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Biomedical subjects

G Bartolomei

Publications and source records attributed to G Bartolomei.

At least 19 recordsLinked to original sources
PubMed1994

Renal excretion of ascorbic acid in insulin dependent diabetes mellitus.

Serum ascorbic acid (AA) is reduced in diabetic patients. Aim of this study was 1) to verify whether such a decrease might be due to an altered urinary excretion of AA, and 2) whether this latter was modified in presence of early diabetic nephropathy with microalbuminuria (albumin excretion rate [AER] > 20 micrograms/min) in a group of 21 patients affected by insulin-dependent (type 1) diabetes mellitus (IDDM) as compared with 13 healthy controls matched for sex, age, dietary AA intake, and creatinine clearance per 1.73 m2 (CCl). Mean serum AA (+/- SD) was lower in diabetics (40.3 +/- 14 microM/l) than in controls (85.1 +/- 23.5 microM/l; p = 0.0001) and there was no difference between serum AA of patients with or without microalbuminuria. Urinary excretion of AA to creatinine x 100 (UAA/Cr) was higher in micro- (n = 6; 4.6 +/- 1.7) as compared to normoalbuminurics (n = 15; 1.6 +/- 0.9) or controls (1.5 +/- 1.2; p = 0.0001). For values exceeding renal threshold of tubular AA reabsorption (39 microM) the regression line of serum AA to UAA/Cr was significantly (p = 0.001) steeper in diabetics than in controls, suggesting an impaired tubular reabsorption of filtered AA in IDDM. The ratio of AA clearance to CCl was moreover related to AER (r = 0.48; p = 0.03) and to blood glucose (r = 0.51; p = 0.01), being unrelated to uric acid clearance, glycosuria and to urinary excretion of both alanine aminopeptidase and N-acetyl-beta-glucosaminidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1994

Effect of chronic ACE inhibition on glucose tolerance and insulin sensitivity in hypertensive type 2 diabetic patients.

We studied 14 moderately overweight Type 2 diabetic patients with essential hypertension in stable metabolic control after a run-in period, and again after 3 months of antihypertensive treatment with the angiotensin-converting enzyme (ACE) inhibitor captopril. Glucose tolerance was tested with a 75g oral glucose load (OGTT) and insulin sensitivity was measured by the insulin suppression test (IST) while dietary and drug treatment of the hyperglycemia was maintained constant. In the whole group, mean blood pressure (MBP) fell progressively over 3 months from a baseline value of 123 +/- 3 mmHg (1 mmHg = 0.133 kpa) to a final value of 115 +/- 2 mmHg (P < 0.005). After treatment, fasting plasma glucose, insulin, free fatty acid (FFA), potassium, and glycosylated hemoglobin concentrations were unchanged from baseline. There were no significant differences in glucose tolerance and insulin sensitivity between pre- and post-treatment values. Neither endogenous (oral glucose) nor exogenous (IST) insulin caused any change in plasma potassium concentration. This resistance to the hypokalemic action of insulin was not affected by captopril.

Blood Glucose↗
PubMed1993

Relation of birthweight to maternal plasma glucose and insulin concentrations during normal pregnancy.

Maternal diabetes mellitus is complicated by fetal macrosomia and predisposes the offspring to diabetes, but recent evidence indicates that a low, not high, birthweight is associated with a higher incidence of Type 2 (non-insulin dependent) diabetes in adult life. To clarify the relationships between maternal glucose and insulin levels and birthweight, we measured oral glucose tolerance and neonatal weight in a large group (n = 529) of women during the 26th week of pregnancy. Women with gestational diabetes (n = 17) had more familial diabetes, higher pre-pregnancy body weight, and tended to have large-for-gestational-age babies. In contrast, women with essential hypertension (n = 10) gave birth to significantly (p < 0.01) smaller babies. In the normal group (without gestational diabetes or hypertension, n = 503), maternal body weight before pregnancy and at term, maternal height, week of delivery, gender of the newborn, and parity were all significant, independent predictors of birthweight, together explaining 23% of the variability of neonatal weight. In addition, both fasting (p < 0.006) and 2-h post-glucose (p = 0.03) maternal plasma glucose concentrations were positively associated with birthweight independent of the other physiological determinants, accounting, however, for only 10% of the explained variability. In a subgroup of 134 normal mothers with pre-pregnancy body mass index of less than 25 kg.m-2, in whom plasma insulin measurements were available, the insulin area-under-curve was inversely related to birthweight (p < 0.02) after simultaneously adjusting for physiological factors and glucose area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effect of chronic ACE inhibition on glucose tolerance and insulin sensitivity in hypertensive type 2 diabetic patients.

