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Giorgio Valenti

Publications and source records attributed to Giorgio Valenti.

At least 19 recordsLinked to original sources
PubMed2006

Association of hormonal dysregulation with metabolic syndrome in older women: data from the InCHIANTI study.

Metabolic syndrome (MetS) is a strong risk factor for type 2 diabetes and cardiovascular disease. Conditions associated with hyperandrogenism are often associated with glucose intolerance and other features of MetS in young women. As the prevalence of MetS increases with age and is probably multifactorial, it is reasonable to hypothesize that age-related changes in androgens and other hormones might contribute to the development of MetS in older persons. However, this hypothesis has never been tested in older women. We hypothesized that high levels of testosterone, dehydroepiandrosterone sulfate (DHEA-S), and cortisol and low levels of sex hormone-binding globulin (SHBG) and IGF-I would be associated with MetS in a representative cohort of older Italian women independently of confounders (including inflammatory markers). After exclusion of participants on hormone replacement therapy and those with a history of bilateral oophorectomy, 512 women (>/=65 yr) had complete data on testosterone, cortisol, DHEA-S, SHBG, fasting insulin, total and free IGF-I, IL-6, and C-reactive protein (CRP). MetS was defined according to ATP-III criteria. Insulin resistance was calculated according to HOMA. MetS was found in 145 women (28.3%). Participants with vs. those without MetS had higher age-adjusted levels of bioavailable testosterone (P < 0.001), IL-6 (P < 0.001), CRP (P < 0.001), and HOMA (P < 0.001) and lower levels of SHBG (P < 0.001). After adjustment for potential confounders, participants with decreased SHBG had an increased risk of MetS (P < 0.0001) vs. those with low SHBG. In a further model including all hormones and confounders, log SHBG was the only independent factor associated with MetS (OR: 0.44, 95% CI 0.21-0.91, P = 0.027). In older women, SHBG is negatively associated with MetS independently of confounders, including inflammatory markers and insulin resistance. Further studies are needed to support the notion that raising SHBG is a potential therapeutic target for prevention and treatment of MetS.

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PubMed2006

Low testosterone levels and the risk of anemia in older men and women.

BACKGROUND: Anemia is a frequent feature of male hypogonadism and anti-androgenic treatment. We hypothesized that the presence of low testosterone levels in older persons is a risk factor for anemia. METHODS: Testosterone and hemoglobin levels were measured in a representative sample of 905 persons 65 years or older without cancer, renal insufficiency, or anti-androgenic treatments. Hemoglobin levels were reassessed after 3 years. RESULTS: At baseline, 31 men and 57 women had anemia. Adjusting for confounders, we found that total and bioavailable testosterone levels were associated with hemoglobin levels in women (P = .001 and P = .02, respectively) and in men (P<.001 and P = .03, respectively). Men and women in the lowest quartile of total and bioavailable testosterone were more likely than those in the highest to have anemia (men, 14/99 vs 3/100; odds ratio [OR], 5.4; 95% confidence interval [CI], 1.4-21.8 for total and 16/99 vs 1/99; OR, 13.1; 95% CI, 1.5-116.9 for bioavailable testosterone; women, 21/129 vs 12/127; OR, 2.1; 95% CI, 0.9-5.0 for total and 24/127 vs 6/127; OR, 3.4; 95% CI, 1.2-9.4 for bioavailable testosterone). Among nonanemic participants and independent of confounders, men and women with low vs normal total and bioavailable testosterone levels had a significantly higher risk of developing anemia at 3-year follow-up (21/167 vs 28/444; relative risk, 2.1; 95% CI, 1.1-4.1 for total and 26/143 vs 23/468; relative risk, 3.9; 95% CI, 1.9-7.8 for bioavailable testosterone). CONCLUSION: Older men and women with low testosterone levels have a higher risk of anemia.

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PubMed2006

Relation of angiotensin-converting enzyme inhibitor treatment to insulin-like growth factor-1 serum levels in subjects >65 years of age (the InCHIANTI study).

