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Biomedical subjects

M Varricchio

Publications and source records attributed to M Varricchio.

At least 55 records · Page 3Linked to original sources
PubMed1997

Congestive heart failure predicts the development of non-insulin-dependent diabetes mellitus in the elderly. The Osservatorio Geriatrico Regione Campania Group.

Congestive heart failure (CHF) is an insulin-resistant state which constitutes the main risk factor for the development of non-insulin-dependent diabetes mellitus (NIDDM). Our study investigated the predictive role of CHF on the development of NIDDM in 1,339 elderly subjects with a mean ( +/- SD) age of 74.2 +/- 6.4 years. CHF had a 9.5% prevalence, and 14.7% of the subjects had NIDDM. After stratification by age, subjects between 80 and 84 years had the highest prevalence of CHF and a total of 29.6% of CHF patients had NIDDM. In multiple logistic regression analysis, CHF was associated with NIDDM [odds ration (OR) = 2.0, 95% confidence interval (CI) - 1.6-2.5] independent of age, sex, family history of diabetes, body mass index, (BMI), waist/hip ratio, and diastolic blood pressure. When only untreated CHF patients were taken into account, the association between CHF and NIDDM was even stronger (OR = 4.0, 95% CI = 3.4-5.8). When untreated CHF patients were grouped into those with low (I and II) and high (III and IV) New York Heart Association (NYHA) classes, the association of CHF and NIDDM was stronger with the worsening of CHF. In a longitudinal study, CHF predicted NIDDM independently of age, sex, family history of diabetes, BMI, waist/hip ratio, systolic and diastolic blood pressure, and therapy for CHF (OR = 1.4, 95% CI = 1.1-1.8). CHF was associated with a higher prevalence of NIDDM and was a risk factor for its development. Elevated FFA concentrations may play a pivotal role.

Aged↗
PubMed1997

Detection of low copy number inversions in mouse genomic DNA with unidirectional PCR primers.

The recessive brachypodism (bp) mutation, located in the growth/differentiation factor 5 (GDF5) gene, causes highly specific skeletal changes in the limbs of brachypod mice. Although Southern blot analysis does not distinguish sequence disruptions in the GDF5 sequence of brachypod mice, sequencing and mapping GDF5 mRNA reveals the bp mechanism to be an inversion preceded by a small deletion. We report here a simple and sensitive method of bp detection from mouse genomic DNA. Previous bp detection used degenerative PCR sequencing. However, without automation, sequencing is a laborious effort for GDF5 inversion detection. The method developed utilizes two unidirectional primers in PCR (UP-PCR), which allow for quick and sensitive analysis of gel electrophoresed PCR products. UP-PCR of the GDF5 gene in wildtype mouse genomic DNA cannot amplify a fragment due to the unidirectional primers. However, UP-PCR of the GDF5 gene in bp mouse genomic DNA does amplify a fragment from the GDF5 gene. Amplification occurs because of the inverted fragment in bp GDF5. This fragment changes the direction of the second forward primer 180 degrees to the position of a reverse primer. UP-PCR detection of the bp inverted fragment is highly sensitive. Amplified fragments were obtained from the bp genomic DNA in the presence of wildtype genomic DNA in ratios up to 1:10(6), respectively. The sensitivity and simplicity of this method allow for quick, inexpensive, and reliable detection of the bp inversion.

Animals↗
PubMed1996

Hyperinsulinemia is associated with ventricular premature complexes.

