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Biomedical subjects

Giovanni Davì

Publications and source records attributed to Giovanni Davì.

26 records · Page 2Linked to original sources
PubMed2003

Association between serum leptin levels and 24-hour blood pressure in obese women.

OBJECTIVE: To assess the relationship between serum leptin and 24-hour blood pressure (BP) in obese women, according to body fat distribution. RESEARCH METHODS AND PROCEDURES: A cross-sectional study was carried out in a population of 70 nondiabetic, normotensive, obese women (40 with android and 30 with gynoid type of obesity) and 20 nonobese healthy women as a control group. All subjects underwent 24-hour ambulatory BP monitoring. Blood samples were collected for serum leptin and plasma insulin measurements. Total cholesterol and high-density lipoprotein cholesterol were also measured. RESULTS: Serum leptin levels were significantly higher in obese subjects than in controls, and they were more elevated in android obese women than in gynoid ones. Leptin levels were positively related to body mass index (BMI), insulin, and waist and hip circumferences in the android group. Among gynoid subjects, leptin levels showed positive associations with BMI and insulin. In women with android obesity, strong positive correlations (p < 0.001) were found between leptin levels and 24-hour systolic BP (SBP), daytime SBP, nighttime SBP, 24-hour diastolic BP (DBP), and daytime DBP. Multiple regression analyses, including age, insulin and leptin concentrations, BMI, and waist and hip circumferences on 24-hour and daytime SBP and DBP, showed that only leptin levels contributed to the variability of BP. CONCLUSIONS: Our study shows that serum leptin levels are directly related to 24-hour BP levels in normotensive women with android fat distribution, independently of BMI.

Adult↗
PubMed2003

Association of inflammation markers with impaired insulin sensitivity and coagulative activation in obese healthy women.

Insulin resistance is associated with a low chronic inflammatory state. In this study we investigated the relationship between impaired insulin sensitivity and selected markers of inflammation and thrombin generation in obese healthy women. We examined 32 healthy obese women (body mass index > or = 28), with normal insulin sensitivity (NIS, n = 14) or impaired insulin sensitivity (n = 18), and 10 nonobese women (body mass index < 25). Impaired insulin sensitivity patients had significantly higher levels of C-reactive protein (CRP), TGF-beta 1, plasminogen activator inhibitor-1 (PAI-1), activated factor VII (VIIa), and prothrombin fragment 1 + 2 (F1 + 2) compared with either control subjects or NIS patients. On the other hand, NIS patients had higher CRP, TGF-beta 1, PAI-1, and factor VIIa, but not F1 + 2, levels than controls. Significant inverse correlations were observed between the insulin sensitivity index and TGF-beta 1, CRP, PAI-1, factor VIIa, and F1 + 2 levels. Moreover, significant direct correlations were noted between TGF-beta 1 and CRP, PAI-1, factor VIIa, and F1 + 2 concentrations. Finally, multiple regressions revealed that TGF-beta 1 and the insulin sensitivity index were independently related to F1 + 2. Our results are the first to document an in vivo relationship between insulin sensitivity and coagulative activation in obesity. The elevated TGF-beta 1 levels detected in the obese population may provide a biochemical link between insulin resistance and an increased risk for cardiovascular disease.

Adult↗
PubMed2002

Association between enhanced soluble CD40L and prothrombotic state in hypercholesterolemia: effects of statin therapy.