Observational studies have shown that the use of angiotensin-converting enzyme (ACE) inhibitors is associated with the maintenance of greater muscle strength and physical performance in older subjects. However, the mechanism that underlies these beneficial effects remains poorly understood. Because ACE inhibitors block the production of angiotensin II, which is a potent inhibitor of insulin-like growth factor-1 (IGF-1) production, it was hypothesized that treatment with ACE inhibitors is associated with higher levels of IGF-1. This hypothesis was tested in 745 subjects (417 women, 328 men) enrolled in the Invecchiare in Chianti study. Of these, 160 were receiving ACE inhibitors. The association between ACE inhibitor use and serum IGF-1 was tested by linear regression models. After adjusting for multiple potential confounders, serum levels of total IGF-1 were significantly higher in participants receiving ACE inhibitors (mean +/- SD 129.0 +/- 56.1 ng/ml) compared with the rest of the study population (mean +/- SD 116.5 +/- 54.8 ng/ml) (p <0.001). Participants with short (<3 years) and long (3 to 9 years) treatment durations had higher serum IGF-1 levels than participants who were not receiving ACE inhibitor treatment, but the difference was statistically significant only for the short-duration group (p <0.05). In conclusion, in older subjects, treatment with ACE inhibitors for <3 years is associated with significantly higher levels of IGF-1. This may be 1 of the mechanisms by which ACE inhibitors might slow the decreases in muscle strength and physical function that are often observed in older subjects.

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PubMed2006

Estrogen receptor (ER)-beta, but not ER-alpha, is present in thyroid vessels: immunohistochemical evaluations in multinodular goiter and papillary thyroid carcinoma.

OBJECTIVE: Estrogen receptors (ERs) have been demostrated in the vessel structures of several systems. Little is known on the presence of ERs in the thyroid vessels. DESIGN: We immunohistochemically evaluated both ER-alpha and ER-beta immunoreactivity (IR) in both vascular and follicular thyroid cells in tissue samples from 17 cases of multinodular goiter (MNG) and 17 cases of papillary thyroid carcinoma (PTC). MAIN OUTCOME: ER-alpha IR was undetectable in either tissue examined. In 100% of MNG samples, nuclear ER-beta IR was detected in both endothelial and follicular cells. In PTC samples, endothelial nuclear ER-beta IR was found in 100% of cases, whereas the nuclear staining of follicular cells was found in 83% of cases. The intensity of staining of the endothelial ER-beta IR was comparable between MNG and PTC. However, when follicular cells were considered, a tendency toward a decrease in nuclear staining and a significant increase in cytoplasmic staining were found in PTC lesions as compared to MNG. CONCLUSIONS: This study demonstrated that ER-beta, but not ER-alpha, IR is present in the endothelium of thyroid vessels. Furthermore, although data need to be confirmed in larger observations, these results suggest the lack of differences in the pattern of vascular ER-beta IR between MNG and PTC.

Adult↗
PubMed2006

Association between hormones and metabolic syndrome in older Italian men.

OBJECTIVES: To determine whether low levels of testosterone, sex hormone binding globulin (SHBG), insulin-like growth factor-1 (IGF-1), and dehydroepiandrosterone sulfate (DHEAS) and high levels of cortisol and leptin would be associated with metabolic syndrome (MS). DESIGN: Cross-sectional. SETTING: Population-based sample of older Italian men. PARTICIPANTS: Four hundred fifty-two men aged 65 and older enrolled in the Invecchiare in Chianti (InCHIANTI) study. MEASUREMENTS: Complete data on testosterone, cortisol, DHEAS, SHBG, fasting insulin, IGF-1 and leptin. MS was defined according to Adult Treatment Panel III criteria. RESULTS: MS was present in 73 men (15.8% of the sample). After adjusting for confounders, total testosterone (P < .05) and log (SHBG) (P < .001) were inversely associated, whereas log (leptin) was positively associated with MS (P < .001). Independent of age, log (SHBG) was positively associated with high-density lipoprotein cholesterol (P < .05) and negatively associated with abdominal obesity (P < .001) and triglycerides (P < .001). Log (leptin) was significantly associated with each component of MS. Cortisol, DHEAS, free and bioavailable testosterone, and IGF-1 were not associated with MS. Having three or more hormones in the lower (for hormones lower in MS) or the upper (for hormones higher in MS) quartile was associated with three times the risk of being affected by MS (odds ratio = 2.8, 95% confidence interval = 1.3-6.9) (P = .005), compared with not having this condition. CONCLUSION: Total testosterone and SHBG are negatively and leptin is positively associated with MS in older men. Whether specific patterns of hormonal dysregulation predict the development of MS should be tested in longitudinal studies.