The study investigated a possible association between fasting plasma insulin (FPI) levels and ventricular premature complexes (VPCs). One hundred eighty-six subjects without coronary artery disease (CAD), diabetes, hypertension, and left ventricular hypertrophy were recruited. All subjects underwent 24-hour electrocardiographic monitoring and oral glucose tolerance testing. The subjects were slightly overweight, normotensive, and nondiabetic. Subjects at the third tertile of FPI concentrations were the oldest and heaviest, with prevalent upper-body fat distribution, and had enhanced fasting plasma triglyceride and potassium concentrations, lower fasting plasma high-density lipoprotein (HDL) cholesterol concentration, and a greater number of VPCs versus subjects at the first and second tertiles. Independently of age, sex, body mass index (BMI), and waist to hip ratio (WHR), VPCs were correlated with FPI concentration (r = .19, P < .01). Multiple logistic regression analyses in which the presence or absence of VPCs was the dependent variable demonstrated that FPI concentrations were associated with VPCs independently of age, sex, BMI, WHR, daily physical activity (DPA), left ventricular mass index (LVMI), plasma low-density lipoprotein (LDL)/HDL cholesterol ratio, and triglyceride concentration (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.0 to 1.6). After addition to the model of fasting plasma free fatty acids ([FFA] OR, 0.7; 95% CI, 0.6 to 1.3) or potassium (OR, 0.7; 95% CI, 0.6 to 1.1) concentrations, the association between FPI concentrations and VPCs is no longer significant. In conclusion, FPI concentrations are associated with VPCs in nondiabetic, normotensive, nonischemic subjects.

Adult↗
PubMed1996

Glucose tolerance and insulin action in healthy centenarians.

Advancing age has been found to be associated with a decline in insulin action. Nevertheless, no study has been conducted in healthy centenarians. Our study investigates glucose tolerance and insulin action in centenarians. Fifty-two subjects were enrolled. The subjects were divided in three groups as follows: 1) adults (< 50 yr; n = 20);2) aged subjects (> 75 yr; n = 22); and 3) centenarians (> 100 yr; n = 14). Body composition was studied by bioimpedance analysis. In all subjects, an oral glucose tolerance test and euglycemic glucose clamp were performed. Centenarians have a lower fat-free mass (FFM) than aged subjects and adults, whereas fasting plasma glucose, triglycerides, free fatty acids, urea, and creatinine were not different in the groups studies. Centenarians had a 2-h plasma glucose concentration (6.0 +/- 0.2 mmol/l) that was lower than that in aged subjects (6.6 +/- 0.5 mmol/l, P < 0.05) but not different from adults [6.4 +/- 0.4 mmol/l, P = not significant (NS)]. During the clamp, plasma glucose and insulin concentrations were similar in the three groups. In these conditions, centenarians had a whole body glucose disposal (34.1 +/- 0.6 mumol.kg FFM-1.min 1) that was greater than that in aged subjects (23.3 +/- 0.5 mumol.kg FFM-1.min-1 P < 0.01) but not different from adults (34.6 +/- 0.5 mumol/kg x min, P = NS). In conclusion, our study demonstrates that centenarians compared with aged subjects had a preserved glucose tolerance and insulin action.

Adult↗
PubMed1996

Non-insulin-dependent diabetes mellitus is associated with a greater prevalence of depression in the elderly. The Osservatorio Geriatrico of Campania Region Group.

We investigated the association of non-insulin-dependent (Type 2) diabetes mellitus and depression symptoms in a representative community-dwelling elderly population independently of other conditions such as gender, age, status, disability, cognitive impairment and a number of chronic medical conditions such as chronic obstructive lung disease, degenerative joint disease, heart disease, cirrhosis of the liver, cholelithiasis, peptic ulcer and kidney stones. A total of 1339 elderly subjects living in southern Italy were randomly selected from electoral rolls and evaluated. All subjects were tested by the Geriatric Depression Scale to detect depression, the Mini-Mental State Examination to study cognitive function and the Activity Daily Living Index to evaluate disability. Non-insulin-dependent diabetes mellitus affected 14.7% of our sample. Depression was more prevalent in women over 75 years of age than in younger women (15.9 vs 8.1%, p < 0.001). In multiple linear regression analysis, diabetes mellitus was found to be significantly associated with depression independently of age, gender, loneliness, cognitive impairment, chronic obstructive lung disease, degenerative joint disease, heart diseases, cancer, kidney disease, cirrhosis of the liver and cholelithiasis. It is concluded that non-insulin-dependent diabetes mellitus is significantly associated with depression in the elderly, which may have clinical implications for the achievement of sufficient blood glucose control.