BACKGROUND: Hypercholesterolemia is associated with inflammation and the prothrombotic state. CD40-CD40 ligand (CD40L) interactions promote a prothrombotic response in nucleated cells. The aim of this study was to characterize the in vivo expression of soluble CD40L (sCD40L) in hypercholesterolemia, to correlate it with the extent of the prothrombotic state, and to investigate whether it may be modified by statins. METHODS AND RESULTS: We studied 80 hypercholesterolemic patients and 80 matched healthy subjects. Hypercholesterolemic subjects had enhanced levels of sCD40L, factor VIIa (FVIIa), and prothrombin fragment 1+2 (F1+2) compared with healthy subjects. sCD40L correlated with total cholesterol and LDL cholesterol. Moreover, sCD40L was positively associated with in vivo platelet activation, as reflected by plasma P-selectin and urinary 11-dehydro-thromboxane B2, and with procoagulant state, as reflected by FVIIa and F1+2. Inhibition of cholesterol biosynthesis by pravastatin or cerivastatin was associated with comparable, significant reductions in sCD40L, FVIIa, and F1+2. CONCLUSIONS: This study suggests that sCD40L may represent the molecular link between hypercholesterolemia and the prothrombotic state and demonstrates that statin therapy may significantly reduce sCD40L and the prothrombotic state.

CD40 Ligand↗
PubMed2002

Urinary excretion of lipoxin A(4) and related compounds: development of new extraction techniques for lipoxins.

LX are tetraene-containing eicosanoids generated by lipoxygenase (LO) transformation of arachidonic acid (Serhan and Romano, 1995). LX possess potent anti-inflammatory activity in vivo, and temporal biosynthesis of LX, concurrent with spontaneous resolution, has been observed during exudate formation (Levy et al, 2001). Limited results are currently available on the involvement of LX in clinical settings. Recently, a rabbit anti-LXA(4) antiserum has been raised to produce an enzyme-linked immunosorbent assay (ELISA) kit for LXA(4) (Levy et al, 1993). Although specific and accurate with isolated cells, this kit has not been tested with complex biological matrix such as urine. Initial attempts to determine urinary excretion of LXA(4) using the LXA(4) ELISA kit were unsuccessful because of high unspecific absorbance readings. In this report, we show that the LXA(4) extraction procedure indicated in the ELISA kit is inadequate for urinary measurements of immunoreactive (i)LXA(4). We present the development of a new extraction technique, more selective for LX, that abolishes background contamination and minimizes the unspecific readings. Using this method, we show for the first time that urine from healthy subjects contain (i)LXA(4) material and identify a urinary tetraene with the physical properties of a LXA(4) metabolite. Although reliable methods have been previously established to quantitate LXA(4) from whole blood (Brezinski et al, 1992), the present extraction technique, which optimizes for LXA(4) recovery from human urine, represents a substantial achievement for LX investigation and may open a new avenue of clinical studies on LXA(4).

Adult↗
PubMedDate not supplied

Platelet activation in obese women: role of inflammation and oxidant stress.

CONTEXT: Obesity, in particular abdominal adiposity, is associated with increased cardiovascular morbidity and mortality through mechanisms possibly linking the metabolic disorder to platelet and vascular abnormalities. OBJECTIVE: To investigate the clinical and biochemical determinants of lipid peroxidation and platelet activation in obese women. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional comparison, conducted between September 1999 and September 2001, of urinary 8-iso prostaglandin F(2alpha) (8-iso PGF(2alpha)) and 11-dehydrothromboxane B2 (11-dehyhdro-TxB2) excretion levels in 93 women: 44 with a body mass index (BMI) higher than 28 and a waist-to-hip ratio (WHR) of 0.86 or higher, android obesity; 25 with a BMI higher than 28 and a WHR lower than 0.86, gynoid obesity; and 24 nonobese women with a BMI lower than 25. An additional study was conducted to determine the short-term effects of weight loss in 20 of the 44 women with android obesity. INTERVENTION: During a 12-week period, 20 women with android obesity followed a weight loss program to reduce caloric intake to about 1200 kcal/d. MAIN OUTCOME MEASURES: Plasma C-reactive protein, insulin and leptin levels, and urinary 8-iso PGF(2alpha) (marker of in vivo lipid peroxidation) and 11-dehyhdro-TxB2 (marker of in vivo platelet activation) excretion. Weight loss was defined as successful when the initial body weight decreased by at least 5 kg after a 12-week period of caloric restriction. RESULTS: Women with android obesity had higher levels of 8-iso PGF(2alpha )(median [interquartile range [IQR]] 523 [393-685] vs 187 [140-225] pg/mg creatinine) and 11-dehyhdro-TxB2 (median [IQR], 948 [729-1296] vs 215 [184-253] pg/mg creatinine) than nonobese women (P<.001). Both 8-iso PGF(2alpha)and 11-dehyhdro-TxB2 were higher in women with android obesity than women with gynoid obesity (P<.001). Based on multiple regression analysis, C-reactive protein levels and WHRs of 0.86 or higher predicted the rate of 8-iso PGF(2alpha) excretion independently of insulin and leptin levels. Of 20 women with android obesity, 11 achieved successful weight loss, which was associated with statistically significant reductions in C-reactive protein (median change, 23%; P<.05), 8-iso PGF(2alpha) (median change, 32%; P =.04) and 11-dehydro-TxB2 (median change, 54%; P =.005). CONCLUSIONS: Android obesity is associated with enhanced lipid peroxidation and persistent platelet activation. These abnormalities are driven by inflammatory triggers related to the degree of abdominal adiposity and are, at least in part, reversible with a successful weight-loss program.