The question, of whether long-term treatment of essential hypertension with angiotensin-converting enzyme (ACE) inhibitors is capable of modifying glucose tolerance or insulin sensitivity in Type 2 (non-insulin dependent) diabetes, is still unsolved. We studied 14 moderately overweight Type 2 diabetic patients with essential hypertension in stable metabolic control after a run-in period and again after 3 months of antihypertensive treatment with the ACE inhibitor, captopril. Glucose tolerance was tested with a 75-g oral glucose load and insulin sensitivity was measured by the insulin suppression test, while dietary and drug treatment of the diabetes remained constant. In the whole group, mean blood pressure (MBP) fell progressively over 3 months from a baseline value of 123 +/- 3 mmHg to a final value of 115 +/- 2 mmHg (p < 0.005); in six patients, the change in MBP was < 5 mmHg (non-responders), thus giving a clinical response rate of approximately 60%. After treatment, fasting plasma glucose, insulin, free fatty acid (FFA), potassium, and glycated haemoglobin concentrations were unchanged from baseline. During the oral glucose tolerance test, the incremental glucose area-under-curve was 0.75 +/- 0.05 mol 120 min l-1 before and 0.76 +/- 0.06 mol 120 min l-1 after treatment (p = ns). Endogenous insulin response and suppression of plasma FFA levels were superimposable on the two occasions. During the insulin suppression test, steady-state plasma glucose levels were 14.4 +/- 1.3 vs 14.2 +/- 1.1 mmol l-1 before and after chronic ACE inhibition, respectively, at comparable hyperinsulinaemic plateaux (291 +/- 21 vs 287 +/- 14 pmol l-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

Erythrocyte spermidine levels in IDDM patients.

OBJECTIVES: To evaluate whether erythrocyte levels of polyamines spermidine and spermine (expressed in nmol/ml packed erythrocytes [PRBCs]) are modified in insulin-dependent diabetes mellitus (IDDM) and are associated with the presence of retinopathy or nephropathy. RESEARCH DESIGN AND METHODS: We studied erythrocyte spermidine and spermine levels in 38 IDDM patients with or without persistent microalbuminuria (urinary albumin excretion rate [AER] between 20 and 200 micrograms/min), macroalbuminuria (AER greater than 200 micrograms/min), or retinopathy compared with 60 sex- and age-matched control subjects. RESULTS: Mean +/- SD erythrocyte spermine content was similar in both diabetic (9.7 +/- 5.5 nmol/ml PRBCs) and control (8.8 +/- 3.5 nmol/ml PRBCs) subjects, whereas spermidine was higher in diabetic (19.1 +/- 7.2 nmol/ml PRBCs) than in control (14.5 +/- 4 nmol/ml PRBCs, P = 0.0007) subjects. Moreover, spermidine was significantly higher in the groups with microalbuminuria (n = 11, 22.5 +/- 9.2 nmol/ml PRBCs) and macroalbuminuria (n = 4, 22.2 +/- 5.7 nmol/ml PRBCs) than in both normoalbuminuric (n = 23, 16.9 +/- 5.6 nmol/ml PRBCs) and control (F = 9.78, P = 0.0001) subjects, and correlated with log AER (r = 0.41, P = 0.009). Similarly, proliferative retinopathy was associated with a significant increase in spermidine (n = 5, 20 +/- 7 nmol/ml PRBCs compared with control subjects [P = 0.0009]). CONCLUSIONS: Our data suggest that erythrocyte spermidine content is increased in IDDM patients associated with both diabetic nephropathy and advanced retinopathy.

Adult↗
PubMed1988

The combination of a low-Na/high-K salt with metoprolol in the treatment of mild-moderate hypertension. A multicenter study.