Aged↗
PubMed1995

Low-dose Iloprost infusion improves insulin action and non-oxidative glucose metabolism in hypertensive patients.

Fourteen hypertensive (174.3/98.3 mmHg) non-diabetic patients were given a euglyceamic glucose clamp along with infusion of 0.9% NaCl and the prostacyclin (PGI2) analogue Iloprost (0.7 ng x kg x min(-1)). Substrate oxidation was also determined by indirect calorimetry. Over the last 60 min of the clamp, Iloprost vs saline improved whole body glucose disposal (WBGD) (35 vs 28.3 micromol x kg(-1) LBM) and non-oxidative glucose metabolism (24.7 vs 18.1 micromol x kg(-1) LBM x min(-1). Iloprost delivery was associated with a significant decrease in membrane microviscosity (0.253 vs 0.205), but did not affect arterial blood pressure and heart rate. In nine patients, skeletal muscle blood flow (SMBF) and insulin-stimulated glucose uptake (GU) were also studied. At the end of the study, despite a similar SMBF (37 vs 38 ml x min(-1) x kg(-1)), GU (0.55 vs 0.46 mmol x l(-1)) was significantly increased by Iloprost infusion. Percentage decrease in membrane microviscosity was correlated with percentage increase in WBGD (r = 0.65) and non-oxidative glucose metabolism (r = 0.68). In conclusion, low-dose Iloprost infusion improves insulin action and non-oxidative glucose metabolism in hypertensive patients.

Blood Glucose↗
PubMed1995

Opposite effects of short- and long-term fatty acid infusion on insulin secretion in healthy subjects.

Our study investigates short- and long-term effects of infusion of non-esterified fatty acids (NEFA) on insulin secretion in healthy subjects. Twelve healthy individuals underwent a 24-h Intralipid (10% triglyceride emulsion) infusion at a rate of 0.4 ml/min with a simultaneous infusion of heparin (a bolus of 200 U followed by 0.2 U/min per kg body weight). After an overnight fast (baseline), at 6 and at 24 h of Intralipid infusion and 24 h after Intralipid discontinuation (recovery test), all subjects underwent an intravenous glucose tolerance test (iv-GTT) (25 g of glucose/min). Intralipid infusion caused a threefold rise in plasma NEFA concentrations with no difference between the 6- and the 24-h concentrations. Compared to baseline acute insulin response (AIR) (AIR = 63 +/- 8 mU/l), short-term (6-h) Intralipid infusion was associated with a significant increase in AIR (86 +/- 12 mU/l p < 0.01); in contrast, long-term (24-h) Intralipid delivery was associated with inhibition of AIR (31 +/- 5 mU/l) compared to baseline (p < 0.001) and to the 6-h (p < 0.03) triglyceride emulsion infusion. Intralipid infusion was associated with a progressive and significant decline in respiratory quotient (RQ). A positive correlation between changes in fasting plasma NEFA concentrations and AIR at the 6-h infusion (r = 0.89 p < 0.001) was found. In contrast, at the end of the Intralipid infusion period, changes in plasma NEFA concentrations and AIR were negatively correlated (r = -0.87 p < 0.001). The recovery test showed that fasting plasma NEFA concentrations, RQ and AIR had returned to baseline values. In the control study (n = 8) 0.9% NaCl infusion did not mimick the effect of Intralipid. In conclusion, our study demonstrates that short- and long-term exposures of beta cells to high plasma NEFA concentrations have opposite effects on glucose-induced insulin secretion.

Adult↗
PubMed1995

Metabolic benefits deriving from chronic vitamin C supplementation in aged non-insulin dependent diabetics.