Adult↗
PubMedDate not supplied

Lipid peroxidation in diabetes mellitus.

There is considerable evidence that hyperglycemia represents the main cause of complications of diabetes mellitus (DM), and oxidative stress resulting from increased generation of reactive oxygen species plays a crucial role in their pathogenesis. In fact, in the absence of an appropriate response from endogenous antioxidant mechanisms, the redox imbalance causes the activation of stress-sensitive intracellular signaling pathways. The latter play a key role in the development of late complications of DM, as well as in mediating insulin resistance (i.e., resistance to insulin-mediated glucose uptake by some cells) and impaired insulin secretion. This review, focused on lipid peroxidation in DM, will examine the mechanisms and clinical readouts of oxidative stress in this setting, the relationship between lipid peroxidation and antioxidant status in type 1 and type 2 DM, the effects of hyperglycemia and metabolic control on in vivo markers of lipid peroxidation (i.e., isoprostanes), and the association between isoprostane formation and platelet activation. Finally, possible targets of antioxidant therapy for diabetic vascular complications will be discussed.

Animals↗
PubMedDate not supplied

[The "problem obesity": viewpoint of the internist].

The prevalence of obesity has reached epidemic dimension in industrialized countries and it is known that obesity is associated with increased risk of cardiovascular morbidity and mortality. Commonly, obesity is defined by the Body Mass Index (BMI). However, BMI fails to consider body fat distribution. The relationship between the risk of metabolic-cardiovascular diseases and body fat distribution indices such as the waist-to-hip ratio (WHR) and the waist circumference, rather than measures of the degree of body fatness as expressed by BMI, has long been recognized. Recently, clinical and epidemiological research has found waist circumference to be the best anthropometric indicator of both total body fat and intra-abdominal fat mass. Android or visceral obesity is associated with metabolic syndrome and increased cardiovascular morbidity and mortality through a variety of molecular mechanisms possibly linking the metabolic syndrome to hemostatic and vascular abnormalities. Obesity guidelines suggest the need for weight reduction using behavioural change to reduce caloric intake and increasing physical activity. A realistic goal for weight reduction is to reduce body weight by 5% to 10% over a period of 6 to 12 months. Combined intervention of a low calories diet, increased physical activity, and behaviour therapy provides better outcomes for long-term weight reduction and weight maintenance than programs that use only one or two of these modalities. The drugs used to promote weight loss have been anorexic drugs or appetite suppressants. All classes of anorexic drugs affect neurotransmitters in the brain. The new agent sibutramine has norepinephrine and serotonin effects. Another new agent, orlistat, has a different mechanism of action, the reduction of fat absorption. Weight loss drugs approved by the FDA for long-term use may be useful as an adjunct to diet, physical activity and behaviour therapy for patients with a BMI of > or =30 with no concomitant obesity-related risk factors or diseases, and for patients with a BMI of > or =27 with concomitant obesity-related risk factors or diseases.

Anti-Obesity Agents↗