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PubMed2005

Correlation between testosterone and the inflammatory marker soluble interleukin-6 receptor in older men.

CONTEXT: An age-associated decline in testosterone (T) levels and an increase in proinflammatory cytokines contribute to chronic diseases in older men. Whether and how these changes are related is unclear. OBJECTIVE: We hypothesized that T and inflammatory markers are negatively correlated in older men. DESIGN: This was a cross-sectional study. SETTING: A population-based sample of older men was studied. PARTICIPANTS AND MEASURES: After excluding participants taking glucocorticoids or antibiotics or those with recent hospitalization, 467 men, aged 65 yr or older, had complete determinations of total T, bioavailable T, SHBG, albumin, IL-6, soluble IL-6 receptor (sIL-6r), TNF-alpha, IL-1beta, and C-reactive protein. RESULTS: After adjusting for potential confounders, sIL-6r was significantly and inversely correlated with total T (r = -0.20; P < 0.001) and bioavailable T (r = -0.12; P < 0.05). T was not correlated with any other inflammatory marker. CONCLUSIONS: These preliminary findings suggest an inverse relationship between T and sIL-6r. Longitudinal studies are needed to establish the causality of this association.

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PubMed2005

A meta-analysis of inferior thyroid artery variations in different human ethnic groups and their clinical implications.

We have recently found ethnic differences in superior thyroid artery (STA) variational anatomy. Therefore, we now focus on the inferior thyroid artery (ITA). In particular, we analyze whether presence, numerical variations and site of origin of ITA are influenced by ethnic group and gender, whether and which neck side has the largest arterial caliber, whether differences occur between the presence of ITA and STA, to which extent a non-selective thyroid angiography is effective in visualizing ITA, also in comparison to STA, and which clinical value this information may have in selected pathologies of the thyroid, parathyroid and larynx. A meta-analysis has been performed, including 33 library- and Medline-selected publications on Caucasoids (European and non-European) and East Asians, and a set of original data on European Caucasoids. A total of 6285 Caucasoid and 847 East Asian items, comprising half bodies and arteries, were analyzed. After testing the homogeneity of the available data sources in relation to the anatomical variables under study we calculated a cumulative value for each selected anatomical parameter and evaluated differences using non-parametric statistics. The effectiveness of non-selective thyroid angiography was determined using sensitivity, specificity, positive and negative predictive values. The ITA was more frequently absent in East Asians than in Caucasoids, and respectively either more or less frequently arising from thyrocervical and subclavian arteries, in East Asians versus Caucasoids. In contrast, the ITA was less frequently present both in Caucasoids and East Asians than the STA. In addition, the ITA was more frequently present on the right than on the left side in both ethnic groups, but no neck side predominated in size of arterial caliber in European Caucasoids. Finally, the ITA was more frequently present in East Asian males than females, and the effectiveness of a non-selective thyroid angiography showed higher numbers for ITA than STA in Caucasoids. Statistically significant variations occur in some ITA parameters between Caucasoids and East Asians, and in its presence with respect to STA, within each ethnic group. These differences, together with a sexual dimorphic presence of ITA in East Asians and high effectiveness of its visualization by non-selective angiography in European Caucasoids, may represent an evidence-based supply of anatomical information for analysis in selected pathologies of the thyroid, parathyroid and larynx.

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PubMed2005

Insulin resistance and muscle strength in older persons.