OBJECTIVE: Our study investigated the metabolic benefits deriving from chronic pharmacological vitamin C administration in aged non-insulin dependent (Type II) diabetic patients. METHODS: Forty type II diabetic patients (age: 72 +/- 0.5 years) underwent placebo and vitamin C (0.5 g twice daily) administration in double-blind, randomized, cross-over fashion. All patients were treated by oral hypoglycaemic agents which continued throughout the study. After baseline observations, treatment periods lasted 4 months and were separated by a 30-day wash-out period. RESULTS: Patients' antropometric data were unchanged throughout the study. Chronic vitamin C administration vs placebo was associated with a significant decline in fasting plasma free radicals (0.26 +/- 0.06 vs 0.49 +/- 0.07 p < 0.03) and insulin (90 +/- 4 vs 73 +/- 6 pmol/L p < 0.04), total- (7.3 +/- 0.5 vs 5.8 +/- 0.4 mmol/L p < 0.03), LDL-cholesterol (5.6 +/- 0.6 vs 4.1 +/- 0.3 mmol/L p < 0.05) and triglycerides (2.58 +/- 0.07 vs 2.08 +/- 0.04 mmol/L p < 0.04) levels. In 20 patients, chronic vitamin C administration improved whole body glucose disposal and nonoxidative glucose metabolism. Percent increase in plasma vitamin C levels correlated with the percent decline in plasma LDL-cholesterol (r = 0.44; p < 0.007) and insulin levels (r = 0.42; p < 0.006). Finally percent increase in plasma vitamin C levels was correlated with the percent decline in plasma free radicals and increase in GSH levels. CONCLUSIONS: Chronic vitamin C administration has beneficial effects upon glucose and lipid metabolism in aged non-insulin dependent (type II) diabetic patients.

Aged↗
PubMed1995

Chronic intake of pharmacological doses of vitamin E might be useful in the therapy of elderly patients with coronary heart disease.

Thirty elderly (mean +/- SEM: 73.8 +/- 2.1 y) nondiabetic, moderately obese (body mass index = 28.3 +/- 0.6 kg/m2) patients with stable effort angina underwent an oral-glucose-tolerance test and a euglycemic hyperinsulinemic glucose clamp before and after vitamin E supplementation (900 mg/d for 4 mo). The study was of a randomized, placebo-controlled, double-blind, and crossover design. Anthropometric indexes were stable throughout the study. Despite similar fasting and 2-h plasma glucose concentrations, vitamin E administration (compared with placebo) lowered fasting (88 +/- 14 and 68 +/- 9 pmol/L, P < 0.02) and 2-h (348 +/- 43 and 263 +/- 28 pmol/L, P < 0.05) plasma insulin concentrations, plasma triglyceride concentrations (1.34 +/- 0.06 and 1.07 +/- 0.03 mmol/L, P < 0.05), and the ratio of plasma LDL to HDL cholesterol (7.64 +/- 0.31 and 5.52 +/- 0.38, P < 0.02). Vitamin E administration was associated with higher nonoxidative glucose metabolism (18.1 +/- 0.5 and 10.6 +/- 0.7 mumol.kg lean body mass-1.min-1, P < 0.03) than was placebo administration during the euglycemic glucose clamp. We conclude that chronic intake of pharmacological doses of vitamin E might be useful in the therapy of elderly insulin-resistant patients with coronary heart disease.

Aged↗
PubMed1995

Body composition, body fat distribution, and resting metabolic rate in healthy centenarians.