To extend our previous findings that a low-Na/high-K salt (S) reduces BP in hospitalized patients, a multicenter study was performed. After a placebo period during which patients were informed by written instruction how to avoid only foods with a high Na content, 143 out-patients (84 males and 59 females, mean age 50.7 years, range 28-69) with DBP greater than or equal to 95 mm Hg randomly received for 4 weeks either metoprolol (M) 200 mg SR qd (67 patients), or S, 2 g bid to add to foods (76 patients). At the end of this period patients with DBP still greater than 90 mm Hg combined the two treatments for a further 4 weeks. Mean blood pressure (mm Hg), HR (bpm), 24-hrs urinary Na and K excretion were measured fortnightly. In comparison to pretreatment values MBP was significantly (P less than 0.01) reduced by both treatments, although to a greater extent in the M group already at the second week, without any further decrement thereafter. In the S group MBP decreased by 4.4 mm Hg and 27/76 patients were responders (DBP less than or equal to 90 mm Hg), while in the M group it was reduced by 9.0 mm Hg and 28/67 patients were responders. In the S group urinary Na excretion was significantly (P less than 0.01) lower than in the M group, and this difference was present until the end of period 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Plasma renin activity does not predict the antihypertensive efficacy of chlorthalidone.

It has been established that angiotensin II stimulation may limit the antihypertensive potential of diuretic therapy in some patients. It is less clear, however, whether renin-angiotensin II stimulation is the cause of the flat blood pressure dose-response relationship to diuretics. To investigate this, 75 out-patients with essential hypertension were treated with chlorthalidone 12.5, 25 or 50 mg o.d. for 3 weeks, in a double-blind, placebo controlled cross-over study. Chlorthalidone significantly reduced blood pressure in all the groups, a plateau being reached at 25 mg o.d. Similarly, plasma renin activity was increased by each dose level of chlorthalidone, but it showed a different trend, being increased to a comparable extent at 12.5 mg and 25 mg o.d., and still higher at 50 mg o.d. Thus, greater stimulation of renin was coincident with the levelling of the blood pressure response to chlorthalidone. However no significant correlation was found between interindividual plasma renin activity and change in blood pressure, either in the entire series, or in each treatment subset. The data suggest overall that renin stimulation may influence the characteristic dose-hypotensive response relationship to diuretic agents in antihypertensive therapy, but it is unlikely that measurement of individual plasma renin activity will provide an useful guide to the optimal dose of a diuretic agents.

Adult↗
PubMed1986

Plasma fibronectin in diabetic retinopathy and macroangiopathy.

To establish the relation between plasma fibronectin (PF) and vascular complications of diabetes mellitus, we studied 163 normotensive diabetic outpatients, of whom 53 were treated with insulin (15 type I, 38 type II) and 110 with sulfonylureas, and compared them to 34 control subjects. Diabetic patients were divided, according to their therapy, into four groups: with retinopathy (classified as background or proliferative) detected by fluorescein angiography (m), with macroangiopathy, assessed by clinical criteria (M), with both vessel complications (mM) and without vascular disease (N). PF was not related to glycosylated hemoglobin (HbA1) in each treatment group (r = 0.26; P = 0.051 in the insulin treated patients and r = 0.09; P = 0.356 in the group on oral drugs). PF levels were similar in M groups, either on insulin or sulfonylureas and in controls. Both m and mM subsets of patients were, conversely, characterized by significantly raised mean PF concentrations when compared to N subjects or controls, but proliferative retinopathy was not associated with a significant PF increase compared to background retinopathy. The differences of PF levels among m, mM and N groups remained significant after processing the data by means of stepwise discriminant analysis with age, duration of diabetes, body weight and HbA1 entering the model as covariates. We conclude that diabetic macroangiopathy is not associated with modifications of mean PF levels, which, on the contrary, appear increased only in diabetic patients with retinopathy, regardless of their therapy.

Adult↗
PubMed1982

[A and B apoproteins and serum lipids in clinically healthy males].

Serum levels of total cholesterol (TC), triglycerides (TG), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), Apoprotein A (Apo A) and Apoprotein B (Apo B) were determined in 125 healthy male subjects (bank clerks), aged 20-59 years, in order to screen risk factors of atherosclerosis (ATS) in our population. TC, TG, LDL-C and Apo B increase with aging, while HDL-C and Apo A do not. HDL-C correlates inversely with LDL-C, Apo B ad TG and positively with Apo A. LDL-C, TC and TG show a positive correlation with Apo A. Weight index, cigarette smoking, systolic blood pressure (SBP) negatively affect HDL-C levels which present a positive relation with alcohol intake. Apo B, TC and TG are, moreover, significantly increased by smoking and body weight. A multiple linear regression analysis choosing HDL-C and Apo B as dependent variables indicates that Apo A, TG, SBP, age and alcohol consumption are the attributes mostly associated with HDL-C while TC, smoking, Apo A and SBP are the independent variables which best explain total variance of Apo B. It is worth noting, in this respect, the effect of smoking on Apo B: such a result could provide a further explanation of the well-known connection between smoking and ATS.

