11 subjects with cirrhosis of the liver with ascites(C.E.) and in 6 subjects with chronic active hepatitis (E.C.A.) in comparison with 15 healthy and euthyroid controls. Serum T3,FT3,T4 and FT4 levels were decreased significantly and serum rT3 values increased significantly both in the subjects with C.E. and in patients with E.C.A. Moreover no significantly changes of TSH and TBG levels has been found in 3 groups studied. These data suggest that the alteration of circulating thyroid hormones in chronic liver disease, may represent a compensatory way of reducing the patient's metabolic requirements.

Adult↗
PubMed1984

Behaviour of serum T3, rT3, TT4, FT4 and TSH levels after exercise on a bicycle ergometer in healthy euthyroid male young subjects.

In order to know thyroid function during physical activity, just studied by several authors without univocal findings, we have submitted 10 young subjects, non athletes, aged 22-25 years (mean age 23, 6 +/- 1, 43) to a biologically maximal exercise on a bicycle ergometer. We have also examined the change of TSH serum levels during exercise. Our data show an evident increase of T4 (18, 60% at 10'), p less than 0.025, an increment of FT4 (28, 49 soon after the strain), and no relevant change of T3 and rT3 serum levels. Moreover TSH values show a reduction at 30' (-26, 15%) in comparison with the basal level. Our findings confirm the known increment of T4 and FT4 serum level after physical activity. It can be due, more than an hemoconcentration supported by others, to a real rise of thyroid incretion as in our opinion TSH levels reduction suggests. Concluding we think that the increase of T4 and decrease of TSH could be due to a direct influence of the physical activity on the system interested in their production.

Adult↗
PubMedDate not supplied

Thyroid function and release of thyroid-stimulating hormone and prolactin from the pituitary in human obesity.

Thyroid function, basal serum thyroid-stimulating hormone (TSH) and prolactin concentrations, and the effects of 200 micrograms TSH-releasing hormone (TRH) given intravenously on TSH (delta TSH) and prolactin (delta prolactin) were investigated in 25 euthyroid obese subjects and 20 lean controls. No significant differences in serum thyroid hormone concentrations, glucose metabolism parameters, or basal TSH and prolactin concentrations were detected between groups, but a significant (P less than 0.01) increase in delta TSH and a significant (P less than 0.01) decrease in delta prolactin were observed in obese subjects. No significant differences in basal TSH and prolactin were observed in obese men and women compared with corresponding lean controls, but delta prolactin decreased significantly (P less than 0.01) in obese men and women compared with lean controls and TSH increased significantly (P less than 0.01) in obese men and women. No correlation was found between delta TSH or delta prolactin and body mass index. The study suggests that hyper-responsiveness of TSH and hyporesponsiveness of prolactin to TRH in obese subjects can be related to changes in the central serotoninergic system.

Adult↗