Our study investigated body composition and body fat distribution in healthy centenarians. Body composition, body fat distribution, and resting metabolic rate (RMR) were studied in 40 adult subjects aged < 50 y, 35 aged subjects > 75 y, and 15 healthy centenarians aged > 100 y. Body composition was determined by bioimpedance analysis, body fat distribution was calculated as waist-hip ratio (WHR), and RMR was calculated by using the Arciero-Poehlman formula. Healthy centenarians had a cognitive impairment and degree of disability greater than aged subjects. Despite such differences, fat-free mass (FFM) and RMR were not different in centenarians compared with aged subjects but were lower than in adult subjects. In contrast, healthy centenarians had a WHR lower than that of aged subjects but not different from that of the adult subjects. After the level of physical activity and degree of disability were adjusted for, FFM (44 +/- 2.7 and 40 +/- 1.1 kg; P < 0.05) and RMR (6757 +/- 761 and 5891 +/- 723 kJ/24 h; P < 0.05) were significantly higher in healthy centenarians than in aged subjects, respectively. Independent of age, sex, body weight, degree of disability, level of physical activity, and fasting plasma triiodothyronine, there was a strong correlation between RMR and FFM (r = 0.50, P < 0.05) in healthy centenarians. In conclusion, healthy centenarians had a lower FFM and higher body fat content than aged subjects. Level of physical activity and degree of disability seem to be the major determinants for explaining such differences.

Adipose Tissue↗
PubMed1995

Left ventricular hypertrophy is associated with a stronger impairment of non-oxidative glucose metabolism in hypertensive patients.

Hypertensive patients with left ventricular hypertrophy (LVH) have a higher degree of hyperinsulinaemia than hypertensive patients without LVH. Obese patients with LVH have also been demonstrated to have a very low glucose disappearance rate after an intravenous glucose bolus. No studies have investigated the difference in insulin action and substrate oxidation in hypertensive patients with and without LVH. For this reason 36 subjects were enrolled for our study: (1) healthy control subjects (n = 10); (2) hypertensive patients without LVH (n = 12); and (3) hypertensive patients with LVH (n = 14). All subjects underwent an oral glucose tolerance test (OGTT, 75 g of glucose) and a euglycaemic hyperinsulinaemic glucose clamp (insulin infusion rate, 7.1 pmol (kg min)-1 for 120 min). In this latter test indirect calorimetry allowed substrate oxidation determination. Echocardiographic methods allowed LVH assessment. Hypertensive patients with LVH had the lowest insulin-mediated nonoxidative glucose metabolism compared to hypertensive patients without LVH (P < 0.01) and to healthy subjects (P < 0.001). In the whole group of hypertensive patients (n = 26), partial correlations showed left ventricular mass index (LVMI) associated with fasting plasma insulin levels (r = 0.44 P < 0.005), insulin-mediated whole body glucose disposal (r = -0.41 P < 0.01) and nonoxidative glucose metabolism (r = -0.33 P < 0.04) independently of age, body weight, systolic blood pressure and plasma catecholamines levels. In conclusion, our data provide evidence that LVH in hypertensive patients is associated with a worsening in nonoxidative glucose metabolism.

Blood Glucose↗
PubMed1995

Low-dose iloprost infusion improves insulin action in aged healthy subjects and NIDDM patients.

OBJECTIVE: To investigate the effect of iloprost infusion on insulin action. RESEARCH DESIGN AND METHODS: Thirteen healthy subjects and 13 non-insulin-dependent diabetes mellitus (NIDDM) patients matched for age (68.2 +/- 0.5 vs. 67.9 +/- 0.5 years, NS), gender ratio (7 men:6 women vs. 6 men:7 women), body weight, body fat distribution, arterial blood pressure, and plasma triglyceride levels (1.89 +/- 0.09 vs. 1.87 +/- 0.08 mmol/l, NS) were studied. In eight healthy subjects and eight NIDDM patients, we studied insulin action by euglycemic glucose clamp (insulin infusion rate 2 mU.kg-1.min-1) along with saline and iloprost delivery (0.7 ng.kg-1.min-1). In the other five subjects of each group, forearm blood flow and insulin-mediated glucose uptake during saline and iloprost infusion (0.7 ng.kg-1.min-1) were investigated. RESULTS: Iloprost infusion improved insulin-stimulated whole-body glucose uptake and oxidative and nonoxidative glucose metabolism in both study groups. Forearm blood flow under basal conditions and with insulin infusion (2 mU.kg-1.min-1) did not show any significant difference from that during saline and iloprost infusion (0.7 ng.kg-1.min-1) in healthy subjects and diabetic patients. CONCLUSIONS: Iloprost infusion improves insulin action in healthy subjects and NIDDM patients.