BACKGROUND: The functional consequences of an age-related insulin resistance (IR) state on muscle functioning are unknown. Because insulin is needed for adequate muscle function, an age-related insulin-resistant state may also be a determining factor. We evaluated the relationship between IR and handgrip muscle strength in men and women from a large population-based study (n = 968). METHODS: The degree of IR was evaluated by the homeostasis model assessment (HOMA) and muscle strength was assessed using handgrip. RESULTS: Simple sex-stratified correlations demonstrated that, in men, body mass index-adjusted handgrip strength correlated positively with physical activity (r = 0.321; p < .001), muscle area (r = 0.420; p < .001), muscle density (r = 0.263; p = .001), plasma albumin (r = 0.156; p = .001), insulin-like growth factor-1 (r = 0.258; p < .001), calcium (r = 0.140; p = .006), and testosterone (r = 0.325; p < .001) concentrations, whereas a negative association was found for age (r = -0.659; p < .001) and myoglobin plasma levels (r = -0.164; p =.001). In women, body mass index-adjusted handgrip strength correlated positively with physical activity (r = 0.280; p < .001), muscle area (r = 0.306; p < .001), muscle density (r = 0.341; p = .001), plasma albumin (r = 0.140; p =.001), and insulin-like growth factor-1 (r = 0.300; p < .001), whereas a negative association was found for age (r = -0.563; p < .001), myoglobin levels (r = -0.164; p = .001), and IR (r = -0.130; p = .04). CONCLUSIONS: Sex-stratified analyses adjusted for multiple confounders showed that the relationship between IR and handgrip strength was found significant in women, whereas it was negligible and not significant in men.

Adult↗
PubMed2004

Insulin-like growth factor 1 as a predictor of ischemic stroke outcome in the elderly.

PURPOSE: To examine whether serum insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3) concentrations, determined early after the onset of stroke, are predictive of clinical outcome in elderly patients. METHODS: The sample comprised 85 patients (mean [+/- SD] age, 83 +/- 7.4 years; range, 67 to 99 years; 34% male) who were admitted with acute stroke to a geriatric ward between January 1998 and June 2000, and 88 control patients who were similar in age and sex. Clinical and laboratory assessments, computed tomographic scan of the head, carotid ultrasonography, and electrocardiography were employed to define the clinical and etiologic stroke subtype. Fasting blood samples were collected within 24 hours of admission for IGF-I and IGFBP-3 measurement. Univariate and multiple logistic regression analyses, with adjustment for other related clinical covariates, were used to assess the relation of IGF-I and IGFBP-3 to poor outcome, defined as severe disability (Barthel index <60/100) or death, at 1 month (or at discharge), 3 months, and 6 months. RESULTS: Mean (+/- SD) IGF-1 levels were lower in patients with stroke than in controls (69 +/- 45 ng/mL vs. 102 +/- 67 ng/mL, P adjusted for age = 0.001). The mean IGF-1/IGFBP-3 molar ratio was also lower in stroke patients (0.12 +/- 0.07 vs. 0.19 +/- 0.09, P adjusted for age <0.0001). However, there was no relation of hormone levels to either the clinical subtype of stroke or the extent of neurologic impairment. IGF-1 levels were inversely related to poor outcome (mainly death) at 3 and 6 months, independent of other clinical covariates that were highly predictive of outcome, such as age and stroke scale score on admission (hazard ratio for death at 6 months for each 20-ng/mL increase = 0.7; 95% confidence interval: 0.5 to 0.9). An independent association of the molar ratio with death at 3 and 6 months was also found. CONCLUSION: Low levels of circulating IGF-1 may predict the clinical outcome of stroke in elderly patients.

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PubMed2004

A meta-analysis of superior thyroid artery variations in different human groups and their clinical implications.