Adult↗
PubMedDate not supplied

Serum spermidine oxidase activity in patients with insulin-dependent diabetes mellitus and microvascular complications.

Metabolism of polyamines (spermidine and spermine) is known to be strictly related to the growth processes of eukaryotic cells. Since cell replication processes appear altered in insulin-dependent diabetes mellitus (IDDM), especially when associated with its microvascular complications, the aim of this study was measuring serum spermidine oxidase activity (SOA), a key enzyme in the metabolic pathway of polyamines, in 47 patients with IDDM as compared with 63 healthy control subjects matched for age and sex. Mean SOA levels +/- SD were significantly lower in IDDM patients (177.4 +/- 57.2 mu kat/l) than in controls (247.6 +/- 68.1 mu kat/l; p less than 0.001), being SOA inversely related with daily insulin dose. SOA was moreover significantly higher (but similar to controls) in the group with increased urinary albumin excretion rate (AER persistently greater than 20 micrograms/min); (n = 17; 213.1 +/- 62.6 mu kat/l) in comparison with normoalbuminuric subjects (n = 30; 156.6 +/- 43.5 mu kat/l; F = 21.78; p = 0.0001). SOA was correlated with AER (r = 0.45; p = 0.001), independently of age, duration of disease, serum creatinine, body weight, blood pressure and metabolic control, as shown by a multiple regression analysis model (p = 0.003). Presence of background retinopathy was not associated with modified levels of SOA, which was conversely higher, although not significantly, in the patients with proliferative retinal lesions. In conclusion serum SOA is deeply altered in IDDM patients, being markedly reduced in the whole group of patients and conversely independently increased up to the mean values of controls in presence of increased AER or advanced retinopathy.

Adolescent↗
PubMedDate not supplied

Raised plasma fibronectin concentration is related to the presence of diabetic retinopathy.

Plasma concentrations of fibronectin were studied in 152 diabetics (77 males, 75 females), divided according to their hypoglycemic treatment, and in 60 normal subjects (30 males, 30 females) closely matched for age. In both sexes no significant difference of plasma fibronectin (PF) levels was observed between controls and treated groups. In the whole group of diabetics PF levels were weakly correlated with age (r = 0.16; p less than 0.05) and not associated with HbA1 or duration of illness. Both male and female diabetics, either on sulfonylureas or insulin, with retinopathy (background, except for 2 proliferative in the group of insulin-requiring females) were characterized by significantly higher PF concentrations than either controls or patients without retinopathy.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Increased plasma fibronectin concentration in diabetic patients with microalbuminuria.

Raised levels of plasma fibronectin (PF), an alpha 2-glycoprotein produced by vascular endothelia, have been previously described in diabetic patients with retinopathy and overt nephropathy. The aim of this study was to investigate whether the presence of microalbuminuria is associated with increased PF concentrations. Twenty Albustix-negative diabetic outpatients with microalbuminuria [median albumin excretion rate (AER): 30.2 micrograms/min; range 12.1-194 micrograms/min] were compared with 58 sex- and age-matched patients without microalbuminuria (median AER 3.1 micrograms/min; range 0.8-12 micrograms/min) and 34 control subjects (median AER 2.8 micrograms/min; range 0.8-12.1 micrograms/min). Mean PF was significantly higher in the group with microalbuminuria (406.7 +/- 85.5 micrograms/ml) than in the group without it (325.3 +/- 76.5 micrograms/ml or in control subjects (334.5 +/- 76 micrograms/ml; P less than .05). PF increase associated with microalbuminuria was independent of the presence of retinopathy. Furthermore, in the whole group of diabetic patients, PF was significantly correlated with AER (r = .33; P = .003). Such correlation also remained significant (P = .0002) after covariance analysis by a stepwise discriminant procedure taking into account age, duration of disease, sex, blood pressure, body weight, therapy, and HbA1. In conclusion, PF increase is associated with microalbuminuria independent of the other considered variables; its role as a possible marker for early diabetic nephropathy remains to be fully clarified.

Albuminuria↗