Aged↗
PubMed1995

Lisinopril administration improves insulin action in aged patients with hypertension.

Thirty elderly, mildly hypertensive patients were enrolled for a single-blind, randomised cross-over placebo controlled trial in which placebo and lisinopril (20 mg/day before breakfast) were given for 4 and 8 weeks, respectively. A wash-out period of 3 weeks between placebo and lisinopril was observed. In each patient a euglycaemic glucose clamp with simultaneous indirect calorimetry allowed us to determine whole body glucose disposal and substrate oxidation. Changes in morning SBP and DBP were also determined. Lisinopril vs. placebo significantly improved whole body glucose disposal (40.4 +/- 0.4 vs. 30.3 +/- 0.4 mumol/kg LBM x min; P < 0.01), non-oxidative glucose metabolism (18.1 +/- 0.7 vs. 10.9 +/- 0.6 mumol/kg LBM x min; P < 0.01) and fasting plasma potassium levels (4.8 +/- 3 vs. 4.4 +/- 0.4 mmol/l; P < 0.05). SBP (175 +/- 3.3 vs. 160 +/- 3.0 mm Hg; P < 0.001) and DBP (106 +/- 2.3 vs. 95 +/- 2.0 mm Hg; P < 0.001) were significantly reduced by lisinopril administration. After ACE inhibition, fasting plasma potassium levels correlated with the decline in mean arterial BP (r = -0.71; P < 0.006). In conclusion, lisinopril administration reduces arterial BP and improves insulin sensitivity in elderly hypertensive patients.

Aged↗
PubMed1995

Low fasting and insulin-mediated intracellular magnesium accumulation in hypertensive patients with left ventricular hypertrophy: role of insulin resistance.

Twenty-five hypertensive patients (13 males/12 females) with left ventricular hypertrophy (LVH) and 12 hypertensive patients (6 males/6 females) without LVH were studied. Both groups were matched for age, sex, body mass index, percentage body fat, arterial BP and known duration of hypertension. After a seven day wash-out period from antihypertensive treatment each subject underwent: (1) an oral glucose tolerance test, (2) an euglycemic hyperinsulinaemic glucose clamp (insulin infusion rate 7.1 pM/kg per min), (3) an echocardiographic determination of left ventricular mass index, and (4) 24h ECG Holter monitoring. All tests were performed in random order and on different days. All investigators were unaware of the patient groups. Hypertensive patients with LVH had lower fasting intracellular (erythrocyte) magnesium concentrations (1.85 +/- 0.06 vs. 2.07 +/- 0.04 mM; P < 0.001) but higher fasting plasma insulin concentrations (86 +/- 4 vs. 59 +/- 5 pM; P < 0.001) Glucose clamp study demonstrated a lower insulin-mediated glucose disposal (24.8 +/- 0.4 vs. 30.1 +/- 0.3 microM/kg of lean body mass per min; P < 0.05) and a net change in intracellular magnesium accumulation (17.9 +/- 1.3 vs. 27.3 +/- 1.8%, P < 0.01) in response to insulin infusion in hypertensive patients with LVH than in those without LVH. After adjustment for fasting plasma insulin levels and insulin-mediated glucose uptake, fasting and insulin-mediated erythrocyte magnesium accumulation were no longer different between the two groups. In conclusion, hypertensive patients with LVH compared with those without LVH have a lower intracellular magnesium content due a higher degree of insulin resistance.

Double-Blind Method↗
PubMed1994

Evidence for a relationship between oxidative stress and insulin action in non-insulin-dependent (type II) diabetic patients.