We have investigated whether the presence, numerical variations and site of origin of the superior thyroid artery (STA) are influenced by the ethnic group and gender, whether the origin and caliber of this vessel are symmetrical, to what extent a non-selective thyroid angiography, either conventional or by digital subtraction, is effective in visualizing it, and whether this information may be useful in selected clinical conditions. A meta-analysis has been performed, including 24 library- and Medline-selected publications on Caucasoids (European and non-European) and East Asians and a set of original data on European Caucasoids. A total of 3453 Caucasoid and 931 East Asian items, including entire bodies, half bodies and arteries, were used. After testing the homogeneity of the available data sources in relation to the anatomical variables under study we calculated a cumulative value for each selected anatomical parameter and evaluated differences by non parametric statistics. Effectiveness of non-selective thyroid angiography was determined using sensitivity, specificity, positive and negative predictive values. A higher frequency of origin from the external carotid artery was present in Caucasoids than in East Asians. In contrast, a higher frequency of origin from common carotid artery was observed in East Asians versus Caucasoids. No gender differences were found for any of the parameters analyzed in East Asians. In addition, an equal probability of either asymmetrical or symmetrical origin on the two sides of the neck for STA was found in East Asians. In contrast, a symmetry of caliber for STA was found in European Caucasoids. Finally, only a moderate effectiveness of non-selective thyroid angiography, either conventional or by digital subtraction, was determined for visualization of STA in European Caucasoids. Statistically significant variations in some STA anatomical parameters occur between Caucasoids and East Asians. These differences, together with the high frequency of asymmetry for STA origin in East Asians and low effectiveness of STA visualization by non-selective angiography in European Caucasoids, may result in useful information for clinical reasoning in selected conditions of the thyroid region.

Arteries↗
PubMed2004

Effect of DHEAS on skeletal muscle over the life span: the InCHIANTI study.

BACKGROUND: It has been suggested that the reduced production of dehydroepiandrosterone sulfate (DHEAS) may be partially responsible for the decline of muscle strength and mass that often occurs with aging. However, this hypothesis has been only tested in small series of normal volunteers, with little consideration for potential confounders. Using data from a representative sample of 558 men (20-95 years) we tested the hypothesis that circulating DHEAS is independently associated with muscle strength and mass. METHODS: Data are from InCHIANTI, an epidemiological study conducted in the Chianti geographic area (Tuscany, Italy). DHEAS serum levels were related to lower extremity muscle strength assessed by hand-held dynamometry and calf muscle area estimated from quantitative computerized tomography. Confounders included age, anthropometrics, physical activity, smoking, energy and alcohol intake, albumin, lipids, interleukin-6, comorbidity, depressive symptoms, and disability in activities of daily living. RESULTS: In fully adjusted models predicting lower extremity muscle strength and calf muscle area, we found significant age*log DHEAS interactions, suggesting that the relationship between DHEAS levels and muscle parameters differs across the life span. In age-stratified models adjusted for confounders, serum DHEAS was an independent predictor of muscle strength (p <.02) and mass (p <.01), but only for men between 60 and 79 years of age. After adjusting these models for serum-free or bioavailable testosterone, results were unchanged. CONCLUSIONS: In men aged 60-79 years, circulating DHEAS is an independent correlate of muscle strength and calf muscle area. The possible causal role of declining DHEAS in age-related sarcopenia should be further explored in longitudinal studies.

Adult↗
PubMed2004

[The indication to statin therapy in primary prevention patients with dyslipidemia: implications for using national risk functions in the Italian population].

BACKGROUND: Risk functions for cardiovascular risk estimation, specific for the Italian population, have recently been developed. It is possible that using them, instead of the Framingham algorithm, to assess risk and define the indication to cholesterol-lowering therapy might substantially change the rate of statin prescription in primary prevention. METHODS: In this study, two different national risk functions, the CUORE Project algorithm and the risk function incorporated in the software Riscard 2002, have been compared to the Framingham algorithm in a cohort of 517 dyslipidemic asymptomatic patients consecutively addressed to a lipid clinic. Contingency tables and kappa value estimation have been used to assess the extent of concordance between them in classifying patients into risk categories, as well as in identifying among them those deserving statin therapy, according to two different sets of guidelines, such as the Adult Treatment Panel III and the reimbursement criteria for statins set by the Italian National Health System. RESULTS: Both national algorithms gave lower risk estimations, in comparison with the Framingham algorithm. A low concordance was found even between the two national algorithms, with lower risk estimates by Riscard 2002. As a consequence, less patients were selected for treatment according to national risk functions. However the prescription rate was more strongly affected by the set of guidelines used to assess the indication to treatment, independent of the method used to estimate risk. CONCLUSIONS: Our study confirms that using different risk functions can substantially change risk estimation in dyslipidemic patients, with some implications for statin prescription rate. However, the latter is mainly influenced by the set of guidelines used to identify patients for treatment. Furthermore, the two national algorithms so far available for risk estimation in the Italian population strongly differ in risk estimates, suggesting the need for further testing their accuracy.