Ten healthy subjects and 30 non-insulin-dependent (type II) diabetic patients matched for age, gender ratio, body mass index, lean body mass (LBM), waist to hip ratio, and arterial blood pressure volunteered for the study. In all subjects, fasting plasma free radical (O2-) levels and basal membrane lipid fluidity (MLF) and protein mobility (MPM) were determined. The whole group of subjects underwent a euglycemic hyperinsulinemic glucose clamp with simultaneous indirect calorimetry for substrate oxidation determination. Diabetic patients versus controls displayed higher fasting plasma glucose (8.3 +/- 0.4 v 5.1 +/- 0.4 mmol/L, P +/- .001), O2- (0.48 +/- 0.02 v 0.16 +/- 0.02 mumol/L x min), and hemoglobin A1c ([HbA1C] 7.9% +/- 0.4% v 5.7% +/- 0.3%, P < .03) levels and a stronger reduction in basal MLF (0.243 +/- 0.006 v 0.318 +/- 0.009, P < .003) and basal MPM (0.348 +/- 0.003 v 0.518 +/- 0.010, P < .002). Whole-body glucose disposal (WBGD) and oxidative and nonoxidative glucose metabolism were also significantly lower in diabetics than in controls. In diabetic patients (n = 30), plasma O2- levels correlated with basal MLF (r = -.59, P < .005), basal MPM (r = -.84, P < .001), fasting plasma insulin level (r = .51, P < .004), WBGD (r = -.53, P < .002), and nonoxidative (r = -.45, P < .01) glucose metabolism. In conclusion, our results demonstrate that a relationship between plasma O2- levels and insulin action occurs in non-insulin-dependent diabetics.

Aged↗
PubMed1994

Total-body and myocardial substrate oxidation in congestive heart failure.

Congestive heart failure is a condition associated with increased plasma norepinephrine levels, which have been demonstrated to impair glucose handling. In the present study, 10 patients suffering from congestive heart failure and 10 healthy age- and body mass index-matched subjects were submitted to a hyperinsulinemic (insulin infusion rate, 0.5 mU/kg.min-1) glucose clamp, while simultaneous D-3H-glucose infusion and indirect calorimetry allowed for determination of glucose turnover parameters and substrate oxidation, respectively. On a separate day, basal local (myocardial) indirect calorimetry was also performed. Our data demonstrate that in congestive heart failure, fasting myocardial glucose oxidation (Gox) was inhibited with a simultaneous increase in lipid oxidation (Lox). In our patients, a significant decrease in total-body insulin-stimulated glucose metabolism (31.0 +/- 0.5 v 20.3 +/- 0.4 mumol/kg.min-1, P < .01) and nonoxidative glucose metabolism (18.9 +/- 1.1 v 11.0 +/- 0.5 mumol/kg.min-1, P < .05) was also found. Such latter changes were also associated with a simultaneous overdrive of Lox (0.4 +/- 0.2 v 1.9 +/- 0.2 mumol/kg.min-1, P < .02) that was correlated with an enhanced availability of plasma free fatty acids (FFAs).

Aged↗
PubMed1994

Pharmacological doses of vitamin E and insulin action in elderly subjects.

Twenty elderly (77 +/- 0.4 y), nonobese [body mass index (in kg/m2) 26.4 +/- 0.5] subjects with normal glucose tolerance were submitted to a euglycemic hyperinsulinemic (3.5 pmol.min/kg) glucose clamp in a double-blind, crossover, randomized procedure after 4 mo treatment with either vitamin E (900 mg d-alpha-tocopherol/d, Ephynal; Roche, Milan, Italy) or placebo. Body mass index was practically unchanged throughout the study. After the glucose clamp, insulin-mediated stimulation 2 of whole-body glucose disposal (18.4 +/- 0.5 vs 26.1 +/- 0.6 mumol.min/kg lean body mass P < 0.02) was significantly potentiated by vitamin E rather than placebo administration. Furthermore, net changes in plasma vitamin E concentrations correlated with net changes in insulin-stimulated whole-body glucose disposal (r = 0.60 P < 0.003). Plasma vitamin E concentrations seem to play an important role in the modulation of insulin action in elderly people.

Aged↗