Adult↗
PubMed2003

Effects of raloxifene on carotid blood flow resistance and endothelium-dependent vasodilation in postmenopausal women.

Raloxifene is one of the most important selective estrogen receptor modulators currently employed for the treatment of postmenopausal osteoporosis. However, it has also been suggested that this compound affects the vascular system. We evaluated both carotid blood flow resistance and endothelium-dependent vasodilation in 50 healthy postmenopausal women randomly assigned to receive, in a double blind design, either raloxifene (60 mg per day; N=25 subjects) or placebo (N=25 subjects) for 4 months. Indices of carotid blood flow resistance, such as the pulsatility index (PI) and resistance index (RI), as well as the flow-mediated brachial artery dilation were measured both at baseline and at the end of treatment. Changes in PI were -1.86+/-2.24 and -2.15+/-2.22% after placebo and raloxifene treatment, respectively, with no significant differences between groups. Changes in RI were -0.77+/-1.72 and -1.81+/-1.54% after placebo and raloxifene treatment, respectively, with no significant differences between groups. At the end of the treatment period, the increments in artery diameter measured after the flow stimulus were 10.79+/-2.39 and 6.70+/-1.23% for placebo and raloxifene, respectively, with no significant differences between groups. These results demonstrate no significant effects of raloxifene on either carotid blood flow resistance or brachial artery flow-mediated dilation in postmenopausal women.

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PubMedDate not supplied

The role of lipid profile in determining the risk of ischemic stroke in the elderly: a case-control study.

In this study, we investigated the association of lipids with ischemic stroke and its different subtypes in elderly patients. In particular, lipid parameters not extensively investigated so far in previous case-control studies specifically focused in the old population, such as lipoprotein Lp (a) and Apoproteins AI (ApoAI) and B (ApoB), have been taken into account. Seventy nine patients (mean age 83 +/- 7.4, range 67-99), consecutively admitted to a Geriatric Ward between January 1998 and June 2000 with acute stroke (first event) were studied. A complete clinical and laboratory assessment, including neurological evaluation, head CT scan, carotid ultrasonography and ECG, was employed to define the clinical and etiologic stroke subtype, according to standardized criteria. Fasting blood samples were collected within 48 h from admission, for determination of total cholesterol (TC), triglycerides (TG), High Density Lipoprotein-cholesterol (HDL-C), Lp(a), ApoAI and ApoB; Low Density Lipoprotein-Cholesterol (LDL-C) was estimated by Friedwald formula. Eighty eight age and sex-matched outpatients, referred to the hospital for non-inflammatory disorders of joints and musculoskeletal system, served as controls. Patients showed HDL-C and HDL-C/ApoAI ratio significantly lower than controls, with higher LDL-C/HDL-C ratio. Analysis on quartiles of lipoprotein concentrations showed also a significant increase in odds of stroke for LDL-C concentrations over 100 mg/dl, in absence of a linear relationship between LDL-C levels and risk. Multiple logistic regression, adjusting for non-lipid risk factors for stroke, confirmed the independent association of low HDL-C and HDL-C/ApoAI with all strokes, as well as with each subtype. In conclusion, these data suggest that lipids give some contribution to stroke risk even in the elderly, with a more prevalent role for HDL than LDL, and that lipid profile assessment must be taken into account in estimating the individual risk of stroke.

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